Where are the ATP synthases synthesised?

Question: The nano-machinary of energy production ATP synthase is well known to exist on mitochondrial inner membrane and chloroplasts. But how and where are they formed or synthesised ?
Comment: Welcome to SE Biology. Please read the Help on asking questions, where you will see that you are expected to show the research you have done before posting. Have you searched for ATP Synthase or Synthesis of Mitochondrial Proteins. There must be Wikipedia entries on this topic.
Comment: Sorry that I have no such things to add. I'm only a 12th grade student just interested in the topic. Thank you for the advice , I'll try to improve the way I post questions.
Comment: Yeah : ) questions don't even end there. One can go on and on endlessly to new levels of understanding. I would definitely be delighted to feed my 'what's next's but  it's inevitable after a certain level there will be none to answer. That doesn't curb the quest though ;) thank you for finding me those topics !
Answer: The interesting thing is that the mitochondrial ATP synthase consists of many subunit proteins, both encoded by nuclear DNA and mitochondrial DNA. It has long been unclear exactly how these synthases are assembled, and what differences exist between bacteria, yeast, and humans - where ATP synthase formation is normally studied. Regardless, each of these proteins is translated on ribosomes from mRNA transcripts of genes, just like regular proteins. However, these must come together correctly (in the right order) and end up in the correct location.
There are recent publications that answers your question rather directly.
Assembly of the membrane domain of ATP synthase in human mitochondria
In short:

We have shown that the assembly of human ATP synthase in the inner [mitochondrial] membrane involves the formation of a monomeric intermediate made from 25 nuclear-encoded proteins into which the two mitochondrially encoded subunits are inserted and then sealed by association of another nuclear-encoded protein, thereby dimerizing the complex. Association of a final nuclear protein oligomerizes the dimers back-to-face along the cristae [inner membrane of the mitochondrion] edges.

A commentary on the paper is also available, which provides insight into the historical and biological context and difficulties which the paper addresses and overcomes. It may be worth reading their synopsis first. You can find it here:
Assembling the mitochondrial ATP synthase
Comment: I admire the elucidation. Thank you !
Comment: And sorry that the question was closed. The mods and voters are quite overly zealous here sometimes. Neither a duplicate nor a homework question. Interesting question, certainly.
Comment: At first it somewhat disappointed me too. being a newcomer in SE I had problems understanding a dialogue box, which stated that somone suggested there's something similar to my question out there and asked me if it meets my queries. Finding that question resourceful and interesting I clicked yes and right after that my question turned duplicate . Surprised me ! Anyway, the tiny piece of machine inside our cells is marvelous enough to ignore all that, Thanks :)


Error when creating animation in XAML

Question: New to XAML... i want to do some simple animations. I was trying to follow MSDN's example code from this link: Click Here
<StackPanel>
    <StackPanel.Resources>
        <Storyboard x:Name="myStoryboard">
            <DoubleAnimation
          Storyboard.TargetName="MyAnimatedRectangle"
          Storyboard.TargetProperty="Opacity"
          From="1.0" To="0.0" Duration="0:0:5"
          AutoReverse="True" RepeatBehavior="Forever" />
        </Storyboard>
    </StackPanel.Resources>

    <Rectangle Loaded="Start_Animation" x:Name="MyAnimatedRectangle"
     Width="100" Height="100" Fill="Blue" />

</StackPanel>

I keep getting this error: "All objects added to an IDictionary must have a Key attribute associated with them. Line 11 Position 18"
What does this error mean? How do i fix it?
Answer: The StackPanel as every FrameworkElement has a property Recources which is a ResourceDictionary and you can only add elements to there with the x:Key attribute to identify them (basically this a IDictioanry<string, object>). So you need to add a x:Key to your storyboard:
<Storyboard x:Name="myStoryboard" x:Key="myStoryboardKey">

The sample on MSDN is wrong or they meant x:Key="myStoryboard" instead of x:Name="myStoryboard".
Answer: Replacing x:Name="myStoryboard" with x:Key="myStoryboard" should be enough to fix this issue.
The reason you need a Key in this case is because the code-behind is using a IDictionary, which requires an unique key for identification.
http://msdn.microsoft.com/en-us/library/xfhwa508.aspx

Error when creating animation in XAML


What does dual wielding do, without the Dual Wielding talent?

Question: In Torchlight you can wield any two one-handed weapons.  There is a Dual Wielding talent that adds damage when wielding two weapons, but what happens when dual wielding without the talent?  Does it simply alternate back and forth?  If the weapons are exactly the same, is there any DPS benefit?  How does it work with one melee and one ranged weapon?
Answer: The only effect of the dual wielding talent in Torchlight is to increase the damage done while dual wielding - the act of using a weapon in each hand, itself, is unrelated.
If you have two melee weapons, you will alternate back and forth on your attacks. If you have a melee weapon and a ranged weapon, you will only swap to the melee weapon if you are within range, otherwise you will exclusively use the ranged weapon.
Comment: @C.Ross Dual-wielding simply alternates attacks but special effects on either weapon apply to both.  For example if you dual wield 1 sword with hp steal and 1 with mana steal, both weapons should steal both hp and life.  Basically the point of dual wielding is to get extra enchants and bonus damage from the dual wielding skill.  It doesn't improve DPS in any other way as the weapons simply alternate.
Comment: Do you simply alternate, so there is no benefit besides more variety or shared benefits from one weapons?
Comment: @C.Ross some abilities require dual-wielding. It may also, slightly, increase attack speed (as it does in Dibalo II) but I'm not sure about that.


Why is momentum quantized in a 1D box even though the operator doesn't give eigenstates?

Question: We don't get eigenstates of momentum when we operate momentum operator in the wave function of particle in a 1D box problem yet we say momentum is quantized in this situation. Why is it so?
Comment: You do get eigenstates when you impose periodic boundary conditions.
Comment: Related: http://physics.stackexchange.com/q/45498/2451 and links therein.
Comment: Momentum isn't quantized for the particle in a box.
Answer: Taking the standard $[0,L]$ problem, eigenfunction and energy eigenvalues are:
$$
\varphi_n=\sqrt{\frac{2}{L}}\sin\frac{n\pi x}{L}, \qquad E_n=\frac{\hbar^2\pi^2n^2}{2mL^2}.
$$
This means that stationary 1D box systems (e.g. insulated ones) only admit states with a discrete set of possible energies, as above.
Now, that as far energy is concerned. What about linear momentum? We know that by observing momentum we force the system to collapse into a momentum eigenstate, which would be of the form:
$$
\phi_p = \frac{1}{\sqrt{2\pi\hbar}}e^{ipx/\hbar},
$$
where $p$ is continuous. Indeed, the probability for a measurement performed on an insulated 1D box system in the $n$-th energy level to produce the momentum value p is given by:
$$
|\langle\phi_p|\varphi_n\rangle|^2.
$$
However, we can think of the wave vector $k$ namely:
$$
k=\frac{n\pi}{L}
$$
which is of course quantized, and then invoking the analogy between this writing and the usual theory of harmonic waves write:
$$
p=\hbar k = \frac{n\pi\hbar}{L},
$$
such formula looks reasonable, since
$$
E=\frac{p^2}{2m}=\frac{\hbar^2\pi^2n^2}{2mL^2}
$$
and we recover the correct formula for the energy levels.
However, that expression for $p$ is just based on analogy and does not actually mean that the momentum measurement on the $n$-th energy eigenstate will yield $n\pi\hbar/L$ as a result.
Answer: Recall the Heisenberg principle which tells us that a we cannot know both position and momentum at the same time
$$\Delta x \Delta p \geq \hbar/2$$
For a particle, we have actually at most $\Delta x = L$, so that we cannot in principle have a sharp momentum state.
Fortunately, there are eigenstates which are eigenstates of $\hat{P}^2$, that is, states superposed of eigenvalues $p$ and $-p$. However, the gap in between them cannot be arbitrary small, so the momentum $p,-p$ gets quantized as $p_n = \pm \frac{n h}{2 L}$.
That is, we find particles only with discrete (quantized) momenta $\pm p_n$ but once measuring the momentum, we actually did not collapse the wave function on a $p_n$ state but on the $\pm p_n$ superposition and in a second measurement we cannot be sure about the sign of the momentum. The classical picture of a particle bouncing of elastically of the walls can be of help to understand this.
Comment: The energy eigenstates for the particle in a box aren't eigenstates of $P^2$. They have a continuous spread of momenta.
Answer: I change totally my answer and acknowledges that indeed the momentum does not have stationary eigenvalues in this problem. That is because there is no invariance of the system by spatial translation and therefore translational momentum is not conserved. This implies for a start that it does not commute with the hamiltonian and that thus hamiltonian eigenstates are not momentum eigenstates.
The physical reason is pretty easy to grasp. A stationary state in a box involves  a quantum particle bouncing back and forth against the walls of the box. This means that if you start with an initial state which is a momentum eigenstate with momentum $p$, it will reach a wall of the box within a time of the order of $mL/p$ with $m$ the mass and $L$ the size of the box.
Comment: The eigenfunctions of momentum are $exp(ikx)$ but these functinos don't satisfy the boundary conditions of the particle in a box. Operate with $p$ on $\psi(x)=\theta(x)\theta(1-x)\sin(n \pi x / L)$ -- you don't get an eigenvalue.
Comment: Hm. You say momentum is quantized in a 1D box, but if you take the fourier transform of the energy eigenstates $\psi(x)$ you get a continuous range of momenta. So what do you mean by momentum is quantized?
Comment: I don't get it...the wave functions in a box are $\psi_n(x) \propto e^{ik_nx}$ with $k_n = \frac{2\pi n}{L}$ and the eigenvalues of $P$ are then $p_n = \hbar k_n$. If this is not quantized, I wonder how you call it.
Comment: My bad, I am too used to the treatment in statistical mechanics....
Comment: Both {cos(kx),sin(kx)} and {exp(ikx),exp(-ikx)} form orthogonal bases. If you impose periodic boundary conditions on Aexp(ikx)+Bexp(-ikx) you still get sin(pi*n*x/L) (from Euler's identity), and k=2pi*n/L are the momentum eigenvalues. Is this helpful?
Comment: @RyanL: what I meant is that when you replace the hard wall boundary condition (which imposes that the wave function has to be zero at the walls) by a periodic boundary one then you indeed continue having harmonic functions as solutions but they need not (and they shouldn't) be zero at the walls.
Comment: My apologies, that was a brain flop. I was reading periodic but thinking fixed.
Answer: Solving the schrodinger equation gives us:
$$-\frac{\hbar^2}{2m}\frac{d^2\psi}{dx^2}=E\psi\:\:\:\xrightarrow{\kappa^2\:\equiv\:2mE/\hbar^2}\:\:\: \frac{d^2\psi}{dx^2}=-\kappa^2\psi\:\:\:\rightarrow\:\:\:\psi(x)=Ae^{i\kappa x}+Be^{-i\kappa x}$$
With the boundary condition and normalization, the solution takes the form
\begin{align}
\psi_{n}(x)&=A\sin(\kappa x)=\sqrt{\frac{2}{L}}\sin\left(\frac{n\pi}{L}x\right)\\
\\
E&=\kappa^2\hbar^2/2m=\frac{n^2\hbar^2\pi^2}{2mL^2}
\end{align}
This wavefunction is not the eigenfunction of momentum operator.
\begin{align}
\hat{P}\psi(x) &= -i\hbar\frac{\partial}{\partial x}\psi(x) = -\sum_{n=1}^{\infty}i\hbar c_{n}\frac{\partial}{\partial x}\psi_{n}(x)=-\sum_{n=1}^{\infty}i\hbar c_{n}\sqrt{\frac{2}{L}}\frac{n\pi}{L}\cos\left(\frac{n\pi}{L}x\right)\\
\hat{P}^2\psi(x) &= -\hbar^2\frac{\partial^2}{\partial x^2}\psi(x)=\sum_{n=1}^{\infty}\hbar^2c_{n}\sqrt{\frac{2}{L}}\left(\frac{n\pi}{L}\right)^2\sin\left(\frac{n\pi}{L}x\right)=\left(\frac{n\hbar\pi}{L}\right)^2\psi(x)\end{align}
Since energy eigenstates are not momentum eigenstates implies $[H, P]\ne0$ and thus we can not simultaneously find all eigenstates of both $\hat{H}$ and $\hat{P}$. However $\hat{P}^2$ does have an eigenstate with eigenvalue $(n\hbar\pi/L)^2$. Nevertheless, it would be naive to directly associate $p=\hbar\kappa$ to assert that momentum is quantized.
To quote wiki

In this sense, it is quite dangerous to call the number $k$ a wavenumber, since it is not related to momentum like "wavenumber" usually is. The rationale for calling k the wavenumber is that it enumerates the number of crests that the wavefunction has inside the box, and in this sense it is a wavenumber. This discrepancy can be seen more clearly below, when we find out that the energy spectrum of the particle is discrete (only discrete values of energy are allowed) but the momentum spectrum is continuous (momentum can vary continuously) and in particular, the relation $E=\frac{p^{2}}{2m}$ for the energy and momentum of the particle does not hold. As said above, the reason this relation between energy and momentum does not hold is that the particle is not free, but there is a potential V in the system, and the energy of the particle is $E = T + V$ , where T is the kinetic and V the potential energy.

But there are solutions like this :
$$\psi_{n}(x)= -A\theta(x)\theta(L-x)e^{\frac{n\pi}{L}x}$$
with normalization $A=\frac{1}{L}$
But this is momentum eigenstate with complex eigenvalue
$$\hat{P}\psi_{n}(x)=  -i\hbar\frac{n\pi}{L}\psi_{n}(x)$$
Just like this post implies about momentum operator. There are other solutions as well with different eigenvalues of the momentum operator. But from this, it is clear that even though $\hat{H}$ and $\hat{P}$ share some common eigenstate. They don't share them all and thus it may not be possible to always diagonalize them. However, $\hat{H}$ and $\hat{P}^2$ can be diagonalized simultaneously. Thus the interpretation of $p=\hbar\kappa$ is wrong. The parameter $\kappa$ is not wavenumber and so does not imply quantization of momentum.
Comment: The logic in your answer breaks at the point of "The solution takes the form ... this has no momentum eigenstate". The solution you put there is just the energy eigenvalue solution. But there are many more solutions to the TDSE, which are all linear combinations of the type of solution you have written down. So this does not prove that there is no momentum eigenstate, only that the energy eigenstates are not simultaneous energy and momentum eigenstates.
Comment: @doublefelix Thanks for correcting me


Downloading Ubuntu 16.04

Question: I was downloading Ubuntu 16.04 but it has downloaded a 4.86MB iso file whereas the 1.4 GB ubuntu download is still going on. Can anyone tell me why 2 files are being downloaded?
Comment: Are you using WiFi or ethernet.And when you ping is there packet loss
Answer: Welcome to AskUbuntu!
There is no 4.86 MB Ubuntu ISO file; the absolute smallest one is 54MB.
It's possible that your browser is storing the partial download in a temporary file; you can check to see if that file's size changes as your download progresses. If it is increasing in size, then your download is probably fine, and your browser will automatically merge the two files when the download is complete.
If you're having persistent download issues, you could try using a different browser, a download manager, or use the torrent download option for the Ubuntu ISO: http://www.ubuntu.com/download/alternative-downloads
Comment: Your edit on [this question](http://askubuntu.com/q/792896/451919) got rejected because it conflicted with another edit I was doing at the same time. Could you do the edit again?
Answer: What browser are you using? Firefox, for example, will create a file with the same name as the file being downloaded with the extra suffix ".part", and this file will store all the data that has been downloaded so far. It will grow in size and eventually reach the final size of the file, whereupon it is renamed to the final file name.
Comment: I'm using Chrome.
Answer: There are 2 things I can think of that could cause this with the information given:
1) The first option is that this is a temporary download file as mentioned above. Even though both those answers suggest you are using Firefox, Google Chrome still must save any downloaded data somewhere on your computer.
2) The other option is that the download failed and automatically restarted itself.
Answer: Or try alternativly this link https://wiki.ubuntuusers.de/Downloads/Xenial_Xerus/
Answer: this maybe due to two reasons of which both are not harmful in any way to your download
1) You must be using firefox because this has happened to me a lot of times (mainly in the case of rar/zip files)
When I download a file,
Firefox does 2 things: changes the file name to gobbledy-gook of letters and numbers, AND, adds a .part extension -- therefore the files won't open. This is a NEW problem.
If I manually remove the .part extension in the download folder, the file will open, but I still have the problem of the name change. I believe that the .part extension is supposed to go away when the download is finished, Also, my downloads always used to come with their original name, not a numbers/letters name.
2)Your Antivirus has some serious permissions which you might have given it while installation
so each and every part of data is reviewed for virus and put in another temporary file until the whole download is complete
Comment: I'm using Chrome.
Comment: What? The second reason is wrong, a badly installed antivirus will never do that..

Downloading Ubuntu 16.04


Why are waves in the electromagnetic spectrum all the same speed?

Question: A sound wave is much slower than a gamma wave, But the only difference is their frequency/wavelength. But if a gamma wave is faster than a sound wave due to frequency/wavelength, why for example arent gamma waves faster than infrared and visible light faster than infrared?
Answer: Although sound waves and electromagnetic waves  are both waves these phenomena are nothing alike. The major difference is that sound is  a mechanical wave, while an electromagnetic wave (=light) is non-mechanical.
Think of a mechanical wave as  "many" harmonic oscillators (=springs) which are coupled. The sound disturbs the equilibrium position of the spring.
It's the disturbance of the medium which constitutes the sound wave.
Without the medium a sound wave does not exist. This simple fact  lies at the heart of the  mechanical wave picture and it  can be used to explain many facts: E.g. why the velocity of the sound differs from different media (e.g. air vs. water), or why the sound velocity different for different frequencies (dispersion). Historically, it was hard to imagine that any wave could exists which does not need a medium to propagate in. Therefore, before 1900 it was assumed that light propagates in an otherwise non-observant medium called aether. It took a great physicist (Albert Einstein) to realise that such a medium is not necessary. By realising that all experimental results point towards the non-existence of the aether, he contemplate this idea and came up with the special theory of relativity. At the heart of this theory lies the fact that light does not need a medium to propagate.
Answer: Sound waves are not in the electromagnetic spectrum. You should hence be careful about comparing the two.
Sound waves always need a medium to propagate in, and hence their speed always depends on the medium.
An EM wave (light) can also propagate in vacuo, where its speed is a constant (and it's invariant). This is the fundamental postulate of special relativity.
When travelling in a medium, EM waves do travel at different speeds depending on their wavelength (i.e. where they sit in the spectrum) because the index of refraction depends on frequency.
EDIT
The generic formula for the speed of a sound wave $v_s$ is:
$$ v_s = \sqrt{\frac{B}{\rho}}, $$
where $B$ is the bulk modulus and $\rho$ the density of the medium.
The generic formula for the speed of an EM wave is $c_s$:
$$ c_s = \frac{1}{\sqrt{\epsilon \mu}} = \frac{1}{\sqrt{\epsilon_0 \epsilon_{\mathrm{r}} \mu_0\mu_{\mathrm{r}}}} = \frac{1}{\sqrt{\epsilon_{\mathrm{r}}\mu_{\mathrm{r}}}}\cdot\frac{1}{\sqrt{\epsilon_0\mu_0}} = \frac{1}{\sqrt{\epsilon_{\mathrm{r}}\mu_{\mathrm{r}}}} c, $$
where $c$ is the speed of light in vacuo (constant, invariant). $\epsilon_{\mathrm{r}}$ ($\mu_{\mathrm{r}}$) is the relative permittivity (permeability) of the medium, which is equal to $1$ in vacuo.  $\sqrt{\epsilon_{\mathrm{r}}\mu_{\mathrm{r}}}$ is actually the refractive index $n$ of the material, so that the speed of light in a material just becomes $c_s = c/n$.
Comment: whats the formula for calculating a waves speed which includes the density of the medium its traveling in?
Comment: Which wave, sound or EM?
Comment: Both, but arent they tbe same (except that if the density of the medium is 0 then the sound wave would stop)?
Comment: @Octavylon They aren't the same. If they were the same we'd use different names. Sound waves are sound waves. Electromagnetic waves are electromagnetic waves.  Comparing sound waves to electromagnetic waves is like conspiring waves in the sea with electromagnetic waves
Comment: Then what differes them except frequency and wavelength? and whats the formula for both in a specific medium?
Comment: @Octavylon Added required info in the answer.
Answer: The speed of a wave is determined by the medium in which it propagates. There are actually two types of 'motion' here. In the presence of a wave, the medium 'oscillates'. The pressure or Electro-Magnetic (EM) field go up and down for sound and light respectively. The speed of these oscillations (more precisely their period) is determined by the wave frequency $\omega$. When the wave frequency $\omega$ is large, then the wave moves up and down rapidly. Analogously, the wave-length $\lambda$ determines the spatial 'oscillations'. When $\lambda$ is short, then the spatial oscillation pattern is squeezed. This spatio-temporal pattern is however not directly related to the actual speed of propagation of the wave, which is given by the ratio $v=\lambda/\omega$ and is usually a fixed constant.
This may be easier to understand in terms of waves on a pond: Imagine a smooth water surface with a floater in the middle. When the floater is shaken, the water moves up and down at a speed that depends on how fast and strongly it is shaken. This determines the wave frequency $\omega$ (or equivalently wave-lengths since $\lambda = v\omega$, with $v$ fixed). At the same time, it is also possible to observe the different process of wave propagation as the disturbance moves away from the floater. There are some technicalities here, but it turns out that the speed of this propagation is given by $v=\lambda/\omega$ and does not depend on how fast the floater is shaken.
I would rather (somewhat boldly) say that independently of their frequency, sound waves propagate much slower than EM waves. The names 'gamma', 'Ultraviolet', 'visible', 'Infrared' or 'radio', which apply to EM waves, denote different ranges of frequencies. The analogous terms for sound waves are ultrasound, acoustic and infrasound. A gamma waves oscillates faster than a radio wave but propagates at the same speed. It is possible for some sound and EM waves to have the same frequency, but their speed (and therefore wavelengths) will be different because they do not propagate in the same medium.
This is a very simplified answer. Wave propagation can get quite complicated:

The medium is generally affected by waves that go though it. When the waves are strong enough, then this effect can change the wave-speed. This ultimately leads to a velocity that depends on the wave frequency. This is a complicated effect that is often weak and negligible.
Sound waves are pressure waves. Their theoretical description rely on the approximation that there is some air to propagate through. If you drive them in an extreme way, then you will affect the physical properties of the air. This can lead to shock-waves or cavitation, for example. For this reason, I would not try to drive a sound wave at the same frequency than a gamma wave. This will probably bring you to a regime where the underlying approximations break down and more complicated 'waves' emerge.


Harden my dirt parking spots

Question: I just bought a house in the mountains and have 3 parking spots "off road" style. There are many pine trees so lots of loose dirt , rocks and dry pine needles. I'm afraid that when it snows and rains, it'll turn into a mud pit. How can I harden my dirt? Or recommendations on what to do that's not too expensive and still attractive but simple. Lol. This is my first house, so learning a lot of DIY techniques. Thanks for your time and help in advance.
Answer: What is the soil type in this area? If the soil is sandy, it will not turn to mud when wet. A layer of the right kind of gravel might be both functional and pleasing to the eye, but don't put just anything down. Look around at what are others doing.
Parking cars on a bed of pine needles sounds to me like it would be a fire risk (catalytic converters get very hot). Ask the fire control authorities about whether the pine needles should be raked away from the car parking area.
Comment: +1 for getting rid of the organic material (pine needles) both for fire safety and for mud issue.

Harden my dirt parking spots


Iphone Scrollview Question

Question: i am quit new at iphone development and trying to make a photo collage software while learning it. Right now i have a lil problem and hope you can help me out.
I have an UiviewController with a view in it, in this view i have 7 scrollviews with uiimagevies in them for zooming and scollign images within these scrollviews.
All that works well but now i want to make these 7 scrollviews dragable and maybe if possible zoomable (so that the image within the given scroolview zoom together with the scrollview).
It should be possible to drag them all around the screen and if possible even overlap them
and by the way rotating would be great ;-) hope that is not to much asked for.
Would be great if someone can help me out with this..
Answer: Well you've got to decide on some other choice here because the functionality you are asking for overlaps, and you can't ask the app to magically know which the user wants to do. What I mean by this is that when you touch and drag within a scroll view, it's going to try to scroll itself, rather than drag the entire scroll view around.
As for rotation and zooming - that gets more complicated, because you start dealing with vector math and the like. You can check out my question on rotation here. The link I gave you has the code to get both rotation and zooming to work.

Iphone Scrollview Question


iPad app to manage photos stored in cloud?

Question: I currently have several thousand (15GB) photographs stored on a PC. I would like to move them all to the cloud somewhere and use the iPad to manage them - change names, put in folders, etc. I also want to be able to copy pictures from the iPad to my collection in the cloud. I'm not committed to where in cloudland I should store my pictures - maybe PicasaWeb, dropbox, Amazon S3, or something else. I'm happy to choose based on what would work the best with an iPad management app.
Answer: Adobe Revel ($5.99pm or $59.99py)
Adobe Revel (previously called carousel) is a cloud photo editing and storage app, similar to Adobe Lightroom with the added function of being able to store images in the cloud. It is a subscription based service.
However this is currently only available on iOS, and Mac, with both Windows and Android currently in development.
If you were desperate to use this solution, you can get the iPad app, and sync the photos over iTunes and then use the app to pop the images in the cloud, however this would be time consuming, the Adobe website has a notify me, button on Windows/Android, so this platform will be available.
Comment: Sounds intriguing when there is a Win version, otherwise I'll have to transfer the 15gb library to a bow wowed Mac and then transfer them to Adobe. But, if no better solution pops up, maybe I'll do that. It's nice that Revel has a thirty-day free trial so I can check how this works.
Comment: I've looked into Revel more and it's not really a "cloud storage" app, in the sense that it would replace my local computer as the primary storage place. Revel **assumes** that your primary store of images is on your local Macintosh (and eventually Windows). It does apparently make copies into the cloud, but this is NOT considered to be primary. **As evidence of this, they don't provide a way to back it up!**  So I guess I'm still looking for a solution where the cloud is the "center" of the storage strategy.
Comment: You could use Dropbox as the source folder on your desktop. That way you would be syncing to a cloud based service which is also on your desktop? Its not totally cloud based but it does offer that back-up option.


Better camera over the smartphone

Question: I am not a professional photographer, but I travel a lot, and I want to be able to take better photos on the way. Currently Im using my smartphone - Samsung Galaxy S7 Edge. I want to buy a camera for this purpose, for up to ~400 euro. Will such a camera be better than my current smartphone? Or do I have to actually pay much more for this to be better?
Comment: You can go for a point & shoot camera in your budget.
Comment: @samjay [Please don't post short answers as comments](https://photo.meta.stackexchange.com/questions/4655/short-answers-as-comments-please-resist-the-urge)
Answer: There are basically two things to consider: 1) Focal length, and 2) connectivity.
Although modern smartphones comes with great sensor resolution, they still can't compete with rather inexpensive pocket cameras that can give you even 30x optical zoom. An optical zoom gives you a possibility to take pictures of far away details and closeup shots.
Connectivity is where a smartphone is superior, because you can easily share your shots right away on social media. So, if you are looking for a good pocket camera, make sure it also has WiFi connectivity. That makes it possible for you to connect your smartphone and the camera. Some new cameras also let you use your smartphone as a remote control.
So, all in all, and based on my own experience, it is possible to find a good pocket camera with 30x zoom and WiFi. And that will give you much more variety and possibilities. I have tried somewhat all kind of a trips: with a smartphone only, with a pocket camera, and with DSLR. Pocket camera with 30x zoom has been and is the best solution for me.
Other options to consider
"One inch" sensor pocket cameras, as suggested by Fkraiem. Those give much better image quality in small size than any smartphone or cheaper pocket cameras.
"Water-, dust-, and shock-proof" pocket cameras is another option to consider. Although some smartphones are at least "rain proof", one may wish to have a tough, durable camera that still gives a rather extensive optical zoom.
Some additional tips to keep a pocket camera in good condition
If you have a "bad habit" to carry a pocket camera in your overcoat pocket, then  slip your camera inside a small plastic zipper storage bag before slipping it into the overcoat pocket. Plastic bag provides enough protection against condensation and dust (overcoat pocket is a very dusty place), and is surprisingly easy to use. It even works as a small "umbrella" when held above the camera while shooting. Also learn to use the wrist strap that often comes along with pocket cameras, to avoid dropping your camera. And if you indeed do carry your camera in your pocket, try to remember it is there, and not to smash your phone accidentally (e.g. between car seat and door).
Comment: If someone finds this additional comment as spam, then just please flag. I have Panasonic Lumix TZ60, and later models like TZ70 is for example still available and costs less than 400$/€.
Answer: One can also consider sensor size: a camera like the Sony RX100 is also in the $400 range ($448 on Amazon as of this writing) but has a larger sensor, which will give better performance than a smartphone in difficult, low-light conditions. It also has better optics, which should give sharper images all around. On the other hands, its zoom is more modest (3.6x).
For reference, the RX100 is how I took most of those.
Comment: What about the Nikon D5300 ? It's a DSLR, but not a big one. Is it worth buying this over the smartphone?

Better camera over the smartphone


Solving Partial differential equation , distinguishing the meaning of boundary condition and Initial condition.

Question: I have started my Differential equation course recently.
And My professor was interchangeably using the term boundary condition and initial condition.
I'm wondering what are the differences of their meaning in this context when dealing with the partial differential equations.
I thought one would not need a boundary condition if a system extends to infinity, but the case of wave on a string would need, since it's a finite system
For the initial condition, it always mean the initial state of the system.
Can anyone tell me if my understandings are correct.
Thank you!
Answer: If you think of a differential equation being defined on the coordinates of a certain object, that is mathematically like a number or a time line, and physically like a boundary.
So if $y(0)$ is given, in terms of time, that would be an "initial condition."
But if $y(0)$ and/or $y(L)$ are given for a differential equation that determines the temperature of a rod of length $L$, then $y(0)$ is more appropriately understood to be the "boundary condition" because it gives the temperature of the rod at the boundary of the rod.
Boundary conditions can be understood philosophically as being able to see only outside effects of something, but not directly measure the internal state of an object. The laws of physics governing the internal state of the object are used to formulate differential equations which can be solved to infer the internal state of the object based only on the external state that is known. This is like finding a criminal based on the evidence he leaves behind when committing a crime, and the large field of solving such problems is known as "Inverse Problems."
Comment: So in this case, boundary is to do with The boundary of a system*
and Initial condition * is to do with how system evolves with the time * right? And boundary means external state? Thanks for your answer
Comment: Yes, boundary basically is like the external state which can be measured without entering the object being considered. In a way, the "future" is like the internal state of the object which we cannot penetrate. So the initial condition when time is 0 (the present time), is like the boundary of the object that represents the future. So initial conditions are very closely related to boundary conditions. The initial condition when time equals zero is simply the boundary condition at the edge of the object that represents the future.


Who, or what, are the "four living creatures", as introduced in Revelation 4:6,7 & 8?

Question: It would appear that the answer can hardly be found in the "Earthly" realm. The answer has to be found in the "Heavenly" realm, given the close relationship to the "Almighty", Himself, (not to mention the fact that John is actually seen to be in heaven when relating his story). But in what manner, is the thing? Symbolism is obviously at play here, but of what exactly??
Answer: The 4 living creatures, first introduced in Rev. 4:6-9, are the fourth aspect of what is before God's throne in heaven. There is not space here to preface the answer with the three other aspects, helpful though that would be.  But the number 4 is too significant to ignore, and pertains to your query about these 4 living creatures being in heaven, so not earthly.
Ah, but the symbolic meaning of the number 4 in scripture pertains to the Earth and speaks of earthly things, e.g. the 4 chariots of Zechariah ch. 6 going to the north, south, east and west on the Earth, with the 4 spirits going forth from God's throne. Earthly creatures are depicted on the 4 faces of the 4 living creatures before God's throne; lion, calf, man, eagle. Here is an explanation of what they represent, as given in the book below:

"These represent the whole Creation, just as four is the number of the
earth. They are full of eyes before and behind. Behind, their
intelligent sight beholds all that was cherished in the garden of
Eden, and in the entire Creation. Before lies a new Creation, and
they see it, and pertain to it, though now they await the end of this world, and the consummation of all things...
If they had wings, this was for heavenly movement: that is, the
heavenly ascent of Creation's concepts. If full of eyes within, that
is of the Holy Ghost, and, glorifying Christ, signifies the creatures'
innate intelligence that they belong to him who was in heaven, who
had been rejected on earth. They corresponded inwardly with the mind,
and the right, of God in and to his own creation of the earth and its
fulness.
Such creatures were first named - but not described - in Genesis 3:24,
after fallen man was expelled for ever, when the earth was cursed, and
the world had begun its mad and ever-accelerating career downwards
through time into greater and greater evil, and more and more
ingenious evil imaginations. But all this time the symbol of the
cherubim stood at the gate of the lost paradise. Now 'cherubim' means
'grasped'. Man had let it all go. But God had let go nothing. It was
'grasped'.
Those creatures, representing God's grasp upon the nature of the
Creation, and of the creature, despite man's having brought this
Creation and its creatures to perpetual ruin in the Fall, I say,
these cherubim appeared in the tabernacle. They also appeared in the
temple. In the holy place, God signified that nothing of his was
lost, whatever man had relinquished.
Something of the like appeared also to the prophet Ezekiel, called by
him 'living beings', associated with the glory of God, yet evidently
earthly creatures with heavenly movement laying a claim to a dominion
which man had lost, a Creation beyond that which man had irrevocably
ruined, and a world and age that could never be answered by that which
is present. For God had let nothing go: the throne of world dominion
was claimed in his testimony set amidst a disobedient and rebellious
people."  The Revelation of Jesus Christ, pp.101-102, John Metcalfe

The author then speaks of Isiah and the seraphim and the wheels, with much more about the cherubim. But I will conclude this lengthy quote with just two final points he makes:

"It is a question of divine movement, it is the whole question of
movement in relation to Creation. All is lifted up off the earth and
caught up into heaven, as though the fallen chaos that actually exists
down here were forgotten... When John describes the new Creation in
the closing chapters of Revelation those creatures appear no more.
Because then fallen man and the present world will have passed away in
judgment. But every thought of God, all his mind in Creation for
Christ, will have come to pass for eternity. The time for mysterious
symbols is over. Reality comes with eternity." (Ibid. p. 104)

I hope this will give the start of some insight into your query, "Symbolism is obviously at play here, but of what exactly?"
Comment: Not sure why I didn't comment on this A, as I try to comment on all A's, given to my own Q's, below being case in point. I did, however, upvote it and on the very day that you answered. I just thought that Metcalfe didn't quite nail it, although he did make some good points for sure. Obviously, I've attempted to nail it myself and apparently, it would seem, came up short. I found it very difficult to answer, even went out on a limb trying and may well have gotten out there in left field. Nevertheless, I've now linked a video, which may be of interest to you, seeing as it's about the GP of G.
Comment: @Olde English   Noted. I would just add that nobody is going to "nail it" this side of eternity! Not least because there's a significant point in the Revelation where John is told not to write down what he heard 'the seven thunders' utter.- Rev. 10:1-4
Comment: Aahh, yes!! How can we *truly* know where we are in the overall scheme of things. We need to carry on believing in, not to mention, have understanding of, the **"Ransom Sacrifice"**, which enables us to be heard, particularly when being *truly* repentant of our sins, and have "faith" that all will turn out right for all those that have the *"spirit"* of the Almighty and His son, within them. Yes, I know you, being *trinitarian*, would word that last bit differently. If you haven't already watched the "Documentary", I *highly* recommend that you do, but if you do, watch with an **open** mind.
Answer: Since they are in the company of the "elders", I suggest first looking at the symbolism of the elders in order to gain an insight into the symbolism of their companions.
The elders are there as the symbolic leaders and representatives of the saints. The relevant O.T. parallel is Exodus ch24 vv9-11. On that occasion, Moses and Aaron, Nadab and Abihu "and seventy of the elders of Israel" went up the mountain to see "The God of Israel". What they saw, of course, was an image accommodated to their understanding, which is the only way that men can "see God". For "no man has ever seen God", in the true sense (John ch1 v18). An important detail of this image is that "there was under his feet as it were a pavement of sapphire stone, like the very heaven for clearness" (v10, RSV). This detail is shared by the mobile-throne vision of Ezekiel ("There was the likeness of a firmament, shining like crystal"- Ezekiel ch1 v22). It is also shared with the Revelation ch4 scene ("before the throne there is as it were a sea of glass like crystal" v6). These are three scenes of a similar type.
On that basis, I maintain that the elders in Revelation ch4 have the same function as the elders of Exodus ch24. They are the delegated representatives of God's people, the saints.
Coming now to the four living creatures, we see that we have the figures of a lion, and eagle, and an ox, each of which is a leading species in its own sphere (animals, birds, domesticated creatures). There is also a figure of a man, a species designated as having "dominion" over the living creatures of the earth in Genesis ch1 v28. So, on the analogy of the elders, I suggest their symbolism is that they represent all the living creatures of the world.
At the same time, there also seems to be a sense in which the living creatures in Ezekiel ch1 and this chapter represent "the four winds", which might be supposed, in the original concept, to be holding up God's throne in the clouds. They call forth the four horsemen in ch6, and the devastation of ch6 is associated with the "four winds" in ch7 vv1-3. That is, the four angels hold back the four winds; the next angel then explains (for our benefit) that this "holding back" amounts to a postponement (for the time being) of the further harm that could be done to the earth. We might compare God's threat in Jeremiah to send "the four winds of heaven" to scatter Elam (Jeremiah ch49 v36).
In short, they seem to be combining two sets of symbolism; "the four winds" of God's power at work, and "the living creatures of the world at large".
Comment: The elders here do indeed represent the saints, as you say. They would also seem to represent the leaders of groups of 6000, making for a priesthood of 144,000 to stand on the heavenly Mount Zion, ready to rule (note the crowns) with the Lamb, Jesus Christ. See **Rev, 14:1-4**. However, this is not the focus of the **Q**. The "living creatures", as depicted, are indeed representative of leading species. The man, here depicted, being a leading angel, *of a sort*. The symbolism, however, I feel is much more than you ascertain. As for "the four winds" *angelic* sense, that's something else IMO.
Answer: The key to understanding any passage in Revelation is to find which passage it alludes to, usually in the OT.  In the case of the four living creatures, there is no doubt that it alludes to the four creatures of Ezekiel 1.  Note the following similarities:

four faces of a man, lion, ox, eagle
covered in eyes
in the midst and around the throne of God
had four (Eze 1) or six (Rev 4) wings each
associated with fire and torches
above the throne of God is a rainbow

[Aside: The Ark of the Covenant appears to be a representation/caricature of this throne scene because it has two cherubim surrounding the throne of God (the mercy seat), and augmented by two more cherubim on the temple wall of the most holy place see Ex 25:18-22, 37:7, 1 Kings 6:27, 32, 35, 8:7, 2 Chron 3:7, 10, 11, 5:8, Eze 10:1, 9, 19, Heb 9:5, etc.]
Thus, four cherubim appear to be integral to the functioning of God's throne.  In Eze 1 & 10 it appears these living creatures are cherubim whose job is to transport the throne wherever God wishes to go.  That is, no description of the throne of God is really without those four living creatures also known as cherubim.  See also:

1 Sam 4:4 - So the people sent men to Shiloh, and they brought back the ark of the covenant of the LORD Almighty, who is enthroned between the cherubim. And Eli's two sons, Hophni and Phinehas, were there with the ark of the covenant of God.
2 Sam 6:2 - He and all his men went to Baalah in Judah to bring up from there the ark of God, which is called by the Name, the name of the LORD Almighty, who is enthroned between the cherubim on the ark.
2 Kings 19:15 - And Hezekiah prayed before the LORD: "O LORD, God of Israel, enthroned between the cherubim, You alone are God over all the kingdoms of the earth. You made the heavens and the earth.
Ps 80:1 - For the choirmaster. To the tune of "The Lilies of the Covenant." A Psalm of Asaph. Hear us, O Shepherd of Israel, who leads Joseph like a flock; You who sit enthroned between the cherubim, shine forth
Ps 99:1 - The LORD reigns; let the nations tremble! He is enthroned above the cherubim; let the earth quake!

Thus, it appears that the description of God on His throne supported/between the cherubim, may have some literal elements to it.
Comment: There is no mistaking that the *four* "living creatures" allude to the four creatures in **Ezekiel 1**, the similarities are unmistakable. The **cherubim** may have a supernatural mobility in their *cultic* role as throne bearers of God, but I'm looking for an answer that concentrates on how these *presumptive* **cherubim** are depicted, particularly as pertains to their facial caricatures.
Comment: @OldeEnglish - I am not sure how to answer except to say that is simply the depiction of the Throne of God and its constant attendants.
Comment: I have a theory, as to what the "caricatures" represent, but *before* putting forward my own response, to my own question, I wanted to see what thoughts might be out there in **BH** land first. Stay tuned....The composition involved, in order to answer competently, I'm not looking forward to, but hopefully, once completed, it can be well received.
Comment: @OldeEnglish - there is an early (unbiblical) theory that the four faces represented the four evangelists, Matthew, Mark, Luke and John as these are the regular symbols for each of them.  I have also heard another (unbiblical) theory that they represent the "four character" types of the saved.  Unfortunately, there is no Biblical basis for any such theory.
Comment: @Dottard Do you have a breakdown/post disproving the two theories?
Comment: @O.J. - it is not necessary to disprove a theory that has no Biblical basis.  If something simply uses Biblical language but has no actual textual support, it is unbiblical.  For example, Why not say the four faces represent, the USA (eagle), Russia (bear), England (lion) and Australia (human), or any other fantastic theory?
Answer: I appreciate that the question asks about the 'four living creatures'
as I agree that that is the correct translation. (Not 'beasts'.)
The following is an extract from my book 'The Cherubim of Glory'
and all is relevant to the question.

In Christ, who is exalted, in humanity, above every name that is
named - who is exalted above the heaven to the very throne of
the Father - in him, and under his Headship, is a new humanity
which is risen out of the old and is seated in the heavenlies with
Christ. Such a humanity is that which is according to God's
eternal purpose. In such humanity - in sonship - does the Father
delight.
This living - expressed fourfold - is seen round the throne.
It is thoroughly wrong to translate zown, in Chapter Four, as 'beast',
thus causing confusion with therion, 'beast', in Chapter 13:1, and
thereafter, which beasts are associated with the Drakon, another
matter altogether.
The four living, they should be called, and they are around
throne in company with the twenty four elders, all the wisdom
come out of Israel and come out of Apostleship. Together, the
living and the wisdom combine and are seen again as the
hundred and forty four thousand, the full complement of both
testaments multiplied in divine activity.
There is another hint of what is here seen in the two angels, in
white, which Mary saw in the sepulchre. They are described as
'sitting', kathezomai. Downsitting, kata, but with the word zoe,
life, added. I take this to imply sitting upright, either literally or
metaphorically. Six times is the word used and it is instructive to
see of whom it is used. But here I see an emphasis on living.
Seated, in that the attitude is one of rest, in sabbath, yet not inactive. Lively, quick, for all that they are 'dwonseated'.
And here also is a hint of what cherubim convey. The angelic two
sit at the head and feet of where the body of Jesus had lain, very
reminiscent of cherubim atop the ark. Rightly seen, the
sepulchre is where the ark completes its journey. Then - he is not
here; he is risen !
The full complement are seen again, an exceeding great
multitude which no man number. Angels minister to these,
holding back the winds of final judgment till all be gathered and
sealed, Revelation 7:3. These angels stand about the throne, and
they are about the elders and, within, are both about the living.
All fall upon their faces before the throne and worship God,
saying, Amen: Blessing and glory and wisdom and thanksgiving
and honour and power and might be unto God for ever and ever.Amen.
Cherubim are an abstract concept. I do not believe they are,
strictly speaking, a representation of the people of God in
themselves. Nor do I believe they are a representation, as such,
of angelic beings or angelic activity itself. Nor yet do I accept that
they are an expression of animal life, as such.
I believe that cherubim are an abstract concept representing something in God. It is a matter of God's purpose.
It is that which he purposes in everlasting. It is that which, ultimately, will
express God in a substantial creation. That which is within God -
his desire, his purpose - shall, through first creation, redemption
and new creation, be fully expressed in the manifesting of God
through humanity.
But the first humanity failed of that purpose. Hence redemption
in Christ. But redemption in Christ does not re-instate the first
humanity. Redemption in Christ brings in a new humanity - in
Christ - of which he is the Head. He also is the firstbegotten from
the dead. He is also the Prototokos - the first token, the firstfruits
of investment.
In Christ is the restitution of all things, Acts 3:21.

Reproduced from 'The Cherubim of Glory' (pp 11-123) by Nigel Johnstone
published by Belmont Publications. The book is available in PDF form
on the website of Belmont Publications. See my profile for the details.
Comment: With all due respect, I see a lot of *flowery* prose here, but I fail to see how this answers the question of the symbolism of the *four* "living creatures" and what might they, themselves, *truly* represent, if indeed we are talking about a **who**, as opposed to a **what**.
Comment: @OldeEnglish I agree with your question statement 'symbolism is at play'. Regards.
Answer: The spiritual world is perceived subjectively, so visions of the four living creatures and other angelic beings may differ. John of Patmos' vision is certainly related to that of Ezekiel. It basically agrees with Ezek. 1 but not with Ezek. 10. One of John's creatures has the face of an ox where Ezek. 10 speaks of the face of a cherub. In addition, Ezekiel describes each cherub having four faces, while John seems to describe four creatures, each with a different face.
Ezekiel 10:14

Each living creature had four faces: the first a cherub, the second a
human being, the third a lion, the fourth an eagle.

Revelation 4:

The first creature resembled a lion, the second was like a calf, the
third had a face like that of a human being, and the fourth looked
like an eagle in flight.

To summarize: In Ezekiel 10's vision, the four faces are 1) cherub 2) human 3) lion and 4) eagle. In John's vision the faces are 1) lion 2) calf 3) human and 4) eagle. In other words, Ezekiel sees a calf (or ox) while John sees the face of a cherub.  To complicate the matter, Ezek. 41:18 portrays the cherubim as each having not four, but two faces, as depicted in Ezekiel's vision of the restored Temple.

The question arises as to what the "face of a cherub" looked like in Ezekiel 10's vision. For this we may turn to artifacts left by other semitic cultures. The creature pictured above - with the face of a king, the body of a lion, and eagle's wings - was discovered in the ancient Assyrian city of Nimrud (located in modern Iraq) and dates for the 8th or 7th centuries B.C. Other sphynx-like winged creatures have been found elsewhere in the area. We cannot know for certain that this is what Ezekiel described as "the face of a cherub" but since he presumes that the reader knows what such a face looks like, there was probably some well known visible referent. In other words, the face of a cherub was probably sphynx-like, which would also explain why it could be described as a human face in Ezek. 1 and Rev. 4.
Symbolism. In terms of what the four faces represent, there are many opinions. A fairly simple and likely one is that they symbolize four domains of God's sovereignty. The lion represents wild animals; man represents humanity; the ox or calf represents domestic animals, and the eagle represents birds. If we substitute Ezekiel's cherub for John's ox, then the four realms would be angelic beings (cherub), humans (man), land animals (lion) and flying animals (eagle). Other interpretations are certainly possible, but this one, emphasizing God's sovereignty over all, is hard to argue against.
Comment: Well done! Your explanation as to Ezekiel's cherub would appear to have merit. + 1.
Comment: Having been in jail, so to speak, for the last 7 days, for stepping out of line with another poster, instead of "flagging" the poster, I am now back, and on the advice of "Moderation" have now edited my own answer here, which is now a *fuller* and better referenced exposition, and with even more (gasp) material. It may now be too long for most members here, but hopefully less confusing. Nevertheless, I just reread your answer here and I had forgotten the "cherub for ox" differential. Thinking about my added material, I wonder if the new "makeup" of the 12 tribes can explain the differential.
Comment: When all is said and done, keep in mind that all 4 "living creatures" are actually "cherubs" in their own right, consequently, one can presumably also have - cherub for man; cherub for lion; and cherub for eagle. They are all still collectively "cherubim". Even though Ez, 10, speaks of a cherub, instead of ox/bull/calf, that doesn't necessarily mean that it's not still depicting of an ox/bull/calf. The fact that John's "cherubs" go back to the same as described in Ez, 1, would seem to be factual confirmation. As for the "Millennium" scene, in EZ, 41:18,19, IMO the man/lion faces depict Jesus.
Answer: Who, or what, are the "four living creatures", as introduced in Revelation 4:6,7 & 8?
I have often wondered as to the significance of the "four living creatures" appearances, specifically with regard to the facial. What could they possibly be emblematic of. There are indeed similarities to the four creatures of Ezekiel 1. Even though the cherubim analogy would seem to have some merit, in that they may have a supernatural mobility in their cultic role as throne bearers of God, I think there is more here than meets the eye, or should I say eyes. Let's take the following bible verses for instance:

Luke 21:25 & 26, NASB
And there will be signs in sun and moon and stars, and upon the earth dismay among nations, in perplexity at the roaring of the sea and waves, men fainting from fear and the expectation of the things which are coming upon the world; for the powers of the heavens will be shaken.

Also, brackets/boldness mine,

Isaiah 19:19 & 20, NASB.
In that day there will be an altar (pyramid) to the Lord in the midst of the land of Egypt, and a pillar (monument/testimony) to the Lord near its border. And it will become a sign and a witness to the Lord of hosts in the land of Egypt; for they will cry to the Lord because of oppressors , and He will send them a Savior and a Champion, and He will deliver them.
Job 38:3-7, NASB.
"Now gird up your loins like a man, and I will ask you, and you instruct Me! Where were you when I laid the foundation of the earth! Tell Me if you have an understanding, who set it's measurements, since you know? Or who stretched the line on it? On what were its bases sunk? Or who laid its cornerstone, when the morning stars sang together, and all the sons of God shouted for joy?
Rev, 21:12, NASB.
It (heavenly holy city of Jerusalem), had a great and high wall, with twelve gates, and at the gates twelve angels; and names were written on them, which are those of the twelve tribes of the sons of Israel.

It is widely accepted that the verses from Luke, here depicted, may well not only encapsulate 70 AD but may also refer to the "End Times". It is not as widely accepted that the verses from Isaiah may well indeed encapsulate, the Great Pyramid of Giza. The Revelation verse will be gone into in due course, within this presentation.
However, the verses within Job 38: 3-7, especially where I have highlighted, would seem to be a veiled (but yet future) inference to this pyramid. See, also, Jeremiah 32:20 ... who has set signs and wonders in the land of Egypt ...
Verse 7 is particularly interesting. Here we see a reference to the first stars (of creation) and the (angelic) sons of God in universal praise of God's worldly creation. Could the first stars (of the creation) be, also, a cryptic reference to the "four living creatures", God's cherubim perhaps. Ellicott, in his bible commentary on this verse, makes an interesting inference (emphasizes mine):

The morning stars. - The context seems to suggest that by the stars are meant the angels entrusted with their guardianship, from whence Milton has borrowed his conceptions. The magnificent sublimity of the expression and the thought needs no comment.

Matthew Poole's commentary, is descriptive of actual stars - "morning stars", that is ... because of their excellent lustre and glory, for which they are called "angels of light".
I have taken the liberty, above, of italicizing the words: signs, stars, heavens, altar, sign and witness. More on these to follow. But for now, some "background" information:-
Precession of the Equinoxes, a 26,000 year cycle

What we call the "astrological ages" are a way of interpreting history by dividing time into chunks of about 2160 years, each one being associated with a particular sign of the zodiac. By this scheme, we're currently in the "Age of Pisces" and soon to enter the "Age of Aquarius", although some argue we're already there. This disagreement gives us our first clue that the "Ages" are less than straightforward and not remotely "scientific". However, there is a real phenomenon at work behind the idea. The "Ages" come about due to the precession of the equinoxes, and the separation of the tropical zodiac from the constellations.
The zodiac is a band of space that sits either side of the ecliptic - the path the sun appears to take as we orbit around it, and where the moon lines up with the sun causing eclipses (hence the name).Western astrology uses the "tropical zodiac" which is aligned with the seasons in the northern hemisphere, and starts at (0) Aries [mid point of Aries to be more precise], marking the vernal point, otherwise known as the spring equinox.
So precession measures the [apparent] retrograde motion of the spring equinox as it [apparently, but not definitively] moves along the ecliptic and backwards through the zodiac. After about 1000 years, or so, the vernal point/equinox proves to be in a different zodiacal area.
It takes about 72 years for the equinox to move just 1 degree through the zodiac, so each sign of 30 degrees takes 2160 years. The whole cycle is then completed in about 25,920 years.

The above, which is somewhat condensed, is taken from the Astro Journal ... The Age of Aquarius and Precession of the Equinoxes, by Jessica Davidson, 01/02/2021 [with a slight alteration, by me, to the last sentence of the penultimate paragraph, for, as it was, it didn't make sense. All this type of brackets [ ] mine also]. Stay with me!! This is confusing, I know, but try and stay with me to the end, as I, myself, found all this truly insightful, to say the least.
The Revelation of the Pyramids (Documentary)

An apocryphal view on the pyramids, starting in awe at the amazing achievement of the Pharaonic architecture and sculpture, mostly at Giza, given Cheops'  (Khufu's) pyramids size, weight, incredibly precise carving, four pairs of slightly shifted half sides, stunningly precisely measured shapes and symmetry. Then it questions and challenges conventional Egyptology beliefs, which it calls unproven, or even impossible to verify, such as the absence of machines, a dwarf duration of only 20 years, or even accidental equinox-orientation. Next it elaborates the theory that other major pyramid technology sites in pre Columbian America, Easter island and China, can't coincidentally lie on two lines intersecting at Giza, even if not contemporaneous and without known contacts in their ages, and have several improbable things in common, like some of their cultures. Elaborate mathematical theories and measurements indicate the Egyptians must have known some astronomy, like pi and the golden number, maybe even the meter, and such knowhow may even have been secretly passed on!!!

Taken from the introductory narrative for the above documentary, by Jacques Grimault, who also wrote the book of the same title, and which is narrated by Patrice Booyard, now available on Vimeo. The documentary goes on to speculate that maybe the secret was passed on by a lost civilization, or even aliens, but then, to their credit, juxtaposed that it all may just have been God.
Specific Purpose

The builders of the Great Pyramid, left nothing to chance. They apparently were able to measure the earth; they designed their scaled model after it, in the shape of a pyramid, in which scientific parameters were featured; they had lined up their familial location/archaeological sites on a strip as long as the equator - but at 30 degrees from the traditional equator - such as: Easter Island; Machu Picchu; Ollantaytambo; Paracas civilization; the Dogon country and Mohanjo-daro. The builders also seemed to be familiar with the speed of light and even incorporated the rotation of the earth. All to a specific purpose, such as to benefit a future civilization on earth ... ours ... a message of the utmost significance.

Critical astronomical cycle of our planet

If one picks a star in the sky, it will be one degree off 72 years later. It will take almost 26,000 years for this star to accomplish a complete orbit. The 26,000 year span represents a precession of the equinoxes cycle. To precisely locate the earth, and the universe, modern astronomers use the zodiac constellations, which are a simple means to observe the positions of the stars. The constellations targeted by the Sphinx's eyes, for instance, have shifted over time. The pyramidion found at the foot of the Sneferu Red Pyramid, a corner stone if you will, was providing another bit of significant information. Its perimeter was precisely 12 cubits long and the presence of pi referred to a circle, a 12 zone cycle, a zodiac.

The above narratives were taken from the voice over of the aforementioned documentary, edited slightly in the interests of brevity.See link: https://watchdocumentaries.com/the-revelation-of-the-pyramids/
Corner Stone

Acts 4:11, NASB.
He, (Jesus) is the stone which was rejected by you, the builders, but which became the very corner stone.
Mark 12:10 & 11, NASB.
"Have you not even read the scripture:
THE STONE WHICH THE BUILDERS REJECTED,
THIS BECAME THE CHIEF CORNER STONE: THIS CAME ABOUT FROM THE LORD, AND IT IS MARVELOUS IN OUR EYES?
Psalm 118:22 & 23, NASB.
The stone which the builders rejected has become the chief corner stone. This is the Lord's doing; it is marvelous in our eyes.

Israel was the stone that the builders of civilization had rejected, but God made his people the cornerstone of his plan for the world (now spiritual Israel, it would seem). The apostles referred to Jesus also, as the stone that was rejected, and he is now the all important cornerstone of God's kingdom.
Zodiacal Signs

The pyramid of Giza's four angles refer to four zodiacal signs TAURUS, LEO, SCORPIO and AQUARIUS. In the ancient world Scorpio was represented by an EAGLE and Aquarius by an ANGEL, as it occurs on the front of our cathedrals. Four stars are assigned to those four signs. Among the shiniest ones, they used to be called the four guardians of heaven, are ALDEBARAN, in the Taurus constellation; REGULUS in Leo; ANTARES in Scorpio, and FORMALHAUT, on top of Pisces today but formerly in Aquarius, before modern astronomers proceeded to some modifications. Those stars seem to keep the same position between themselves and have been used as steady reference points through time. Looking down (from space) on top of the Giza pyramid, we have from bottom left to top right, the Taurus/Scorpio axis, formerly known as the Taurus/Eagle axis, that Babylonians depicted by a winged bull. Then we have from bottom right to top left, the Leo/Aquarius axis, or Leo/Angel axis, according to the ancient calling, whose representation happens to be right here on the Giza Plateau, in the manner of the Sphinx, a man's head on a lions body....

The whole sites geometry then allows for some magical geometrical confluence lining, which can only be explained properly by watching the documentary video.

.... The Giza plateau then takes on the appearance of an astronomical clock, whose style was those four steady reference points; the four stars. This clock's needle, the Sphinx's  gaze (if you will), turns around itself, in a bit less than 26,000 years and enables to point precisely the earth's position in this big cycle. The starting point being Regulus ....

Again one would need to see the video.

.... in the Leo constellation. When the Sphinx's eyes, will precisely gaze at Regulus, or when the Sphinx's axis will be lined up with the Leo/Aquarius' axes, then a new "precession of the equinoxes" cycle will start anew.

Taken, as best as I can, with emphasizes mine, again from the voice over (which is in a French accent) in the documentary video.
CONCLUSION
The video goes on to talk about "climatical changes", as a result of the "precession of the equinoxes". For, after all, the glacier and heat cycles are in sync with the earth's orbital parameters. But, let's stop here with the science of it all. The philosophical hypothesis that I have tried to evidence here (this hasn't been easy), is that maybe, just maybe, the "four living creatures", as portrayed in the heavens, around God's throne, with their distinctive faces and full of eyes all around, and within, may be depicting, the four steady reference points; the four stars, and their respective zodiacal signs, that incorporate the Lion, the young Bull, Man and flying Eagle, around the Great Pyramid of Giza...
OR,
...they could be depicting the four heads of the 12 tribes of Israel!!!! Now this is interesting....
If you were to now read Ezekiel, chapter 1 - remember I referred to this in the very first paragraph of this exposition - you will notice that the image has four faces: that of a lion; an ox; a man; and an eagle. These faces represent the Four tribes of Israel, led by:-

Judah, whose symbol was a lion.
Ephraim, whose symbol was an ox.
Reuben, whose symbol was a man.
Dan, whose symbol was an eagle.

Taken from an article entitled "Who is America", by one Linda Watson, an historian, which although centers around the fate of the tribes of Ephraim & Manasseh, does also make reference to the 12 tribes of Israel and their four respective splits, encompassing three tribes in each. Then, Judah for instance, along with the principals of Issachar and Zebulun (three persons) would be representative of three pairs of arms (6 in all) - a reference to the - three pairs of wings - perhaps, attributed to each of the "four living creatures". Also, encampment of the tribes, were to the East; West; South and North, respectively. With the Levitical priests, along with Moses; Aaron and sons, not to mention the Tabernacle Tent, being central to all. The "throne in heaven" scene, in Rev, 4:1-11, immediately comes to mind, even though the tribal makeup is slightly, but not exponentially, different.
NB
Further interesting facts:
Ark of the Covenant dimensions are an even multiple of the dimension of the King's Chamber of the Great Pyramid, the granite sarcophagus could even be an earthly reference to the ark.
Sir Isaac Newton discovered the sacred Jewish inch measurement within the pyramid. The result was that he dedicated the rest of his life to Bible Study.
The pyramid depicts True North at time of it's erection.
Pyramid is situated in geographical center of the land surface of the whole world, on the equal surface projection. Centralized in the Northern Hemisphere, the longitude (from Greenwich) is 30 degrees East. Latitude is, even, 30 degrees North.
Finally, and probably most importantly, it is said that the Well Shaft, within the pyramid, may be depicting: Escape from evil world by acknowledging the "RANSOM SACRIFICE". But then, maybe we should leave that for another time ....
Comment: I am familiar with this creative eisegetic none-sense.  The link was full of factual errors.  This site is not the place to debate this so I will refrain.  The worst problem with this astrology-based material is that it distracts from the central message of Jesus.
Comment: I cannot see how any of this is even vaguely Biblical - 26000 years is unbiblical, Zodiac signs are unbiblical, the great pyramid of Giza is unbiblical, etc.  However, it is qyite imaginative and creative.
Comment: @Dottard - I guess my thoughts with regard to the word "biblical" - of relating to, or being in accord with the Bible - encompass more of a fullness of meaning. Astrology, may not exactly be Astronomy, but it can be relative, horoscopes and palm reading and the like, aside for sure.  *"Let now the astrologers, those who prophesy by the stars, those who predict by the new moons, stand up and save you from what will come upon you ..."* **Isaiah 47:13**. God is saying that astrologers will be able to give accurate info' about future events, but this won't save rulers who oppose God....tbc...
Comment: If God created everything, then he created the 26,000 year cycle, of which to this point "mankind" has only experienced the first 6,000 years (3 ages). To my mind, and not just mine, the **Great Pyramid of Giza** is indeed of *great* biblical importance, it's just not part of Christianity's mainstream thinking yet. It's just like an heavenly angelic messenger, only it's an earthly message, from the absolute center of the earth, the "Meridian", after all, passes right through it. But, thank you for the...quite imaginative and creative...line.
Comment: @Dottard - https://medium.com/belover/astrology-in-the-bible-5d4abecac741 Please, if you will, check this out.
Comment: @Dottard - Having just got back from my venture abroad, I have now added further content to my answer, in an attempt to convey further understanding, in light of further study. I can understand your concern with astrology based material and the sampling I pointed you to, may not have been the best. The central message of Jesus aside, I think the central message of **God**, as pertains to the earthly, rather than the heavenly, is extremely well depicted within, and around, the **Great Pyramid of Giza**. I just can't stress/express this enough. The written word, however, is still the ultimate.
Comment: I wish the answer were more brief but I'm upvoting it because it taught me something new - about Giza and the four zodiacal signs. I also agree that knowing non-Jewish cultural parallels is sometimes very helpful. On the other hand I wouldn't rule out several other symbolic 4s.  I do disagree with you when you say that allusions the cherubim of Ezekiel are not helpful. My answer suggests 4 realms of God's sovereignty. Based on Occam's razor, this is the one I prefer.
Comment: In a sense, ancient history of the region provides biblical context and might have shaped prototype patriachal Israel as it emerged from the late bronze age as heritage.   So cultures of  Egypt, Mesopotamia, and Greece provide context of what Israel was set to leave behind in its faith and culture.  It's well worth understanding IMHO, because if nothing else some of it would have been in Israel's legend.  Astrology was pervasive in various cultures, even if rightly banished from scripture, though stars  and omens still had importance and symbolism.  Because of this I upvoted it.
Comment: @Thermion - Well said. Thank you for taking the time. Hopefully you watched the "linked" documentary. I've watched it a dozen or more times and after every time I glean something new. I highly recommend it. You will never look at the Great Pyramid in the same way ever again.


Proving that every product of $n$ consecutive integers contains its prime factors at least as many times as $n!$ does

Question: In response to a request by @Ari for a proof by induction that the product of $n$ consecutive integers is divisible by $n!$, I attempted what I thought was an argument more plain and direct. Taking a product of $n$ consecutive integers $k(k+1)(k+2)...(k+n-1)$, then since $1$ divides $k$, and $2$ divides $k$ or  $(k+1)$, and $3$ divides $k$ or $k+1$ or $k+2$...and $n$ divides either $k$ or $k+1$ or $k+2$...or $k+n-1$, therefore $n!$ divides $k(k+1)(k+2)...(k+n-1)$.  But I was brought by @JMoravitz to see that the  conclusion does not follow.  For taking $6!$ and $11\cdot13\cdot17\cdot4\cdot5\cdot6$, every integer $\le6$ divides $11, 13, 17, 4, 5,$ or $6$, but $6!$ does not divide $291720$.  This is of course because $6!$ contains $2^4$ and $3^2$, while $291720$ contains only $2^3$ and $3^1$.  The proof thus requires the fulfillment of a second condition, namely that the product of $n$ integers contain all of its prime factors at least as many times as $n!$ does.  This seems to be assured by the fact that the $n$ integers are consecutive. If so, what is a good way to prove it?
Comment: Well, there's always the proof by binomial coefficients.  $\binom {k+n-1}n=\frac {(k+n-1)!}{n! (k-1)!}=\frac {k(k+1)\cdots (k+n-1)}{n!}$  and of course the binomial coefficient is always an integer.
Comment: [Link to the original question that OP is referring to](http://math.stackexchange.com/questions/2084008/can-anyone-help-me-proving-this-with-mathematical-induction).  The double-induction proof which I alluded to in the other post still seems strongest and I do not see a convenient way around it yet, especially with both $n$ and $k$ varying.  Regardless, I'll give someone else the chance to try explaining this time.
Comment: @lulu One could argue that, at least without the presence of combinatorial arguments, this is circular logic. The given question here is exactly what you need to prove if you want to prove arithmetically / algebraically that the binomial coefficients are integers.
Comment: @Arthur But of course you do have the combinatorial arguments.  The quotient is the number of ways of choosing $n$ objects out of $k+n-1$.  I entirely agree that this is critical to the argument.
Answer: As shown in equation $(3)$ of this answer, the number of factors of $p$ in $n!$ is given by Legendre's Formula:
$$
v_p(n!)=\frac{n-\sigma_p(n)}{p-1}\tag{1}
$$
where $\sigma_p(n)$ is the sum of the digits of the base-$p$ representation of $n$. Therefore, the number of factors of $p$ in $\frac{(n+k)!}{k!}$ is
$$
v_p\left(\frac{(n+k)!}{k!}\right)=\frac{n-\sigma_p(n+k)+\sigma_p(k)}{p-1}\tag{2}
$$
The difference of $(1)$ and $(2)$ is
$$
v_p\left(\frac{(n+k)!}{k!}\right)-v_p(n!)=\frac{\sigma_p(n)+\sigma_p(k)-\sigma_p(n+k)}{p-1}\tag{3}
$$
and $(3)$ is the number of carries when adding $n$ and $k$, and therefore, greater than or equal to $0$.


Page Closing Event Or Preview Unloaded?

Question: Firstly, thank you for taking the time out to read this post.
Let me get straight to my questions.
Is there any way to catch if a WPF page is closing before it is closed? i.e. some kind of PreviewClosing event? I have noticed that there is an Unloaded event, but I need something to trigger before the page is closed.
My applications has a Window. The main body of the Window contains a Frame, the frame is then used to navigate to a Page.
WPF Window XAML
<Grid>
    <Frame x:Name="_mainFrame" />
</Grid>

C# Navigates my Window Frame to a Page named SpecEditor
_mainFrame.Navigate(new SpecEditor(customerDetails));

I need some way to trigger an event in the SpecEditor Page when the hosting Window is trying to close (i.e. a PreviewClosing event), so that I can perfrom various checks. Mainly to prompt the user to save any unsaved work.
Any ideas how I can get around this as the page doesn't seem to have any PreviewClosing or PreviewUnloaded events.
Thank you again for your time.
**** EDIT ******
Ok I've managed to figure out what I need.
In the main window I assign the PreviewClosing event:
private void RadWindow_PreviewClosed(object sender, WindowPreviewClosedEventArgs e)
    {
    }

To access the "Frame" in the main window you can use the following (note I named my frame to _mainFrame):
this._mainFrame.Content

In my case, the page which is hosted in the Frame is named "SpecEditor" which contains a docking control. So to access the content of my page I can do the following:
((SpecEditor)this._mainFrame.Content).radDocking

It casts the content of my frame (which is the page) to my custom page class (SpecEditor) which allows me to access it's content, such as my Docking control.
For good coding it is worth checking that the frame content is actually the page you're trying to cast to. You can do this like so:
if (this._mainFrame.Content is SpecEditor)
    {
      ((SpecEditor)this._mainFrame.Content).radDocking
      .... etc etc
    }

I hope this helps.
Answer: If you are really using frames, this post shows an alternate approach:
https://highfieldtales.wordpress.com/2013/07/27/how-to-prevent-the-navigation-off-a-page-in-wpf/
The author uses the events for the frame's navigation facility.

Page Closing Event Or Preview Unloaded?


Flash Alternatives

Question: Does anyone know any good alternatives for flash to do simple animations for web  sites? Haven't had much luck with my googling.
Comment: How simple? Gif simple (you'd be surprised how nice an optimized palette looks)? Javscript + png simple?
Answer: Silverlight jumps out as a flash alternative.
The main thing that you need to remember is that your users need to be able to view it. If it's some obscure plug-in, no one is going to download or install it. Flash is the main event with Silverlight in a close second. You can do some cool stuff with HTML5 but not a lot of browsers support it even partially yet.
Comment: Flash is Flash. It's an Adobe product in a proprietary format owned by Adobe. If you want to design something in Flash, you need Adobe Flash Pro. If you want to design in Silverlight, there is an SDK and Visual Studio 2008 has some tools for that as well. If you want to just put a dirty animation up, perhaps the suggestion of an animated GIF is enough for you.
Comment: Interesting. Is there maybe a flash plugin that makes it quicker and easier to do simple animations?
Answer: Responding to the comment on MarkM's answer: you can create Flash animations in lots of ways without using Adobe Flash.  I like and own SWiSH Max 3 from SWiSHzone.  It has most of the power of Flash, including scripting, for $99 US.  They have even simpler and cheaper tools, depending on exactly what you need.
There are at least 10 other non-Adobe Flash animation creators, but I've only used Flash (including Flex) and SWiSH Max.
Answer: Gordon: An open source Flash™ runtime written in pure JavaScript (github.com)
Demos here.
Comment: LOL Great name for the project! It looks like it's still very young code. I haven't verified it but just by the looks of the code it doesn't appear to support older browsers (which makes sense, i guess, since they'll have to support SVG anyway).
Answer: Processing is excellent for creating animated visualisations. It runs on Java so you could embed it in a web page as an Applet. Alternatively, it has been partially ported to JavaScript/HTML5 as Processing.js.
Comment: My brother is getting into this and he's made some really cool stuff with it. Maybe I should have him teach me.
Answer: Anonymous raises a good point. How simple? Do you program? Do you want to work with time-lines? Do you just need a bouncing ball or a spinner? Do you just want simple special effects on text? The type of animation, even simple, varies tremendously and your level of understanding of different techniques and approaches will also influence how best to approach the problem.
JavaFX will soon have a designer, will be incredibly easy to do animation, and is built on Java. The Java plug-in may not be as pervasive as Flash but it's, in my opinion, better than Silverlight. But i agree with CarlF that you might want to look for different ways to create Flash animations. There are tons of them. Without knowing the answers to the questions above, it's hard to answer your question. It might just take more googling and trying out everything you come across.
In my opinion, until most browsers support <canvas> and developers create designers for canvas/JavaScript, Flash is, and will remain, king.

Flash Alternatives


How to transfer MC resource packs created on Windows 10 to SWITCH/XBOX

Question: I created some resource packs on Windows 10 edition.
Is there any way I can transfer the pack over to my Xbox/switch and use it
there?
I would prefer a way to do it without downloading additional UN-trustworthy software on my PC, I know there is a simple way to do it, I just cant find it
Comment: So you say you know there's a simple way to do it. Just curious but, how do you know this? Last I heard those resource packs were DLC you had to buy.
Comment: Well, no. i'm talking about resources i created, not the DLC.
Comment: I think you misunderstood my comment. You say you *know* there is a simple way to do it, but how do you know it's even possible to upload custom resource packs *at all*?
Comment: ha, no im sorry, im just assuming im stupid and there's probably an easy way to do it. although im not sure, that's why im here. but i know i did create a resource pack on windows 10
Answer: On the Switch and Xbox, there's only one official way.
On the Nintendo Switch and Xbox Bedrock Edition, you can use a resource pack on a Realm if you install the Resource pack onto the Realm on a non-console device (if you install the resource pack onto the Realm from Windows 10 edition or the Pocket Edition.) When you join the Realm on the Switch/Xbox, they will be installed and used on the Realm, but once you leave, they will be automatically removed from the device.
If you wanted to permanently install it (until you feel like removing it, of course), there's one way to do it on the Switch. However, that will void your warranty and can possibly brick/corrupt your system. This will require you to install Homebrew on to it, which you can read here:
http://www.mcbedrock.com/showthread.php?786-How-to-get-Custom-resource-packs-on-Switch-Bedrock
On the Xbox, you'd need to do some more research as to how to hack it (which I'm sure will also void your warranty and risk corrupting your system as well.) If you really want to take the risk, I'd recommend reading the guides all the way, possibly with help from an experienced user. IMO if you just want to do it to install resource packs, it's not worth the risk.
Comment: I think its fair to assume that if you find a way to run code that did not pass through an approval by Microsoft on Xbox you are doing some stuff that will void your warranty. I'm surprised the realms thing works, to be honest.


Open Bootstrap modal from dynamicallly created button?

Question: I'm building a table in PHP using...
echo '<button type="button" class="btn btn-default btn-xs" id="edit_'. $info['tablename'] .'">Edit</button>	';

I have this #editModal modal in my html lifted straight from Bootstrap...

    //Modal content from Bootstrap example.

When I click the "Edit" button, nothing happens. No console errors, nothing. The delet commands that I've left out work just fine but it doesn't involve modals. Here's the jQuery I'm trying to use...
$(document).on('click',".table .btn",function (e) {
    e.preventDefault();
    var array = String($(this).attr('id')).split('_');
    var id = array[1];
    //Get the command off the button id.
    var command = array[0];

    if (command == "delete" ){
        //do delete stuff
    }
    if (command == "edit" ){
        // I want to show this modal but it doesn't work.
        $('#editModal').modal({
            "show":"true"
        });
    }
});

Answer: I think you just need the following.
if (command == "edit" ){
    // I want to show this modal but it doesn't work.
    $('#editModal').modal("show");
}