<story><title>With &apos;The Machine,&apos; HP May Have Invented a New Kind of Computer</title><url>http://www.businessweek.com/printer/articles/206401-with-the-machine-hp-may-have-invented-a-new-kind-of-computer</url></story><parent_chain><item><author>jawns</author><text>For those of you who are unfamiliar with what a memristor is, as I was, HP has an easy-to-understand analogy on its FAQ page about memristors:&lt;p&gt;&amp;quot;A common analogy for a resistor is a pipe that carries water. The water itself is analogous to electrical charge, the pressure at the input of the pipe is similar to voltage, and the rate of flow of the water through the pipe is like electrical current. Just as with an electrical resistor, the flow of water through the pipe is faster if the pipe is shorter and&amp;#x2F;or it has a larger diameter. An analogy for a memristor is an interesting kind of pipe that expands or shrinks when water flows through it.  If water flows through the pipe in one direction, the diameter of the pipe increases, thus enabling the water to flow faster. If water flows through the pipe in the opposite direction, the diameter of the pipe decreases, thus slowing down the flow of water. If the water pressure is turned off, the pipe will retain it most recent diameter until the water is turned back on. Thus, the pipe does not store water like a bucket (or a capacitor) – it remembers how much water flowed through it.&amp;quot;&lt;p&gt;Source: &lt;a href=&quot;http://www.hpl.hp.com/news/2008/apr-jun/memristor_faq.html&quot; rel=&quot;nofollow&quot;&gt;http:&amp;#x2F;&amp;#x2F;www.hpl.hp.com&amp;#x2F;news&amp;#x2F;2008&amp;#x2F;apr-jun&amp;#x2F;memristor_faq.html&lt;/a&gt;</text></item></parent_chain><comment><author>jacquesm</author><text>Interesting tidbit: a while ago, I was talking about memristors with a physics trained person. And he told me something that really stuck:&lt;p&gt;It is impossible to make an inductor (coil) without resistance and without capacitance. It is impossible to make a capacitor without some inductance and a little bit of leakage. It is impossible to create a resistor that does not have self-inductance or a bit of capacitance.&lt;p&gt;If you followed all that and you agree with it (because you&amp;#x27;ve done some electronics) or you&amp;#x27;ve heard of &amp;#x27;parasitic capacitors&amp;#x27; and such, then you can see that it must somehow follow that parasitic mem-resistance must have been with us all along, but is such a small effect that we simply failed to notice it. No resistors, capacitors or coils that we normally use exhibits this effect in such a way that we adapt our designs to it to minimize it.&lt;p&gt;That&amp;#x27;s in part the reason why it took so long to manifest in a usable form, if the effect would be as devastating as resistance on powerlines, as capacitance on wiring, as induction on large capacitors then we&amp;#x27;d have exploited it long ago.&lt;p&gt;So it&amp;#x27;s going to be something exceedingly subtle when and if it comes to market.</text></comment>
<story><title>With &apos;The Machine,&apos; HP May Have Invented a New Kind of Computer</title><url>http://www.businessweek.com/printer/articles/206401-with-the-machine-hp-may-have-invented-a-new-kind-of-computer</url></story><parent_chain><item><author>jawns</author><text>For those of you who are unfamiliar with what a memristor is, as I was, HP has an easy-to-understand analogy on its FAQ page about memristors:&lt;p&gt;&amp;quot;A common analogy for a resistor is a pipe that carries water. The water itself is analogous to electrical charge, the pressure at the input of the pipe is similar to voltage, and the rate of flow of the water through the pipe is like electrical current. Just as with an electrical resistor, the flow of water through the pipe is faster if the pipe is shorter and&amp;#x2F;or it has a larger diameter. An analogy for a memristor is an interesting kind of pipe that expands or shrinks when water flows through it.  If water flows through the pipe in one direction, the diameter of the pipe increases, thus enabling the water to flow faster. If water flows through the pipe in the opposite direction, the diameter of the pipe decreases, thus slowing down the flow of water. If the water pressure is turned off, the pipe will retain it most recent diameter until the water is turned back on. Thus, the pipe does not store water like a bucket (or a capacitor) – it remembers how much water flowed through it.&amp;quot;&lt;p&gt;Source: &lt;a href=&quot;http://www.hpl.hp.com/news/2008/apr-jun/memristor_faq.html&quot; rel=&quot;nofollow&quot;&gt;http:&amp;#x2F;&amp;#x2F;www.hpl.hp.com&amp;#x2F;news&amp;#x2F;2008&amp;#x2F;apr-jun&amp;#x2F;memristor_faq.html&lt;/a&gt;</text></item></parent_chain><comment><author>frik</author><text>Conceptual symmetry between the resistor, capacitor, inductor, and the memristor:&lt;p&gt;&lt;a href=&quot;http://en.wikipedia.org/wiki/Memristor#mediaviewer/File:Two-terminal_non-linear_circuit_elements.svg&quot; rel=&quot;nofollow&quot;&gt;http:&amp;#x2F;&amp;#x2F;en.wikipedia.org&amp;#x2F;wiki&amp;#x2F;Memristor#mediaviewer&amp;#x2F;File:Two-...&lt;/a&gt;&lt;p&gt;The scales fell from my eyes. Now the electronics math makes sense - Memristor was the missing puzzle piece.</text></comment>