<story><title>Latest EmDrive tests at Dresden University shows it does not develop any thrust</title><url>https://www.grenzwissenschaft-aktuell.de/latest-emdrive-tests-at-dresden-university-shows-impossible-engine-does-not-develop-any-thrust20210321/</url></story><parent_chain><item><author>RyEgswuCsn</author><text>There is a difference here:  cars are built by car mechanics; they know cars inside out --- cars are never designed to drive in reverse. Physicists, on the other hand, didn&amp;#x27;t invent physics, so they know their current understanding of physics could be wrong.</text></item><item><author>prof-dr-ir</author><text>There were days on the internet when a car analogy was appreciated -- let me try here.&lt;p&gt;Suppose there was a rally driver who would claim that rally cars could go much faster if they were always driven in reverse. He did some rudimentary experiments and might have found a significant improvement. The general public and other racing drivers, who in my analogy can all be wonderful people but happen to know little about the mechanics of cars, are naturally enthusiastic: a potential breakthrough in driving! But clearly we need more experiments. So other rally drivers get to work: they set up an elaborate system with ropes and pulleys so they can reverse the driver&amp;#x27;s position in the car and run a car as fast as they can, but in reverse, on a test track. What do they find? Sadly, their answer is somewhat inconclusive, probably negative, but perhaps the test track had many bends. So they would like to repeat the experiment on a track with a few more straight segments: they write grant proposals, build a track, and plan other test runs... and all the time their progress is eagerly followed by the general public.&lt;p&gt;Now suppose you are a car mechanic in all this. What are you to do? This cannot work! It flies completely in the face of the way cars are set up, not to speak of the disadvantages in air flow. So you can loudly dismiss the claim as preposterous early on, but then you will be called a pessimist and the public point out that at least the rally drivers are trying something new - what the bleep have you been doing all this time? So you just wait the whole thing out, see it come... and go.&lt;p&gt;I guess I should at least be happy that I did not buy any shares in EnDrive Inc?</text></item></parent_chain><comment><author>plutonorm</author><text>This idea that we are so sure of everything is pervasive. The kind of people who like science are often the kind of people who crave certainty. And so for them science becomes like a religion, it provides them with a sense of certainty. Consistency. So when they rally against stories like this what they are really doing is reaffirming their own faith in an orderly universe, reaffirming their own faith in their scientific religion. It serves an emotional need. Which is why, paradoxically, their arguments are not alterable through logic.&lt;p&gt;If you go read what the real experts in a field have to say about the state of knowledge, they are often incredibly humble. They state that there is so much that they do not know. That are so many things that could be wrong. That there are even bigger pictures just beyond their grasp.&lt;p&gt;Now these reactionless thruster concepts don&amp;#x27;t look to be doing too well. But I for one am not particularly convinced that mach &amp;#x27;s principle is so stupid.</text></comment>
<story><title>Latest EmDrive tests at Dresden University shows it does not develop any thrust</title><url>https://www.grenzwissenschaft-aktuell.de/latest-emdrive-tests-at-dresden-university-shows-impossible-engine-does-not-develop-any-thrust20210321/</url></story><parent_chain><item><author>RyEgswuCsn</author><text>There is a difference here:  cars are built by car mechanics; they know cars inside out --- cars are never designed to drive in reverse. Physicists, on the other hand, didn&amp;#x27;t invent physics, so they know their current understanding of physics could be wrong.</text></item><item><author>prof-dr-ir</author><text>There were days on the internet when a car analogy was appreciated -- let me try here.&lt;p&gt;Suppose there was a rally driver who would claim that rally cars could go much faster if they were always driven in reverse. He did some rudimentary experiments and might have found a significant improvement. The general public and other racing drivers, who in my analogy can all be wonderful people but happen to know little about the mechanics of cars, are naturally enthusiastic: a potential breakthrough in driving! But clearly we need more experiments. So other rally drivers get to work: they set up an elaborate system with ropes and pulleys so they can reverse the driver&amp;#x27;s position in the car and run a car as fast as they can, but in reverse, on a test track. What do they find? Sadly, their answer is somewhat inconclusive, probably negative, but perhaps the test track had many bends. So they would like to repeat the experiment on a track with a few more straight segments: they write grant proposals, build a track, and plan other test runs... and all the time their progress is eagerly followed by the general public.&lt;p&gt;Now suppose you are a car mechanic in all this. What are you to do? This cannot work! It flies completely in the face of the way cars are set up, not to speak of the disadvantages in air flow. So you can loudly dismiss the claim as preposterous early on, but then you will be called a pessimist and the public point out that at least the rally drivers are trying something new - what the bleep have you been doing all this time? So you just wait the whole thing out, see it come... and go.&lt;p&gt;I guess I should at least be happy that I did not buy any shares in EnDrive Inc?</text></item></parent_chain><comment><author>pif</author><text>&amp;gt; they know their current understanding of physics could be wrong.&lt;p&gt;Sure, we do know!&lt;p&gt;And we know how to recognise when someone masters current literature (a.k.a. factual knowledge) and proposes a breaktrough in a yet uncovered field, and when someone is speaking out of his ... nothing!&lt;p&gt;If you prefer a non-car analogy: we all do &lt;i&gt;know&lt;/i&gt; that a hundred consecutive heads is possible, still you are not going to bet your week pay on it, even if you were promised 2^100 weeks of pay in return.</text></comment>