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Horsefeathers. To name two examples. The Einstein-Podolsky-Rosen's paper on entanglement “Can Quantum Mechanical Description of Physical Reality Be Considered C

Horsefeathers. To name two examples. The Einstein-Podolsky-Rosen's paper on entanglement “Can Quantum Mechanical Description of Physical Reality Be Considered Complete?” (Einstein et al. 1935) ignored as trash for decades. The Casimir effect was predicted from quantum theoretical calculations, but again, no-one did the experiment for decades because they felt it was a trash prediction that couldn't be true 'cause it ignored basic physical laws that everyone knew had always held and always would. Empty space just couldn't do that. And on and on and on - I've just covered this century a tiny bit, not all the time since Newton. Dark energy anyone? Knowledge of the mechanisms behind X doesn't always precede discovery of X (why would anyone think it would always do so?) Lack of a known mechanism was why John Newlands version of the periodic table was greeted with contempt, and Mendeleev didn't find it easy sledding at first, either. But the contempt was unjustified. Birds were able to fly before the airfoil was discovered or airflow understood. Electricity was a broad field of study (Maxwell's equations, etc) long before the electron was discovered. The how usually trails the what in the history of science. I won't be shocked if the Emdrive is a wrong turn, but the idea we could know that in advance is sciencism - the satanic inversion of science - not empirical science.

whatshisface 8y ago
There is still some place for using theoretical predictions to guide experiments. For example, I have developed a rune that may be used to cast Fireball - it consists of three triangles carved in to a very expensive gold-titanium laminate. If that test fails, I suppose we also ought to try four triangles, a triangle and a circle, the word 'fireball' engraved on the perimeter of a hexagon, three triangles engraved onto a momentum-nonconserving cone... More seriously, there was a good reason to strongly suspect that the EM drive wouldn't overturn physics: we have probed electromagnetic interactions at energy densities far higher (gamma ray scattering) and far lower (radio telescopes) and everything in-between, and they all seem to be points on a continuous surface defined by Maxwell's equations applied to quantum mechanics. A working EM drive would actually be very close to the magic rune I described above: a wildly noncontinuous point where the laws of physics became massively different for one particular arrangement of matter, and then go right back to normal if you step in any direction around it.
- Nomentatus 8y ago
  The general use of experiments in science (as opposed to a Homo Erectus experimenting with rock types when making hammers) is to test what we think we know, to see if it's really so. IIRC the "inventor" of the Emdrive had a theory of his own to go by that led him to his device. We probably agree that it's the use of theory to preempt and prevent any experimentation that is pernicious. (reply to below comment) While not all experiments are equal, there's no right answer, and plenty of room for good and bad luck. The marketplace of ideas ensures enough variety that we don't miss toooo much (maybe.) Yet very often, it's those with the most eccentric and false ideas, such as Keplar, who stumble onto the right path because at least they're looking where nobody else is, for correlations no-one else thought to! So my bias is toward the most novel experiments that are still extremely likely to fail, as I think you agree. Just this week I was reading up on the Stern-Gerlach Magnet experiment, which discovered spin; something the experimenters absolutely weren't looking for. The idiots (or recipients of blind luck) win a lot of rounds in science, 'cause they're at least trying something genuinely new. Slightly different alloy = slightly different string theory?
  - whatshisface 8y ago
    >We probably agree that it's the use of theory to preempt and prevent any experimentation that is pernicious. So, there's a point about philosophy of science to be made here. If you test one bronze alloy for antigravity, and then test a slightly different bronze alloy for antigravity, and so on, finding all of them to fall when dropped, how can you know when it's reasonable to stop testing bronze alloys for antigravity? Presumably, you should eventually say "this idea has already been tested," and then stop. However there will always be a new ratio of metals to try: the only way to say "this has been tested" or "this hasn't" is to establish enough of a theory to make predictions about the effect of gravity on every bronze alloy, and then trust it when it says it will not become negative (at least, trust it enough to let it rule out potential experiments from grant approval.) When we say, "a new arrangement of photons will still conserve momentum," we are performing exactly the kind of interpolation from other experiments involving photons in cavities that, previously, stopped us from making more and more bronze bars in the search for antigravity.
hn_throwaway_99 8y ago
You're misunderstanding my post, so I'll try to put it another way. Suppose I tell you I have proof I created a perpetual motion machine. You'd probably laugh me off as a crank, or at least demand an extremely high level of evidence, to even listen to me. The EMDrive breaks the known laws of physics as much as any potential perpetual motion machine would, so for it to be correct would imply as much is wrong as our knowledge of physics as the existence of a perpetual motion machine would.
- roywiggins 8y ago
  And indeed, you can build a perpetual motion machine out of a reactionless drive. "any device with a thrust-to-power ratio greater than the photon rocket would be able to operate as a perpetual motion machine" https://arxiv.org/abs/1506.00494 https://arxiv.org/abs/1506.00494
  - Nomentatus 8y ago
    The Casimir effect already produces perpetual motion (in that sense.) Which raises the specualtive question of whether the Emdrive exploits the Casimir effect to obtain a tiny thrust (in which case a drive subdivided into a vast number of really small trapesoidal sections might produce much more thrust.
    - roywiggins 8y ago
      There's a simple way to get free energy out of a working em-drive: "at some point, the kinetic energy of the device-driven mass exceeds the energy input, and if this energy is collected via decelerating the mass (via regenerative electromagnetic braking, for example), then there would be a net gain in energy." How do you get a net gain in energy out of the Casimir effect?
      - Nomentatus 8y ago
        Vibration is continuous. Free energy you can get - whether we'll ever harness it to obtain thrust or electric power I don't know - but endless minor amounts of heat, yes.
e12e 8y ago
> The Casimir effect was predicted from quantum theoretical calculations (...) Thank you. That led me to learning about: https://en.m.wikipedia.org/wiki/Alcubierre_drive https://en.m.wikipedia.org/wiki/Alcubierre_drive And: https://en.m.wikipedia.org/wiki/Krasnikov_tube https://en.m.wikipedia.org/wiki/Krasnikov_tube

whatshisface 8y ago

There is still some place for using theoretical predictions to guide experiments. For example, I have developed a rune that may be used to cast Fireball - it consists of three triangles carved in to a very expensive gold-titanium laminate. If that test fails, I suppose we also ought to try four triangles, a triangle and a circle, the word 'fireball' engraved on the perimeter of a hexagon, three triangles engraved onto a momentum-nonconserving cone... More seriously, there was a good reason to strongly suspect that the EM drive wouldn't overturn physics: we have probed electromagnetic interactions at energy densities far higher (gamma ray scattering) and far lower (radio telescopes) and everything in-between, and they all seem to be points on a continuous surface defined by Maxwell's equations applied to quantum mechanics. A working EM drive would actually be very close to the magic rune I described above: a wildly noncontinuous point where the laws of physics became massively different for one particular arrangement of matter, and then go right back to normal if you step in any direction around it.

Nomentatus 8y ago
The general use of experiments in science (as opposed to a Homo Erectus experimenting with rock types when making hammers) is to test what we think we know, to see if it's really so. IIRC the "inventor" of the Emdrive had a theory of his own to go by that led him to his device. We probably agree that it's the use of theory to preempt and prevent any experimentation that is pernicious. (reply to below comment) While not all experiments are equal, there's no right answer, and plenty of room for good and bad luck. The marketplace of ideas ensures enough variety that we don't miss toooo much (maybe.) Yet very often, it's those with the most eccentric and false ideas, such as Keplar, who stumble onto the right path because at least they're looking where nobody else is, for correlations no-one else thought to! So my bias is toward the most novel experiments that are still extremely likely to fail, as I think you agree. Just this week I was reading up on the Stern-Gerlach Magnet experiment, which discovered spin; something the experimenters absolutely weren't looking for. The idiots (or recipients of blind luck) win a lot of rounds in science, 'cause they're at least trying something genuinely new. Slightly different alloy = slightly different string theory?
- whatshisface 8y ago
  >We probably agree that it's the use of theory to preempt and prevent any experimentation that is pernicious. So, there's a point about philosophy of science to be made here. If you test one bronze alloy for antigravity, and then test a slightly different bronze alloy for antigravity, and so on, finding all of them to fall when dropped, how can you know when it's reasonable to stop testing bronze alloys for antigravity? Presumably, you should eventually say "this idea has already been tested," and then stop. However there will always be a new ratio of metals to try: the only way to say "this has been tested" or "this hasn't" is to establish enough of a theory to make predictions about the effect of gravity on every bronze alloy, and then trust it when it says it will not become negative (at least, trust it enough to let it rule out potential experiments from grant approval.) When we say, "a new arrangement of photons will still conserve momentum," we are performing exactly the kind of interpolation from other experiments involving photons in cavities that, previously, stopped us from making more and more bronze bars in the search for antigravity.

hn_throwaway_99 8y ago

You're misunderstanding my post, so I'll try to put it another way. Suppose I tell you I have proof I created a perpetual motion machine. You'd probably laugh me off as a crank, or at least demand an extremely high level of evidence, to even listen to me. The EMDrive breaks the known laws of physics as much as any potential perpetual motion machine would, so for it to be correct would imply as much is wrong as our knowledge of physics as the existence of a perpetual motion machine would.

roywiggins 8y ago
And indeed, you can build a perpetual motion machine out of a reactionless drive. "any device with a thrust-to-power ratio greater than the photon rocket would be able to operate as a perpetual motion machine" https://arxiv.org/abs/1506.00494 https://arxiv.org/abs/1506.00494
- Nomentatus 8y ago
  The Casimir effect already produces perpetual motion (in that sense.) Which raises the specualtive question of whether the Emdrive exploits the Casimir effect to obtain a tiny thrust (in which case a drive subdivided into a vast number of really small trapesoidal sections might produce much more thrust.
  - roywiggins 8y ago
    There's a simple way to get free energy out of a working em-drive: "at some point, the kinetic energy of the device-driven mass exceeds the energy input, and if this energy is collected via decelerating the mass (via regenerative electromagnetic braking, for example), then there would be a net gain in energy." How do you get a net gain in energy out of the Casimir effect?
    - Nomentatus 8y ago
      Vibration is continuous. Free energy you can get - whether we'll ever harness it to obtain thrust or electric power I don't know - but endless minor amounts of heat, yes.

e12e 8y ago

> The Casimir effect was predicted from quantum theoretical calculations (...) Thank you. That led me to learning about: https://en.m.wikipedia.org/wiki/Alcubierre_drive https://en.m.wikipedia.org/wiki/Alcubierre_drive And: https://en.m.wikipedia.org/wiki/Krasnikov_tube https://en.m.wikipedia.org/wiki/Krasnikov_tube