Comment by whatshisface | Hacker News Reader

Comment by whatshisface | Hacker News Reader

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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.

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?

>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.

Sure, but is that line of reasoning similar to the situation with the EMDrive? I thought the interesting part was that there was an actual as-yet unexplained result / measurement. So, going back to the bronze alloys, it's more like "crazy person X has found a bronze alloy that almost seems like antigravity, and it seems to break all fundamental laws of physics". Should we disregard, or humour it look into it? It was always very likely to be some kind of error, but it's a fundamentally less silly exercise.

there was an actual as-yet unexplained result / measurement

  1. "actual" isn't that actual if enough independent 
  scientists aren't duplicating it using scientifically 
  accepted testing procedures.

  2. "actual" isn't that actual when the quantity is down 
  at around noise level.

crazy person X has found a bronze alloy that almost seems like antigravity

You're using words like "almost seems" that just don't match up to the results seen, especially considering the flawed testing methods used.

"Experiments of destroying Mites by several Fumes: of the equivocal Generation of Insects: of feeding a Carp in the Air: of making Insects with Cheese, and Sack: of killing Water-Newts, Toads, and Sloworms with several Salts: of killing Frogs by touching their skin, with Vinegar, Pitch, or Mercury: of a Spiders not being Inchanted by a Circle of Unicorns-horn, or Irish Earth, laid round about it." [Thomas Sprat: from The History of the Royal Society, 1667]

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