What false hints of new physics were most notable?

  • #26
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A great historical example is the hunt for the planet Vulcan (https://news.nationalgeographic.com...ry-astronomy-theory-of-relativity-ngbooktalk/)

Essentially, astronomer's saw that Mercury's orbit did not match the predictions of Newtonian mechanics. Scientists therefore hypothesized that another undiscovered planet must be influencing the orbit of Mercury. We now know that mercury's orbit does not match the predictions of Newtonian physics because of special general relativity. Special General relativity accurately explains Mercury's orbit, "proving" that Vulcan does not exist.
That's oversimplified. Vulcan (hypothetical planet) - Wikipedia has more detail on this hypothetical intra-Mercurian planet. Over much of the nineteenth century, several astronomers claimed to have observed some intra-Mercurian planet transit across the Sun, and some astronomers claimed to have seen it in total solar eclipses. However, it was hard to get a coherent orbit out of those observations, and many astronomers were not successful in making similar observations. So by the late 19th cy., astronomers had become skeptical about its existence, and some astronomers started speculating about modifying the law of gravity.

Einstein's General Relativity was, it must be admitted, a modified-gravity theory.
 
  • #27
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most notable were the hidden dimensions.. Lisa Randall RS1 AND RS2 were nowhere to be found..

also the so called subquarks (preons).. is it not LHC has cornered them to almost non-existence? since ohwilleke claimed to haved authored Preon entry in the wikipedia.. could he give us insight into the subquark side of it?
 
  • #28
ohwilleke
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most notable were the hidden dimensions.. Lisa Randall RS1 AND RS2 were nowhere to be found..

also the so called subquarks (preons).. is it not LHC has cornered them to almost non-existence? since ohwilleke claimed to haved authored Preon entry in the wikipedia.. could he give us insight into the subquark side of it?
I'd chime in on that topic in another thread, but it is off topic in this one.
 
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  • #29
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Some people here are misunderstanding the original question. One person said that faster than light travel should be included in a list of things physicists initially believed but were later disproved because it was "widely reported", including a newspaper headline that said "Roll Over Einstein". That should not be your criterion. A lot of crazy stuff is "widely reported". It was "widely reported" that an astronaut's DNA changed.

https://www.theatlantic.com/science/archive/2018/03/scott-kelly-dna-fake-news/555794/

Or other silly nonsense such as you can read here.

https://gizmodo.com/the-worst-reported-science-stories-of-2017-1821271490

Other people misinterpreted the original question to mean "things predicted by current theories that have not yet been observed because they are very difficult to detect". One person included proton decay, even though if you include supersymmetry, the lifetime of the proton would be 10^23 years, so it would extremely difficult to distinguish from the background so you would not expect a five sigma discovery. Another person mentioned extra dimensions. Well obviously, extra dimensions, predicted by string theory, have not been ruled out. They would be very difficult to detect. The earliest simplest version of the Randall Sundrum Braneworld model was just a starting point for later more advanced realistic models in the same way than Alan Guth's earliest model of inflationary cosmology, which he knew could not be literally true in its earliest form, was superseded by more realistic models which are now assumed to be true. Braneworld cosmology remains an active vibrant arena for current research. The fact that we have not directly detected extra dimensions yet is not surprising because they would be very difficult to detect. There are lots of things that are predicted but have not yet been observed, but have not yet been ruled out. We have not yet detected neutrinoless double beta decay, but that's not surprising because it would very difficult to detect.

The original question was not asking for examples that were always known to be wrong, or are not yet known to be wrong, but instead examples that were initially thought to be not wrong but were later proven to be wrong.
 
  • #30
ohwilleke
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Another one, although not a very famous one: The hyperfine puzzle in Bismuth-209.

The observed hyperfine splitting in a Bismuth-209 atom stripped of all but one of its electrons was 7 sigma from the QED prediction for its hyperfine splitting (i.e. basically the gaps between different discrete energy states of the electron).

Why?

Because the QED prediction overlooked a factor that turned out to be important.

Calculating the hyperfine splitting from the experimental data requires an accurate value for the nuclear magnetic moment of bismuth-209. Nörtershäuser along with Darmstadt’s Michael Vogel and colleagues used nuclear magnetic resonance spectroscopy to measure the magnetic moment of the nucleus. This was done by placing an aqueous solution of bismuth nitrate in a powerful superconducting magnet and measuring its radio-frequency spectrum.

An important challenge in making this measurement is accounting for the effect of the bismuth nitrate solution on the local magnetic field that is felt by the bismuth nuclei. This was worked-out by Skripnikov and colleagues, who did sophisticated quantum-mechanical calculations that revealed that the effect on the local field was much greater than expected.

When the new value of the magnetic moment was used to calculate the hyperfine splitting, the result was in good agreement with the original experiment.
 
  • #31
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The first item on your list does not belong on the list! The reason is because any physics undergraduate with paper and pencil ca prove in five minutes than faster than light travel or communication is impossible.
This proves only that faster than light travel or communication is impossible according to existing, established theory. It cannot, even in principle, prove that the experiment was wrong. The question was about experiments which suggested new physics.

By the way, your links do not even establish that it is incompatible with established physics, but only with established metaphysics. So,
http://www.askamathematician.com/2012/07/q-how-does-instantaneous-communication-violate-causality/ writes:

"But, if you accept the basic tenet of relativity, that everything no matter how it’s moving is on equal footing, then one person’s instantaneous signal is merely traveling very fast to someone else, or even slightly backward in time to another someone else." But, sorry, this means "if you accept the metaphysics of the spacetime interpretation of SR and reject, for whatever reasons, the Lorentz ether interpretation of the same SR".

In special relativity, a particle moving FTL in one frame of reference will be travelling back in time in another. FTL travel or communication should therefore also give the possibility of travelling back in time or sending messages into the past. If such time travel is possible, you would be able to go back in time and change the course of history by killing your own grandfather.
No. It would give this possibility only if there is no preferred frame. The FTL communication would have a preferred frame, and therefore violate the equivalence principle. But so what? In the strong form - that there is no real difference - it is a metaphysical belief. In the weaker, physical form there is no observable effect which allows to distinguish them. But new physics could give new observable effects which would allow to distinguish them. The FTL communication would be simply new physics, and give us an observational possibility to identify a preferred frame which is now hidden from observation.
There is a difference between a statement being factually wrong, and a statement being meaningless. The statement that the Great Pyramid of Giza has a volume of three cubic inches is factually wrong. The statement that the Great Pyramid of Giza has a volume of -45 cubic feet is meaningless because the volume of an object can not be a negative number. To claim that the velocity of a neutrino could be faster than light is a similar meaningless statement.
The only meaningless statement would be a combination of "there exists FTL communication" and "there is nothing violating Lorentz symmetry".

So, the superluminal neutrinos have their place in the list.
 

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