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Tsung-Dao Lee, physicist who challenged a law of nature, has died

nytimes.com

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Re: Tsung-Dao Lee, physicist who challenged a law of nature, has died

#31

Post by perihelions »

DonaldFisk wrote: post #30
AaronM wrote: post #28

Earlier quoted context omitted.

I thought about this for a bit. One easy to use explanation for left and right is a number line. Smaller numbers are on the left and larger numbers are on the right. It's still an assumption that alien species would count that way.

What if they draw a number line with smaller numbers on the right and larger numbers on the left?

Indeed.

There's nothing you possibly draw on paper that answers the question, in isolation. A diagram on paper means exactly the same thing if you simultaneously (i) flip it, and (ii) flip your mental interpretation if it.

Or: if you run a software program on a raster image, there exists a different program that returns identical output given an input image which is mirror-flipped copy of the first one. (It's just the first program, plus a pre-processing step that flips its input (which is computable). If f is a computable program, and f(img) = "left" and f(flip(img)) = "right", there exists a computable program g=f∘flip such that g(img) = "right" and g(flip(img)) = "left").

Similarly: there's nothing you can do in complex analysis that can distinguish the case where all +sqrt(-1)'s are swapped with -sqrt(-1)'s. Nor can you invent any math whatsoever that has an isomorphism to the plane, that works differently if the plane is mirror-reversed.

Re: Tsung-Dao Lee, physicist who challenged a law of nature, has died

#32

Post by KingMob »

sampo wrote: post #24
Jun8 wrote: post #8

Chien-Shiung Wu, who conducted the experiment that proved Lee’s (and Yang’s) theory didn’t share the Nobel Prize with them in 1956. When I read people lamenting the fact that Rosalind Franklin didn’t get the Nobel due to sexism I wonder why Wu is not mentioned. For more information on the circumstances see https://physicsworld.com/a/overlooked-for-the-nobel-chien-sh...

> the fact that Rosalind Franklin didn’t get the Nobel due to sexism The primary reason why Rosalind Franklin didn't get a Nobel is that she died in 1958. It's maybe not easy to speculate what would have happened in the alternate timeline where she had lived until the Nobel nominations started to happen.

For those unaware: the Nobel is not awarded posthumously.

Re: Tsung-Dao Lee, physicist who challenged a law of nature, has died

#33

Post by pnut »

netdevnet wrote: post #14

Is it just me or does anyone also get this odd feeling when people use phrases like "challenged a law of nature". Makes it sound like he did something that is physically impossible when he actually attempted something that was believed to be impossible or highly unlikely

Well he ended up dying, so the lesson is clearly, be careful who you challenge.

Re: Tsung-Dao Lee, physicist who challenged a law of nature, has died

#34

Post by dotancohen »

perihelions wrote: post #12

Feynman wrote a exceptionally clear explanation of this experiment and what it meant: - "To illustrate the whole problem still more clearly, imagine that we were talking to a Martian, or someone very far away, by telephone. We are not allowed to send him any actual samples to inspect; for instance, if we could send light, we could send him right-hand circularly polarized light and say, “That is right-hand light—just…

Why couldn't we just tell the aliens to observe the direction of the field lines of electromagnetism? We could define for them "lower potential energy direction" by describing gravity, then use that phrase for describing the motion of the electrons in a conducting wire around a magnetic coil.

Re: Tsung-Dao Lee, physicist who challenged a law of nature, has died

#37

Post by luxuryballs »

perihelions wrote: post #12

Feynman wrote a exceptionally clear explanation of this experiment and what it meant: - "To illustrate the whole problem still more clearly, imagine that we were talking to a Martian, or someone very far away, by telephone. We are not allowed to send him any actual samples to inspect; for instance, if we could send light, we could send him right-hand circularly polarized light and say, “That is right-hand light—just…

physicist L100, human anatomy L1 (the heart is in the center)

Re: Tsung-Dao Lee, physicist who challenged a law of nature, has died

#38

Post by lokimedes »

KwisatzHaderack wrote: post #20

> Lee became Dr. Fermi’s sole doctoral student in theoretical physics, meeting with him every week. It was an extraordinary learning experience, partly because of Dr. Fermi’s teaching technique, which Dr. Lee explained in the 2007 interview with the Nobel Institute. “‘You see,’ he said, ‘there are things that I would like to know,’” Dr. Lee recalled Dr. Fermi saying. “‘Lee, why don’t you look up and give me a lecture…

Pope without pontification!

Re: Tsung-Dao Lee, physicist who challenged a law of nature, has died

#39

Post by InitialLastName »

AaronM wrote: post #28
perihelions wrote: post #12

Feynman wrote a exceptionally clear explanation of this experiment and what it meant: - "To illustrate the whole problem still more clearly, imagine that we were talking to a Martian, or someone very far away, by telephone. We are not allowed to send him any actual samples to inspect; for instance, if we could send light, we could send him right-hand circularly polarized light and say, “That is right-hand light—just…

I thought about this for a bit. One easy to use explanation for left and right is a number line. Smaller numbers are on the left and larger numbers are on the right. It's still an assumption that alien species would count that way.

Is the number line even universal among humans? Do cultures that read top-to-bottom or right-to-left still conceptually sort the larger numbers to the right?

Re: Tsung-Dao Lee, physicist who challenged a law of nature, has died

#40

Post by nyc111 »

davrosthedalek wrote: post #26
nyc111 wrote: post #21

“subatomic particles, contrary to what scientists thought, are always symmetrical.” This cannot be called challenging a law of nature. He questions what his colleagues generally believed. He challenges a convention of physics profession not a law of nature. But we know that media must exaggerate to sell papers.

No. What he challenged was an assumed law of nature. All laws of nature are assumed, as you cannot prove them, or only proof them in the context of a theory (which you then have to assume). It was not a convention.

So, before Lee made his discovery physicists believed (or assumed, or conjectured, or theorized) that “the laws of physics were identical whether observed directly or as a mirror image." Lee and Yang proposed that this did not always hold. Their proposal was later confirmed by experiments.

So, what physicists believed before Lee, was not a law of nature. Lee challenged what his colleagues believed to be true.

But you are right all so called laws of physics are provisional.

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