Leonard Susskind on Feynman, the Holographic Principle, and Unanswered Physics | Hacker News Reader

Leonard Susskind on Feynman, the Holographic Principle, and Unanswered Physics

blog.ycombinator.com

76 points4ad12 comments

Nit: its "physics canon," not "cannon." Like "canonical."

For those who were attracted by "Feynman" in the title, here's Susskind's talk about Feynman, also mentioned in the interview:

https://www.youtube.com/watch?v=hpjwotips7E

Feynman reminds me of a more material/practical Alan Watts. Also, kudos to the article for the index.

Not sure what it is, but his lectures are amazing to go to sleep to. Thinks it's the voice.

Also really interesting stuff too.

Listening to this, I realized how being a skeptic as led me away from my physics background. Namely, how ER=EPR is a fact due to recent findings even though our history of science is being "correct" until we find new information to discredit past beliefs.

The idea that old physical theory always becomes false or incorrect when a new theory supersedes it is elementary mistake. For example "Classical physics is wrong" or "all theories are proven wrong in time" fallacies.

You;re right. i incorrectly stated the ended of my post. I was speaking in the context of this podcast, where Susskind constantly talked about how we've discredited past theories but now we know the truth.

I certainly did not mean to state anything similar to your fallacy examples. Obviously thinking in absolutes either way in incredibly arrogant.

It isn't really a fallacy, just pedantic. We can't really assert a philosophical concept of 'truth' in physics, because there is always uncertainty. By extension, any statement that 'this is how the world is working' has a good chance of being wrong in theory and practice.

For example, as I know we have random variables in the current models of quantum physics. Based on our historic experience with the universe, they may yet prove not to actually be random. Until quantum physics, random variables were always a theoretical construct to fill in gaps in our knowledge - eg, "experimental error" was expected to be limits in our ability to measure rather than something fundamental.

Classical physics is really handy, but it doesn't accurately model how the world works in a can-I-simulate-reality-according-to-our-best-knowledge sense. That falsifies the theory.

Nope. The randomness of quantum mechanics cannot be erased with more detailed knowledge-- ascribing any number of "hidden" properties to particles to explain their quantum behavior produces mathematical inconsistencies. See:

https://en.wikipedia.org/wiki/Bell%27s_theorem

It can if the properties are non-local

Actually technically Bells Theorem says you can’t have hidden variables if you want to retain _locality_. If you allow nonlocality Bells Theorem still allows hidden variables.

It's not "just pedantic" or related to uncertainty.

Classical electrodynamics or classical mechanics did not switch from true to false, they turned into good effective theories. Just like quantum field theory is already considered to be effective theory without any known theory that is more complete.

When the limitations of the quantum field theory theory are known and it works within those limits, the theory is not falsified with new discoveries outside those limits.

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