It's sad to say this but it's hard to see anybody after Feynman who can be comparable in terms of insight and importance of his-her contribution, maybe only Murray Gell-Mann being close for his contribution to QCD and the completion of the standard model.

That's a bit of shame and a reflection on the nature of popular celebrity, but rest assured in the realm of Physics Feynman was as much a celebrity as Hawking.

Anyway, you're not a nincompoop.

There have been quite a few great ones after Feynman, the problem (or better said, the big difference) is that after QCD and the completion of the standard model in general, all the later developments have been in theoretical areas, without experimental confirmation (I mean big things, of course there have been experimentally confirmed advances but not changing radically the existing theories). That's why I mentioned Gell-Mann in my other post as possibly the latest of those who really changed the big theories. The standard model is the last big theory which so far has passed every experimental test.

But of course there have been very important people, John Wheeler made important contributions to the refinement of quantum theory, Roger Penrose, Alan Guth for the inflationary theory which although not experimentally confirmed is widely supported, George Smoot and his team confirmed experimentally the important fact that the universe expansion is accelerating, Veneziano or Edward Witten in string theory, Leonard Susskind or Lee Smolin in cosmological theories, Zumino and the other guys who developed supersymmetry, David Deutsch made much progress in quantum computing etc etc.

But on one hand, most of these people either did not really make big changes to the existing theories (such as QED or QCD were at their time), or their contributions, while possibly important have remained theoretical without experimental confirmation.

Another thing is that recently most advances are done by teams along certain time, it's not anymore the case that a single guy radically changes physics with his own insight such as Einstein and co did. If you take important recent developments such as supersymmetry, string theory, quantum loop gravity etc, it's hard to pinpoint a single person as the "inventor" or "discoverer", they are usually the result of the sum of several people's work.

Yeah they may not be great physicists themselves but they do a good job at bringing science to the wider public, and this alone is worth a praise for them. Sometimes they exaggerate a bit though, listening to Greene you would think that string theory is the solution to the Theory of Everything question when it is not the case, and Kaku too often makes a shortcut from accepted physics to imaginary possibilities, but OK, it's good that they try to get people interested in science.

 

What I meant is that they are just good communicators, none of them has made really significant contributions to the science itself as physicists (they have done some good stuff, sure, but nothing really outstanding). But yes, communicating about science is also very important nowadays when very few people seem interested in it, and for that alone Greene and Kaku deserve praise. It's a bit like what Carl Sagan did in the 1980's about astrophysics and cosmology.

? 

Attenborough is not a scientist, he's a TV presenter of nature documentaries.

Then why mention him here?

I thought this was a thread about who is the most important physicist not who is the best TV science presenter. If that's the case then I vote for Dr. Helen Czerski. 

I can't know what would attract Feynman's interest, but there are quite some open questions in physics.

The first and most obvious is the attempt to reconcile Relativity with Quantum Mechanics, this is considered the Holy Grail of physics. There is no absolute reason why they should be possible to reconcile, but it seems nice that they should, we always strive for unification as it seems to infuse deeper meaning to the phenomena we observe in the universe.

The next major challenge is the nature of dark energy and dark matter, after all our best theories can only account for 4% of the universe surrounding us, so that is not very uplifting.

Life is another big challenge (and the phenomenon of complexity in general) which no current theory is capable to explain. Why and how do the constituent elements of the universe combine into ever more complex structures? and why and how do these structures reach a point when they become masters of their own destiny, apparently overtaking the very laws of nature?

On a more abstract plane, the subject of FreeWill is also one of the big questions, to which extent is the world pseudo-deterministic (we know at root, quantum level, it is not, it is random, but on larger scales the laws of nature seem to be pretty deterministic. Where is the border and why is there such a border?).

Related to this last point, the subject of quantum decoherence is also still a mystery (why the quantum rules and the macroscopic rules are so different). Where and how does the quantum world become the macroscopic world?

And marimba as I recall, and throat singing. 

Hawking provided vocals for Pink Floyd's Division Bell.

That's a bit of a clanger

Someone who will just have the insight to see something, some relatively simple principle which is just eluding everybody else because everybody is looking from the wrong perspective, even if his technical proficiency is not one of the best? (such as Einstein, he was not technically a top scientists, he just had the insight of realising things, basic principles, which the others did not see. He actually had to learn non-euclidean maths to develop mathematically what he had just realised by intuition, general relativity).

Or perhaps a super-skilled mathematician? who may come up with solutions to for example the unification of relativity and quantum mechanics from purely mathematical grounds?

Or perhaps someone more in the field of cosmology? (given that several of the biggest enigmas are in this field, dark energy, dark matter, black holes...).

As great as Feynman was, I am not sure that he would have been able to crack the current enigmas, for some reason we seem to have hit a barrier of a different level. It is not normal that with so many scientists and resources nobody is able to make significant fundamental progress in 45 years, this had not happened in the last few centuries. 

 

Simple answer: No they are not, in exactly the same way that eating fish doesn't make you a marine biologist or being awarded a gold star in kindergarten for producing a nice picture doesn't make you an astronomer.

I guess that one could say that psychology is physics taken to its ultimate complexity level. But along the way up the complexity ladder there seems to be some point were the physics is not anymore describable by our usual understanding of laws of physics, precise mathematical equations, at some point it seems likely that other things such as "principles", "trends", "patterns", "attractors" etc take over definite mathematical laws. There has been some progress in the study of complexity and mostly it has result in identification of some general principles, pattern trends etc rather than any mathematical equations in the traditional physics sense (that's why many hardcore physicists still hesitate to recognise complexity as a real branch of physics in the same rank as the traditional areas).

No but you can explain them that music and harmony were considered a pure science by Pythagoras and Co.

Several very clever people have said that at some moment, but most more modern reviews of the subject by very clever people conclude that one thing has nothing to do with the other. Godel's theorem basically says that any sufficiently complex formal system (and which complies with a couple of requirements such as arithmetic does) will have undecidable propositions. Translated into a physics theory this would mean that even if we knew the "Theory Of Everything", the theory would predict (or allow) the possibility of things which we could never know if they do actually happen in the physical world or they don't, even if we never observe them we could never prove that they can not or do not happen, the theory would remain necessarily undecissive about it.

An analogy is the decidability of the randomness of a sequences of numbers. We can never prove that a sequence of numbers is truly random, but we can prove that it is not random by finding a more compressed form. Not finding any more compressed form is not a proof that it is uncompressible (truly random), it can be that it truly is or it can be that we have not yet found the compression algorithm.

A different angle to the question is that knowing a theory does not equal to knowing or even being in principle able to know its manifestations. Quantum theory has the famous Heisenberg Uncertainty Principle, we know the mathematical theory but it tells us that we can never know precisely certain features of the world. Similarly, there are theories we know mathematically (such as general relativity) for which computing solutions is in practice is often impossible. And yet another take is chaos physics, where knowing the mathematical theory does not help in being able to know what the system will do after a short time.

A Theory Of Everything, even if it exists and it could ever be found, does not absolutely mean that we could know, deduce or compute much about the physical world.