Brian Cox is simply brilliant.

I thought I was following it really well until that point.

By the way, what hi-fi does Brian Cox have ????? And if it's Naim, why doesn't he post on this forum

I too struggled with the concept that all the electrons in the universe adjust to make sure they're all on different levels.  Also the word instantly can't be right, as whatever the medium by which they communicate their levels to each other, i doubt the 'message' travels much faster than the speed of light (unless it's via Neutrinos?! - whatever next?).

I seem to remember that 'scientists' had managed teleportation at the atomic level recently but can't remember the experiment - perhaps this was adjusting an atom and seeing and electron in another location changing 'state'? Can anyone remember?

As regards Brian Cox, he did pretty well but i was put off by his reading of the autocue often getting the punctuation wrong - a bit odd.

Phil

If I remember correctly, there is more than one effect.  BC is talking about tidal forces caused by the difference in gravity along the length of the body - assuming falling feet or head first - which means that your feet accelerate faster that your head...so you stretch. It's a real event in the reference frame of the faller.. [That's exactly how tides work on earth - its the difference in attractive force that matters.  It's why you get 2 high tides a day - the part of the ocean nearest the moon is pulled up just that bit more than the parts further away beside them, while at the diametrically opposite side of the earth the high tide point is caused by the ocean being less attracted than the parts just beside it]  In the case of a black hole significant tidal stretching might not occur outside the event horizon so it might not even be visible to a hypothetical observer at a far distance.

The whole question about what that observer would see (assumed to be using electromagnetic waves) is a whole different kettle of fish.  I have a very vague recollection that you'd get visual distortion, but you'd also get colour shifts and loss of intensity (as the light red shifts and loses intensity as it climbs out of the gravity well).  It was always interesting but a tad hard.  [After all, in the real universe there is a lot of dust around, especially near a black hole]

Of course, I may have forgotten something - in which case I apologise to my various professors....but it has been the best part of 30 years.  Wikipedia does seem to agree with me  which worries me a little. [Though it has the right references in there]

Most of this is straightforward classical general relativity - unlike the Hawking radiation, of course.

The assertion that every electron must exist in a different energy state has never, so far as I am aware, been proven nor ever measured.

Well, its a bit hard to measure it.... rather a lot of electrons.  On the other hand, what can be measured (eg electron states in neutral atoms) is consistent with the principle.

As for proving it.....  That depends on what you take as first principles, doesn't it?  Most quantum field theories obey the exclusion principle (indirectly) but it could be argued that they actually assume it in some way....   You pays your money.....takes your choice....

A couple of Neils Bohr quotes:

If anybody says he can think about quantum physics without getting giddy, that only shows he has not understood the first thing about them.

If quantum mechanics hasn't profoundly shocked you, you haven't understood it yet.

He wasn't kidding was he?

Nonsense. He's a highly respected professional physicist and a full blown professor of Particle Physics at Manchester University. He has got kids interested in the sciences again. According to some teacher friends they're seeing a renewed interested in physics in particular and it's attributed largely to him.

He is no lightweight and we should be grateful that people like him and Jim Al Khalili are getting so much tv time.

He used to be a Naim man and posted here occasionally. His name was drbri and his posts still exist.

ISTR(*) that he came on here telling us why the quality of interconnect cables and power cables was important and saying all this because he was some sort of university lecturer and knew these sorts of things.

Unfortunately, this was before he was famous, and way before Naim had invented their Hi-Line and Power-Line cables; and Burndies were Burndies, not Black Burndies or Grey Burndies.

Inevitably he got shot down in flames.

Now, if he had only joined the forum after he was famous and more importantly,after Naim had inveted said products, he would have been welcomed as the hifi messiah of the Naim Forum.

Cheers

Don

(*) my memory is failing.............badly

Well Phil....that can't be right either.... can it??

Since the time it takes for light to reach us from the origin point of the big bang is now thought to be approxm 13 Billion years that would mean communication between electrons at opposite ends of the universe would be rather delayed 

I'm a Physics teacher and cannot bring myself to watch his programs. Don't quite know what it is about him I don't like but there is something. I agree with a former post that he was far more watchable a decade ago.

There are some old videos of Richard Feynmann (I think somewhere on the Microsoft website). Now that man I could watch all day, a brilliant Particle Physicist with a superb style of talking and engaging the audience (admittedly probably not the same audience that would watch BBC at prime time). 

Brian Cox is a respected scientist and good populariser but can get on your nerves after a while. It's probably not his fault - down to directors and producers I suspect - but all those shots of him looking gorgeous and windswept on top of mountains are distracting and make him look like a tit.

Jim Al-Khallili is where it's at these days

I didn't see his programme and I haven't a clue about quantum theory but,

If BC and other scientists theorise that every electron in the universe "knows" the state of every other electron and they all ensure that they each exhibit a different state at all times, and if this is physically true, then talk about the speed of light seems to me to be irrelevent.

ISTR that there is a gulf between quantum theory and the theories of relativity. Each helps us predict the outcome of certain events, but the two don't sit well together.

One day, we might understand why.

Cheers

Don

Its not so much that the speed of light being irrelevant....  One of the niggles I have with all of the science programs in this topic area is that they focus on a standard set of topics and vary the presentation (eg Brian Cox emphasising the wonder and Jim A digging in the detail).  What that misses out is some of the truly awkward stuff that few professional scientists decide to try to resolve.  When you try to visualise 'how can all the electrons know what state each other is in' you run into one of these.  Current experimental state of the art indicates that the whole idea of 'local' (that the electrons are in any way 'each in their place') isn't consistent with the results. [Again wikipedia has a fair description here] Its not totally lock solid, but most people working in this area take it as a given.  [Indeed, the alternatives - at least as worked out by Bell - have nastier theoretical - and moral - consequences than going with the flow.]  

Most physicists won't dedicate themselves to this sort of area since its very hard, and unlikely to be successful (and physicists have families to feed as well... doing hard sums for a living is partly about choosing problems that are hard enough to impress but not so hard that you don't get an answer/make some sort of progress).

Media representation of this sort of topic tends to be occasional at best, in my experience.  Its just too wild, and most TV producers/directors tend to struggle with how to present/pitch it: it's difficult to explain without the background, and undermines so much of how you conceive that background (unless you're in the maths) that shrieks "inconclusive"...

Bell's inequality isn't the only case. [Don't get me started on renormalisation in quantum gauge theories....just because it works - and cleverer people than I say its OK to do it -  doesn't mean its right]  In a way these are just some of those examples that show that physics is a science and science is never finished.  Its never definite.

Good grief guys

This time last year Don was setting logic questions only half of which I could answer...this year we're solving Quantum Physics. Next year can we do world peace and the year after design a speaker that everybody likes.

Was it Einstein who said that problems cannot be solved at the level of thinking we were at when we created them?

Not withstanding the above, apparently I'm getting the book for Xmas from the mother in law (probably to keep me quiet) ...will you guys be on tap to answer all my questions?

Regards

Martin

Ha! a man with a real sense of humour !

Cheers

Don

Slioch is right. Most physicists are mostly interested in the 'known to be false' side of quantum theory because that is where the research grants and teaching posts are. I will stick to Profs. Stapp and Menskey and a small handful of others plus Graham Smetham and B.Alan Wallace. Cox is a good jobbing physicist but, as far as I know, he has not said or written anything insightful when it comes to the ultimate questions posed by quantum theory.  

When I said that the speed of light was irrelevant in discussions about quantum theory, I thought I had picked the least controversial of the options that seem to be consequences of our (limited) understanding of the universe, based on quantum theories.

The first is that we mustn’t ask awkward questions about quantum theory itself.

The other options seem to be

that something binds the universe with an instantaneous communication system (not orange or O2!)

Sub-atomic particles can move back and forth in time

Consciousness affects the behaviour of sub-atomic particles

Parallel universes exist

There may be more options.

None of them seem plausible to me, but then, much of relativity seems implausible to me (*). As I said before, who knows, one day we might understand it all. At least, I hope so.

(*) I accept the practical science that comes from both quantum theory and relativity, so for example, we know that atomic clocks in the GPS satellites run at a different speed to those on earth, and this difference is in line with predictions from relativity. But we don’t seem able to link all of our scientific knowledge together into a neat all-embracing theory – at least not yet.

I presume Dr Brian was explaining the various options and enigmas that currently exist in our understanding of the physics of the universe?

Cheers

Don

I think the main characteristic of quantum theory (specifically those broadly in the same family as the standard model) is that they do have lots of awkward questions being asked....they also provide some of the most accurate predictions of any physical theory we have (ten in a billion for the fine structure constant).  So any  alternative needs to hold out some chance of matching that.... if you're making career choices, what do you do?

Consequently those areas are ones that jobbing physicists (in that general set of topics) are wary of wasting time on, and and only intermittantly get covered in general science media (so I'd include all broadcasters and most magazines like the New Scientist and SciAm in that list).

As for other options - well, quantum measurements behave in a nonlocal way to the limit of current experiments.  And the relationship of consciousness to measurement remains a pretty argumentative area. You can square that with special relativity (no violation of causality in local measurements).

Quantum theory and general relativity on the other hand.....that's been pretty stuck for fifty years.  That's what makes the LHC measurements of potential Higgs particle masses so interesting - the theory guys now have a very busy 2012 as the results (specifically the potential mass) cull out quite a few of the candidate theories.  That should concentrate the mind wonderfully.

In an oversimplified way, I see quantum theory and relativity in a similar light to the more classical physics such as Newton's Laws of Motion, thermodynamics, the gas laws, Bernoullie's laws etc etc. ie the y all provide incredibly useful predictions about the way the universe works and can also provide very, very practical predictions for use by scientists and engineers who want to make our lives more secure and comfortable.

But like those classical "laws" of physics, these (newish) ideas have their limitations, and to an awful lot more people, they are more difficult to grasp than classical physics. IMHO, it's therefore good of people like BC and magazines such as New Scientist, to at least attempt to bring these ideas to our attention and to hopefully stimmulate young minds to want to continue the exploration of the workings of our surroundings and to motivate others to cover their costs.

Cheers

Don

I completely agree on all counts.  I've heard BC talk quite eloquently of what he sees as the science community's responsibility to explain as widely as possible (and as clearly as they are capable) about what they do and why.  Its not because he thinks it needs excusing in some way (he thinks it benefits humankind as a whole in the medium term if not before ) but because its only practical - and the benefits are greater - if it done on that species scale.

I see physics a a series of ever more sophisticated and complex models. They are conceptual models that are described mathematically, and which provide ever more accurate ways of predicting the behaviour of the physical world. But can they ever actually explain anything in a fundamental sense? That seems much less clear to me. I don't know that it really matters. Our ability to model and predict behaviour provides very real benefits in any case.

Popularization of science is important. Advances are increasingly difficult. To become expert enough in a field within one lifetime to make real advances now requires a great degree of specialization. This might ultimately prove a limiting factor - we don't live long enough to get to know this stuff well enough.

The pope has just called for people to value faith over reason in his Xmas message. Completely unhelpful. 

Ah ha !

I can't remeber which chemistry book we used at school. However, I do recall the "gist" of a few words in the preface, something like:-

"If you wnat to understand in a bit more detail how something works, read-on. If, on the other hand, you wnat to know why something works - ask God"

Now, I don't suppose it matters which God you believe in or whether your faith is based on there being no God, I think those were wise words. Well, at least they made me think.

Cheers

Don