Thursday, June 12, 2014

Extra Dimensions

Here's a video on the idea of extra dimensions and the possible link to why gravity is so weak.



Zz.

5 comments:

johnduffield said...

General relativity is one of the best-tested theories we've got. A concentration of energy "conditions" the surrounding space altering its metrical properties, whereupon we talk of curved spacetime. IMHO Don Lincoln ignored all that in favour of mystery-peddling cargo-cult crap. In a very smug patronising way. I found it really irritating myself, and was left thinking no wonder HEP funding is forever getting cut.

ZapperZ said...

I think you are being too harsh on him, and the intent of the video.

He's trying to explain as to what these "extra dimensions" are, and what brought it about. These are stuff that a lot of people, especially laymen, have asked. So he's telling them what they are (and what they are not), and why there are theories that employ such a concept to explain why gravity is weak.

In other words, I see this video as a response to the frequent questions that I've seen, especially online, on these extra dimensions and gravity. It certainly isn't out to sell the concept to anyone.

Zz.

johnduffield said...

I just don't buy it Zapper. See Rod Nave's hyperphysics where he brings home the enormous strength of the raw electromagnetic interaction. We don't puzzle about why the current-in-the-wire force is so weak. We know that the forces that result from field interactions don't quite cancel. And we know the same is true when we stop the current. Because we know about gravity and electromagnetism and Einstein's attempts to unify the two, and more besides. And about action h in E=hf, and that for every action there is a reaction. But HEP theorists ignore all that and say it's a mystery and nobody knows and peddle stupid speculative woo with a condescending smirk. Take a look at Woit's blog for more. Physics is going to hell in a handcart Zapper. And I don't like it.

ZapperZ said...

Again, your displeasure at the subject matter is overpowering your ability to understand the main purpose of the video. It is NOT to sell the idea of extra dimensions. I do not see that at all and do not get that message from the video! This is not about trying to argue for the presence of extra dimensions, but to address the many and frequent questions that a lot of people have asked regarding what it is, and how it is related to gravity!

Are you telling me that if someone asked you to explain what "supersymmetry" is, you will simply go on a tangential rant on why it is wrong, all the while ignoring to answer that person's question? This is essentially what you are doing here!

I do NOT buy this extra dimension stuff, not because I have some a priori bias against it, but because there are no experimental evidence for it YET! I had even mentioned about it several times on here. See this entry, for example:

http://physicsandphysicists.blogspot.com/2007/03/more-predictions-falsified-and-will.html

So stop telling me what's wrong with it, because you seem to think that I'm totally ignorant of it, and that's irritating because that's isn't the point!

And what's with this "physics is going to hell" crap? This area of physics occupies such a small phase space in physics, and commands minuscule amount of research money, even if it is something the LHC might be looking for. Somehow, the fact that the largest portion of physics and practicing physicists are NOT doing anything remotely close to this field has been completely overlooked! How come you are using the small minority to be the standard bearer of physics as a whole?

Zz.

johnduffield said...

All points noted Zapper. It looks like the main purpose of the video is to impress a public who Don Lincoln thinks is gullible and stupid. But it's condescending, counterproductive, etc.

If somebody asked me to explain supersymmetry I'd say something like Don Lincoln did here. But I'd also want to say why I think it's ill-conceived and has been bad for physics.

The "physics is going to hell" stuff isn't crap. Physics has funding problems, and woo in HEP, which is "the flagship of physics", is a big part of the problem. Again, look at Woit's blog.