Comments on: Two cheers for string theory

By: Plato

Plato — Tue, 27 Jun 2006 14:44:03 +0000

There are certain conceptual leaps when moving to a fifth dimensional perspective?

A black hole is an object so massive that even light cannot escape from it. This requires the idea of a gravitational mass for a photon, which then allows the calculation of an escape energy for an object of that mass. When the escape energy is equal to the photon energy, the implication is that the object is a “black hole.”

Such “conceptual leaps” then take on a life of their own?

By: David

David — Tue, 27 Jun 2006 11:51:20 +0000

Why is it that there is no alternative to light being either a particle and/or a wave? Does the logical impossibility of the third have any relation to string theory?

By: The String Theory Backlash | Cosmic Variance

The String Theory Backlash | Cosmic Variance — Mon, 19 Jun 2006 17:57:20 +0000

[...] But I don’t actually agree with what the books are saying. Here is the main point I want to make with this post, trite though it may be: the reason why string theory is so popular in physics departments is because, in the considered judgment of a large number of smart people, it is the most promising route to quantizing gravity and moving physics beyond the Standard Model. I don’t necessarily want to rehash the reasons why people think string theory is promising — I’m not positing an objective measurement of the relative merits, but simply an empirical observation about people’s best judgments. Rather, I just want to emphasize that, when you get right down to it, people like string theory for intellectual reasons, not socio-psycho-political ones. It’s not a Vast String Theory Conspiracy, funded by shadowy billionaires who funnel money through Princeton and Santa Barbara to brainwash naive onlookers into believing the hype. It’s trained experts who think that this is the best way to go, based on the results they have seen thus far. And — here’s the punchline — such judgments could change, if new results (experimental or theoretical) came along to suggest that there were some better idea. The way to garner support for alternative approaches is not to complain about the dominance of string theory; it’s to make the substantive case that some specific alternative is more promising. (Which people are certainly trying to do, in addition to the socio-psycho-political commentating about which I am kvetching.) [...]

By: Approaches to Quantum Gravity | Cosmic Variance

Approaches to Quantum Gravity | Cosmic Variance — Thu, 01 Sep 2005 19:07:44 +0000

[...] Over on Musings, Jacques has given a rather nice (technical) description of some of the motivations for looking beyond quantum field theory for an approach to formulating quantum gravity, and why the stringy approach is so promising. It supplements nicely some of the discussion we’ve had over here in posts such as this, this, and this. [...]

By: Brian C

Brian C — Sat, 30 Jul 2005 07:25:02 +0000

I am of the opinion that string theory is complete and utter garbage. It shouldn’t even be considered a part of physics. Rather, it’s an incredibly complex and convoluted mathematical system with no connection to the physical world.

The truth is, string theory is an embarrassment to the theoretical physics community. I can’t believe so many physicists actually buy into the mathematical gobbledy gook of branes and 10-dimensional strings.

By: Clifford

Clifford — Fri, 29 Jul 2005 02:05:41 +0000

Excellent comment. A quotation to guide us all. Thanks Ijon Tichy! -cvj

By: Ijon Tichy

Ijon Tichy — Thu, 28 Jul 2005 22:14:42 +0000

Because I have no original thought of my own, but still wanted to contribute a comment to this post (if only to push the count closer to the magic 100), I thought the following quote by a master from the past, Emilio SegrÃ¨, might be considered relevant and not entirely worthless. I suppose you could think of it as one part of the explanation of why a quantum theory of gravity is proving such a tough nut to crack:

“The ultimate goal of physics is to describe nature and predict phenomena. It is impossible to do this starting with a priori theories; we would be stymied after a few steps, and every error would be compounded and would send us further from the right path. On the other hand, using experiments alone, we would soon be lost in a bewildering array of disconnected facts without any hope of making sense of them. It is the combination of theory and experiment, brought about by the use of mathematics as a language, that permits the astounding results physics has attained. It is Galileo’s immortal accomplishment to have clearly understood the power of this alliance and to have indicated ways of achieving it.”

[p. 61, Chpt. 4, "From X-Rays to Quarks: Modern Physicists and their Discoveries", Emilio SegrÃ¨, (1980)]

By: Juan Maldacena

Juan Maldacena — Thu, 28 Jul 2005 02:13:30 +0000

I agree with Fredrik that studying the Landscape is very important.
It would be nice to find a smaller number of vacua, so that
predictions are possible. But we would only find out if this number is large or
small if people
study models carefully and find more and more controlled constructions.

A large number of vacua is
the only explanation we have today for \Lambda in string
theory. Hopefully we will have a better one soon, but since this is
the best we have, it should be studied and I am glad that excellent people
are studying it.

By: Levi

Levi — Wed, 27 Jul 2005 15:27:50 +0000

Since you seem to be counting, just keep in mind that you have 97, not 102…

(I just wanted to bring this thread back to the Recent Comments line)

By: evolgen

evolgen — Wed, 27 Jul 2005 13:37:20 +0000

Tangled Bank #33

Tangled Bank – Table of Contents Alert

A New Issue of the Tangled Bank has been made available:

27 July 2005; Vol 1, No. 33

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IN THIS ISSUE
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