Wednesday, September 16, 2009

Physics Quote Of The Day.

Sorry to quote David Tong two days in a row, but this guy has some good quotes.

From David Tong's Lectures on String Theory:
Our current understanding of physics... is 15 orders of magnitude away from the Planck scale. Why do we think the time is now ripe to tackle quantum gravity? Surely we are like the ancient Greeks arguing about atomism. Why on earth do we believe that we’ve developed the right tools to even address the question?

The honest answer, I think, is hubris.
Wow, it just doesn't get any more candid than that.


  1. To relate about tools is interesting, because the theories we are using are tools anyway, some are more or less close to reality, but the progress does bring us closer and closer to reality. On the top of that we can think about chemistry for example, and how should it be possible to do modern chemistry without the theory of the model of the atom which comes from quantum mechanics ; without this as an example this is not possible to find all the medicines we have actually, so physicians could not be as efficient as they are… These tools are at least as valuable as the material ones, but I do ask myself if in France they do not think that they are free, because they did not pay Descartes (he did not live in France during a long part of his life and the fact they did not give him the money he was asking did help, I think) for his work and they have no problem with the fact to use him in order to bring some credit to France. Finally I fear that they want to do the same thing with me, because they know about me, I did contact quite a lot of persons, sent my work, and publish a big part of it on a French blog ; as well they did not find anything logical against what I have done, may be they want to show me their power on me, and submit me (in USA this is not the same thing, I just begin to relate about what I have done).

  2. Wow, great quote. I often feel like today the physics and astronomy communities are in a similar state of mind now as they were in late 1800's. I get the feeling that many scientists think we're pretty close to having fundamental physics all figured out, and then everything is just chemistry, biology, and engineering. I think we will live to see something revolutionize physics in the same way that relativity or quantum mechanics revolutionized physics and astronomy a century ago.

  3. Nick, I actually agree with that. I think there still needs to be a revolutionary idea or two to figure all this stuff out.

    However, in the mean time, so many incredible ideas have and will come from string theory that I believe studying it will prove to be well worth it.

    String theory is a source of interesting ideas like the sun is a source for photons. :) Surley some ideas/tools will eventually prove to be very vital for many areas of physics.

  4. "Surely we are like the ancient Greeks arguing about atomism."

    My money is on this statement is correct.

  5. I've been hearing from a lot of string folks that the attempt to do quantum gravity was a mistake (as well as not really amounting to much beyond interesting mathematics). What I've been hearing (and maybe this is wrong) is that the big thing in string theory now is finding other applications and just finding quantum gravity pointless until there's some data to work from.

    If so, that's remarkable, although I suspect not that surprising. Whatever one thinks of string theory as science it clearly is quite interesting mathematically. It's just too bad it didn't lead to real revolutions in quantum gravity or even particle physics as I think people in the 90's were hoping.

  6. Clark, it is true many are trying to find applications with data and setting quantum gravity aside. This is a good thing.

    I almost want to say we unfortunately live in a world where current theories are too good. Everything, except gravity, seems to be explained perfectly by the standard model.

    What theorists need is some new data that is really bizarre to help us have a hint of what to do next. In some sense dark matter and energy fit this, but to be honest we need more. There are too many theories that explain both and we need something new to distinguish between them.

  7. Joseph, I think not enough string theorists appreciate the ontological questions though. There are some really interesting philosophical questions though. There was a great book on the philosophy of string theory (and a few related things like Kaluza-Klein and the Hole theorem) in a great little collection from I believe '99. The name escapes me (I have it downstairs somewhere) One paper that sticks with me was called something like "Pre-Socratic Quantum Gravity" which actually was a pretty good little paper and not nearly as pretentious as the name suggests.

    Smolin, in his anti-string screed (which I've not read much of) has a nice chapter arguing that physics needs to embrace philosophy more. (I have read that portion) I think this right and even if you don't think much of LQG I think some of Smolin's philosophical questioning of quantum gravity have to be taken as helpful. (Smolin himself is a Peircean and being very sympathetic to the Peircean perspective on philosophy myself I must admit to liking the basic stance of Smolin)

  8. Well, there is a lot of physical phenomena not really explained (although one could argue that it would fit in the Standard Model). Dark matter and energy being the obvious example. I think if the accelerator ever gets up and running everyone is hoping that something will be proven wrong. While the Standard Model works very few people actually like it I think. It reminds me of the early days of particle physics when it became obvious that there was something underlying everything. It just took a little bit of time to discover it.

    But yeah, I think physicists are praying that some new phenomena that isn't just unexplainable but points the way akin to how destruction of Aether did. When you consider how many decades it has been since theoretical physics has made a major breakthrough it really is remarkable. Especially considering the progression that went on before. It seemed like every 20 years there was a major, major breakthrough. Then....nothing.

  9. "String theory is a source of interesting ideas like the sun is a source for photons."

    It is true that a different way of understanding things can bring to very interesting ideas.

  10. A problem in France as well seems to be that in order to have recognition for a new work, it is better to find some Americans in order to explain them.


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