On the Defensive

There’s another article here about Michael Green succeeding Hawking as Lucasian chair. It emphasizes the idea that this is all about more funding for string theory:

MICHAEL Green, the 18th holder of Cambridge University’s Lucasian Professorship of Mathematics, is clearly a man with weighty issues on his mind.

He apologetically darts out of our meeting to speak to a colleague about how to submit the paperwork for a 1.5 million euros (£1.35 million) grant application he has just heard has been approved by the European Union.

“I suppose it sounds like a lot of money,” he explains, “but it’s not that much really compared to the billions spent on some research. Our work is theoretical – we’re very cheap.”

The money will go towards research on Michael’s specialist subject, string theory…

“I have been thinking about how I can make use of such a prominent position to benefit my colleagues. It is difficult to find funding at the moment, especially for subjects which don’t obviously have an immediate application for something that will make money.

“But the people who discovered magnetism and electricity had no idea what they could be used for. The MRI scanner wouldn’t exist without particle physics. There are so many spin-off industrial investments in things that are being researched, and we need more of this.”

Another blogger has the following comments about this:

There’s only so far that one can run away with this. People “…who discovered magnetism and electricity…” had, in their corner, empirical evidence to at least tell them if they are on the right path or not. This is where the analogy to pursuing String Theory breaks down and the similarity ends. I don’t believe that there has been, in the history of physics, a study in a field of physics that has gone for so long, and garnered THIS much attention, that has been totally devoid of any empirical evidence which indicates one way or the other that it is on a right path. For many of us who value physics as being guided by empirical evidence, this is the most troubling aspect of String theory.

To be fair, Green notes that it’s not all about cashing in for himself and his colleagues, that he would also like to finally have some success with the science:

But, ever the academic, Michael’s eyes twinkle as he admits his “pie in the sky” dream for his tenure of the Lucasian Professorship is not about money, but a breakthrough in the application of his beloved string theory.

“We need something which at the moment doesn’t seem to be a fundamental phenomenon,” he explains. “To find something we know already, but find an undetected explanation out of string theory. It is a radically new theory; what it needs is a radical new prediction.”

I’m not sure though that describing a nearly forty year old theory as “radically new” is really accurate. Any sort of prediction would be radically new.

Also in the business of defending string theory is Sean Carroll, who has a video and transcript up on the Edge web-site on the topic of “Why does the Universe look the way it does?”. It’s unclear to me what this has to do with the topic, but for some reason much of the talk is taken up with a defense of string theory. It’s the usual misleading hype, at great length, leading up to a peculiar defense of the idea that even once you have shown that a speculative theoretical idea is vacuous and can give you anything that you want, you should keep studying it anyway:

How do you show that a theory is not right if you can get anything from it? My answer to that is we just don’t know yet. But that does not imply that we will never know.

From here it’s on to the multiverse and his idea that it explains why you can’t unscramble an egg, and that one is doing observational cosmology over breakfast:

The reason we find a direction in time here in this room or in the kitchen when you scramble an egg or mix milk into coffee is not because we live in the physical vicinity of some important object, but because we live in the aftermath of some influential event, and that event is the Big Bang. The Big Bang set all of the clocks in the world. When we go down to how we evolve, why we are born and then die, and never in the opposite order, why we remember what happened yesterday and we don’t remember what is going to happen tomorrow, all of these manifestations of the difference between the past and the future are all coming from the same source. That source is the low entropy of the Big Bang…

I like to say that observational cosmology is the cheapest possible science to go into. Every time you put milk into your coffee and watch it mix and realize that you can’t unmix that milk from your coffee, you are learning something profound about the Big Bang, about conditions in the very, very early universe. This is just a giant clue that the real universe has given to us to how the fundamental laws of physics work. We don’t yet know how to put that clue to work. We don’t know the answer to the who done it, who is the guilty party, why the universe is like that. But taking this question seriously is a huge step forward in trying to understand how the universe that we see around us directly fits into a much bigger picture.

Update: Carroll this week will be on a lecture tour in Australia giving talks on the Big Bang/egg unscrambling business. The first will be in Sydney where the “internationally-renowned theoretical physicist” will give the 2009 Templeton Lecture.

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16 Responses to On the Defensive

  1. GeofF says:

    I think the flushing of a toilet is a much better analogy than scrambling an egg.

  2. Tom O'Bulls says:

    Thanks for directing my attention to Sean Carroll’s extremely interesting article. He really raises some very profound questions, and it’s good to know that there are people thinking about genuinely interesting problems like the arrow of time, and not just about really boring things like [mumble].

  3. M says:

    GeofF, an even better analogy is: by flushing 1.5 million Euro down a toilet we learn about cosmology. Maybe it can get funded.

  4. piscator says:

    ‘cashing in’, ‘all about more funding for string theory’? This is a parallel universe – do you know the state of funding for particle theory at this moment?

    The UK government has thrown squillions at its banks and is in danger of losing its AAA credit rating. It also wants funding for all research (including even the humanities God help them) to be based on economic impact.

    The idea that this environment is one of squidgy slush funds for string theory is so far from the truth it is comical.

  5. Peter Woit says:


    I understand that the context of this is one of a difficult budget environment for science in the UK. Still, the article’s focus on the Lucasian chair as a vehicle for Green to raise money for his colleagues and his field is remarkable, if only as a sign of the times.

  6. John Rennie says:

    Re the low entropy at the Big Bang: if gravity were replusive then the state of maximum entropy would be an (approximately) uniformly distributed gas. Doesn’t LQG predict that gravity becomes repulsive as you wind back time towards the Big Bang? In that case isn’t it possible that the low initial entropy is due to gravity flipping from a repulsive to an attractive force?


  7. Tim vB says:

    Here are two quotes from the article that I have some trouble making sense of:
    “…with applications in countless different spheres.”
    “The theory … has met with many successes over the years.”

    Should’nt the first one be “with applications, maybe, sometime in the far future, if the theory succeeds”?

    Reading the second one, I thought in this context a success should be something that is of interest to non-string-theorists. The only way I can make sense of this statements is that Green meant that “string theorists succeded in solving many problems that string theory had resp. created”, meaning that, from the point of view of a string theorists, there were many breakthroughs. I could concur with that, but I suspect that this not not what most reades will think.

    P.S.: Green uses his position to fund string theory, this is hardly a surprise. Isn’t that what most people in similar situations do?

  8. Kea says:

    Oh, I’ll be in Melbourne for that Carroll talk … but I’ll be busy doing something too interesting to attend … like my washing, maybe.

  9. Marcus says:

    *Oh, I’ll be in Melbourne for that Carroll talk … but I’ll be busy doing something too interesting to attend … like my washing, maybe.*


    And remember that doing your laundry is a giant clue as to to how the fundamental laws of physics work.

  10. Will Orrick says:

    The reason for the name “Templeton Lecture” is described at this University of Sydney website:

    “In 1990, Charles Birch was awarded the Templeton Prize for progress in religion. He donated part of the proceeds of the prize to establish the annual Templeton Lecture at the University of Sydney, under the auspices of the Centre for the Human Aspects of Science and Technology. This generous gift has brought a succession of distinguished speakers to Sydney.”

  11. Peter Woit says:

    Thanks Will, I was wondering what that was about.

  12. chris says:


    on a cosmic scale gravity IS repulsive.

  13. John Rennie says:

    @chris: I assume you’re referring to dark energy, but this has only recently starred dominating and certainly wasn’t a factor near the Big Bang, or indeed during the formation of galaxies.

    Of course there may eventually be a big rip. If so presumably the state of maximum entropy would again be a roughly uniform distribution. That’s assuming the concept of entropy has any meaning in such a radically non-equilibrium system!

  14. Alejandro Rivero says:

    TInking about being a “nearly forty year old theory” … is there some plan to celebrate the anniversary. If we count from Susskind “violin string or organ pipe”, we should prepare, as it was submitted in 11 July 1969 and published early 1970. If we count from Veneziano, we are already late. We could count from Ramond 1971, as it paves the way to D=10, susy etc.

  15. Thomas Larsson says:

    Veneziano’s and Virasoro’s advisor is no longer with us.

  16. Chris Austin says:

    Forgive me if this is a silly comment, but isn’t the reason that we remember the past but not the future, connected with the fact that field equations in Minkowski signature have well defined solutions when boundary conditions are specified on just a single spacelike surface, i.e. a Cauchy surface? Then, if the boundary conditions on the Cauchy surface do not include non-random correlations between the initial values of the fields at distant points, the time direction away from the Cauchy surface is the direction of increasing time, and we are forced to use retarded potentials in solving, e.g., Maxwell’s equations in the presence of classically moving charged particles.

    If we wanted to use advanced potentials, or mixed advanced / retarded potentials, the boundary conditions on the Cauchy surface would have to include carefully set up incoming spherical waves for the moving charged particles to absorb, and these would have to be correlated with the future motions of the charged particles. Thus Minkowski signature field equations automatically create correlations away from the Cauchy surface, if there are no correlations on the Cauchy surface.

    Furthermore, if the boundary conditions on the Cauchy surface are random, the state of a memory device at any time will in general be correlated with events in its past light cone, and in particular, with events on its past worldline, going back to the Cauchy surface, but cannot be correlated with events on its future worldline except under special conditions of shielding, since events on its future worldline will in general depend on the boundary conditions on the Cauchy surface outside its current past light cone, which have not yet had any impact on the memory device.

    Thus the fact that we remember the past but not the future points to nothing more than that the boundary conditions of physical fields have been specified in the simplest possible way, namely randomly on a Cauchy surface, with no correlations.

    The reason we can’t unscramble an egg is different. First, we have to get the ordered state, i.e. the yolk separated from the albumen. Such locally highly nonrandom states can arise out of initially random states by a long series of ratchet-like processes such as evolution, or by forces that tend to separate the components of a mixture such as a colloid, due for example to differing densities, or high interface energies. Once we have the egg, it is easy to scramble it, because a wide variety of crude driving motions, such as shaking or stirring, can all effectively turn the initial ordered state into a disordered state, via chaotic motions. However the fact that it is difficult to unscramble an egg is a specific property of the yolk / albumen mixture, and tells us nothing at all about other systems. For example, if we “scramble” oil and water together, the mixture will soon separate, due to the differing densities of oil and water, and the relatively high surface energy at the oil / water interface.

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