Brian Greene's new op-ed

Brian Greene has a nice and wise

• op-ed (The Universe on a String)

in the New York Times and the International Herald Tribune (IHT). It starts with Einstein's attempts to find the unified field theory and explains why he couldn't succeed since he didn't know the nuclear forces and deliberately decided to ignore quantum mechanics.



Greene returns to the beginnings of physics and Newton's unification of celestial and terrestrial gravity, electromagnetism, quantum mechanics. It is then explained how Glashow, Salam, and Weinberg made the next important steps to unify the forces. The previous attempts couldn't unify all forces and remove the singularities, string theory can.

A brief history of string theory is followed by many examples of existing or conceivable experimental setups to verify various scenarios or calculations of string theory, including the LHC, mini-black-holes, RHIC, corrections to CMB, and others.



Brian emphasizes that string theory doesn't change anything whatsoever about the scientific method, in a sharp contrast with a rather widely held myth. Although one needs a lot of mathematics, the goals and the criteria to decide about the theory's validity are what they always have been and the experimental verification is the only final arbiter. Brian Greene as well as every other string theorist would stop working on the theory if it were shown that it is internally inconsistent or incompatible with reality - which however hasn't happened.

He points out that even if it is impossible to determine the parameters of Nature uniquely, a unified theory would still be a huge achievement. He also addresses certain comments that a research direction should be given up if it doesn't satisfy an arbitrary timetable. Greene determines that this suggestion is, well, silly.

String theory continues to offer profound breadth and enormous potential. It has the capacity to complete the Einsteinian revolution and answer the deepest questions. Do we know for sure that we will reach the end? We don't know but science requires tolerating uncertainty.

And that's Brian's memo. ;-)

Thanks to David G.

Lahti summit on Russia

The leaders of the EU countries

• gathered in Finland

to negotiate about Russia and the external energy policy of the union. I think that the only leader who approaches all these questions entirely rationally is the Czech president Václav Klaus. The differences could hardly be more obvious.

The average leaders would say that the opinion of the EU countries must be unified. Klaus says that the opinions of the EU countries can't be identical because each of them has different relations with Russia and depends on Russia to a different extent, and there is no problem with these nuances.

The average leaders offer cryptic comments about the deteriorating situation of democracy in Russia. Klaus, on the other hand, doesn't see any great problems with the Russian democracy at this moment and he argues that the situation is as expected given the Russian history and good in comparison with the era of the Soviet Union.

The average leaders tend to propose various bans on different kinds of energy sources in the EU. Klaus argues that the EU countries shouldn't depend on Russian energy that much and the restrictions on the allowed sources, including nuclear and coal-burning plants, make the situation worse. Some restrictions of this type in the past have already made the European position weaker and they were mistakes.

Balkenende and Blair have sent an alarmist letter about the global warming that will breach the tipping point in 15 years, as they suggest. Klaus replied:

• I have read the letter but it is not possible to discuss this issue in such a simple way. Whether there exists global warming and whether the mankind or something else is responsible for this warming, are completely different questions. And yet another question is, assuming that this small global warming will indeed occur, whether this warming would be such a bad thing. It's a serious debate that can't be solved by that letter.

According to a different article, Klaus said:

• The future discussion on the EU's energy policy ... should be conducted on the basis of rational considerations about possible connections of the energy industry and climatic changes. In my opinion, such loose statements as those used in this letter are not of this character. What is concisely referred to as global warming is a fatal mistake of the present time. First, a reply must be given to the question whether something like this does exist, and if it does, whether it is connected with human activities. And if any movement in temperatures does occur, and it will in any case be x-times smaller than what some bearers of disastrous news claim, will it be any problem for man?