## Monday, January 02, 2006

### International year of deserts

Happy New Year! The year 2005 is over, vivat 2006. Because 2005 was the
people got too excited and the bureaucrats in the United Nations had to regulate the excitement. This is why 2006 is the

Kofi Annan probably does not realize how deep idea it was. The Reference Frame is going to celebrate the International Year of the Big Desert Scenario.

Figure 1: Reflections of the Big Desert in a knitted Calabi-Yau manifold.

What does it mean? It means that every comment about high energy physics that you will post here in 2006 should assume that there is the Standard Model (probably the supersymmetric one) below the TeV scale; then nothing for nearly 14 decades - in other words, the Big Desert; and then you hit the GUT scale or the string scale slightly beneath the Planck scale.

If you have any alternatives, please introduce them modestly or keep them for 2007 which is the International Year when the LHC should be activated. ;-)

1. Lubos:

How is your native Czech doing now that the Russians indeed cut off the gas supply to Ukraine. And Ukraine in turn also reduces the gas supply westward to Slovakia and Czech. The Russians had threatened to cut the gas out altogether if it were discovered that Ukraine is "stealing" the gas meant for western Europe, which Ukraine is doing exactly that. The big news is on all major news media so you can't miss it. BTW, the Russians originally wanted trippling the price, and later quadripple, and now it's almost 5 times more. But even at $230 it's still half the price what we see here in the USA. While year 2005 is the year that all the scares happened, year 2006 could well be one where all the bad things really happen. Wait till you see US launches an attack on Iran and it's going to get real messy. By year 2007, people will be all but forget LHC altogether already. Quantoken 2. For comparision agaisnt the dessert magnitude, MacGregor suggest to take a look to the half-lifes of elementary particles. You can download a data table from pdg Z0 has 2495.2 MeV, and the muon has 2.99591E-16 (and yes, there is a bug in the .csv file, you could want to use the old one). This makes 19 decades. In fact you have already 7 decades between muon and tau. And if you are willing to include composite particles, you can count 7.431E-25 MeV (er, I will write pdg about their new data file) for the neutron electroweak decay, so it makes up to almost 28 decades. The point being that huge multiples are not rare in elementary particle physics; the dessert is. (Personally I think nowadays that it is even emptier, just some extra higgs and no susy) 3. Dear Quantoken, thanks for asking. My homeland is doing very well - in fact, better than what I would like exactly at this moment. ;-) We have already heard your oil peak predictions. The LHC predictions of yours are of similar kind. Dear Leucipo, the decay rates of elementary particles are very nonfundamental quantities that are calculated from others - masses of lighter particles and couplings - that we consider more fundamental. It's not surprising that they span a much bigger interval. In nuclear physics, the lifetime of various nuclei decaying by alpha decay are even more diverse - it is because the decay rate may be approximately explained by the tunneling effect, and therefore has the form exp(U). U is pretty big and small relative changes to U result in huge changes of the lifetime. Best Luboš 4. Lubos: The peak oil fact is not a prediction, but a postdiction and in one or two years it will become a verdiction. It's neither a conspiracy theory nor a crackpot theory. The earth has limited fossil fuel resources and that is a fact not in dispute. You don't have a family, you don't have kids, you don't own a house, you don't have a car. You don't pay utility bills for water or for heating. You live your life in the ivory tower, eat only in school cafeteries and live only in on campus apartments with all utilities paid already. Of course you are completely detached from reality. But there are plenty of facts out there. Natural gas price shots up to$17 and now $11, still way above last years top price of$7, and many times more expensive than the $2 which is only 4 years ago. Crude oil is now$60 and you think that's cheap? They flooded the market with strategic petroleum reserve for the past few months so we now see gasoline just slightly above $2 a gallon. You think$2 is cheap. It was ridiculously high back in 2004 when people first saw \$2 gasoline.

Now, Russians cut off the natural gas and Slovakia is receiving only 60% of the gas. And you think Czech is better off and having a normalcy because the Slovakias cut their own gas usage and send all the gas west your way? Wake up from your fantasy. The energy crisis reality is cruel and this is just the beginning.

I consider you an inexperienced young kid. You learned a few fashionable super string classes, but have not learned too much real stuff beyond that. You do NOT even have a solid training in the general physics and basics of quantum mechanics. You meantioned the quantum tunneling and used the expression exp(U). You probably meant U to be the energy potential barrier. You got it completely wrong from the standard textbook. As a starter you missed the negative sign. Big difference.

The correct expression is something more like this:
exp(-sqrt(2MU)*x/hbar)

So the exponent is not proportional to U, but rather to the square root of U. And the exponent also depends on x, the thickness of the potential barrier.

Finally, I want to tell you that the textbook teaching which uses QM potential barrier to discuss delay rates in nuclears is COMPLETELY wrong! Try to guestimate using some typical values of M, U and X you would expect in a nuclear, and you do not get the kind of decay rates you expects.

Further, potential barrier would work both ways, a potential barrier which is hard to penetrate from inside to outside is equally hard to penetrate from outside to inside. But for those long lifetime nuclears, it does NOT seem difficult at all to shot a netron into the nuclear. The incming neutron does not even need to be of any high energy at all. Why the barriers only prevent something from coming out, but do not prevent something from going in?

Example to consider is the U238, which is of extremely long lifetime. But it has no difficulty absorbing a slow moving neutron.

Quantoken

5. Well, that is the point: that routine calculations within the Standard Model do actually cover wide intervals. So the surprising thing about the desert is not the span, but the fact it is empty.

As for the calculations themselves, of course the mechanism is unlike alpha-decay. Let me review them for the general public. There are two basic decay baselines, the one of the neutral pion, anomaly mediated, and the one of the charged pion, electroweak mediated. Both decays differ by about 8 decades. From both baselines, for neutral and charged particles, you can see an aproximate dependende with the cube of the decaying particle, so it comes to cover another eigh or nine decades, entering deep in the terrain of the strongly decaying particles (the ones with a mass number in parenthesis, in the standard notation) In a category of itself, amazingly stable, stands the neutron. And of course, beyond it, the proton, if we buy GUT tickets.

6. Find more about Ukainian Holidays in
Ukraine guide!