- #31
starkind
- 182
- 0
0711061415
I see that I hastily skipped over my notes on the talk by Dr. Landsberg, who spoke on the sixth.
His talk was very interesting for me, because I have long been curious about lab results from colliders. Often conclusions are presented without the actual data, which is in the form of abstract images anyway. Still, I have been fascinated by cloud chamber results, and have wanted to understand the significance of the occasional collision image presented in the general press. Unfortunately, this meant I was often trying to see the slides, not copying notes.
Anyway, Dr. Landsberg, from Brown University, talked about the hierarchy problem, models with extra dimensions, gravity at short distances, astrophysical constraints, collider search for extra dimensions, and the observation of BH at future collider events.
Dr. Landsberg started by pointing out that large hierarchies tend to collapse. He gave humorous examples from competitive social human tower events and political realities. However, he said, there is no physical reason why these collapses have to occur. He said fine tuning does occur in nature, which acts to keep some natural large hierarchies stable. His example was the lunar eclipse of the sun, with its unlikely coincidence that the optical angle of the moon matches the optical angle of the sun nearly exactly. He also pointed to the astounding results of the Florida recount, in which the proportion of votes for one party to the other was 1.000061. I did not ask him if he thought this was a reasonable coincidence, or an impossible result.
The alternative explanation, he said, is the anthropic principle, which, in Missouri, is referred to as intelligent design. This part of his talk was, of course, motivational, and raised the mood of the room considerably.
He then talked about constraints on the size of large dimensions from small distance gravity experiments, which restrict the size of large dimensions to less than about 1mm to 1fm. He mentioned that bulk space is a large extra dimensions idea.
Then he discussed the 1999 Randall-Sundstrom model. He said that in the one plus brane, there are no low energy effects. In the two plus brain and 1TeV Kaluza-Klein modes of gravitation there are low energy effects on small brane, and hierarchy problem is solved naturally.
The best current measure of g at short distances is University of Washington torsion balance experiments, a high-tech remake of the 1798 Cavendish experiments. U. Washington has shown no effects down to r=.16 mm. New ideas include atomic interferometer for precision measurement of acceleration, and evidence from monojets.
At this point there were some pictures of collisions, which have been a long time point of curiosity for me, and my notes end.
However, from my memory, he showed what a BH signature would look like. Its main distinction is that the radiation would be very spherical, due to the fact that the BH is very democratic, and can produce any kind of quanta at all, at any angles. He showed some graphs of data showing the spherical radiations. He also said that the signature of a BH would be very energetic, and would show some energy losses due to gravitons leaving the brane.
I see that I hastily skipped over my notes on the talk by Dr. Landsberg, who spoke on the sixth.
His talk was very interesting for me, because I have long been curious about lab results from colliders. Often conclusions are presented without the actual data, which is in the form of abstract images anyway. Still, I have been fascinated by cloud chamber results, and have wanted to understand the significance of the occasional collision image presented in the general press. Unfortunately, this meant I was often trying to see the slides, not copying notes.
Anyway, Dr. Landsberg, from Brown University, talked about the hierarchy problem, models with extra dimensions, gravity at short distances, astrophysical constraints, collider search for extra dimensions, and the observation of BH at future collider events.
Dr. Landsberg started by pointing out that large hierarchies tend to collapse. He gave humorous examples from competitive social human tower events and political realities. However, he said, there is no physical reason why these collapses have to occur. He said fine tuning does occur in nature, which acts to keep some natural large hierarchies stable. His example was the lunar eclipse of the sun, with its unlikely coincidence that the optical angle of the moon matches the optical angle of the sun nearly exactly. He also pointed to the astounding results of the Florida recount, in which the proportion of votes for one party to the other was 1.000061. I did not ask him if he thought this was a reasonable coincidence, or an impossible result.
The alternative explanation, he said, is the anthropic principle, which, in Missouri, is referred to as intelligent design. This part of his talk was, of course, motivational, and raised the mood of the room considerably.
He then talked about constraints on the size of large dimensions from small distance gravity experiments, which restrict the size of large dimensions to less than about 1mm to 1fm. He mentioned that bulk space is a large extra dimensions idea.
Then he discussed the 1999 Randall-Sundstrom model. He said that in the one plus brane, there are no low energy effects. In the two plus brain and 1TeV Kaluza-Klein modes of gravitation there are low energy effects on small brane, and hierarchy problem is solved naturally.
The best current measure of g at short distances is University of Washington torsion balance experiments, a high-tech remake of the 1798 Cavendish experiments. U. Washington has shown no effects down to r=.16 mm. New ideas include atomic interferometer for precision measurement of acceleration, and evidence from monojets.
At this point there were some pictures of collisions, which have been a long time point of curiosity for me, and my notes end.
However, from my memory, he showed what a BH signature would look like. Its main distinction is that the radiation would be very spherical, due to the fact that the BH is very democratic, and can produce any kind of quanta at all, at any angles. He showed some graphs of data showing the spherical radiations. He also said that the signature of a BH would be very energetic, and would show some energy losses due to gravitons leaving the brane.