I’m starting to write this post in the United Airlines Red Carpet Club at Philadelphia airport, as I wait for a flight to Syracuse that is delayed for (I hope only) 35 minutes. I’ve been traveling since Wednesday and have had a truly enjoyable time at two different conferences.
Extremely early Wednesday morning, I left Syracuse to head to Santa Fe. I flew into Albuquerque, rented a car and drove the final hour to Santa Fe. It is a remarkably beautiful drive that impresses me each time I do it. The landscape is just so very different from the Northeast and England. I always think of the landscapes in old Western movies when I drive through it.
I went to Santa Fe to give a plenary talk at the Particles and Nuclei International Conference (PANIC-05). Because of previous plans, which I’ll get to in a while, I could only be there for a couple of days. But it was enough to have a great time. I spent most of Wednesday afternoon recovering from getting up so early and putting the finishing touches to the talk – Connecting the Dark Side and Fundamental Physics – that I was to deliver first thing on Thursday morning.
In the evening, I got together with my friend and co-blogger JoAnne, and with my other friends, Daniel Holz (from Los Alamos National Laboratory) and his wife partner Jessica, for dinner. We went to an outstanding restaurant in Santa Fe (Geronimo, for those of you interested in a recommendation for next time you’re there), and enjoyed wonderful food, good wine and great conversation. It’s a pleasant fringe benefit of traveling to conferences that one can meet up with good friends who live so far away.
My talk on Thursday morning seemed to go well (although you’d have to ask someone who was in the audience for an unbiased opinion). This was pretty much a standard discussion of how particle physics and cosmology must work together if we are to understand the mysterious components (dark matter and dark energy) that seem to make up 95% of the universe. I also discussed the mystery of the baryon asymmetry of the universe – why the observable universe contains essentially all matter, with negligible primordial antimatter.
Speaking after me was another very good friend who I haven’t seen for a long time – Dan Akerib from Case Western Reserve University. Dan is an experimentalist who works on the Cryogenic Dark Matter Search (CDMS) experiment, and we know each other from when I was a postdoc in Cleveland. Dan gave a very nice overview of the different attempts to detect dark matter directly, by detecting nuclear recoils as the experiment collides with dark matter particles as the Earth flies through the galaxy. These are very cool experiments, which have been steadily pushing down the limits on the cross-section of dark matter particles, and there are high hopes for a detection in the not-too-distant future.
Dan and I had a few drinks after the conference banquet that evening, and then I got a reasonably early night because I needed to get up early Friday morning to drive back to Albuquerque and fly to San Francisco.
I was headed to San Francisco to spend Friday and Saturday at Lawrence Berkeley National Laboratory (LBNL) at a symposium to celebrate the fiftieth anniversary of the discovery of the antiproton. This discovery was announced in a paper titled Observation of antiprotons, by Owen Chamberlain, Emilio Segrè, Clyde Wiegand, and Thomas Ypsilantis, which appeared in the November 1, 1955 issue of Physical Review Letters, making today the perfect day to mention it.
The antiproton was found at a brand spanking new accelerator, the Bevatron. LBL has a nice discussion of the prehistory, the machine and the discovery, in which they write
Even with Ernest O. Lawrence’s invention of the cyclotron in 1931, earthbound accelerators weren’t up to the task. Physicists knew that the creation of an antiproton would necessitate the simultaneous creation of a proton or a neutron. Since the energy required to produce a particle is proportional to its mass, the creation of a proton-antiproton pair would require twice the proton rest energy, or about 2 billion electron volts. Given the fixed-target collision technology of the times, the best approach for making 2 billion electron volts available would be to strike a stationary target of neutrons with a beam of protons accelerated to about 6 billion electron volts of energy.
In 1954, Lawrence commissioned the Bevatron accelerator at his Rad Lab. (Upon Lawrence’s death in 1958, the lab was renamed Lawrence Berkeley Laboratory in his honor.) This weak-focusing proton synchrotron was designed to accelerate protons up to energies of 6.5 billion electron volts. At the time, around Berkeley, a billion electron volts was designated BeV; it’s now universally known as GeV.
Though this was never its officially stated purpose, the Bevatron was built to go after the antiproton. As Chamberlain noted in his Nobel lecture, Lawrence and his close colleague, Edwin McMillan, who codiscovered the principle behind synchronized acceleration and coined the term “synchrotron,” were well aware of the 6 billion electron volts needed to produce antiprotons, and they made certain the Bevatron would be able to get there.
The symposium was fantastic; attended mostly by elderly men and women who are among the great physicists of the last fifty or more years. Owen Chamberlain who, along with Segrè, won the 1959 Nobel Prize for the discovery, was there, even though he is not in great health. Another speaker was Carlo Rubbia, who won the Nobel prize for the discovery of the W and Z bosons at the European Center for Nuclear Research (CERN) in 1984.
I spent a wonderful couple of days listening to and talking with these great scientists. My talk was close to the end of the symposium, in the part called “The Future”. My assigned title was The Search for New Particles and Symmetries, and I discussed the roles that both of these may play in understanding some of the mysteries of cosmology, such as dark energy, dark matter and baryogenesis.
This entire five day trip was a lot of fun, although it was also exhausting and a huge amount of work. I learned a lot – not only physics but physics history as well (If you don’t know the drama behind this particular Nobel Prize, take a look at this obituary for a clue), but I’m glad to be home again and back to a normal routine (for a short while anyway).
November 1st, 2005 at 11:21 am
Why would there be new foreground symmetries discovered but not broken assumed background symmetries? Physics assumes an even-parity universe and repeatedly discovers the contrary (Yang and Lee, New Years Day 1957.) Biology is homochiral – protein L-amino acids and D-sugars. It has a source.
Galileo’s 1638 universality of free fall, Newton’s 1687 invariant proportionality of mass and weight, and Einstein’s 1907 elevator Gedankenexperiment embodied the Weak Equivalence Principle (EP). Local centers of mass are postulated to vacuum free fall identically, independent of test mass composition or internal structure. Gravitation is modeled as parity-even math. Is it?
There is no empirical constraint of gravitation exhibiting a parity anomaly at the 10^(-11) difference/average level or smaller. Given: three compositionally and macroscopically identical solid spheres. One is amorphous fused silica, SiO_2. The other two are carved from single crystal quartz, SiO_2. One quartz sphere is crystallographic parity space group P3(1)21 (right-handed helices of atoms), the other quartz sphere is P3(2)21 (left-handed helices of atoms). Locally vacuum free fall all three spheres. (Actually, use an Eotvos balance to examine the three pairings to 10^(-13) difference/average; and oppose the single crystal spheres first!)
Will the three centers of mass pursue parallel trajectories, or will one parity mass distribution of quartz diastereotopically interact with chiral vacuum and pursue a divergent minimum action path? One cannot test for a left foot with a sock or a left shoe. Only a right shoe is diagnostic. Spacetime geometry has never been challenged with test mass geometry. It is the only remaining untried class of EP test, a parity Eotvos experiment.
Static chirality is an emergent phenomenon. It is volumetric, requiring at least four non-coplanar points in 3-space. Particle physics does not impose constraints. That a parity EP violation could occur through anisotropic mass distribution at atomic lattice scales interacting with the parity-broken symmetry of spatial chiral anisotropy has never been considered. Absence of theory does not enforce absence of discovery. Observation dictates what theory must predict.
Gravitation gets interesting within a 10 A-diameter sphere, /astro-ph/0508572. That would contain 49 atoms of silicon-centered quartz lattice and exhibit powerful geometric parity divergence: 0.933755 of a possible normalized 1.0 exactly. Shouldn’t somebody look – in existing apparatus, by unchanged protocols, with unbiased academic personnel? Risking success after 420 years of null results is not so bad. Heterotic string theory is already in place. Where are physics’ cajones?
November 1st, 2005 at 6:13 pm
Hi cvj,
found this blog via NYTimes.
There is a need & a demand for non-mathematical physics expositions.
I was fairly good at Math, but just cant get Tensors, Group theory etc, so I and most people, need a ‘conversational’ approach. It can be done.
eg the previous comment by Uncle Al has just enough ‘jargon’, not too much.
- enough to look serious, although I couldnt really say.
November 1st, 2005 at 7:42 pm
Interesting that a physicist at Case is working on measuring the effect of the earth flying through space. I happen to remember another well known experiment that took place at Case involving the effect of the earth’s motion, attempted by none other than Michelson and Morely. I know, I walk by the plaque every day to class.
November 1st, 2005 at 8:13 pm
Ah yes, I used to walk by that plaque myself. There’s a little mock-up of the Michelson-Morley experiment on the 1st floor of Rockefeller (the Physics Department) and Bill Fickinger, an Emeritus Professor there, has written an interesting history of it.
November 2nd, 2005 at 1:00 am
[...] Mark has already mentioned the Particles and Nuclei International Conference held in Santa Fe 24-28 October, 2005. This is a major international conference held approximately every 3 years. And it was my first time to attend. By now, I am used to seeing the same familiar faces at conferences, and this one was refreshingly different in that regard. 500 physicists were in attendance, including 80 students. [...]
December 19th, 2005 at 12:15 am
[...] I took some time on Monday to have lunch with Sean and Iggy to make some progress on our joint project, and then later had a nice dinner and some drinks with Sean, Dan Holz (who I’ve mentioned before), Isobel Hook (who I met for the first time at this conference), Ruth Gregory and Ed Copeland. I don’t get to see Ruth and Ed very often, so it was particularly nice to spend some time with them. [...]
January 28th, 2007 at 2:18 pm
[...] Continuing our recent servings of fresh blogging meat, I am delighted to announce the addition of another new member of the Cosmic Variance team. Daniel Holz is a Richard Feynman Fellow in the theoretical astrophysics and particle physics groups at Los Alamos National Laboratory, working on the interplay between general relativity, astrophysics, and cosmology. Dan is a particular expert on gravitational lensing and gravitational waves, but his interests are wonderfully broad and I know he’s going to bring a great new perspective here. As a good friend of some of us already, he’s already been mentioned in at least one of our posts. [...]