The LHC circulated two counter-rotating beams today, and a few hours ago the CMS experiment recorded its first collision event, shown in the display above. This is a fantastic milestone for the LHC and the experiments! (Sorry the event display is fuzzy; I zoomed in on a portion of the larger one.)

The green lines are the tracks of charged particles from the collision, which are typically pions, which are unstable particles consisting of an up quark and an anti-down (or an anti-up and a down). Though they are unstable, they live long enough to nearly always leave tracks in the detector. The yellow rectangles indicate the position of the silicon strip detectors that recorded their passage.

The red and blue boxes indicate where energy was detected in the detectors outside the tracking detector, called the calorimeters. The inner calorimeter is sensitive to electromagnetic energy deposits coming from high energy photons – gamma rays – and from high energy electrons. Deposits in that one are in red here. Now, most of the high energy gamma rays here are coming from decays of neutral pions, which are much more unstable than their charged cousins. A neutral pion is a quark-antiquark combination, and since they are the same “flavor” of quark they can annihilate electromagnetically to two photons in a very short time; we see the two gammas in the electromagnetic calorimeter. Outside the electromagnetic calorimeter is the “hadronic” calorimeter which detects the energy left by charged pions and other hadrons, particles which contain quarks, such as protons, neutrons, kaons, and many others. But most if not all of the particles here are pions.

Where did these pions come from? The beams each had an energy of 450 GeV, the energy at which they were injected into the LHC. In fact the LHC has not accelerated particles to higher energy yet, but may do so soon. The beams were not tightly focused, and so only rarely when the beam bunches passed through each other did collisions occur. And most of the collisions are sort of “glancing blows” that disrupt the incoming protons, breaking them apart, and sending some particles sideways into the detector. This is presumably what we have in this first collision event.

As time goes on and more collisions are made, we will record events in which the constituents of the protons collide with more energy, leading to sprays of particles transverse to the beam direction which we call “jets”. For example, a quark in one proton hitting an antiquark in the other proton with, say, a couple hundred GeV can produce two jets of 100 GeV going in opposite directions (from the beam’s eye view). Such dijet events will provide a very useful sample of data for aligning and calibrating the detector.

Only after the beam intensity and the center of mass energy is a lot higher will we expect to see rarer and more interesting processes like W and Z boson production, and top quark pair production (top-antitop pairs). There are plans to collide at 2.4 TeV (higher than the 1.96 TeV at the Tevatron) before the end of the year if all goes well, and to 7 TeV early next year. And all is definitely going well so far!

Addendum: from a friend’s Facebook page I snagged this display of a collision event in the ATLAS detector! So cool!!

Here is the event display for the first collision in CMS:

Looks like 2 hard jets.  A running commentary of the day’s events at CMS can be found here.

Let the science begin!

Shuttle launches witnessed: 1
Shuttle launches since 1981: 129
Shuttle launches remaining: 5
“Shuttle Experience” rides experienced: 1

Cost of Space Shuttle Atlantis [dollars]: 1.7 billion
Total cost of the International Space Station [dollars]: 157 billion
Science publications resulting from research by the International Space Station: ~200
Total cost of the Hubble Space Telescope [dollars]: ~4-6 billion
Science publications resulting from Hubble Space Telescope data: >8500

Years between first trans-Atlantic air passenger and first man walking on Moon: 42
Years since last human walked on moon: 37
Moons of earth where water was found: 1

Cities visited, where snow was visible: 2
Cities visited, where it has never snowed: 2
Cities visited with a “Disney Land/World”: 2
Mickeys seen: 0
Alligators seen: 2
Geckos seen: 1
Astronauts met: 1
Space geeks met: ~ 40

Tweets sent at first “tweetup”: 24
Tweets sent in lifetime: 24
Number of distinct words heard starting with an extraneous “tw”: >15
Days after my first tweet that Palin decided to resume tweeting: 4
Books released by Sarah Palin: 1
Stewardesses I saw that were the spitting image of Sarah Palin: 1

Oceans swum in: 1
Oceans I was close enough to swim in: 2
Places visited that are the Holiest site of a religion: 1
People met that are writing a book about escaping that religion: 1
Points bowled: 67
Team place out of nine teams of bowling scientists: 1st

Flights taken: 7
Amount of carbon emitted by those flights [lbs]: 2240
Net amount of energy generated by my solar panels [kW/hrs]: ~100
Equivalent amount of carbon not emitted [lbs]: 100
Cost of offsetting that 2240 lbs of carbon [dollars]: 12.63

Talks given on completely different topics: 3
Talks listened to: 41
Talks listened to without my laptop open: 15
Non-astrophysics talks I heard that mentioned dark matter: 10

NSF proposals submitted (as Co-PI): 2
HST Multi-Cycle Treasury proposals submitted (as Co-I): 2
Total number of HST MCT proposals submitted by the community: 39
Total number of HST orbits requested by those 39 proposals: 26801
Interviews given: 3
Days with at least 3 nearly identical deadlines: 2

Emails received @ work address: 768
Emails sent: 253
Emails still in my inbox: 361

Average number of hours slept per night: 5
Brain cells lost by multi-tasking: Uncountable.

That all changed rather dramatically in recent years, with the founding of the Institute for Physics and Mathematics of the Universe at the University of Tokyo. The IPMU was one of the World Premier International Research Centers that were founded in Japan in 2007, to foster excellence in research but especially to lower barriers between Japan and the rest of the world. The IPMU acted aggressively to hire scientists from outside Japan and host programs that would bring visitors from around the world. And the effort succeeded, with astonishing swiftness; I know that among people I talked to, IPMU was quickly recognized as an attractive place to go with top-notch scientists working there. You can see the results through one person’s eyes at the blog of Susanne Reffert, one of IPMU’s postdocs.

Now all of that success is in jeopardy. As detailed in this letter from Hitoshi Murayama, founding director of the IPMU, the new government in Japan “is actively trying to slash support for programs in science,” and the IPMU is one of the targets. New commissions (staffed by non-experts) have been tasked with reviewing a wide spectrum of programs, and recommending everything from 30% cuts to 50% cuts to outright termination. These cuts are extending throughout science, although new efforts like the World Premier centers are in particular danger.

Admittedly, we live in a time when budgets are tight, and nobody is going to completely escape the pain of the current global economic crisis. But this would be a very short-sighted move on the part of Japan, to undo the great strides they had made in connecting with the international effort in fundamental physics.

Fortunately, there’s something you can do! Hirosi Ooguri here at Caltech informs me that the Japanese Ministry of Education and Science is actually soliciting input from the worldwide scientific community. You can send an email to “nak-got [at] mext.go.jp”, with a subject line “No. 14, WPI.” That will reach people who matter, including Senior Vice Minister Masaharu Nakagawa and Vice Minister Hitoshi Goto.

It would mean a lot if the Japanese government understood how much the rest of the world appreciates the close connections with scientists in their country. Science is not a zero-sum game; when it’s succeeding somewhere, everyone benefits. Here’s hoping the IPMU makes it through this episode intact, and continues to flourish in the future.

Once beam has circulated stably in both rings, some time next week the LHC team will attempt to collide protons at the injection energy of 450 GeV (a total center of mass energy of 900 GeV). While this is much less than the Tevatron is colliding presently, it could provide some sorely needed initial data for the detectors to do timing and calibration of the various subsystems. There will even hopefully be a few collision events recorded with clear “dijet” structure – collisions where quarks and/or gluons inside the protons hit head on and effectively bounce sideways into the detector, giving two back-to-back collimated sprays of particles. Pictures of such events will be great to see, at long last!

You can follow progress live on twitter: http://twitter.com/cern and I will update this post as I learn more.

10:32 PST: The LHC has gotten beam around clockwise, to Point 6! Woo hoo!

10:45 PST: Magnet quench – should be recovered soon…

11:25 PST: Beam has reached Point 7!

11:30 PST: Point 8! Next beam will be sent past Point 1 where ATLAS is…

11:39 PST Beam all the way around the ring! WOO HOO!! It’s baaaaaack! The LHC Page 1 display shows that the injection probe beam made it more than once around the machine:

11:54 PST: Next goals: do the same with the counterclockwise beam. Will they attempt RF capture tonight? Trying to find out…

13:11 PST: Turns out (no pun intended) they decided to go for RF capture of the clockwise beam rather than probe counterclockwise. They are up to 10 million turns with the RF on! Fantastic!

13:30 PST: Having captured the beam for several minutes, the LHC will now switch to counterclockwise.

14:53 PST: About to go for a full orbit of the counterclockwise beam…done!! Now to RF capture!

15:30 PST: Counterclockwise beam is RF captured! The LHC is operational…colliding beams within a week? Stay tuned.

Unfortunately the video doesn’t seem to be embeddable, but you can go to the video page and click on the “David Gross” entry. (The others are good, too!)

You all know my perspective here — time probably exists, and we should try to understand it rather than replace it. But I’ll agree with David — let’s not ignore more “practical” problems, but not be afraid to tackle the big ideas!

It’s been a mixed bag so far; while I’ve had great fun interacting with people here in Australia, I’ve also been struggling with a nasty cold I picked up on the flight over. Spent yesterday mostly in bed, too fogged up to even work on my talk for Friday. But when I’ve had the strength to be up and about, it’s been a treat. Here’s an iPhone snap of the University of Sydney; that clocktower in the middle houses, appropriately enough, the Centre for Time.

One of the perks of civilization that hasn’t quite caught on in these parts is affordable internet access in hotel rooms, so don’t expect a lot of blogging over the next week or two. Instead, I can point you to a couple of recent videos. One is an extended interview for Edge, entitled Why Does the Universe Look the Way it Does? It is an interview (presented in text and video), not a carefully pre-planned document, so not all thoughts are arranged as elegantly as one might like. Here is some of the flavor:

We are in a very unusual situation in the history of science where physics has become slightly a victim of its own success. We have theories that fit the data, which is a terrible thing to have when you are a theoretical physicist. You want to be the one who invents those theories, but you don’t want to live in a world where those theories have already been invented because then it becomes harder to improve upon them when they just fit the data. What you want are anomalies given to us by the data that we don’t know how to explain.

The other one is a panel discussion on Time Since Einstein, from the World Science Festival. As the description there says, it features Roger Penrose, David Albert, and some other people it would be too exhausting to list individually. Here’s part 1 of 5:

World Science Festival 2009: Time Since Einstein, Part 1 of 5 from World Science Festival on Vimeo.

Now if only my immune system would finish off the little viral buggers inside me, I could get out and see a bit of this interesting country.

Well, the race is on! Here’s the data on what I know of so far. We’re up to 8 proposals at 24 hours before the deadline. With the enormous sample of two, count ‘em, two data points, we’re on the same curve as we were for Cycle 17 (plotted in black), but scaled down by a factor of 27. The blue line is extrapolating an exponential to the current rate of proposal submission. Both tracks argue for about 30 proposals going in. The scaling factor of 27 suggests that there will be an average of 27 people on each proposal, if Steinn’s argument that the number of proposals is set solely by the size of the community holds. The late-time development of this curve could be way off, however, because there is no way to put one of these together at the last minute. (On the other hand, the proposed experiments are so immensely complicated, that maybe the only way you get them done is waiting until the last minute).

I’ll update the plot if people give data in the comments! (Updated! I cut the blue exponential fit in the revised plot, as it was a lousy match.)

At 2:28 pm Eastern Standard Time, the space shuttle Atlantis left Earth. It was a flawless launch.

It is, of course, hard to describe the experience of watching it go up. I was surprised by just how bright it was. It’s like a mini-Sun, which is roughly right since it burns its liquid hydrogen/oxygen fuel at 3000 C, just a factor of two short of the temperature of the Sun. And, of course, it is loud. Not “hurt my ears” loud. More like “my whole body is vibrating” loud. Very intense.

The whole thing was over in a couple of minutes. I guess the shuttle was eager to get to space. It’s been all dressed up and waiting for days. All too soon the painfully bright light had disappeared. The overwhelming sound had subsided. And the only sign of the absolutely amazing event we’d just witnessed were the slowly dissipating clouds of smoke.

At the end of the day, it is an incredible accomplishment. We have just shot six people into space.

Wow.

- 5 astronauts have masters degrees. 3 were successful football players. 1 has a PhD (and an MD as well, just for good measure). I’m not sure what that says about the requirements to go into space.

- The astronauts go into quarantine for a week before the launch. They don’t want any swine flu in space.

- We are on hallowed ground. This is where humans left the Earth to touch the Moon.

- This is the 129th space shuttle launch. The first was in 1981, for an average of one launch every three months. The whole idea was to make space launch “routine”.

- I calculate that it takes roughly thirty times more energy to get to the space station than it does to get a jet aircraft to altitude. Radius of the Earth: 6,400 km. Altitude of a jet: 12 km. Altitude of the space station: 350 km. (Gravitational potential energy goes as one over the distance.) However, it is to be noted that you want to actually stay up there once you get there, which means you need to be moving pretty fast (specifically, 28,000 km/hour at the altitude of the space station). Kinetic energy goes as velocity squared. This is why you need a kiloton bomb (see my previous post) to get up there.

- As a mission control specialist described launch: “It’s like going over the top of a rollercoaster. Forever.” Actually, that sounds more like what it must be like in orbit: free-fall.

- They monitor everything that happens on the space station. Including light switches and toilet flushes. Think big brother.

- The countdown clock is not linear. There are a number of planned “holds”, where they STOP THE CLOCK and check various systems, and then resume.

- We are roughly 3 miles from the launchpad. This distance was selected by calculating, should the unthinkable happen, how far a 50 pound chunk of debris would fly. We are just beyond that distance, trying not to think about what 40 pounds might do to the media tent.

We are now 1:35:37 from launch.