Category Archives: APS March Meeting 2008

Cats and dogs with their tails tied together

Yesterday I went to a news conference given by five physicists who believe that materials called “block copolymers” could help the electronics industry continue its relentless drive towards smaller and smaller devices — and even help battle some cancers.

Block copolymers are a hot topic in nanotechnology because of their ability to self-organize into tiny structures.

They are essentially two different kinds of polymer that are joined end-to-end to create one long strand. The two polymers normally repel each other — creating something akin to “cats and dogs with their tails tied together”.

Similar polymer ends are attracted to each other and the competing forces tends to organize the copolymers into one of several possible solid structures, depending on external parameters such as temperature.

These strucutures have features on length scales of tens of nanometres, which is just about the right size for future generations of electronic devices.

One possibility, according to Chris Ober of Cornell University is that block copolymers could be used to create patterns on the surface of a silicon wafer with features much smaller than is possible using standard lithography techniques. An etching process — with the block copolymer acting as the etch resist — could then be used to create nanometre-scale electronic devices. Indeed, Ober believes that computer chips could be made this way in the next five years.

Other electronice applications include high-density magnetic memory chips and “low-K” insulators, which which would allow tiny circuits to run faster.

Dan Savin of the University of Vermont believes that block copolymers could be used to create tiny capsules that would deliver drugs to specific parts of the body. For example, a capsule that was the right shape and size to get from the bloodstream and into a tumour.

However, one serious drawback of self assembly at the moment is that there are a limited number of structures that the block copolymers can form. But I’m guessing that this could be expanded by using more than just two ends — maybe cats and dogs and mice with their tails tied together!

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baseball and steroids

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How much do drugs affect the performance of athletes and more interestingly how can we quantify such enhanced performance? That was the question that Roger Tobin, a condensed matter physicist from Tufts University, posed in his talk on ‘Sox and Drugs: Baseball, steroids and physics’. Quantifying enhancement is an interesting question, if someone takes drugs and it increases their performance to, say, score one more goal per season or hit a golf ball a few centimetres farther is it really worth it to make a fuss?

The sport in question in Tobin’s talk was of course baseball. In other sports such as weight lifting, taking steroids can have an obvious effect. But what about other sports where strength is an advantage, but cannot easily correlate with results.

He characterized two eras, namely before and after steroid use became well documented (which he put as around 1990s onwards). If one looks at the record home runs in a single season, this explodes in the late 1990s when Sosa hits 66 and Bonds hits 73 home runs in a single season. This increased effect for baseball is around 20% (from the previous efforts of Ruth). Imagine a 20% increase in the 100 m sprint, this would mean a sprinter taking around 8 seconds to run it. If steroid use is the culprit, how can steroid use affect baseball so much but not other sports?

Tobin says that the only advantage of using steroids in baseball comes in the bat speed. It’s pretty straight forward — steroids build muscles, or increase muscle cross section, which allows the player to exert more force on the ball, which then gives the ball more speed. He calculates that steroid use could increase the ball speed by about 3%. Which if one thinks about it is not a lot…

However, here comes the catch. If I took steroids (don’t worry I am not planning to do the experiment) and started playing baseball, it wouldn’t automatically mean that I am going to beat Babe Ruth’s previous home run record, but as Tobin says the player must already “be pretty special.” So what happens? Well, if you look at the hit distribution of a top player, he may hit 10% of all shots as home runs in a season, but he will hit many that are near home runs, in fact the distribution will have a peak at the place which are nearly home runs. What Tobin says is that steroid use shifts this peak so that all those previous near home runs, now become, well, home runs, so this shift alone increases a players 10% home runs to around 15% in a season — all with the help of a few more percent in ball speed…and some steroids.

Seems like condensed matter physicists are spreading their wings, he also plans to extend his work to other sports, so footballer and golfers beware…

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Stingy Uncle Sam

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Here I am doing my bit to persuade the US government that it should give a little more money to the nation’s physicists.

The photo was taken by the APS’s Tawanda Johnson, who was trying to get American physicists to write letters to their members of Congress asking them to support the provision of “supplemental appropriations” for 2008. In other words, an extra $510 million in funding that would go to the National Science Foundation, NIST and the Department of Energy — three major sources of money for physics research.

The campaign is in response to the surprise cuts in 2008 research funding that were announced in a recent bill. Hardest hit were fusion and particle physics research, which suffered 10% and 8% reductions respectively.

The letter that the APS would like its members to send describes these and other cuts as “devastating blows [to] science research”…”resulting in significant layoffs of scientists and engineers”. The letter also says that the funding cuts will thwart US efforts to reduce its reliance on foreign oil, mitigate global warming, and put a lid on escalating energy costs. “In short, the enacted bill is bad for our energy and economic future”, the letter says.

At about four in the afternoon, more than 400 letters had been sent and Tawanda expects that a total of about 1200 physicists will put pen to paper at the APS.

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Annealing at 1K

My first session was on supersolid He-4, up bright and early for the 8am start. The paper under discussion for the first talk appeared in Nature last year by Xi Lin and colleagues from Penn State University. They looked at the heat capacity of He-4 at low temperature (T < 0.5 K), and reported a peak centered around T = 0.08K.

It also became apparent the difficulties of making accurate measurement at such temperatures, they reported that they constructed 20 low temperature cells for the measurement, and only one of them was heat leak proof.

A large question in the area of supersolid He-4 is what the role of He-3 impurities are, in the final talk of the session given by Philip Anderson this question seems to have even got the better of the Nobel prize winner himself, when he openly admitted to not knowing the answer.

The supersolid peak is independent on the amount of He-3 impurities with Lin presenting samples with 0.3 ppm (parts per million) and 1ppb (parts per billion) of He-3 impurity. But the peak did slightly decrease in temperature when the samples was annealed for longer, so it seemed to depend on how the sample is made. A comment was later made that the supersolid peak could be intimately linked with disorder.

Unfortunately the session did break up a little when the second speaker didn’t show up – which was supposedly a knock on effect from the storm that was over the east coast at the weekend.

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Cold Fusion as Policy Posterboy

The March Meeting has everything, including a session on cold fusion.

It is almost 20 years since Pons and Fleischmann told the world that they had seen nuclear fusion in what is essentially an electro-chemistry experiment. The idea is that if you packed enough deuterium into a piece of palladium metal, the deuterium nuclei would somehow overcome considerable electrical repulsion (perhaps being screened by palladium electrons) and fuse together, releasing lots of energy.

The announcement set off a furore that pitted chemists against physicists and led to allegations that big-energy interests and the physics “establishment” were trying to cover up a genuine breakthrough. And sadly, as nuclear physicists scrambled to do experiments involving hydrogen and electricity, there was at least one deadly explosion.

However, other researchers were unable to confim cold fusion and today most of the physics community has forgotten it. Except for a small band of researchers who have somehow convinced the APS to give them a session at the March Meeting.

This year’s session included a talk from a non-physicist, Thomas Grimshaw, who teaches public policy at the University of Texas at Austin. Grimshaw has adopted cold fusion as “a posterboy for rational policy making”. He looked at cold fusion research results using “evidence-based policy making” analysis techniques — the sort of thing a government would use to decide if lower speed limits save lives on the roads.

His conclusion is that there is a “preponderance of evidence” that funding cold fusion research is in the public interest. The minimum response, he believes, is that the US government should reinstate its cold fusion programme — and it would be a reasonable response to give cold fusion the same funding status as conventional approaches to fusion such as magnetic and interial confinement.

While I doubt that this public-policy approach will raise the profile of cold-fusion research, there is something admirable in the fact that the people in session A14 have battled against conventional wisdom for nearly two decades. But writing as someone who did a cold fusion experiment in 1990, my personal opinion is that whatever they are seeing — it’s not fusion.

You can read more about Grimshaw’s work here.

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Streetcar to the Garden District

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It’s a lovely day in New Orleans and I managed to get a sunburn walking around the French Quarter this morning….I suppose I’m a real redneck now!

Our hotel is right across the road from the convention centre and there are now lots of physicists milling about — the excitement is building. Like myself, many of them look like they haven’t seen the sun for quite some time, so local pharmacies better stock up on sunburn cream!

After lunch I took an ancient streetcar (tram to our European readers) out to the Garden District — a leafy area of huge moss-covered oak trees, ornate Victorian houses and of course, fragrant gardens.

As I was coming back on the St Charles streetcar, I noticed that the branches of the trees at the side of the road were festooned with hundreds of garish necklaces of every possible colour. I’m guessing that these were thrown from floats during a Mardi Gras parade.

I might go back to the Garden District and try to find the City of the Dead — a cemetery where all the tombs are above ground. Maybe I can persuade the IOP crew to make the journey tonight after dark!

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Arrived and ready

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The 21 hour door-to-door trip is past us now as we focus on the start of the conference tomorrow. We arrived at the hotel early on Sunday morning after a quick connection in Chicago. The whole trip from Heathrow to New Orleans went quite smoothly, except for the need to change planes in Chicago after we were all seated and ready to go – apparently there was a problem with the braking system, so I wasn’t complaining to change planes. It was also on the flight from Chicago that it became apparent that there were possibly many physicists on-board, most of them armed and ready with poster tubes.

Today, we had our first chance to see some of New Orleans. We had a brief walk around the French Quarter and along the Mississippi river where most of the hotels are situated near to the convention center. Though it was not immediately clear from these areas the devastation that was inflicted by hurricane Katrina in 2005.

I popped into the convention center itself, and already saw a mass of physicists queuing up to register. Coming to the center is the first time the scale of the APS March meeting hits you – containing massive halls where the exhibitions are held. Some people already have their hands on the thick conference book, meticulously studying it, though no doubt looking for the location of colleague’s talks.

After a few too many shrimps this afternoon, we are ready for the conference tomorrow and look forward to keeping you updated on all the in’s and out’s of the 2008 APS March meeting.

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Off to New Orleans

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Michael and I are leaving for New Orleans bright and early tomorrow morning — along with five other colleagues from IOP Publishing. Our journey begins in Bristol at about 9.30 in the morning and if all goes well, we will arrive in New Orleans just before midnight (local time). I reckon that’s about 21 hours door-to-door. Unless, we get snowed-in in Chicago!

We have just put the finishing touches on our battle plan for what promises to be a intensive week of condensed matter physics. Actually, more than just condensed matter is on the agenda. Michael will be looking into “econophysics” and physics of the stock market, while I’m looking forward to learn about the physics of hurricane formation and climate change.

See you in the Big Easy!

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