Explaining Cosmic Rays

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gary zankWell, before disappearing into a long session of thinking about some funny behaviour my strings are up to (more later) I’d like to do a quick report on the departmental colloquium that I went to just now. We had Gary Zank, the Director of the Institute for Geophysics and Planetary Physics of the UC system (he’s based out of UCR) give us a talk entitled: “Particle Acceleration in Cosmic Plasmas”, and it was quite fascinating (and very well presented).

It is all about the physics of cosmic rays (here’s a NASA link called Cosmicopia for a little background on them). Here is a section of the abstract he sent to us prior to the talk:

An outstanding problem in astrophysics is to explain the origin of the almost featureless cosmic ray spectrum extending up to energies of some 1020 eV. A very small feature is apparent at between about 1013 – 1015 eV, the “knee.” In the late 1970’s, a suite of papers was published establishing the idea of diffusive shock acceleration for cosmic rays, essentially a first-order Fermi mechanism, which appeared to provide an explanation for the observed cosmic ray spectrum up to the knee. Diffusive shock acceleration is probably the most widely used particle acceleration mechanism in astrophysics and space physics, yet the theory is based on some stringent simplifications. The detailed [plasma] physics of the acceleration mechanism requires elucidation. We are fortunate in that very detailed observations of particle acceleration at shock waves, particularly in the guise of Space Weather, are providing considerable experimental insight into the basic physics of particle acceleration at a shock wave.

He gave us an overview of the remarkably detailed series of studies that his group has been carrying out (with the aid of an impressive multitude of computer simulations of the magnetohydrodynamics involved) in converting the various suggested acceleration mechanisms into detailed output that can be compared to experimental observations. Here’s a bit from their website:

The dynamical acceleration of particles at shocks waves propagating in the heliosphere is very poorly understood, yet shock waves are ubiquitous and almost all shocks are observed to energize ions and electrons. An understanding of particle acceleration at solar wind shocks has far reaching astrophysical implications. Furthermore, since energetic particles accelerated in either solar flares or in CME-driven shocks arrive at the Earth well before solar ejecta driven disturbances, an understanding of particle acceleration at interplanetary shocks is an integral part of the NSF and NASA Space Weather program.

He spoke quite a bit about shock wave mechanisms and how they work in supernovae Click to continue reading this post →

There’s Still Life in the Old Dog

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Did you catch Clinton on the Daily Show last week? It was nice. Good humoured. Nice to hear him chat about his initiatives, and nice to hear him still with enough footwork to avoid the “will Hilary run?” questions artfully.

But did you catch him on the weekend, interviewed by Chris Wallace on Fox News Sunday? I did not, since I’ve largely given up on TV news and related programs. The signal to noise ratio is just terrible. But this was good! The news is running all around the web. Apparently he was full of fire in response to questions about the hunt for Bin Laden and others on his watch. Here’s part of a transcript from Crooks and Liars:

CW: Do you think you did enough, sir?

WJC: No, because I didn’t get him.

CW: Right…

WJC: But at least I tried. That’s the difference in me and some, including
all the right-wingers who are attacking me now. They ridiculed me for
trying. They had eight months to try and they didn’t. I tried. So I tried
and failed. When I failed, I left a comprehensive anti-terror strategy and
the best guy in the country: Dick Clarke.

So you did FOX’s bidding on this show. You did you nice little conservative hit job on me. But what I want to know..

CW: Now wait a minute, sir…

WJC: [..]

CW: I asked a question. You don’t think that’s a legitimate question?

WJC: It was a perfectly legitimate question. But I want to know how many
people in the Bush administration you’ve asked this question of. I want to know how many people in the Bush administration you asked ‘Why didn’t you do anything about the Cole?’ I want to know how many you asked ‘Why did you fire Dick Clarke?’ I want to know…

CW: We asked…

WJC: [..]

CW: Do you ever watch FOX News Sunday, sir?

WJC: I don’t believe you ask them that.

CW: We ask plenty of questions of…

WJC: You didn’t ask that, did you? Tell the truth.

CW: About the USS Cole?

WJC: Tell the truth…

CW: I…with Iraq and Afghanistan, there’s plenty of stuff to ask.

WJC: Did you ever ask that? You set this meeting up because you were going to get a lot of criticism from your viewers because Rupert Murdoch is going to get a lot of criticism from your viewers for supporting my work on Climate Change. And you came here under false pretenses and said that you’d spend half the time talking about…

CW: [laughs]

WJC: You said you’d spend half the time talking about what we did out there to raise $7 billion plus over three days from 215 different commitments. And you don’t care.

CW: But, President Clinton…

WJC: [..]

CW: We were going to ask half the [interview time] about it. I didn’t think this was going to set you off on such a tear.

WJC: It set me off on such a tear because you didn’t formulate it in an honest way and you people ask me questions you don’t ask the other side.

Wow….. actual unfiltered sense on TV! That’s pretty rare indeed. A bit more: Click to continue reading this post →

Southern California Strings Seminar

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Southern California String SeminarOn Friday and Saturday of next week (September 29th and 30th), the next Southern California Strings Seminar will be happening! It’s a regional meeting for people doing research in string theory and related topics, and as I’ve said before, I’d especially like to see more young people come out and take part. We make a special effort to ask the speakers to spend a little time at the beginning of their talk setting the scene (speaking about motivations, what has gone before, etc) so that the series can be of great value to people who are trying to learn what’s going on in a particular topic at research level (this can be students, postdocs, or faculty, in fact).

If you’re doing this kind of physics research anywhere in the Southern California region, and want to take part, please come. See the website for details, and try to let the hosts -this time it is USC- know that you’re coming so that we can arrange lunches, etc. (We’ll be asking for a contribution of about $5-$10 to help with lunches, cookies, coffee, and other goodies that will be on tap during the day.)

From the main page of the website, I wrote:

ken intriligator at scssJoin us as we (members of several of the local groups with interest in string theory and related topics) sit together to discuss new ideas and developments (both general and technical) in the field. The presentations will be accompanied by plenty of discussion and in the first part of each talk the speaker will take special care to set the scene and context of the work in a pedagogical manner so as to encourage participation by younger members of the field.

Also, here’s what I mention about the inaugural one, which was in May 2005, hosted Click to continue reading this post →

Branson’s On Board!

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In more news from the battle to get action on Global Warming, from Reuters a short while ago:

Billionaire Virgin Group Chairman Richard Branson on Thursday committed an estimated $3 billion over the next 10 years, or all of the profits from his airline and rail businesses, to combating global warming.

“We are very pleased today to be making a commitment to invest 100 percent of all future proceeds to the Virgin Group from our transportation interest, both our trains and airline businesses, into tackling global warming,” Branson told a news conference at the Clinton Global Initiative in New York.

Excellent news….

“We must not be the generation responsible for irreversibly damaging the environment. We must hand it over to our children in as near pristine condition as we were lent it from our parents,” Branson said.

Hmmm. It is already too late for that, my friend. We are that generation. However, we do need to stop ourselves from further sliding into the hole we’ve dug for ourselves. Your money will help. Please tell your friends. Start a new and useful trend amongst the super-wealthy, please.

-cvj

Go Figure!

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hyperbolic crochetSo I think maybe I died and went to cvj heaven. Let me explain. I mentioned to you a while ago the freshman seminar entitled “The Art and Science of Seeing and the Seeing and Science of Art”, for which there was an enrollment snafu. Well, it is continuing, and on Wednesday afternoons, I sit under the trees with two students for an hour and a half (KC Cole pulled out, since it would be a ridiculous professor-student ratio otherwise) and talk about a huge spectrum of things that fall into this category, as well as some of the things that come up in the Visions and Voices series.

Last week and this week, we discussed -with illustrations- two pretty obvious topics that come up first in people minds when the words “Science” and “Art” are in the same sentence. Those two topics are Fractals, and Escher. Quite obvious as “science-meets-art” topics go (and tiresomely so sometimes) but nontheless I believe it would be neglectful of us not to explore some of the interesting and wonderful themes, images, and techniques that those topics touch upon. Escher last week, Fractals this week. It was a lot of fun. I will tell you a bit about it later, in view of the lack of time (I had a breakthrough in a little computation that I really should get back to before I have to prepare a class).

Anyway, I come away from these sessions thinking how great it is to let oneself broaden the canvas upon which one can jot down one’s reflections upon and reactions (emotional, intellectual, otherwise) to when one looks at a piece of art. The broadening I refer to means simply to include science. Either directly or indirectly. This is the tack we’ve been taking in this seminar, and so far I think we’ve been having a lot of fun and learning a lot. I’ve been reflecting on how wonderful it would be if more people, in the context of art appreciation, would allow themselves the latitude to do this. Sadly, ignorance of what science is about, and the fear of science, topics that I talk about a lot on this blog, maintain huge barriers between art and science in most people’s minds, and so there is a whole dimension of appreciation that goes unlocked as a result (not just in the obvious context of Escher, etc, but in appreciating any art form). It was especially sad to see six freshmen disappear from the enrollment on the class principally because the word “science” was inserted into the title of what they thought would be an art appreciation seminar. Well, it is still an art appreciation seminar, but those who are coming are learning to look at art, and the world around them, with new eyes, and maybe seeing a broader and/or deeper spectrum.

So I go into “What if…” mode for a while on my ride back to my office and feel a little sad that even bright young people who are on campus to learn new things are selecting themselves out of such opportunities to engage with their world because of the word “science”. Sigh.

So imagine my delight last night (having finished a seminar on fractals earlier that day, pointing out several examples of “fractal geometry” in art and nature) when and architect friend of mine* emailed me a link to an institute, right here in LA, that seems to be right on the same track I’m talking about!

It is the Institute for Figuring, (founded by science writer Margaret Wertheim) right Click to continue reading this post →

Well, That’s a Novel Approach

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When the President of the Union of Concerned Scientists, Kevin Nobloch, spoke to an audience at the Aspen Center for Environmental Studies earlier this Summer (more here) on the subject of Global Warming, he very much emphasized the initiative of individual states as a means by which progress can be made while the Federal Government spins its tires, and does all that it does to suppress supporting scientific information. He did a very good job of talking about the spectrum of effects that global warming has on individual states, and the spectrum of activities that individual states can be engaged in, in order to take part in the effort to do something positive to help themselves. For example (bearing in mind the large number of ski-industry-related people in the audience), he spoke of the 3 degrees (F) average increase in temperature in places like Aspen over the last 25 years (1 degree for coastal regions, on average), and the resulting 20 snow days that have been lost over that time. He pointed out that this rate would give Aspen a climate approaching that of Amarillo, Texas, by the end of the century.

In talking about efforts that we can make, with regards to where we get our energy, and how we use our energy, he talked about several things. The USA is about twice as wasteful as Europe in this regard, and about half as efficient. So there are clearly lots of obviously attainable goals with existing technology. But he talked about the need to go further and focus on research into alternatives, reduction of emissions, and greater energy efficiencies. This is one of several ways in which states can make individual strides ahead, not waiting for the leadership of the Federal Government to arrive. 20 states already passed significant amount of legislature concerning renewable energy. 9 North East states already have regional cap and trade schemes on greenhouse gas emissons. Numerous city mayors have committed their municipalities to meet the Kyoto targets. 9 state governers joined California in more strict tailpipe emissions standards, etc. He talked about the need to do research and invest in the new industries that should arise around the technology of alternative energy, efficiency, etc. Why is the US not leading the way in hybrid car technology? Why is it so far behind? This is one of many areas to which states can be looking to invest, from the purely pragmatic perspective of attracting new industry, new jobs, new investment.

Well, we all know that California is leading the way in many areas. Not long ago we discussed the recent news of California’s commitment to reduce greenhouse gas emissions by 25% by the year 2020. But, I have to admit, I did not anticipate a lawsuit as the next salvo in the battle! From the BBC (for example), in a report yesterday: Click to continue reading this post →

Encounters On the Road Less Travelled

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Well, I snapped this shot of this awfully cool woman while I waited at the lights….

lady on tricycle

… and then as I cycled by on my own “funny-looking bike”, I waved to her and yelled “nice wheels!” (since “nice bike!” would be inappropriate, and “nice trike!” sounds like she’s a 5 year old, rather than her 50+? years). I was so pleased to see her.

I hope that I did not scare her.

-cvj

Flying Clams

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freshwater clamThere’s a lovely new book (or it sounds that way) out, about Darwin. It’s a biography by David Quammen, called “The Reluctant Mr. Darwin: An Intimate Portrait of Charles Darwin and the Making of His Theory of Evolution”. There was a very nice radio piece on it on NPR’s Morning Edition, on the segment by Robert Krulwich, with an interview with the author. I recommend it, as it is a very pleasant and interesting conversation. From the website (from where you can find the audio archive):

Quammen describes what happens when a meticulous, shy, socially conservative man comes up with a revolutionary, new, dangerous idea. Darwin gets so nervous thinking what he’s thinking, yet he is so sure that it’s a promising idea. He can’t let it out but he can’t let it go. Instead, he spends years, decades even, checking and double checking his evidence. He wanted to be surer than sure about his ideas on natural selection. But, of course, in science you can never know what you don’t know, and so painfully, gingerly, and on occasion delightfully, he tried to anticipate his critics and get his idea ready. But it was slow to gestate. Very slow.

There’s a rather nice discussion of how Darwin, with his butler and also with his sons, Click to continue reading this post →

Yau Fights Back?

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Well… yikes! Remember my article on the New Yorker piece on the Fields Medal, the Poincare Conjecture, and the mathematicians Perelman and Yau? Remember that I said:

I cannot comment upon whether the hero of the story (Grigory Perelman) is as heroic as painted, or whether the villian of the piece (Shing-Tung Yau) is really as villainous. The anecdotes that are used to do the painting may well be able to be supplemented by other anecdotes that tell another story, as is sometimes the case. I simply don’t know.

Well, it seems that Yau is quite sure that it is not going to stop there. There was a letter sent to the New Yorker and the authors of the article (apparently) on his behalf by legal counsel. It is discussed and can be found on a web page under Yau’s name. The page is in the form of a press release, and I quote:
Click to continue reading this post →

On The Potential of Women Scientists and Engineers in Academia

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Today, the National Academies released their long awaited report on the potential of women scientists and engineers in academia. The title is “Beyond Bias and Barriers: Fulfilling the Potential of Women in Academic Science and Engineering”, and it can be obtained here. This is a hugely important topic, and they seem to have done quite an extensive amount of work on this. Here are some quotes from the press release, and then I’ll make some comments of my own at the end:

“Women are capable of contributing more to the nation’s science and engineering research enterprise, but bias and outmoded practices governing academic success impede their progress almost every step of the way,” said Donna E. Shalala, president of the University of Miami, former secretary of the U.S. Department of Health and Human Services, and chair of the committee that wrote the report. “Fundamental changes in the culture and opportunities at America’s research universities are urgently needed. The United States should enhance its talent pool by making the most of its entire population.”

Much the same can be said (and has been said in, e.g., my earlier blog posts on CV) about the largely untapped talent pool of minorities in general, of course. Click to continue reading this post →

Converting The Enemy

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An interesting development in the world of chemistry caught my eye just now. Imagine taking that carbon dioxide that is in so many of our emissions, and that is one of the principal agents in the processes contributing to global warming, and using solar energy, converting it into fuel. Now that would really be an interesting possibility, wouldn’t it?

Well, it is possible. Whether it will ever be a viable scheme that makes any practical sense is another matter, but you’ve got to start somewhere. A team of chemists represented by Gabriele Centi of the University of Messina (Italy) presented new results on this process to the American Chemical Society meeting in San Francisco. From New Scientist:

The researchers chemically reduced CO2 to produce eight and nine-carbon hydrocarbons using a catalyst of particles of platinum and palladium confined in carbon nanotubes. These hydrocarbons can be made into petrol and diesel.

To begin with, the researchers used sunlight plus a thin film of titanium dioxide to act as a photocatalyst to split water into oxygen gas plus protons and electrons. These are then carried off separately, via a proton membrane and wire respectively, before being combined with CO2 plus the nano-catalyst to produce the hydrocarbons.

Here’s the actual abstract of the talk:

Click to continue reading this post →

Ranch Style

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Well, I noticed a resonance over the last couple of days. In pictures:

horses in griffith park

I know what you’re thinking. Another exotic place, right? Actually, no more exotic than Los Angeles. Yes, as I keep saying, it is not all concrete, despite what people say. This is essentially in the middle of the Los Angeles area, overlooking the city. The lovely Griffith Park, at the top of Mount Hollywood, where I was hiking with a friend and came upon this scene. Did not have enough camera to make the best of it, but this will do. As confirmation of the central location, you can see the Hollywood sign in the top right hand corner (click for closeup).

Next:

bluegrass in market

The Rainwater Bluegrass band. They’re part of the wonderful weekly fresh food Click to continue reading this post →