Sunday, October 26, 2008
Practical Physics News
When the tape is peeled removing the adhesive-electrons are released generating electric currents. In the photo to the left you're seeing visible light emission from these electrons. It turns out they also emit x-rays, so many that its possible to x-ray a human finger. I was about to try an experiment and x-ray my painful tooth but that's on hold because apparently you have to do this in a vacuum.
OK here is the kicker-physicist Seth Putterman says the process could be used for nuclear fusion. I'm a bit skeptical about that given the history of table top fusion attempts so far. You can read the details here:
From a Strip of Scotch Tape, X-rays
Wednesday, October 22, 2008
Models or Reality?
"Right and wrong aren’t parts of the fundamental description of reality. That description has to do with wave functions and Hamiltonian dynamics, not with ethical principles. That is what the world is made of, at a deep level."
This is exactly how I used to think about things. Lately though, I have become more of a positivist. This is the viewpoint that scientific theories are just models. A good model makes predictions that agree with experiment. The fact that the models often change with time as better data or ideas come to the fore shows that its naive to take the models as absolute descriptions of reality. For a simple example you might consider the Bohr atom. If you recall, Bohr thought of the atom as a little solar system, with the nucleus playing the role of the sun and electrons occupying fixed orbits at different distances from the nucleus. As they jumped from one orbit to another, they emitted or absorbed photons of light.
We now know an atom isn't quite like that, and that instead the wave function of the electron allows us to make probabilistic predictions as to where the electron will be found. Each orbit is described by a different wave function, giving the "electron cloud" picture of the atom. The Bohr model of the atom, even though it agrees with a lot of experimental data, isn't real.
The positivist would say that the electron cloud is no more reality than Bohr's atom was. It simply makes better predictions. At our current level of technology and predictive capability, it seems to work perfectly. But that doesn't mean that in the future a better model of the atom won't come about. And-despite its drawbacks-the Bohr model of the atom actually works quite well in many circumstances. In nuclear engineering its often if not always adequate enough to think of the atom in terms of Bohr's picture. On the other hand, if you're doing quantum chemistry then you need to think in terms of the electron cloud model.
This goes to show that taking "wave functions" and "Hilbert space" to be reality itself is a naive viewpoint. Wave functions and Hilbert space are just tools that allow scientists to make predictions. They are good tools to be sure, but confusing a good tool that exists on paper and only in the minds of arrogant physics professors to be fundamentally real is an extremely naive approach to life.
The positivist viewpoint makes a lot more sense. Stephen Hawking summed it up well in his best seller A Brief History of Time when he wrote:
"Any sound scientific theory, whether of time or of any other concept, should in my opinion be based on the most workable philosophy of science: the positivist approach put forward by Friedrich Hayek and Karl Popper and others. According to this way of thinking, a scientific theory is a mathematical model that describes and codifies the observations we make. A good theory will describe a large range of phenomena on the basis of a few simple postulates and will make definite predictions that can be tested… If one takes the positivist position, as I do, one cannot say what time actually is. All one can do is describe what has been found to be a very good mathematical model for time and say what predictions it makes."
At the time I read this back in 1990, I was disappointed Hawking felt this way. Now with some maturity under my belt I realize that this is a far better description of what science does than taking some equations on a blackboard-which are good, useful tool to be sure-to really be reality itself.
Monday, October 20, 2008
Progress in ALS Research
Swamping Bad Cells With Good In ALS Animal Models Helps Sustain Breathing
ScienceDaily (Oct. 20, 2008) — In a disease like ALS - one that's always fatal and that has a long history of research-resistant biology - finding a proof of principle in animal models is significant.This week, Johns Hopkins researchers report that transplanting a new line of stem cell-like cells into rat models of the disease clearly shifts key signs of neurodegenerative disease in general and ALS in particular - slowing the animals' neuron loss and extending life.
The new work supports the hypothesis that artificially outnumbering unhealthy cells with healthy ones in targeted parts of the spinal cord preserves limb strength and breathing and can increase survival.
Read the rest on Science Daily
Opera about the making of the Atomic Bomb
By DENNIS OVERBYE
Is it the horror or the beauty that makes science cool?
Sometimes it seems as if horror is the only story that science has to tell, or the only one we want to hear. Somebody has a gadget they have to build, an experiment too sweet to resist, forces they need to probe, regardless of the consequences. Think of Eve with her apple, Frankenstein with his monster, a stock trader with a foolproof get-rich-quick scheme.
I shouldn’t have to tell you that it usually ends badly.
The tug of war between beauty and horror is the theme of “Doctor Atomic,” the opera by John Adams and Peter Sellars about the building of the atomic bomb, which opened last week at the Metropolitan Opera. It stars Gerald Finley as J. Robert Oppenheimer, the brilliant philosopher-king of the secret society of scientists and engineers who were plucked from academia and assembled on a New Mexico mesa during World War II and told to make a bomb before the Germans did — a man as sung by Mr. Finley equally in love with the Bomb and his own inscrutability.
The opera follows events on two nights — one in June and then on the eve of July 16 during the countdown to the first test explosion at Alamogordo amid lightning and rain — as the scientists wrestle with doubts about whether “the Gadget,” as they refer to the bomb, will work, or work too well, setting the atmosphere on fire, and whether it should be dropped on humans.
As a love-starved Kitty Oppenheimer, sung by Sasha Cooke, sings, “Those who most long for peace now pour their lives on war.”
“Doctor Atomic” was surely born on the dark side of science mythology. Pam Rosenberg, then director of the San Francisco Opera, wanted to do an opera about an American Faust, namely Oppenheimer, whose life certainly seemed to follow a tragic trajectory. Wealthy, articulate and effortlessly fluent in far-flung domains of learning and culture, he was the young American prince of the new science of quantum mechanics as well as a bohemian and a pal of communists (his brother Frank and his ex-lover Jean Tatlock). Less than a decade after he was hailed as the deliverer of Promethean fire and the symbol of American science, Oppenheimer was stripped of his security clearance and banished from government circles.
Read the rest on the NY Times
Sunday, October 19, 2008
It from Bit Speculations
So in the year 2050 a woman (we'll call her Betty) is scanned and her data saved. Now suppose that technology has also advanced enough so that we could read the information and assemble the atoms together into the same state as Betty in 2050. Suppose this is done in the year 2150 long after Betty has died.
It would seem to me that for all intensive purposes, if you could do this-arrange the same types of atoms/molecules together in the same state as Betty in 2050, the recreated Betty 100 years later would be completely indistinguishable from the original. I can't think of any scientific test that could be done even in principle that would tell you it wasn't really Betty, just a copy. So why not just say it is the original Betty? This would be a scientifically implemented resurrection.
What this says is that consciousness is more of an informational phenomenon, and in some sense it already exists in the universe and always exists provided the energy is there to do these sorts of things (i.e. arrange atoms together in the right way). In other words, the woman I've named Betty in the particular state she is in at some moment in 2050 including her conscious awareness is a packet of information. Rearrange the right atoms into the same state at any time in the history of the universe where it is plausible (not in the distant future when everything has decayed away though), that state is recreated and so is the consciousness that goes along with it.
You could ask what if we recreate Betty on the spot. Of course you couldn't do it instantly, no matter how advanced technology got there would be some finite time required to scan an organism and then construct the duplicate. So what would happen to Betty's consciousness then? Would it somehow split? Or is consciousness distinct and evolving, in other words you aren't really the same consciousness you were 2 seconds ago.
Maybe in the distant future it would be possible to even recreate previous states of the universe in some kind of quantum simulation. Then it might be possible for an infinitely advanced civilization to resurrect the past including its living inhabitants. Where would all this information be stored? In Hilbert space of course.
Saturday, October 18, 2008
B. Allan Wallace on Consciousness
John Hagelin on Consciousness
Anyway so the debate over John Hagelin (TM Fame) over on Not Even Wrong led me to these YouTube videos which include interviews with Hagelin. Honestly I don't think Hagelin is all that wacky. Some of his thoughts actually make more sense than reductionist biology which has completely failed to explain how consciousness has arisen from the brain (hint: explaining what brain cells are responsible for vision does not explain why there is an entity inside my head WATCHING the show).
Friday, October 17, 2008
More on the Creation Museum
The Quantum-Classical Connection
Mathematicians Illuminate Deep Connection Between Classical And Quantum Physics
ScienceDaily (Oct. 17, 2008) — In a seminar co-organized by Stanford University and the American Institute of Mathematics, Soundararajan announced that he and Roman Holowinsky have proven a significant version of the quantum unique ergodicity (QUE) conjecture.
Read the full story on Science Daily
Thursday, October 16, 2008
Creationist Museum Draws Big Crowds
"One display shows humans coexisting with dinosaurs — despite the two species being separated by 65 million years in most science texts."
What? What science texts have humans coexisting with dinosaurs? The worst thing about this quote is its from the reporter who wrote the story-not from some nut that works at the creation museum. Visitor Bill Michaletz says:
"I do believe in creation, that God created it all," said Michaletz, who has five children. "I'm appreciative that there is a place to go for ourselves and our kids, to look at that view."
Can't we be sensible here? I think you have to be really deluding yourself to believe literally in Genesis and a 6,000 year old earth. A reasonable compromise is in order, you can believe in Christianity and accept the findings of modern science as Kenneth Miller shows. The museum was founded by wack-job Ken Ham, whom I believe is Australian.
Tuesday, October 14, 2008
Too much publishing?
I was also thinking about the Nobel prize. Maybe we shouldn't give one every single year. After all the Fields medal is only given out every 4 years. The Nobel prize has such an air about it, yet we have to give one year in and year out regardless of whether Nobel quality work is really being done. How many of the Nobel prize winners in the last ten years are really equivalent to say, Albert Einstein or Marie Curie? Probably none. Yet by giving a Nobel prize every year, we give many people an automatic stamp of genius that many don't quite deserve. It will never happen, but I think the scientific world would be better off if Nobel prizes were cut back to one every four years.
And stop publishing so many papers! Every calculation you do isn't worth writing up.
Monday, October 13, 2008
Physics Quote of the Day
Poll on Nuclear Power Plants
Wake up people. Building new nuclear power plants is going to be a necessity, not an option in the future. Coal and oil are limited resources. You can build "clean burning" coal plants, but nuclear is still going to be a far better option on that front since it releases no greenhouse gases. Of course uranium is a limited resource too, to help deal with that there will have to be reprocessing.
The great hope long term is really nuclear fusion.
Sunday, October 12, 2008
Ecstasy May Damage Brain in Single Dose
I think many young people view the drug as harmless. Well here is something even more damning-recent research indicates that a single dose can cause permanent memory loss. The study indicates that not only does a single session with ecstasy damage your memory but that the amount of drug consumed is irrelevant. Sounds like a substance you want to stay away from, especially if you're interested in physics. You're going to need those brain cells to learn quantum mechanics.
Read about it here.
Friday, October 10, 2008
Does God Exist? Sean Carroll Knows the answer is No
"I look forward to a day when discussions of deep questions concerning the origin of the universe and of life can take place without the concept of God ever arising."
Why would you look forward to that? This comment brings to mind something I've always thought-that atheism is actually a religion in itself. Strict atheism is actually a fanatical religion. Let's admit one fact. Its impossible to know whether or not God exists. Just because a causal chain for physical events can be taken back to the big bang, nobody knows with certainty that the universe wasn't made by a supernatural being. You may believe that the universe "just happened", and that's fine, but a more agnostic point of view is far more defensible.
Wanting a discussion of "deep questions" concerning the origin of the universe without the concept of God ever coming up is intellectually vacuous. The deep questions are not mechanical details, such as is the universe expanding, what is dark energy, is there a cosmic landscape. The fact is none of that matters to most people in a deep sense. What matters to people is meaning. Science will never give people meaning and that's why religious thought is still going strong.
The fact is there are lots of intelligent people, many of whom that are educated in science, that disagree with Sean Carroll. One of them is John Polkinghorne, a man with a PhD in physics that became an Anglican priest. John Polkinghorne is not some wacko, he is a very intelligent and thoughtful man who believes in everything modern science tells us about the universe but also believes that God created it. Polkinghorne has several books out that are thoughtful, interesting reads-not rants by a creationist fanatic.
As mentioned in this post Kenneth Miller attended the origins conference. I don't find Millers arguments very compelling, but he is another example of a scientist that accepts science just fine but he is also a very religious man. Interestingly, in that post Sean Carroll, who is supposed to be an intellectual leader, shows a bit of immaturity by stating that people that don't share his view are "crazy". In fact he uses the exact phrase:
"sheer unadulterated looniness of the remaining speaker, Hugh Ross. "
Describing someone participating in a conference this way is pretty much a "straw man" attack. It would be far more professional to say Hugh Ross is misguided, and I disagree with his views because of .....instead of simply stating he is loony. Ross has views that can be described as more extreme, and his views are not very defensible, but attack his positions instead of just labeling him a crackpot.
Many other professional scientists are believers in God. Francis Collins, who headed the DNA decoding project for NIH, is one of them. So while Richard Dawkins may be especially vocal, there are biologists that disagree with his viewpoint. The nuclear physicist Gerard Schroeder is also a die-hard believer who has been compelled to write several books on the topic.
The arguments of these people may or may not be persuasive, but saying they should be shut out of a debate on something that frankly can't be resolved scientifically is not productive. If you are really interested in the deep questions of the universe then the issue should at least be discussed. It was interesting that in "A Brief History of Time", while Stephen Hawking concluded (at the time anyway) that the universe was self-contained without much role for a creator, the book talks about God on almost every page. The issue can't be discussed without bringing God into the mix, and a mature, thoughtful debate will have views from all perspectives. The kind of discussion Carroll envisions-a bunch of athiestic scientists sitting around discussing what dark energy is, isn't all that deep at all.
Saying you look forward to a day when discussions about the universe will take place without God ever being mentioned is arrogant, immature, and out of touch with 99% of humanity.
Tuesday, October 7, 2008
Good Professors are Hard to Find
Well today I would like to acknowledge a good, no make that great professor. The guy pictured here is Pedro Embid. Pedro emigrated to the United States at the age of 17 and obtained his PhD in applied mathematics at UC Berkeley. Somehow he ended up at the University of New Mexico. I was lucky enough to be attending UNM (often called the University of Nothing Much) and took one of his courses. I was completely BLOWN AWAY.
Pedro is a model professor. I ended up taking several classes from him over the course of ten years. All that time, I never saw him use lecture notes once. He was like a PhD in a subject field should be-a complete master of his topic. Whether it was a graduate level discussion of distributions and hilbert spaces or partial differential equations-Pedro just knows his shit.
Not only that he delivers clear, perfectly organized lectures. He knows exactly where each and every lecture is going and doesn't miss a beat. He talks with enthusiasm, writes clearly, and makes his expectations crystal clear.
I once had a graduate level differential equations class from Pedro. It was very tough-run like a boot camp. Every week we had a homework assignment due-each assignment was exactly 10 problems. This was graduate level math so they were all proofs/rigorous type problems. It was very tough-but you knew what was going on and what was expected, and if you studied your notes you could get through it. You learned a lot and came out of there feeling like you could conquer anything intellectually.
Pedro lectures off the top of his head, but if you brought a camera in you could just photograph the black boards and publish them as textbooks. He has had at least two visiting professorships at the Institute of Advanced Study at Princeton. Despite this, he is great with students. His office hours are packed with students clamoring to get every ounce of Pedro's mathematical wisdom they can get. I nominate Pedro as my first great professor of the month. Here are a summary of Pedro's skills:
- He really KNOWS what he is talking about.
- He delivers dynamic, interesting lectures.
- He challenges the students.
- His expectations are clear. He is tough but there are no left-field surprises physics professors love to dish out to make themselves look better.
- He knows the history of physics and mathematics, and peppers his lectures with historical antecdotes.
I would like to hear people recommend good professors like Pedro.
Nobel Prize in Physics Awarded
1 American, 2 Japanese Share Nobel Physics Prize
An American and two Japanese physicists on Tuesday won the Nobel Prize in Physics for their work exploring the hidden symmetries between elementary particles that are the deepest constituents of nature.
Yoichiro Nambu, of the University of Chicago’s Enrico Fermi Institute, will receive half of the 10 million kroner prize (about $1.3 million) awarded by the Royal Swedish Academy of Sciences.
Makoto Kobayashi, of the High Energy Accelerator Research Organization (KEK) Tsukuba, Japan, and Toshihide Maskawa, of the Yukawa Institute for Theoretical Physics (YITP), Kyoto University, will each receive a quarter of the prize.
Ever since Galileo, physicists have been guided in their quest for the ultimate laws of nature by the search for symmetries, or properties of nature that appear the same under different circumstances.
However, in the 1960s, Dr. Nambu, who was born in Tokyo in 1921, suggested that some symmetries in the laws of nature might be hidden or “broken” in actual practice.
A pencil standing on its end, for example, is symmetrical but unstable and will wind up on the table pointing in only one direction or the other. The principle is now embedded in all of modern particle physics.
“You have to look for symmetries even when you can’t see them,” explained Michael Turner of the University of Chicago, who described his colleague as “the most humble man of all time.”
In 1972, Dr. Kobayashi and Dr. Maskawa, extending earlier work by the Italian physicist Nicola Cabibbo, showed that if there were three generations of the elementary particles called quarks, the constituents of protons and neutrons, this principle of symmetry breaking would explain a puzzling asymmetry known as CP violation. This was discovered in 1964 by the American physicists James Cronin and Val Fitch - a discovery that also won a Nobel prize.
C and P stand respectively for charge and parity, or “handedness.” Until then, physicists had naively assumed that if you exchanged positive for negative and left-handed and right-handed in the equations of elementary particles, you would get the same answer.
The fact that nature operates otherwise, physicists hope, is a step on the way to explaining why the universe is made of matter and not antimatter, one of the questions that the Large Hadron Collider, the new particle accelerator now preparing for operation, is designed to explore.
Friday, October 3, 2008
China Launches First Willing Manned Mission Into Space
China Launches First Willing Manned Mission Into Space