Sunday, August 31, 2008

Going to the Moon and Beyond

From time to time I've thought about what a waste of money the international space station was. I've always thought the space shuttle and space station were both wastes of money, but the dramatic way that the space station was scaled back made it even more so.

Back in the day when we were actively taking trips to the moon, a lunar base was not out of the question. Maybe the time to revive this idea is now.

Think about it. The moon itself can serve as a "space station". Its only 3 days transit time, and being a ball of solid rock with a surface area about equivalent to the land mass of Africa, it provides a ready-made foundation on which to build space stations, space telescopes, radio telescopes, and other wished for goodies. A space station is a temporary structure, the moon will be up there for a very long time.

Scrub the Hubble telescope and build a telescope on the moon. Hubble is already what, twenty years old? We could build a telescope to replace it on the moon with updated technology that could be accessed readily once it was built, because it would be ground based (albeit on the moon). Radio telescopes could be constructed that would have an unprecedented radio "view" of the universe for general research and also to search for any radio signals of alien life.

I'm sure lots of other uses for the moon could be cooked up, scientific and practical. The main point would be to establish a permanent human presence in space. You might think its expensive, but isn't the war in Iraq expensive? If we can spend $1 billion per week invading another country, why can't we lay out some serious money for space exploration?

Also consider that the Apollo missions, grand as they were, took place during the cold war. Today the world is very different. We could invite Russia, China, India, and Europe on board as direct participants. This would encourage international cooperation, build a sense of shared purpose and enable us to split and share costs.

Carl Sagan once likened the Apollo missions to life coming onto land from the seas for the first time. Going to the moon would be like the first tentative steps of a lung fish leaving the security of the ocean to pursue a life on land. Life ever expanding outward, is now ready to take those first tentative steps off the earth out into the universe beyond.

Its not going to happen unless we start the ball rolling now. Lets go back to the moon, but not the way we did back in the days of Apollo. Instead lets go out there with the purpose of establishing the first permanent presence of life in space that we know of.

Saturday, August 30, 2008

The Feynman Lectures on Physics

Its a no-brainer that Richard Feynman was one of the best physicists of the 20th century. Maybe all around, and I mean as an all around guy, he was tops. A lot of physics people are well, lacking in the social aspect but Feynman seems to have had a great personality besides being really smart and scientifically imaginative.

If you want to study physics being good at math is an important goal, but you've got to remember to focus on concepts too. I think Feynmans three volumes are one of the best resources to get you thinking physically, not just wielding equations. I've decided to dust off my copy of Volume One and re-read it. You should do that too.

Friday, August 29, 2008

The Permian Extinction

If you're like me you have to find the long, painful history of the earth absolutely fascinating. I live in New Mexico and something that is great is an area called Ghost Ranch. Located near a tiny town called Abiquiu (ab-eh-Q), its situated among one of the most bizarre landscapes in the world. Consisting of small mountains, the area has suffered complete erosion to the delight of geologists. The layers of rock from every geological era are completely exposed, giving the landscape a painted layered look, with bands of pink, gold, tan, and dark grayish colored. The banded colors of the rocks and high levels of erosion make the area seem infused with mystery.

The gold rock represents a time when New Mexico was like the Sahara desert. The gray rock, on the other hand, which is on top of the mountains is from an era when New Mexico was actually under water. The state was covered by a large sea. Look at the gray rock up close and its full of fossils of sea creatures. A little museum in Ghost Ranch has a chunk of it you can examine up close.

Once filled with roving bands of dinosaurs, Native Americans called the region home for centuries before the Europeans came. A museum at the ranch tells a little bit of their story with such fascinating objects as a knife that was found embedded in a skeleton, believed to be from someone who lived in the 12th century. Archeologists figured out that the person was killed in a raid over food. The area is high desert and food was often scarce. Drive through there now and you can see why. It must have been kind of magical though, living in an area like that prior to modern civilization and the arrival of the Europeans.

Anyway I digress. The differing geologic eras etched in the rock include the Permian, the era that preceded the arrival of the dinosaurs, which figure so highly at Ghost Ranch. A great extinction occurred that allowed the dinosaurs to come into existence and flourish, its called the Permian extinction.

Unlike the meteor that killed off the dinosaurs, the reason for the Permian extinction is unclear. One theory that had a lot of supporters was that oxygen levels somehow dropped suddenly (volcanoes maybe?) killing off large swaths of life. That sounds kind of hokey to me, but its not like I have any better ideas. But so much for the hypothesis anyway. Recent research seems to discount the idea. So its back to the drawing board. The Permian extinction was so long ago maybe its going to be a lot harder to resolve than the dinosaur extinction. Or maybe they will never figure it out.

Table Top Fusion Bust

A few years back some scientists at Oak Ridge National Laboratory announced an exciting find-they were able to cause fusion using sound waves. Sound too good to be true? It didn't to the journals. The "prestigious" journal Science published the findings which have since turned out to be bogus.

The claims, made by a Dr. Taleyarkhan, involved collapsing bubbles in a liquid using sound waves. There was such force that the collapse of the bubbles cause hydrogen atoms in the liquid to undergo fusion reactions. The original research was conducted at Oak Ridge, but Dr. Taleyarkhan has since moved to Purdue University where he published a follow-up paper which claimed he was able to duplicate the original results, something no other scientists have been able to do. In a recent finding, which didn't dispute the original paper, Purdue punished the professor for research misconduct. Apparently there has been no duplication of the original results.

Hmmm...maybe we shouldn't be so anxious to believe in table top fusion the next time someone announces it. On a positive note, this shows the scientific enterprise works pretty well and roots out false results. Its also a good comment on human nature. Maybe this is less about actual fraud and more about Dr. Teleyarkhan wanting to believe so badly in what he thought he discovered.

Thursday, August 28, 2008

The God Delusion

I came across this review, or maybe what might be more aptly called a description of Richard Dawkins book The God Delusion. Personally I find athiestic scientists amusing. While it is pretty clear from simple observation of the universe that the God of the creationists doesn't exist, at least not within their strict interpretation, the fact is science can't prove God doesn't exist. Even Carl Sagan realized this, when he said in Cosmos (to paraphrase) that the fossil record showed a literal intepretation of the Bible could be ruled out, but that a God with a more indirect temperament could not be.

I find Dawkins and his ilk to be as irritating as the creationists. Dawkins and Daniel Dennett, a philosophy professor who recently joined the God "debate" are zealots as bad as any Chrisitan fanatic. But I want to call their (and your) attention to something. There is no God debate. The vast majority of humanity believes God exists and believes in some form of spirituality. They could care less what Dawkins thinks, even though he might get a lot of attention in intellectual circles.

Dawkins analysis is pretty simplistic. He runs through the same old arguments, like the claim that religion supposedly caused a bunch of wars in the middle ages. Well let me ask you something. If Europe had not been Christian, do you think those wars would not have happened? HELLO. The wars would have still occurred, but under a different banner. European expansion would have still brought them in contact with Native Americans, and if Christianity would not have been a rallying cause something else would have.

The fact is religion gives meaning and comfort to billions of people. I'm not saying because it gives people meaning even if God doesn't exist that we should support it. What I'm pointing out is that Dawkins arguments can't touch the emotional aspect that people get out of religion and spiritual experience.

I have to say I am partial to the religious. The existence of consciousness is enough for me. I think scientists are hard pressed to explain why consciousness should arise in the universe. It doesn't prove anything, I am just saying that for me personally conscious experience tells me there is a spiritual side to the universe. And if you open yourself up-you will experience a spiritual side as well.

OK enough of my soap box. Order the book already and let me know what you think.

String Theory Demystified for International Buyers

I received a query about international shipments. International shipping is $10. International buyers please use this button to order.

Wednesday, August 27, 2008

String Theory Demystified

String Theory Demystified will be available on September 11, 2008. I have 8 copies I need to get rid of so can sell you a direct copy now. I will charge $10 per copy plus $3 for shipping and handling. You can pay via credit card using pay pal. The copies are brand new.

Warning: This is really a string theory book-not a pop book. It was reviewed by a string theory professor to eliminate typos and errors. Get yours early!

Dark Matter

Astronomers are convinced-there is a type of matter that doesn't interact with electromagnetism but interacts gravitationally. The result? Dark matter-something that we can't see because light is electromagnetic radiation. But we see its effects true enough. If you examine the behavior of galaxies there is clearly mass there that cannot be detected visually (or we don't understand gravitation on large scales).

Personally I find either possibility exciting. But dark matter appears to be more likely. And recently, astronomers are claiming to have detected it. In an analysis of the collision of two galaxy clusters, the matter, which consisted of hot visible gas-cooled and slowed down. Just like you would expect. But the "dark matter" did not. This indicates that aside from gravitation it interacts weakly if at all. This is experimental support for the existence of dark matter, something that has only been inferred so far.

Poll on New Physics/Math Book Topics

For readers who are interested in reading math/physics books, I am interested in what people are interested in as far as topics. Some things I am considering are:

  • Partial Differential Equations
  • Ordinary Differential Equations
  • Math Methods for Physics

Also I am thinking of bypassing the traditional publishing model, and selling the books as ebooks available directly from this site. Let me know what you think about that.

Tuesday, August 26, 2008

The Singularity

I don't know whether to be amused or frightened by predictions by computer scientists that by the year 2030 humans and computers will be fused together in an ever-present world-wide network. Or maybe instead computers will be so intelligent that they merely dispense with humanity all together.

Predictions like these come out of the mouths of people like Vernor Vinge, a computer scientist who envisions a future where computers will be physically hard-wired into your brain. Having used Microsoft Vista, I'm not all that excited about the prospect. Vinge and others speculate that in the next 30 years this computer-to-brain connection will have people seeing text messages and data floating across their eyes with computer screens overlaying the real world. Personally I find that nauseating and think computer scientists with this kind of hope for the future ought to get outside a little more often.

Grandiose predictions of what will happen in the future with technology have often, if not always, fallen far short of what was envisioned. It is hard to say what the future will bring, todays cell phones and text messaging may be a premonition of incredible levels of connection, turning the planet into some kind of supermind. At the same time all this talk reminds me of the 1939 Worlds Fair where among other things predictions were made about robots and clean freeways without traffic jams. That world never materialized.

I think the prediction that computers will become so "smart" and capable that they will dispense with humanity fall into that category. What science and technology is capable of is grossly overestimated by lots of people, including scientists themselves and journalists.

A wacky, but thought provoking topic, the era when computers take over the planet could be near. Or not. Check out the Age of Spiritual Machines by Ray Kurzweil for a lively discussion of this issue.

Monday, August 25, 2008

Six Essential Tools to Learn Physics

College physics is hard. If you're getting started on the path to an engineering or physics degree, or planning on taking AP physics, these tools can help you stay one step ahead.

1. The Feynman Lectures on Physics
This classic three volume set covers the
concepts of physics better than any other.

2. Unit Conversion Tutor DVD
Handling scientific notation, units, and dimensions are essential to mastering the
physical sciences. Get a leg up with this four hour video set which teaches working
with units via examples.

3. Calculus 1 & 2 Tutor DVD Set
Calculus is the tool of physics. Learn about limits, derivatives, the chain rule,
solving integrals, logarithms, trig substitution and more. Eight hours of video
instruction all taught by example.

4.Ultimate Physics Tutor DVD Teaches by Example
11 Hours of video instruction, covers material offered in college physics course.
Projectile motion, scalars and vectors, Newton's laws, friction, angular momentum,
gravitation and more.

5.Physics for Dummies
Physics for dummies isn't just for dummies. This well written book is a great course

6.Physics Workbook for Dummies
To learn physics you need to do physics. Follow up on tip #4 with this workbook that
will improve your problem solving skills.

Quantum Theory Lectures by Hans Bethe

This morning I stumbled on a set of three videos of lectures given by the great 20th century physicist Hans Bethe. In the first lecture, which lasts about 50 minutes, he discusses the old quantum theory. This lecture covers Planck and his black body curve and ends with a discussion of the hydrogen atom as described by Neils Bohr.

In the second lecture, he discusses the development of modern quantum mechanics by Heisenberg and others.

In the third and final lecture, Bethe talks about some of the interesting results that have sprung up from quantum theory that make it so interesting, like the Heisenberg uncertainty principle and spooky action at a distance.

Sunday, August 24, 2008

The Flow of Time

Time remains one of the biggest unexplained mysteries in all of science. It plays a central role in our conscious experience, yet only recently has it taken on a serious position in physics. Prior to relativity it remained merely a parameter, marching forward at one second per second without any explanation as to its real meaning or role in the physical world.

In Relativity we confront the notion that time passes at different rates for different observers. This defies common sense. In fact, it challenges the very core of the core of reality as seen by the human mind.

But what is really significant is the link that the passage of time has with the conscious mind. Consciousness is something that seems to elude physics. The first hint that the conscious mind tied in with physics came with the development of QuantumTheory. But that isn't the whole story. Our conscious experience in life is wholly tied up with the passage of time. For me this serves as a clue to what the universe is really about. Time is physical. Its as physical as you can get. It defines the beginning of life. It defines events that have happened and can't be changed, and it defines the end of life. It does all this with a direct relation to the one thing we know to be ultimately real-conscious experience. That inner conscious life that has eluded science for 2,000 years is the most real thing in the universe. Time is its connection to physics.

What time is physically remains a mystery. Even in subjects like string theory, time is just something passing without any real explanation as to what its really about. This should be a red flag for you. String theory and quantum gravity cannot be "ultimate" theories in any real sense. Time and its relation to the human a (and animal m)mind is more real than any electron of Higgs boson. Yet most physicists just view it as a click on their watch, some sideline data to collect while we measure what is "really" happening. Any final theory will have to really explain time and its relation to the conscious mind.

A good book that is a bit more on the rigorous side is The Direction of Time by Hans Reichenbach. Its not going to tell you what time really is, but it puts time under a scientific lens better than any other book I've seen. More on the popular side is About Time by Paul Davies.

Chances are, the true nature of time won't be explained in our lifetimes. But lets get the conversation started.

Saturday, August 23, 2008

Earth Special After All?

Starting with Copernicus, science has routinely demoted man and his home planet from a position of central grandeur to just a mote of dust floating in an endless universe. Billions upon billions of other similar worlds exist, we've been told, with millions of civilizations flourishing on them at the very moment I am typing this message.

Fermi once asked a question in the lunch line "where are they". He was getting at a simple observation-if the universe is teeming with aliens, how come we haven't been visited? Surely in the last 13 billion years a civilization has arisen in the Milky way Galaxy that would have explored it and been to earth?

First lets state upfront that a lot of people do think we've been-and are continuously-visited. That being said, I have to say I don't buy that. Even so, given the sheer number of stars and galaxies, it seems entirely plausible that there are multiple civilizations in existence right now throughout the cosmos (not meant as a direct quote of Carl Sagan). But are there really? I think there are some good arguments that technical civilizations are very rare, indeed.

For starters, there are lots of ways a civilization can screw itself over. Look at where earth is right now. We have a serious energy crisis, threat of nuclear war, threat of terrorism, religious zealots, gl warming and other problems I am not going to bother mentioning. Maybe the plain truth is that when technical civilizations come about, they simply don't last all that long. Not long enough to "make contact" much less to go visiting in person.

Maybe being technically savvy isn't all that advantageous, evolutionarily speaking. Technology has not eexisted all that long on earth, and most organisms aren't smart. Look at beetles. There are 500,000 species of them and they are all over the damn place. But last time I checked they haven't logged on the internet or had a nuclear exchange. Maybe being a beetle, just from an evolutionary standpoint, is superior to being intelligent. Beetles don't have to worry about global warming or terrorists. If Osama bin Laden blows up Los Angeles with a nuclear weapon, there will still be beetles.

Regardless of how you feel about these issues, some frecent research as cast the notion of millions of intelligent life forms populating the galaxy in further doubt. While Carl Sagan had us believing that the galaxy had an earth around every corner, it appears that the kind of solar system we live in-a stable quiet kind of place grandmother would like to call homee, is actually pprobably pretty rare. Sounds like lots of solar systems are violent places, the kind where the evolution of complex life, much less intelligence, is pmay be extremely unlikely.

Well check out the article. What do you think?

New York Times Weighs in on Large Hadron Collider

Will the Large Hadron Collider produce an earth swallowing black hole? The debate continues on the Op-Ed pages of the New York Times.

Digging Ourselves a Black Hole

Seeing Data the Way we Want

An interesting phenomenon in scientific research is what I'll call data blindness. This is where a researcher looks at a set of data and confirms what they are looking for, or ignores something that contradicts their hypothesis. This has been a long-standing problem in paranormal research, where researchers hoping to find some effect ignore data that contradicts what they're looking for. Doing this is only human. Its only natural to get emotionally invested in your research and fall victim to this kind of thing. That's why we have peer review in science.

Being that the Olympics are in full swing, its instructive to look at how the medal count is being reported in different countries. First lets check on how the British see things. The BBC has a table with medal counts that has China ranked #1, since the BBC is ranking based on who has the most gold medals.

Interestingly, Sports Illustrated, an American publication, tracks total number of medals putting the United States at the top. Not surprisingly China ranks by gold medals also, putting them in the #1 spot.

This is a simple example, but it shows how looking at the data the way we want changes the results, in this case being the medal rankings.

Friday, August 22, 2008

Major Ed Dames and Remote Viewing

I'm not sure why, but the term "MAJOR" seems to carry a lot of authority. Strangely this is true even though a major is not all that high rankinga among officers in the military. You would hardly consider a Major to be qualified for Secretary of State, for example, although a General might do.

Despite this Major Ed Dames sounds pretty imposing. If you listen to Art Bell or Coast to Coast, you've probably heard about Major Dames. Using tricks that most modern physicists would call bunk, the Major is able to do remote viewing. In fact it doesn't stop there-he is willing to teach you how to do remote viewing. For a fee.

Now I think remote viewing would be absolutely fantastic. Who wouldn't want to use remote viewing to see what their wife or girlfriend was doing when they weren't around? Well I think most scientists are skeptical. But does Major Dames care?

I for one leave the jury out a little bit on "paranormal" phenomena. I've actually had some strange dreams come true now and then. I think most scientists would try to dismiss it as random events coinciding, but they were so specific I didn't see things that way. And a friend assures me that Dames' program works. I may have to give it a try. Would be nice to see that state trooper hiding around the bend, now wouldn't it?

Running Out of Oil

The Large Hadron Collider controversy got me thinking about big science projects and government spending in general. It would seem to me that the biggest crisis facing us right now in the science/technology realm isn't curing cancer, global warming, developing artificial intelligence or determining if there is life on Mars-its energy. People take energy for granted but we have a bigger problem that most people realize.

The general public seems to have the idea that if we generate all of our electric power from solar and wind, with maybe a little nuclear thrown in, everything is going to be fine. But that just isn't the case. Consider:

  • Petroleum isn't used all that much in power generation. In the year 2000 coal was used to generate 51.8% of power in the United States. Natural gas accounted for about 16% of power generation while petroleum only amounted to 3%.
  • The supply of nuclear fuels is finite. In fact the world supply of uranium is actually running out very rapidly. In fact the only hope for nuclear power over the long term is to reprocess spent nuclear fuel, something that would also solve the waste problem. In the universe at large, including our own solar system, there is probably more than enough uranium, but we're a long way from being advanced enough to make mining uranium on Mars for power generation on earth remotely cost-efficient.
  • Wind power is not very efficient. To power a large city you would need to cover a huge area of land, some 300 square miles. And although designs are getting better, wind turbines do kill lots of birds.
  • Solar power also isn't that efficient, and remains cost prohibitive.
  • A very important point: petroleum products are used across the board in modern society. They're used to make fertilizer, plastics, and what about asphalt? Petroleum products are ubiquitous in the modern world and how to replace all this really hasn't been part of the discussion.
So just getting electric cars and nuclear power with a few wind turbines thrown in isn't going to solve the energy crisis long term. As technology continues to improve, developments in photovoltaic cells will make solar power more attractive, as will the potential to store solar energy.

There is also too much focus on carbon emissions and "going green". Not that these aren't things that need to be addressed but wake up people. Running out of energy is a bigger crisis than global warming. What is needed right now is:

  • A recognition of how important this threat really is. There needs to be a national drive equivalent to the Manhattan project devoting most of our scientific energy to establishing a long-term energy future.
  • A stop-gap strategy should be put in place to decrease our use of petroleum while a major research push takes place that investigates alternatives to petroleum uses in products other that gasoline and power generation. Solar, wind, and nuclear will all be a part of this, as will cars powered by ethanol as well as electric cars.
  • Reprocessing of nuclear fuel needs to be utilized in the United States-its already going on overseas.
  • Instead of relying on a traditional model where power companies have large generating plants that distribute electricity and sell it to the masses, why not incorporate wind and solar power directly into individual structures. That way you don't have to worry about taking up more land for energy generation. Its already there directly built into human habitats.
A big hope for electricity generation in the future is nuclear fusion. Right now the world is forging ahead with the ITER nuclear fusion reactor. Fusion is largely the best hope for long-term energy generation, however, at present fusion remains totally experimental. More money and effort needs to be devoted to this area of research. A big joke in the nuclear fusion community is that fusion is always 25 years away from being practical. Time to recognize how serious the energy problem is and make nuclear fusion power plants a reality.

Thursday, August 21, 2008

Black holes: Size Does Matter

In our society there's an upper class, middle class, and lower class. These days it seems like the middle class is dwindling, but anyway the point is theres a fairly continuous gradation among incomes and wealth from the very poor to the very rich. Apparently some scientists wondered the same about black holes, reports Science Daily.

Black holes generally come in two varieties. There are gigantic black holes with the mass of millions of suns or more located at the centers of large galaxies, and there are smallish black holes caused by the collapse of an individual star. Those might have masses in the range of a few times that our sun.

Some astronomers have been wondering if there was anything in between. Daniel Stern of NASA's Jet Propulsion lab says no.

"Some theories say that small black holes in globular clusters should sink down to the center and form a medium-sized one, but our discovery suggests this isn't true,"

But maybe the jury's still out on this one. Astrophysicists at UT-Austin think they've found a medium sized black hole in a star cluster called Omega Centauri. If their results hold up, there could be a black hole at the center of this start cluster with a mass of 40,000 suns.

Well if you ask me it makes sense that medium sized black holes could and would form. After all those hugely massive black holes in the center of large galaxies didn't start off huge, did they?

Wednesday, August 20, 2008

Book Review: Equations of Eternity

Any aspiring physicist should devote as much time to reading popular books as they do studying math and quantum textbooks. One of the best I've come across in recent memory is Equations of Eternity by astronomy trained David Darling. I love books that tie together science and philosophy and keep you awake at night with deep thoughts-and this book delivers on that in spades. Like many popular books on modern science, it ties together quantum physics, relativity, and consciousness.

The first part of the book is titled "Man". In four very interesting chapters, Darling discusses the emergence of the brain and consciousness and how this fits in with the universe at large. I found these first four chapters completely engrossing. I could hardly put the book down and actually read the first part twice. Its full of memorable passages that kept me awake at night thinking about science, such as:

"Whatever a newborn child does, the universe at large does also, because a human baby--like everything else--is an intrinsic part of the cosmos....A factory in which cars are made is a car-making factory. A planet on which there is life is a living planet because the life-forms are a part and a product of the world's substance. And, on the grandest of all scales, if there is sentience within the cosmos then the cosmos itself is sentient. So we may reasonably view an infant's dawning awareness on two levels: as a consciousness arising in the individual and, simultaneously, in the universe as a whole."

In the second part of the book, Darling enters a very interesting discussion of quantum theory and how mathematics relates to reality. This includes a discussion of the foundations of quantum mechanics and the viewpoints of aritstotle/plato, as well as the debate on how real or fundamental mathematics is as a part of the universe.

The book closes with a four chapter section titled "Mind". The last four chapters were not as satisfying as the early part of the book. That being said, the opening and mid-sections of the book were so powerful I can only give this book 5 stars. Highly recommended for anyone interested in quantum theory, the mind, and how the mind relates to the universe as a whole.

Tuesday, August 19, 2008

Large Hadron Collider Lawsuit

From the ridiculous news files. On September 2, there will be a hearing in Hawaii for a civil suit to prevent the Large Hadron Collider from starting operation. I am not a legal expert but I don't understand how you can file a law suit in Hawaii to stop the operation of a scientific enterprise operating in Europe. This sounds pretty far fetched to me.

The people filing the suit are Walter Wagner and Luis Sancho. Apparently these guys are worried about the possibility of the collider producing deadly mini-black holes, that will swallow the earth in a cataclysmic fury. Wagner has put together this website with an exciting video:

Stop the LHC until we know its safe

Wagner says that this device, which may also produce anti-matter and all-consuming stranglets, will be operated "all in the same of science supporting theories with no practical benefit".

If mini-black holes don't cause you to loose some sleep tonight, maybe strangelets will. Unfortunately I haven't been able to find much information about Luis Sancho, apparently he is some kind of Spanish science fiction writer.

Bohmian Quantum Mechanics

From time to time a friend of mine keeps trying to get me interested in "Bohmian" quantum mechanics. In a nutshell, this is a theory that was developed to try and restore some classical physics to the quantum world and explain the random and "spooky" nature of the quantum theory.

It does this with a device known as the "quantum potential". Whats kind of interesting is that it doesn't dispense with quantum mechanics as you know it at all. It incorporates it into a larger, albeit much more complicated picture. So Schrodingers equation is still with us.

Even more interesting, Bohmian quantum mechanics gives the same experimental predictions as "standard" quantum mechanics. As far as I know nobody has been able to propose an experimental test to distinguish between the two.

Bohmian quantum mechanics isn't exactly fringe, and its not cook science, but its not mainstream either. There are a couple of reasons for this. I would take a guess at them as:

1) Standard quantum mechanics is driven down the throats of budding physics PhD's. They probably won't even hear much about Bohmian quantum mechanics, so why bother with it?
2) Its mathematically nasty. For me, classical mechanics is actually messier and more difficult from a calculational standpoint than quantum mechanics is. Ordinary quantum mechanics just involves some simple PDE's and linear algebra, but classical mechanics is actually a bit more hairy. Bohm brings some of that back and adds to it. So the mathematical machinery might make it distasteful for some to bother with.
3) Occam's razor. Given #2, and the fact that standard quantum mechanics agrees with experiment, why pick the more complicated theory?
4) Religious adherence. I do think that there is a religious fervor about quantum mechanics as its currently laid out. It can't be wrong, can it?

Quantum mechanics is so bizarre that I don't think we should be surprised if someday its found there is more to it. Maybe it is Bohmian quantum mechanics. Isn't it easier to believe that there is a quantum potential filling space-time that guides particles and makes them entangled and all that, instead of just believing by fiat that there is spooky action at a distance and things aren't real until you measure them? I tend to take this view, but think that Bohmian quantum mechanics is on the right track but not the right answer. What Bohmian quantum mechanics really does is restore causality, which was Einstein's point of view. But I don't think Einstein was much of a fan of what Bohm came up with.

Here are some books to read if you're interested in diving into the controversy. First lets start with popular level books by Bohm himself:

Wholeness and the Implicate Order

The Undivided Universe

If you have some mathematical background but aren't an expert, this book is a great intermediate between a popular book and a textbook. I highly recommend it. But I can hardly believe they are charging $80 for it! I bought it way back in 1992 for $20. It has an excellent historical review on the Einstein-Bohr debates, gets to the core of the spookiness of quantum mechanics and introduces some concepts from Bohm:

The Meaning of Quantum Theory

Finally, the only known textbook on Bohmian Quantum Mechanics, sure to give you lots of headaches:

The Quantum Theory of Motion

I encourage everyone to take a look at the Bohmian theory. I for one, know I am real when nobody else is looking.

Monday, August 18, 2008

Astronomers Precisely Measure the Hubble Constant

When I first got interested in theoretical physics, it must have been about 1991. Stephen Hawkings first popular book "A Brief History of Time" had recently come out. It became a best seller and helped generate a lot of interest in cosmology and physics. Thinking back to what was in the book, it amazes me how much has been discovered in physics, astronomy, and cosmology since then.

If you've read the book one of the debates that used to go on among cosmologists was whether or not the universe was going to recollapse on itself or die in a runaway expansion. Neither alternative sounded very pleasant. If the universe recollapses on itself it brings to mind all kinds of bizarre scenarios. Just consider that in that case, which Hawking seemed to favor at the time, the universe would have always existed. A big bang happens, the universe expands, then it reaches a maximum size and shrinks down again, starting over with a new big bang. Since its always been here there have been an infinity of universes, and probably an infinity of life forms. Even though life may be unlikely since the universe has recycled an infinite number of times then countless civilizations must have sprung up through the eons. But the forces of nature are huge, so no matter what the recollapse (the so-called "big crunch") of the universe would leave even the most advanced of beings doomed.

That kind of made life seem like a bad, eerie dream for me. Well no matter. A few years later astronomers discovered that the universe was not only expanding, its expanding at faster and faster rates! This is something undreamed of back in 1991 as far as I know. It was a complete shock and it led to the notion of dark energy. Now we may find out that dark energy, something scientists only recently became aware of, may be a dominant force in the physics of the universe.

As Michio Kaku once said on television, his favorite venue, physicists now believe the universe would not die a fiery death (the big crunch again) but would instead die in ICE! (his emphasis). Basically the mysterious dark energy would push all the galaxies far apart, and everything would eventually cool and decay. In the distant future there won't be anything around except swarms of decaying fundamental particles. A sad end to a universe that gave birth to Brent Favre, Paris Hilton, and Oprah. Little wonder we haven't discovered any alien civilizations-they probably self-destruct in a frenzy of narcissism.

Well I digress. What got me thinking about this was an article in the New York Times about cosmology that appeared today. Astronomers have once again measured the Hubble constant, and it appears that the evidence looks better that the universe is about 13.7 billion years old. If you aren't an NY Times subscriber I recommend going through the pain of becoming one, its free and they have lots of great articles about cosmology and physics.

Linear Algebra Error Sheet

The error sheet/correction (Linear Algebra Demystified Errata) is now posted here.

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Can we take Mathematics too seriously?

Eugene Wigner famously commented on the "unreasonable effectiveness of mathematics" to paraphrase. Why he said this is pretty obvious. Looking at how precisely you can calculate things, like the energy levels of a hydrogen atom or using pure mathematics to come up with something like an atomic bomb, the deep connection between mathematics and the physical universe becomes all too apparent.

But sometimes I read articles like Big Brain Theory and think some physicists have gone off the deep end. Its all too tempting to observe that mathematics works, and works very well in explaining the physical world and in making predictions. Then jump to the conclusion that mathematics is reality. Many physicists (theoretical ones anyway) almost have a platonists view of the world.

This reminds me of the parable of the shadows in the cave. Plato came up with this idea to illustrate what we think of as reality is really just a shadow. I think this is how many theoretical physicists view the universe. The icky, wet, solid universe of things we experience is the shadow, and the precise and tidy world of mathematics is the real universe.

But maybe its the other way around. Maybe math, beautiful as it is, is nothing more than a tool. The math and theories of physics is the shadow. To make this idea more concrete, Einstein's theory of general relativity isn't reality, its just a tool that makes predictions about observations. This would be more of a positivist point of view. I think if you hold this point of view then the solid every day universe we experience has more reality than some mathematical theory. After all, death or injury is all too real, isn't it?

Honestly I am not sure what side of the argument I fall on. My point of view on this changes from time to time. This is a very deep question about the nature of physical science and there aren't any easy answers. Maybe this reflects the Yin-Yang nature of the universe, and both points of view are true.

Sunday, August 17, 2008

Astronomy Picture of the Day

Check out this picture of Jupiter's moon Io. Made famous in the movies 2001 and 2010, Io is the most active volcanic body in the solar system.

Saturday, August 16, 2008

Will they find the Higgs?

The standard model of particle physics has one major problem. The particles are all massless. This uncomfortable situation was remedied using a clever trick by Peter Higgs way back in 1964. The mathematical details can be found in Quantum Field Theory Demystified. We won't review that here, we'll just note that Higgs postulated the existence of a field, now aptly named the Higgs field, which fills all of space-time. Particles interact with this ever present vacuum field, and just like anything else, different particles interact with different strengths. The strength of the interaction determines the mass of the particle. If there were no Higgs field all particles would travel at the speed of light.

I saw a talk once, I don't remember who gave it, where the guy likened the Higgs field to water in a swimming pool. Imagine being underwater and moving your arm up and down. So by analogy you can kind of think of the resistance of the water to the interaction of a particle with the Higgs field. Like all fields, the Higgs field has a particle associated with it. Its called the Higgs boson, and would be the only known fundamental particle with zero spin.

One of the first items of business for the Large Hadron Collider (LHC) is going to be finding the Higgs. But what if they don't find it? Surprisingly there are some other ideas that explore the acquisition of mass by particles in the standard model. So either way, whatever comes of the search for the Higgs at the LHC is going to lead to some interesting physics down the road.

Here is a link to a paper exploring one of these ideas, for the more mathematically inclined.

Soluble Theory of a noncompact Group

Friday, August 15, 2008

Quantum Entanglement

In 1935 Einstein wrote what might be considered his parting shot against quantum theory, his paper with Podolsky and Rosen describing entanglement. Einstein thought it highlighted the fact that quantum theory was incomplete or wrong, calling it "spooky action at a distance". Now more than 70 years later physicists are sure entanglement is a real phenomenon, its routinely produced in the laboratory and even being used in some futuristic practical applications like quantum computing.

But its not the practical applications that really interest me. What intrigues me is the notion that two physical entities in the universe can be connected across vast distances of space. I don't care what the quantum computer geeks say, so what if you can't transmit digital information instantaneously with entanglement? What really matters here in my opinion is the connection. The fact particles are connected in this way shows that the universe is a bit more mysterious-maybe way more mysterious-than we ever imagined.

In a recent article about this topic, which mentions (but did not describe in much detail) an experiment where scientists in Switzerland were looking to see if some signal traveled faster than the speed of light, a physicist named Nicolas Gisin remarks that nature seems able to "manifest events in multiple locations". Gisin goes on to assure us no signal can travel faster than the speed of light. Some have imagined that perhaps a faster-than-light signal connects two entangled particles.

I know there is a lot of evidence in support of special relativity-no reputable scientist disputes it and I'm not going to either. But let's not make it a religion. I think physicists are all too eager to dismiss the notion of a signal of some kind traveling faster than the speed of light. We don't want to be new age quacks but at the same time we need to keep an open mind. All too often in the history of science physicists just "knew" such and such was a fact and it turned out not to be. Maybe there are signals that can travel faster than the speed of light.

In any case, something is connecting the two entangled particles. Maybe they have some kind of link through higher dimensions.

Click here to read the article

Thursday, August 14, 2008

Quantum Physics Reverses Collapse of Wave Function

When you encounter quantum mechanics for the first time, one of the hardest things to wrap your mind around is the collapse of the wave function. To make the strangeness of this idea lets say that the state of the wave function describing its position is a superposition of several basis states. For the sake of argument say that each basis state describes the position of the particle at different locations. So we could imagine that prior to measurement if the wavefunction was a superposition of a large number of states you could say that in some sense the particle was distributed throughout the room. Then you make a measurement to find out where the particle is, and detect it somewhere, lets say by the professors desk. The act of measurement causes the wave function to "collapse" to that particular basis state. Then it begins evolving again if you leave it alone for a bit.

The collapse is easy enough to describe if you're talking mathematics. But conceptually it sounds pretty wacky, if not impossible. If a neutron passes through the room you are sitting in right now, surely it isn't in 1,000 places at once in the room? Then you look at it and BAM it just collapses down to one specific location? You can kind of understand this, I suppose, by thinking about the wave nature of a quantum system, so a wave can be widely distributed throughout space.

Well lately in quantum theory people have been talking about so-called "weak measurements" that allow you to measure the state of a quantum system without disturbing it too much. In this interesting article, they describe an idea proposed by Andrew Jordan at the University of Rochester, where using weak measurements, one can unmeasure a particle and return it to its original state. In other words the collapse of the wave function can be reversed.

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Large Hadron Collider to Begin Operation

The Large Hadron Collider, the long awaited upgrade to the particle accelerator operated by CERN will begin operation on September 10th. Built out of a 17 mile long ring, the hopes of particle physicists throughout the world hinge on its successful operation. For the first time in years scientists will get a chance to see some new data in particle physics, a field which has pretty much languished in the murky world of theory since the discovery of the top quark way back in 1995.

The next few years should prove to be exciting. In addition to "wrapping up" the standard model by finding the higgs boson, a hypothetical particle believed to give particles their mass, the accelerator may be able to test many radical ideas like the existence of "extra" dimensions. Or who knows, maybe it won't find the higgs. Now that would be an exciting result. Scientists would have to go back to the drawing board to explain where mass comes from.

No matter what happens, one thing is for sure. The long-awaited LHC is going to usher in an exciting new era in physical science.

Read more here

Quantum Mechanics Demystified Erratta Sheets

Corrections to know errors in Quantum Mechanics Demystified will be posted here.

Chapter 2:

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Chapter 5:

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Chapters 7,8, & 9:

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