Tag Archives: physics

“The Three-Body Problem” by Cixin Liu

threebodyproblem

<Arrrg, matey, spoilers ahead!  Ye have been warned!>

A young astrophysicist, Ye Wenjie, is working at a secret SETI base in the late 1960’s/early 1970’s.  Her professor father was disgraced, beaten, and killed by Red Guards in the Cultural Revolution, and Wenjie had been working at a nearby logging camp before being pulled into work more suited to her talents.  One day she stumbles upon a method of using the Sun as an amplifier for the radio greeting they are sending out into the cosmos.  She thinks it is a failure.  But several years later, a return message comes.  It’s actually a dire warning – “do not answer!!!”  An advanced, militarized race detected the first transmission and any others will give them a firm fix on Earth.    But, Wenjie is still pretty ticked off about her father and the whole Cultural Revolution in general (who wouldn’t be?) … and replies: “Come here!   Our civilization is no longer capable of solving its own problems.”

And thus a mega force of “Trisolarian” invaders is on the way, ETA around 400 years (they travel pretty fast, but still much slower than radio transmissions).  Also, they have “folded” (?) protons into super-AI Sophons which are already at the Earth, messing up physicists’ particle accelerator experiments.  The Trisolarians were worried that human technology, while currently inferior to their own, was progressing just too exponentially to leave alone for 400 years.

The Trisolarians are named such because they live on a planet revolving around three stars (Alpha Centauri) which experiences an unstable mix of super hot and super cold periods depending on relative distance to each star.  Civilization is routinely (yet randomly!) destroyed in either fire or ice.  After millenia of trying to figure out what was going on with their world, then trying unsuccessfully to solve the three-body problem, they ultimately determine to find some better planet and move.  Wenjie’s description of Earth sounds nice…

Wenjie finds plenty of sympathizers on Earth who agree that humanity needs help, or even that it deserves to be eradicated.  I thought this was going a bit too far – are there really that many eco-terrorist types out there who would root for the aliens over humanity, including their own self and family?  Especially the character of Michael Evans in the book was really hokey.  Billionaire tree-hugger who wants all humans to die and leave the birds and bugs alone.

Some of the group more-or-less worship the unseen Trisolarians (some interesting commentary in the book on how even a solitary confirmation that ET exists, and nothing more, would still fundamentally alter civilization) and put together an odd MMORPG, 3body, to tell about the Trisolarian world and history.  It’s through this game that the protagonist (and we the reader) first learn about what’s going on.  Little bit of reveal at a time.

There is a REALLY funny incident in the game, where a 30 million man medieval Chinese army becomes a von Neumann architecture computer: squads of soldiers with black and white flags become logic gates, scribes become memory, and cavalry becomes the bus.  Pretty ridiculous but funny.

“Einstein: His Life and Universe” by Walter Isaacson

einstein

Great story: Albert Einstein, patent office clerk, upended the scientific world in his “miracle year” of 1905 with four separate revolutionary papers.  The myths about him being a bad student are pretty much untrue; he did end up at the patent office after he had trouble finding an academic job, but that was more due to his contempt for authority and lack of social conformance than any scientific deficiencies.

Einstein was born in the new German Empire, but was disillusioned in his youth with the nationalism that eventually led to WWI.  His concept of political freedom jived more with the Swiss, which is why he went to school in Zurich and worked at the patent office in Bern.   Later, he jumped around a few universities before ending up in Berlin for many years; but left for Princeton in the early 1930’s (although not to Princeton University – he was with the Institute for Advanced Study) as Einstein’s Jewish background and political ideas clashed with the rising Nazis.

As successful as Einstein was professionally, he was mediocre at best or even a failure in the home.  His self-described “happiest point in his life” was when he finalized his general relativity equations … precisely the time as his first marriage had just failed and WWI was in full swing.  They guy was really motivated by his work!!  Before his divorce from Mileva Maric (and later remarriage to his cousin Elsa), they tried separating for a time and even wrote up a spectacular “contract” that included her not speaking to him and serving meals in his room…. sheesh.

Stemming from the 1905 papers, Einstein is considered a founder of both relativity theory (primarily an explanation of gravity) and quantum theory.  He always objected to the key tenant of quantum theory that there is an inherent randomness in the universe, particularly that certain states are unknown and actually indeterminate until they are measured.  He preferred to think of an absolute underlying reality that we just don’t understand enough to characterize.

Einstein’s work past age 40 concerned the quest for a unified field theory, which would unify both gravity and electromagnetism.  Unfortunately, experimental results over the same period pushed physics into the other direction – more fragmentation rather than unity.  Still, Einstein kept at it, but never had much to show.

Favorite Einstein quotes:

To punish me for my contempt for authority, fate made me an authority myself.

I have no special talents; I am only passionately curious.

“Physics for Future Presidents” by Richard A. Muller

With any political issue, there are often as many opinions on the nature of the problem and form of the ideal solution as there are people in the room.  In this book Muller tries to cut through the chaff, writing as a Presidential Science Adviser of sorts, explaining the science behind these problems and solutions.  (Of course, even scientific results can be colored by personal politics, but I’m sure Dr. Muller is totally impartial.  [Right?  Right??])

Pretty interesting read; actually echoed a lot of what I read recently in The World in 2050.  I’ve captured some of the more interesting points in my notes below, following Muller’s main sections for the book.

Terrorism

  •  The collapse of the World Trade Center towers on 9/11 was due to the intense heat of the jet fuel-fed fire, which weakened steel columns until they buckled under the weight of the building.  The impact and explosion was not a big factor.  This brings up an obvious point — gasoline and other fuels have very high energy density, which is why we like them, but that also makes them much more practical for terrorists to use such commonly available materials than exotic stuff like bio or nukes.
  • Continuing that thought — it is very unlikely for any non-state sponsored terrorist group to be sophisticated enough to build a nuclear weapon, large or small.  Even if they could construct a relatively simple “dirty bomb,” the threat is not too high: if they want to affect a lot of people, then the radioactivity will be diluted over a large area and probably be unnoticed.  If they want to affect a small area, then they don’t kill many people … also with any dirty bomb situation, the ones most at risk of a problematic dose of radiation are the terrorists themselves, during construction and deployment of the weapon.  The biggest danger with a dirty bomb is probably the likelihood of the public to panic.
  • Post 9/11 security procedures (TSA, etc.) seem to be working well — we’re basically requiring suicide tactics in order for terrorists to be able to do anything, and those terrorists willing to die for their cause are typically not the sharpest tools in the shed so are easily caught.

Energy

  • Coal is very cheap and there is a lot of it.  It’s even possible to make oil from coal via Fischer-Tropsch (thanks, Nazis!) but not economical until a certain price.  Fears about running out of oil are unfounded — price will increase, driving more exploration and extraction but also will make alternatives like coal more viable.
  • Solar is very promising, but needs much cheaper cells (and probably cheaper battery storage technology) before it gets profitable and starts taking off.   Solar cars are never going to be mainstream, simply due to size … even 100% efficient solar cells on a typical car roof will only generate a few horsepower, whereas most cars today require 50-200 hp.
  • Hybrid cars are a good idea because they cut energy use, but not a money saver – any fuel savings get blown away when the batteries (finite number of charges) need to be replaced, a point many current hybrid owners and enthusiasts have not reached.

Nukes

  • As currently designed, nuclear power plants (fission) cannot produce an atomic explosion, even if all safety mechanisms fail.  We should be building more of them, and keep that fusion research going!
  • Waste storage has been grossly mischaracterized … it is not really necessary to secure waste for tens of thousands of years; it will “only” take maybe 300 years for radiation to fall to natural radiation source levels, which we implicitly deem “ok.”  300 years is still a long time, but makes the storage solution much more manageable.

Space

  •  “The space shuttle is big engineering; it is the dream of man in space; it is an adventure.  But it is not safe, it cannot be made safe, and it is not done for science.”  Unmanned is clearly the cheaper and safer route, if our motivation in space is really scientific research.

Climate

  • IPCC is the only climate group worth listening to, per Muller… very conservative, careful, and scientific approach.  They predict 95% chance that observed global warming is not due to natural variation, and 90% chance at least some of the warming is human-caused.  (Interesting that the 10% ambiguity is due to difficulty in modeling the effect of cloud cover.  Clouds seem to be part of a global warming negative feedback loop: higher temp -> more evaporation -> more clouds -> reflect more incoming sunlight.)
  • Combating climate change if difficult due to the abundance of coal, the a very dirty fossil fuel.  Even if the US drastically cuts fossil fuel use, the world is still going to be in trouble, because China and India will soon surpass us and have no intentions of cutting back.
  • Muller’s solution is to make conservation a bigger priority.  Don’t prohibit or deprive people of energy; just make it more profitable for them to use less, eg by making more energy-efficient products.  Muller calculates that a 2% annual overall energy efficiency increase will lead to a population 10 billion Earth in 2100, all living a current European standard of living but using half as much energy as today.  Sounds good; pour those R&D dollars into making more efficient fridges and stuff!  (Probably another side of this is let energy prices increase … attach more of the true cost to the dollar cost, if there is one.)

Here’s one of my own ideas about dealing with climate change: maybe it is time to accept the fact that it is probably going to be hotter, and start to work on developing drought and heat resistant crops.


Physics for Future Presidents is available from Amazon.

“Coming of Age in the Milky Way” by Timothy Ferris

This book is a great overview of the history of astronomy.  Since advances in astronomy affected many other branches of science as well, particularly physics, one may say that the scope of the book is the history of science as a whole.  This is a very informative book and Mr. Ferris is not afraid to delve into some nitty gritty theories.  Most of the time his explanations are lucid and more easily understandable than in most college textbooks I’ve read.

I did things a little different while reading this book.  I put little strips of paper in at pages where I read something that I wanted to remember and put up here.  So here goes…I’ll list the page number just for the sake of reference.

pg. 30 – one of the first descriptions of the motions of the planets was the Ptolemaic model, consisting of spheres and epicycles.  Although ungainly, it was able to do a decent job of predicting the planetary locations.  Yet is was not the true order of things, as we have seen upon venturing out into the solar system via probes, etc.  This is a good example of the definition and proper frame of thinking about any scientific theory.  It may provide useful results, but is it the truth?  Not always.  We simplify things and try to make them fit observations, and when we are done we may have something that helps predict future results, but we still cannot claim complete understanding of the event.

pg. 116 – “When <Isaac> Newton was asked years later how he had discovered his laws of celestial dynamics, he replied, ‘By thinking of them without ceasing.'”  Wouldn’t it be great if more people thought without ceasing more often?

pg. 120 – Newton admitted that while the law of gravitation predicted planetary motion, he could not explain why it was so.  He maintained a faith that “this most beautiful system of the sun, planets, and comets, could only proceed from the counsel and dominion of an intelligent and powerful Being.”

pg. 192 – Einstein’s theory of relativity predicts that the faster a particle is traveling, the more massive it becomes, and the slower its time relative to non-moving objects.  Weird.  This has all been experimentally confirmed, too.

pg. 262 – Quantum theory predicts what is known as “quantum tunneling,” which enables protons to approach close enough to each other to fuse.  Ferris analogizes this to a cannonball probabilistically penetrating a ten-foot-thick wall sometimes, without passing through it.  Weird yet again.  (pg. 288 – Neils Bohr – “If anybody says he can think about quantum problems without getting giddy, that only shows he has not understood the first thing about them.”)  Quantum theory makes me think of the Ptolemaic system sometimes – it is bizarre, but it does help predict an awful lot of things. But is it truly the way things happen?

pg. 290 – Einstein didn’t like the probabilistic nature of quantum theory, either: “Quantum mechanics is certainly imposing, but an inner voice tells me that it is not yet the real thing.  The theory says a lot, but does not really bring us any closer to the secret of the ‘old one.’  I, at any rate, am convinced that He is not playing at dice….I am quite convinced that someone will eventually come up with a theory whose objects, connected by laws, are not probabilities but considered facts.”

pg. 298 – Leon Lederman, on particle physics: “The standard model … explains so much, but it’s not complete….One of it’s greatest flaws is aesthetic.  It’s too complicated.  It has too many arbitrary parameters.  We don’t really see the creator twiddling seventeen knobs to set seventeen different parameters to create the universe as we know it.  The picture is not beautiful, and that drive for beauty and simplicity and symmetry has been an unfailing guidepost to how to go in physics.”

pg. 373 – on the probability of extraterrestrial life – some combine the probability another Earth-like planet existing, where water is neither frozen or boiling, with the right mixture of elements, and all the biological, social, and cultural variables that must work out so intelligent life can exist and progress to a detectable (ie radio wave generating) state, and come up with some pretty small numbers – something like one in 10^18, which is more than the total of planets in the galaxy.  Ferris points out some faults with this reasoning.  One, we are working with a single example of life…it’s pretty hard to draw general conclusions about anything with just a single example.  Plus, we don’t know everything about Earth or life on it.  So how can we make guesses about the probability of life on other worlds when we don’t fully comprehend ours.  Second, Ferris points out that by the same reasoning, it is extremely unlikely that you would be reading his book – that you exist, were born and educated and went down the path of experiencing everything leading up to reading the book, and he likewise went through all he did before writing it.

Ferris has a neat SciFi-ish idea about how future civilizations in space could communicate via networks of self-replicating probes that go throughout the galaxy and rely information back to each other.  It could take thousands or millions of years to communicate information between two points, but information about distant points were stored and archived more locally, then the time penalty is not nearly so bad.

In the concluding chapter, Ferris writes about how as we have “come of age” as a species and gained some understanding of our place in the universe, we have come to a realization of our ignorance.  The quest for knowledge will be never-ending due to the immense size and variety of the universe.  As we observe and gain more knowledge, our theories will become more and more refined.  Ernst Mach – “Theories are like withered leaves, which drop off after having enabled the organism of science to breathe for a time.”