on 11 January 2004
Science writer Charles Seife, author of the award-wining Zero: The Biography of a Dangerous Idea (2000), begins with two chapters on pre-modern cosmology followed by a chapter on Hubble's discovery of the expansion of the universe using the new 100-inch telescope placed atop Mount Wilson in 1917. Seife sees Hubble's discovery as "The Second Cosmological Revolution." In Chapter Four we learn, thanks in part to the Hubble Space Telescope, that the Hubble constant is not so constant after all and is indeed larger today than it was in the past. Conclusion: the universe is not only expanding, but is accelerating in its expansion. Seife calls this "The Third Cosmological Revolution." The chapter is subtitled, "The Universe Amok."
Maybe the universe is indeed running amok, or maybe it's the astrophysicists and cosmologists themselves who are possessed. Too much data too soon may have untoward consequences, especially when one is feeling about in the dark with limited instruments focused on an immensity perhaps beyond human comprehension.
First there is the problem of the so-called dark matter. With the curvature of the universe at one, meaning that it will expand forever and eventually after many an eon die a cold and lonely death, there will be no big crunch, no bounce, and no time reversal. This is okay. However, when cosmologists go looking for the correct amount of matter and energy to support this flat curvature they come up a little short. About ninety percent short, in fact. In other words nearly all that there is, is not only invisible to our perception, it is completely mysterious except that it does indeed influence gravitationally the rest of the stuff in the universe. As Seife explains, the stars in a galaxy as they rotate around the galactic center are not moving in concert with Newtonian (or Einsteinian) motion; instead the stars furthest from the center are moving at about the same speed as those near the center, an impossibility.
What to do about this? Cosmologists have postulated some "dark matter" surrounding galaxies like a halo. With just the right amount of dark matter (again approximately a whopping nine times that observed) the speed of the stars is nicely accounted for. There is another solution: reject Newtonian/Einsteinian dynamics. That (as radical an idea as one would like to entertain) has been tried and, as Seife notes, it has failed. (See p. 100) Furthermore, as Seife observes in "Darker Still" (Chapter 7), this invisible stuff cannot be all ordinary (baryonic) matter. It has to be of some "exotic" variety that we can't identify.
Okay, let's put the dark matter conundrum on hold and look at the next problem: something from nothing. It appears that, due to the uncertainty principle from quantum mechanics, there is no such thing as nothing. That is, matter is probabilistically jumping in and out of existence down near the Planck level in the "foam" regardless of how complete the vacuum. Indeed, some theorists have imagined whole universes popping randomly out of...what? It would appear that underneath, beneath, inside of--what?--there is, like an unfelt cauldron beneath our feet or inside the very fabric of space/time, something unimaginably immense and/or unimaginably tiny.
This "zero point energy" is now being postulated as the source of Einstein's cosmological constant (lambda) that is expanding the universe. Lambda was once thought to be an error; now "omega sub lambda" is thought to equal 65% of the matter/energy in the universe. Hello!
Seife's book suffers from that familiar plague on the house of popular science writers: trying to explain mathematical ideas without using mathematics, and trying to explain particle physics and quantum mechanics to people who haven't been trained in those sciences. One must rely on analogy and metaphor. Naturally using such devices things can make things even fuzzier than they already are. Also there is some inexactness in Seife's expression employed for what he calls "the sake of clarity."
Sometimes Seife's metaphors reduce to something close to meaningless, as in his ice cream-flavor-slurping hydrogen atoms from page 179. Such metaphors can send chills down the spine of some scientists, and they can mislead. A slightly different example is his statement that "the Heisenberg uncertainty principle forces nature to create and destroy...particles that appear out of nowhere...in the deepest vacuum." (p. 185) Not to disparage the uncertainty principle, but it is "nature" that is doing the forcing and not the other way around. Heisenberg's uncertainty principle is a way of explaining to ourselves what is observed (or not observed, as the case may be).
At other times Seife leaps from the uncertainty of a strained metaphor to runaway dramatics, as on page 183 where we find this: "once scientists figure out what <lambda> really is, they will have unraveled the deepest mystery in physics today...[they will] understand...[what] drove the big bang itself...They will see beyond even the era of the quark-gluon plasma...to a time when the quantum vacuum held the fate of the universe in its grasp."
As for Seife's several attempts at witticism, I will give him a Cheshire cat's smile and applause to extend for the entire half-life of a virtual particle in the foam of space.
Okay, okay. Writing science that is both fair to the science and explicable to nonscientists is no easy task. I don't think Seife is as successful here as he was in "Zero," especially because the writing gets a little beclouded in the latter parts of the book but also because I have the sense that Seife is not as comfortable with physics as he is with mathematics. What is clear is just how removed even well-educated and knowledgeable laypersons are from the cutting edge of physics. Still this is an attractive book that added to my knowledge of cosmology.