Monday, December 30, 2013

Strangeness in the Proportion

One of the most mysterious things about the Universe is its apparent comprehensibility. After a few millenia, or a few hundred millenia of tinkering, we seem to have come up with a cosmogony and a theory of almost everything that explains a whole lot of the Universe and how it works. Twenty-five years ago we might have said everything.

It would not have surprised our ancestors of a few centuries back if other planets, stars and galaxies had turned out to be made of utterly different stuff than us. But they aren't. Or at least the parts we see aren't. Even black holes turned out to be predicted by the theory of a guy who thought in terms of trains and elevators. The stars in those newborn galaxies of ten billion years ago turn out to be made of the same stuff that we are - the same quarks and electrons, the same chemical elements, that exist here and now.

The first clear hint of stranger stuff came just about the time - 70 years ago - when the human race had pinned down a lot of the workings of the ordinary stuff we are made of. Fritz Zwicky had started measuring velocities and material contents in the Virgo galaxy cluster and found that they didn't add up, some additional "dark matter" was needed. Forty years later, we started getting evidence yet stranger stuff - dark energy. At approximately the same time, Evalyn Gates was getting her PhD in theoretical particle physics.

Her book, Einstein's Telescope: The Hunt for Dark Matter and Dark Energy in the Universe is about the those strange newly recognized components of our universe, and more especially about gravitational lensing, probably the most important tool for probing those new components. She starts with a popular introduction to modern cosmology and the topics that underlie our understanding of the subject.

Of course a book on just what we know about dark energy and dark matter would be very short.