Monday, February 27, 2017

When a Physicist Needs to Consult an Economist

As a physicist, I never expected to turn to the results of economics to advance my research. And I never have. But the death this past week of Kenneth Arrrow, a Nobel-Prize winning economist, reminded me of one occasion on which I had to invoke Arrow's work in my role as department chair to settle a dispute. Or rather, to show that it could never be settled. Arrow proved some mathematical results concerning elections that are so bizarre and so disturbing that it's difficult to believe them -- and these results are still largely unknown to most people.

Tuesday, February 21, 2017

Is Technology Taking Us Back to a Victorian Lifestyle?

Imagine making a telephone call in the early 20th century:  you'd just tell the operator the name of the person you wanted to reach, and the operator would connect you. This all changed with the development of automatic switching. It was progress of a sort -- no need to go through a human operator. Instead, you had to memorize a host of phone numbers and dial up (or later, punch in) the number you wanted. But now smart phones have taken us full circle. Just like our forebears, you can simply speak the name of the person you want to talk to (or, at worst, pull up a name on your screen), and the phone does the rest. Telephone numbers (and the need to remember them) are going the way of the buggy whip.

Tuesday, February 14, 2017

A Most Peculiar Holiday

Almost all physics departments host a weekly colloquium, at which an outside speaker presents a talk on a current research topic -- it's traditional to take the speaker out to dinner afterwards. When I began my first appointment as a junior faculty member (at Ohio State), this task often fell to the single faculty members -- our schedules were more open, and we were grateful for the free meals and the company.

One Tuesday evening, a group of five of us (all guys) took the speaker out to a local restaurant, only to discover that they didn't have a free table. This was a bit odd for a Tuesday night, but we simply went to our second-choice restaurant, only to discover that it was full as well. Finally, one of us realized that it was Valentine's Day! That's right, none of us, including the speaker, had remembered that Feb. 14 was of any significance. (This story has a happy ending -- we found a Chinese restaurant with available seating).

Friday, February 3, 2017

Confessions of a Cowboy Cosmologist

We recently watched The Magnificent Seven (the original, not the remake). It's a good movie, even if Yul Brynner, with his bald head and vaguely Eastern European accent, sometimes gives the impression that he wandered in by mistake from an adjacent movie set.

Which way to The King and I?
There's an odd similarity between the closing of the western frontier and my own research field of cosmology. In the early 1980s cosmology was the crazy no-holds-barred Wild West of science.  Cosmologists knew that the Big Bang theory was correct: the universe started out incredibly hot and dense and then expanded and cooled to form the space we inhabit today. But there was so much that we didn’t know. What was the universe made of?  Would it expand forever, or collapse back down and crush us all into an atomic soup? Where did all of the galaxies come from? We didn’t even know how fast the universe was expanding: the two groups measuring the expansion rate kept getting answers that differed by a factor of two! But life on the lawless frontier was great fun for theoretical physicists like me. With so little data to go on, we were free to speculate endlessly -- no theory was too outlandish to publish. We roamed the scientific landscape like cowboys, drifting from one new idea to the next. And theories sprouted like tumbleweeds, only to blow away when the next hot idea came along.

But then the experimentalists came to town and started fencing us in. First came the astonishing discoveries by astronomers mapping out the expansion of the universe on the largest scales. These investigators used distant supernovae, so far away that the light from these cosmic explosions took billions of years to reach us. These supernovae allowed the scientists to peer back in time and measure the expansion rate of the universe billions of years ago.  And they made a shocking discovery: the expansion of the universe isn’t slowing down under the force of gravity; instead, it’s speeding up! Next came the precision measurements of the radiation left over from the early stages of the Big Bang. This radiation contains tiny ripples that encode information about the universe:  its age, how much matter it contains, and what kind of matter it’s made of.