Tuesday, September 20, 2016

Talk at the University of Illinois

I'm giving a talk at the University of Illinois, Urbana-Champaign, this coming Friday at noon on the topic of Science and Science Fiction, followed, at 3:00, by a scintillating colloquium in the Astronomy Department on parametrizing dark energy.

Sunday, September 18, 2016

Announcing the Society of Catholic Scientists

I am happy to announce the formation of the Society of Catholic Scientists. You can tell it's official because we have a website:
The website is still skeletal at this point -- we'll be making additions over the coming month. But you can check out the Board of Directors -- there are some high-powered scientists involved. (I am not one of them. Nor am I a low-powered scientist. I am medium-powered).

Our first major event will be a conference in Chicago in April. The conference dates are on the website, but more details will be posted as they become available.

Friday, September 16, 2016

Enrico Fermi Reimagined as a Marshmallow Bunny

Speaking of Enrico Fermi (as I did in my previous post) brings to mind a competition that the University of Chicago sponsored seven years ago. The competition, open only to U. of Chicago alumni, was to recreate a scene from the campus using Peeps, those marshmallow bunnies and chicks that appear mysteriously every year around Easter and then just as mysteriously disappear. (No one actually eats them, do they?)

I leaped to the challenge, but immediately faced two obstacles. The first was that as a  Ph.D. alumnus of the university, I had spent all of my time at Chicago chained to my desk, with my advisor sliding food under my office door at irregular intervals. So I had no memory of any famous campus scenes to recreate. But one scene did come to mind -- this iconic photo of Enrico Fermi:

There's actually a mistake in this photo -- can you find it?  Answer at the end of the post.
Every physics department has its heroic figures -- creatures of myth and legend who bestrode the department when giants walked the Earth -- and Fermi plays this role at Chicago. But having chosen my Chicago scene, I faced a second obstacle: a complete lack of artistic talent. As I am an oldest child, my mother saved all of my kindergarten artwork, and it clearly shows my development as an artist -- in the course of the year I progressed from drawing stick figures in black crayon to drawing stick figures with many colors. And I haven't gotten any further since then. So I enlisted the assistance of my (then) 11-year-old daughter, Lucy, And here is what we (and by "we", I mean "she") produced:

Enrico Fermi, the marshmallow bunny.  The error in the original photo is repeated here -- how's that for verisimilitude?
So did we win the competition?

Thursday, September 15, 2016

Fermi Meets Sagan

My (very) short story, "Fermi Meets Sagan," will be out in the December issue of Analog.  It was inspired by this nonfiction article I wrote for The Conversation website.

Monday, September 12, 2016

The Affinities, by Robert Charles Wilson

I just finished reading The Affinities, by Robert Charles Wilson. Before I discuss my impressions, the usual disclaimer applies: De gustibus non est disputandum. I have only one criterion when I evaluate a work of science fiction -- did I enjoy reading it? So if your own tastes are similar to my own, you might find my comments interesting. Otherwise feel free to ignore everything I say.

My own interests run strongly toward "hard" science fiction, and I am a particular fan of "idea" stories -- these are stories where an amazing speculative idea is central, rather than character, or writing style. I also like clever endings. All of this is much easier to pull off in short fiction than in a novel. These kinds of stories are characteristic (in the golden age) of Clarke and Asimov, and more recently authors like Vernor Vinge and Greg Egan. Stephen Baxter is also someone whose novels I ought to enjoy, but I've never been able to make it through them. Why not?  I haven't got the faintest idea. I warned you that my opinions are totally subjective -- sometimes I cannot even explain them myself. I do like Baxter's short fiction, though.

As I've aged, I've developed a greater appreciation for realistic characters and a more florid writing style. Perhaps this is incipient senility. It's the latter (wonderfully-drawn characters, not senility) that is Robert Charles Wilson's particular strength. When he's able to combine this with a Big Idea (as he did in Darwinia and Spin) the result is some of  the best science fiction I've ever read.

Thursday, September 8, 2016

The Technology is Dead, but the Words Linger On

In my earlier post I talked about listening to a "book on tape."  It wasn't really on tape, of course -- I was listening to the book on CD. I haven't listened to a book on a cassette tape in over a decade. But the expression "books on tape" lingers on, despite the extinction of the actual technology.

There are lots of other words and expressions that have far outlived the original technologies that they refer to. Have you recently "cc'ed" anyone on an email message? That expression refers to "carbon copy" -- a method for making duplicates of typed manuscripts. The typist would insert a layer of carbon paper (coated in dry ink) between two sheets of paper and -- mirabile dictu -- the typewriter would produce identical text on both sheets of paper!

Carbon paper -- it's a messy as it looks

Carbon paper was already on the way out even when I was young -- superseded by photocopiers. Another holdover from the typewriter era is the "carriage return."  This originally referred to slapping a lever whenever the typewriter got to the end of the line, flinging the carriage (the cylinder holding the paper) back to the beginning of the line, while at the same time rotating the cylinder to pull up a new blank line on the paper (clever, huh?)  Typewriters have vanished, but the carriage return (or <cr>) lives on in their digital descendents.  [At this point I should mention that I was required to take a typing class in high school for one semester. At the time, I considered it to be totally worthless, but when computer keyboards became ubiquitous 20 years later, I realized it was the most useful class I had ever taken. I commend my high school for its foresight].

Tuesday, September 6, 2016

What was the Universe Doing at Your Age?

Pretty much nothing, but that's an interesting story in itself.

Let's assume that you're between the ages of 10 and 100 years old (luckily, many things in cosmology depend only on orders of magnitude). When the universe was the same age as you, it consisted of a soup of protons, electrons, helium nuclei, and radiation. But the soup was very hot -- the temperature was a few hundred thousand degrees Celsius. At that temperature, the radiation was actually more dense than the matter!

But in terms of exciting events, nothing much was going on. The two major events that we understand pretty well in the early universe are the formation of some of the light elements when the universe was a few minutes old, and the release of the cosmic microwave background radiation when the universe was a few hundred thousand years old.  In all of the time in between, the universe just expanded and cooled. Or at least we think it did.

Tuesday, August 30, 2016

Origins of an Old Physics Joke

Here's a joke that often makes the rounds of physics departments:

The 3 stages of a newly-published result are

1.  It's wrong.

2.  OK, it's not wrong, but it's trivial.

3.  OK, it's correct, and it's important, but I did it first.

(I think every theoretical physicist has experienced all three of these, although at different times and on different research projects). It turns out that the origins of this joke are more hoary than I could possibly have imagined -- it dates back to a 19th-century scientist!

Wednesday, August 24, 2016

Get Ready for the Great American Eclipse

In just under a year (Aug. 21, 2017) a total solar eclipse will darken the skies across a wide swath of the U.S. Solar eclipses are exceptionally rare events -- the last one in the U.S. that I can remember occurred in 1970 along the East Coast.  Growing up in St. Louis, I had to watch it on TV, but we were promised a Midwestern eclipse in 2017, and I have been waiting patiently ever since then.

There are dozens of websites devoted to this eclipse, but there's a particularly good one at space.com. The path of totality passes near or through several major cities, including my ancestral home (St. Louis) and my current residence (Nashville). If you can travel to view the eclipse, do it! And be sure to buy some eclipse glasses for safe viewing. The danger in viewing an eclipse is not so much from looking at it during totality, but when the eclipse is still partial -- the problem is that people start looking at the eclipse before it is really total, or keep looking at it after the totality ends. Just don't! You don't want to permanently damage your eyes. Eclipse glasses are cheap and easy to find -- we've already gotten 20 pairs. I imagine they'll be harder to find and the price will go up significantly as it gets closer to the actual date. We'll be selling ours for $100 a piece on Aug. 20.

Tuesday, August 16, 2016

Life on Earth Began on.... Venus???

In the Golden Age of science fiction, Venus was the jungle world -- full of hot, steamy swamps populated by hot, steamy aliens. Ray Bradbury ("All Summer in a Day") imagined a world of constant rain. C.S. Lewis even set a version of the Garden of Eden on Venus in his novel Perelandra.

But the real-life Venus is no Eden -- it's blanketed by clouds of sulfuric acid (ouch!) with temperatures well above 800 degrees F. The surface of Venus is both dark and hot -- not too different from classical conceptions of hell. And did I forget to mention the atmospheric pressure? It's almost 100 times higher than the Earth's.

A typical Venusian, as portrayed on The Twilight Zone
But it's easy to see why science fiction writers were free to speculate about jungles and swamps all those years -- the surface of Venus is hidden by constant cloud cover (that sulfuric acid again!) making it impossible to probe until the advent of the space program. But now scientists at NASA have come up with a startling new idea: they suggest that Venus was at one time a balmy, hospitable place after all, and possibly suitable for life.

Tuesday, August 9, 2016

New Particle at the Large Hadron Collider: It's Dead, Jim

For the past few months, the world of particle physics has been holding its breath.  The experimental groups at the Large Hadron Collider had reported possible evidence of a completely unexpected new particle with about 750 times the mass of the proton, and everyone was waiting for new data to either confirm or rule out this discovery. In the meantime, theorists churned out hundreds of papers explaining this particle. (I make no claim to moral superiority here -- I didn't write anything on this subject only because it's outside of my specialty). Well, the new data has come in, and the verdict is.... no such particle.

The Large Hadron Collider. Nothing to see here. Please move along.
Which leads to an interesting question: when was the last time that a completely unexpected new particle was discovered at an accelerator? The answer is shocking.

Friday, July 29, 2016

Of Water Worlds and Desert Planets

Everyone learns in primary school that the surface of the Earth is about 70% ocean and 30% dry land. But is there any reason to believe that this is the norm across the Galaxy? In this paper, Fergus Simpson argues that most habitable planets should actually be "water worlds," i.e., planets covered entirely with water.

Friday, July 22, 2016

Dark Matter - Where is it ???

Last month I discussed the experiments using vast tubs of liquid xenon to search for dark matter. It turns out to have been a prescient post, because yesterday the scientists from LUX (a liquid xenon experiment buried deep under the Black Hills in South Dakota) posted their latest results. And they saw.... absolutely nothing.  LUX is the most sensitive experiment of its kind, and these scientists were able to push down upper limits on how strongly the dark matter interacts with ordinary matter by a factor of 4.

So why haven't we detected dark matter yet? It might still be hiding just below the current sensitivity of our experiments. But it's also possible that we're barking up the wrong tree.

Wednesday, July 20, 2016

Popular Culture Down the Memory Hole

Popular culture is by its very nature ephemeral. Today's famous actor or musical hit is tomorrow's trivia question. But some types of pop culture are more ephemeral than others, and there's one area that's vanished so thoroughly that it's left almost no trace at all.

See if you can fill in the blanks:

I'd rather fight than _____
I'd walk a mile for a _____
A silly millimeter _____
You've come a long way, _____

My guess is that everyone over the age of 50 will recognize the answers instantly, and nobody under the age of 40 will have the slightest clue what I'm talking about. So what are the answers?

Thursday, July 14, 2016

Mars, and its Rival

For those of you in the Northern Hemisphere, there's a spectacular sight near the southern horizon in the early evening. ("Spectacular" here is a relative term when applied to the night sky -- I'm not talking Disney-fireworks-over-Cinderella's-Castle spectacular). If you look to the south, you'll see a very bright, reddish-looking object -- that's Mars. And if you look to the left of Mars, you'll see two other bright objects. The lower one also has a reddish hue. It's Antares, a red supergiant and the brightest star in the constellation Scorpio, the scorpion. (Yes, I know that none of the constellations looks anything at all like its assigned name. Aside from the Big Dipper). Antares actually means "rival of Mars," because of its red coloration, so this is a rare chance to compare Mars and its rival right next to each other. I'm afraid I'll have to go with Mars -- Antares is pretty weak competition.