First, the Venus-Jupiter update (a continuation of Monday’s, Tuesday’s, and Wednesday’s entries), and then I’ll get to today’s entry.

August 28, 2005	August 29, 2005
August 30, 2005	August 31, 2005

Tonight: the main event! I’ll have new images up around 9:00 p.m. Pacific time Thursday night.

When you look up at the night sky, the overwhelming sense is one of permanence. Things don’t change. Sure, you might get a meteor, and if you watch some stars very carefully you’ll see them change brightness. But the stars are always there, and they don’t move.

But we see the stars from a terrible distance, the scale of which numbs the mind. The nearest star to the Sun, Proxima Centauri, is an incredible 40 trillion kilometers (24 trillion miles) away. That’s a long way to walk. Even light takes 4 years to get here from there.

That distance crushes our sense of perspective. The stars appear motionless in the sky, but in fact they are rushing around at amazing speeds. The Sun is orbiting the center of the Galaxy at 200 km/sec (120 miles/sec). That’s faster than any man-made macroscopic object has ever moved. No rocket, no hyper-accelerated bullet, nothing we have ever made of any size has gone that fast, yet the Sun makes it look stately. Of course, distances are vast: in 240 million years, it’ll circle the Galaxy just once.

All the stars up there are moving at those crazy speeds. Mostly it’s just gravity at the root of this; just like it’s the Sun’s gravity that causes the Earth to orbit it at 30 km/sec (18 miles/sec). The Galaxy has a lot of mass, and so its gravity is strong. An orbiting star has to book along pretty quickly to keep from falling into the center.

But amazingly enough, some stars make those speeds look positively motionless. Astronomers were shocked some years back to discover a class of stars moving considerably faster– some at speeds of more than 500 km/sec. They’re called (for obvious reasons) runaway stars. The problem is, how do you accelerate an entire star to such ferocious speeds?

The stars themselves were already in a special class: they were neutron stars, the ultradense cores of previously normal stars which had exploded as supernovae (I have a series of webpages describing supernovae and neutron stars on my main website). That was a major clue to their speed. For one thing, the stars may have started life in a binary system, in a tight orbit around another star. The leading theory was that when one of the stars exploded, creating the neutron star, the binary was disrupted, and the neutron star shot off like a rock from a sling. This idea is a good one, but it can only account for runaway stars up to a certain speed.

The problem is that runaways are being found with substantially higher velocities. A paper has just come out describing one such star– the poetically named B1508+55 (here’s the press release for it in layman’s terms). The astronomers involved were able to directly determine the distance to this star using parallax, and found it to be 7700 light years away! That’s amazing all by itself. For aficionados, that’s a parallax of 0.415 milliarcseconds, the smallest I’ve ever heard of. They used a radio interferometer to do it.

With the distance in hand, the astronomers could find the speed of this errant star: 1100 km/sec (about 700 miles/second). Think about that: that’s fast enough to cross the diameter of the Earth in about 12 seconds! Yikes.

What could possibly accelerate a star that masses as much as the Sun (more even) to such an incredible speed? It may have been part of a binary system; that would give it some speed. But there must have been a second effect. There are a few possibilities, but they mostly boil down to an asymmetric kick given to the star when it exploded. The explosion energies are vast, certainly enough to do the trick. If the explosion were off-center somehow, it will give the star a push. Magnetic fields might focus that push further, and the matter ejected in the explosion would act like a rocket. It would be like puncturing a hole in the side of a tank of compressed air. Blam! The material rushing away gives the star a huge kick. Getting it up to 1100 km/sec is still puzzling; the models don’t seem to provide that much momentum. But it’s close. It’s probably a combination of several factors. We’ll know better as more of these objects are found, and their characteristics compared.

Imagine! This object is only 10 kilometers or so across, yet masses as much or more than the Sun. It’s already weird; a cubic centimeter of the star weighs billions of tons, far more than the weight of every person on Earth combined. You’d think something that massive would stay put, but it’s the fastest single solid object known!

And the best part, the absolute bestest thing about all this? We humans figured this out. I love that. We’re clever, us apes. That object is so far away it’s invisible to the eye, even using huge telescopes. But we didn’t let that stop us. It’s moving across the sky at a rate equal to watching a guy walking across the street… from 1300 kilometers away. Yet we measured it. The forces involved are so titanic that they make the nuclear arsenal of our entire planet look pathetic, but we figured ‘em out.

There’s hope for us yet. There are smart people out there, and they like to solve puzzles. Curious apes we are, in a Universe full of wonders.

Before I get to today’s rant about astrology, let me first show you something about planets that’s real. This is a continuation of Monday’s and Tuesday’s entries, about Thursday’s conjunction of Venus and Jupiter. I’m taking a picture of the two planets every night to show them getting closer together. Every blog entry over the next few days will have all the images displayed so you can compare them. Here are the images with Tuesday night’s shot added:

August 28, 2005	August 29, 2005
August 30, 2005

It’s hard to get them framed the same way every night, but I’m trying to keep Jupiter (the fainter one to the upper left) more-or-less over that one medium-tall tree. As you can see, every night they get closer!

OK, now that you’ve had some actual astronomy, let’s move on to the antiscience, shall we?

Astrology is funny. Here is something which does not work, will not work, cannot be shown to work, can be shown not to work, and has no reason to work.

Yet, people believe in it.

I needn’t go into details here, since I’ve already written a page debunking it with all the detail you need. The bottom lines are that 1) there is no force that can work as astrology claims, 2) the claims of a force used by astrologers are internally inconsistent, and 3) totally ignoring any existing or non-existing force, tests have still shown that astrology doesn’t work.

Still, astrologers aren’t exactly starving. Sometimes it seems like there are 5 astrologers for every man, woman and child on Earth. They’re like bacteria, or those slugs in the garden that keep eating my roses.

Here’s an interesting question for anyone reading this who thinks astrology works (not likely, but I’m posing a thought question). Astrologers claim they can predict your future, or your personality type, or whatever, based on the position of the planets. They claim they can do this with great accuracy; 80-90% is not an uncommon number used by them. Every planet is important, from Mercury to Pluto. So the question is this: how come astrologers have never, not once, accurately predicted a previously unknown planet?

Astronomers (the scientists, the ones who have a reality-based existence) have recently discovered a largish object out past Pluto, and it’s definitely bigger than Pluto. Why didn’t astrologers predict it? Why didn’t they say, "You know, my predictions are always off by a bit. I bet there must be another planet out there, at such-and-such a distance and in this-and-that constellation." It seems like they’d notice after all these years that their predictions are off.

But they don’t. Like a tick or some parasite sitting on a blade of grass, they simply wait for real scientists to discover a new planet, and latch onto it like they knew it all along.

I made this point as clearly as I could to a New York Times reporter last week, for a report she was doing on how the new “planet” affects astrologers (free registration required to read it). Unfortunately, despite my giving her about a dozen juicy sound bites, she only used one, and it was a little lame.

Still, my point is relevant. She even says:

If [the newly discovered object] is a 10th planet, astrologers say it may have a profound influence over people’s lives, and thus on the forecasts astrologers make.

Let me put this very simply: if its effect may be profound, why didn’t they notice it before?

It gets funnier.

But its potency cannot be discerned until perhaps several years after the astronomical debate is settled, when astronomers have had time to chart its orbit. So astrologers are not inclined to do anything hasty. There will be no tearing up of charts, no hurriedly penciling in a new planet and certainly no crossing out of Pluto, a body that many astrologers hold near and dear.

On the contrary, astrologers seem to have reached an unspoken consensus to take a wait-and-see approach. Wait and see if there is a 10th planet.

What difference does it make if astronomers call it a planet or not? It is what it is, and it doesn’t care what we call it. It sounds like they’re saying that if a group of pointy-chinned astronomers meet in a room somewhere, and decide to indeed call this thing a planet, suddenly astrologers will have to include it in their charts. But if only black smoke appears, astrologers can rest easy knowing their horoscopes have been good all along.

Well, you can’t reasons someone out of a position they didn’t reason themselves into. Case in point:

Leigh Oswald, an astrologer in London, said unknown forces may determine when scientists discover new planets. “A planet is discovered when it’s appropriate for humanity to understand it,” she said. “In other words, when we are ready for it.”

Oh, barf. Unknown forces. Puh-leeze. It takes quite known forces: it takes time, it takes patience, it takes a good telescope and detector, and it takes science. Astrologers can sit in their parlors and gaze into whatever passes for their crystal balls, and the Universe will end before they ever make a single discovery. Except, of course, that there’s a sucker born every minute… and if that birth minute is known, there’ll be plenty of astrologers willing to cast a horoscope based on it.

As promised in yesterday’s BA blog entry, here is another shot of Venus and Jupiter tonight.

Unfortunately, the pictures are slightly different exposures (click on the images to get bigger versions). I cropped the images to get them framed roughly the same. I also took some care to get Jupiter in roughly the same spot as it was last night, and you can see that Venus has moved up and to the left in the past 24 hours! They’re preparing for the main event Thursday night. Stay tuned!

If you look west, shortly after sunset, Venus is hard to miss. It’s a bit south (to the left, if you’re in the northern hemisphere) of the spot on the horizon where the Sun sets, and up about 10 or so degrees, roughly the width of your fist held at arm’s length.

If you wait a few more minutes, and look a bit up and to the left of Venus, you’ll see Jupiter. Normally Jupiter is very bright, and obvious. But it’s on the opposite side of the Sun from us now, over 900 million kilometers (575 million miles) away. Worse, it’s near the horizon, so the twilight dilutes it, and if you have any pollution or haze, it’s dimmed even more. Being so close to Venus in the sky doesn’t help either!

And it’ll get closer. Over the next few days, Venus and the big guy will draw ever closer, and on Thursday night they’ll be about 1 degree apart– the width of a finger held at arm’s length! That’s pretty close.

In reality, they’re about 750 million kilometers apart (about 470 million miles). Venus is brighter because it’s a lot closer to us. But our lack of perspective makes them look right next to each other in the sky. They don’t get this close very often, so this is a real treat. Since they are also the third and fourth brightest objects in the sky (after the Sun and Moon, of course) this apparition, as it’s called, is even more spectacular. You can read more about this at the Sky and Telescope magazine website.

Every day, if I can, I’ll take a picture and post it here so you can see them getting closer. The picture above was taken in my back yard on Sunday night, August 28, an hour or so after sunset. Click it for a higher-res version. At that moment, the planets were about 6 degrees apart.

Now stop looking at my picture and go take a look for yourself!

I am getting approximately one gazillion emails a day now about this “Mars as big as the Moon” meme going around the web. I’ve been meaning to write a page about it, but have always found some excuse to blow it off. Anyway, I finally put it up. Here it is.

Bottom line: tell your friends it’s ain’t true. Mars will be it’s normal self all year, with no gigantic apparitions of it looming over your head.

I rather like Arizona Senator John McCain. He seems level-headed, thoughtful, and unwilling to toe the party line if he disagrees with it.

Or I should say, I liked him, until this came out.

McCain told the Star that, like Bush, he believes “all points of view” should be available to students studying the origins of mankind.

To be fair, this is a small quotation, and I don’t have the whole story yet. Still, we’ve seen this before. As usual, I assume he doesn’t mean the Greek Pantheon, Babylonian creation myths, Native American dream legends, the Flying Spaghetti Monster, or the Great Green Arkleseizure, for that matter.

Given McCain’s history, he may simply be trying not to offend a proportion of his constituency. Still, it would be interesting to try to push for these other myths to be taught alongside ID. Can you imagine how the ID proponents would react if, say, someone advocated that out-and-out atheism should be taught alongside ID? I wonder how they’d react to that… they did say “all points of view”, didn’t they?

Did I mention in an earlier entry that science is beauty?

I didn’t know the half of it. Princeton University has started an annual Art of Science competition. Take a few minutes to look through the entries for this year. Astonishing, amazing, and beautiful.