Blogs / Bad Astronomy

My friend Amanda Bauer just got her PhD in astronomy! W00t! She’s at UT Austin, and you may know her better as astropixie.

She is very cool and deserving and I’m sure all you BABLoggees who read her blog will go over there and wish her well. We have another young scientist — and one who likes to write about it! — in the fold.

Yay!

Update: the video originally linked in this article was evidently not from the source, so it was taken down. However, there is a link below to a legit video.

Joss Whedon is, simply put, a genius. While I never got into "Buffy" or "Angel", "Firefly" is far and away one of the best TV shows ever made, in science fiction or any other genre. In just a few short episodes he wove an entire universe together with characters I really cared about.

He has a new show coming out in January called "Dollhouse", about people who have volunteered to have their personalities rewritten over and over. It’s disturbing and odd, but it looks cool. And they just released a trailer for it. I found it on YouTube, but who knows if it’ll be taken down or not. I couldn’t find an original source for it, though io9 has it too. The SciFi blog io9 has a copy of it you can watch.

Warning: possibly marginally NSFW stuff, including a creepy and unsettling scene between an older guy (well, my ageish or thereabouts) and a young woman programmed to, um, well, fall in love with him.

I don’t know what to make of all this, but it’s Joss Whedon, so I know it’ll be good.

So a guy calls 911 because of someone knocking at his door, then calls a second time because of a suspected drug deal.

Then he calls a third time to find out the phase of the Moon.

Hmph.

Here’s a tip for all you prospective 9-1-1-dialers out there: go to teh intertoobs, type "google.com" in your address bar, and then "moon phase" into the little windowy thingy they give you. I bet that will not involve you being arrested on misdemeanor charges^*.

Via Fark, of course. And I came up with the title of this post before I saw someone make the same joke in the Fark comments, just so’s you know.

For about a year now, I’ve been getting spam calls to my cell phone. This is more than annoying: I pay for my minutes, so this actually costs me money, directly.

A lot of these calls have a recorded voice telling me that this is the second notice of the warranty on my car expiring. Since I own a ten year old Volvo, I think maybe this call is not accurate.

Anyway, I got one of these calls today (the number of the robospammer is the title of this blog post), and I’ve learned not to pick up. So what a fun coincidence that LifeHacker had an article up about Caller Complaints, where you can look up phone numbers to see if others have complained as well. The site itself takes no action, but it’s rather handy if you got a missed call and you’re wondering whether to call it back.

So, 757-990-8980, got anything to say to me now?

Pulsars are intrinsically cool.

Take a massive star. Let it cook for a few millions years. Then the core collapses, and the outer layers explode outward in a supernova. The inner part, the core, can become a black hole, or the almost-equally-bizarre neutron star, an object maybe 10 kilometers across, but packing the mass of an entire star.

The gravity of a neutron star is billions of times the Earth’s, and the magnetic field is even stronger. Not only that, but that sucker can spin: conservation of angular momentum means that it can spin dozens of times per second. The combination of the rapid spin and magnetic field means it sends out radiation like a lighthouse, two beams of radiation and matter that sweep around in a circle several times per second. When the beams sweep over the Earth, we see a little blip, a pulse, and that’s why these are called pulsars.

If the pulsar is in a close orbit with another, more normal star, its gravity can draw material off the star. This adds energy to the spin of the pulsar, speeding it up. Some, called millisecond pulsars, rotate hundreds of times per second. We’re pretty sure this idea is correct, because almost^* every time we see a millisecond pulsar we see a companion star. Not only that, but the pulsar has to be so close to the companion star that its orbit is almost a perfect circle; the rules of gravity and tides ensure that.

But we’ve run into a problem: a millisecond pulsar has been found that has a wide, elliptical orbit. Worse, the companion star is the wrong kind.

The pulsar is dubbed J1903+0327, and it sits about 21,000 light years away, a fair chunk of distance. It’s orbiting a rather Sun-like star, and the orbit is odd: it’s too big, and too elliptical. All other millisecond pulsars have circular, small orbits.

The pulsar itself is more massive than usual for its type, too, which may be a clue to its origin… though astronomers really don’t know.

So what’s going on? Maybe we’re missing something… like a third star.

One idea is that there is another neutron star involved, one that isn’t pulsating so we don’t see it, and the two neutron stars (one pulsing, one not) orbit each other. That would make more sense to me. How would a system like this be created?

In this case, a few million years ago, it looked like this: we actually had three stars; two massive, and one not so massive. The two massive ones orbit each other close together, with the lighter one farther out. One of the big stars explodes as a supernova, leaving behind a pulsar. It draws material from the other massive star, speeds up its spin, and the orbit becomes a very tight circle. That first one is our millisecond pulsar.

Then, some time later, the second massive star explodes. The neutron star formed is a weak pulsar at best for some reason or another (it happens; not every neutron star is a pulsar). When the star exploded, it lost quite a bit of mass, and so its gravity decreased. When that happens, the orbits of the two stars becomes elliptical, a natural consequence of the mass loss. So now we have two neutron stars, one pulsing rapidly, the other one not, on an elliptical orbit. The third star doesn’t play a big role, except that it’s bright in visible light and it’s easy to see from Earth. The other neutron star is much fainter, and hard to see.

So now, today, when we point our telescopes at the system, we see a normal star apparently orbiting a millisecond pulsar, which doesn’t make sense. But that’s because we don’t see the second neutron star.

Is this the correct scenario? Beats me. It’s a guess, but a good one. Still and all, I love it when a good astronomical theory is tested by some individual weird object. It means there are more factors in play, and that means more fun.

The 54th Carnival of Space is up at Altair VI. I love the name of that blog, though I’m surprised I don’t get 403 errors when I go there.

Hahahaha! Get it? Man, I’m a dork.

Every now and again I see a news release that makes me sit back and say, "Really? Wow!" This latest one falls squarely in that category: European and Australian astronomers are reporting that the Universe is almost twice as bright as we had thought.

Really? Wow.^*

The dust in galaxy NGC 4545 blocks our view right along its mid-plane. From the side, our Milky Way would look just like this. Picture courtesy Bruce Hugo, Leslie Gaul, Adam Block/NOAO/AURA/NSF.

Basically, it has to do with dust. What astronomers call dust is actually a relatively complex molecule, based on carbon and created in red giants, exploding stars, and winds from black holes (as matter falls in dust is generated and gets blown outward before the Final Plunge). The Universe is lousy with the stuff. On a clear summer night in the northern hemisphere it’s easy to see: look toward the constellation Cygnus, and you can see the fuzzy glow of the Milky Way split right down the middle by dark stuff. That’s dust.

Dust absorbs starlight and re-emits it in the infrared. So it’s possible, in theory, to be able to determine the amount of dust in the Universe by mapping the infrared light. And since energy in = energy out, you can determine how much energy stars emit as well.

Turns out, according to this new report, our old models were wrong. We knew that already; there were some problems with them. But this new model — where the math appears to check out correctly — indicates that there is twice as much starlight being generated in the Universe than we previously thought.

Whoa.

If you want numbers, then on average, stars in the nearby Universe produce about 4,600,000,000,000,000 Watts per cubic light year, but we see only 2,600,000,000,000,000 Watts of it. The rest is absorbed by dust. That’s enough energy to run a typical American house for… let’s see… carry the two… a gazillion years. More or less.

Seriously, that’s a vast amount of power. Put it this way: a typical rate for electricity is about $0.10 per kiloWatt-hour. So in an hour (if the new model is correct), a typical cubic light year of your local Universe creates $460 billion worth of power.

Awesome. Of course, finding an outlet in a cubic light year (which is 10³⁹ cubic kilometers) might be an issue.

I’m curious to see if this model holds up, but if it does it’ll mean some retooling of models across the board. I don’t know how much this will affect other fields. In some cases, there won’t be much change. For example, the whole idea of dark energy was found due to unexpected brightnesses of distant supernovae; they were fainter than expected. However, all manners of dusty modeling were used in those calculations, and the results held up. So I don’t expect this to change much when it comes to the new model.

But the light from distant clusters of galaxies is measured and used to determine some properties of them. If the intrinsic amount of light is actually higher than previously thought, then astronomers may have to adjust to the new parameters. This will also affect how we model individual galaxies; the amount of light we see from them depends on their angle to us. If we see a spiral galaxy edge-on (like NGC 4565, one of my faves, shown above) then we’ll have to account for the missing light. Seen face-on the change won’t be as great.

Anyway, this should provide some fun fireworks in galactic astronomy over the next few months. It’ll be very interesting to see how this plays out.