Clever Apes #25: Curveballs from space
Often in science, a new insight doesn’t fit in with the old patterns. That means something, of course, is wrong – either the fresh idea, or everything we thought we knew leading up to it. In the latest installment of Clever Apes, we consider two of these curveballs. One has already rewritten the solar system's history. The other seemed, for a while, like it might mean the universe is either left-handed, or shaped like a small doughnut.
For starters, many of us learned in school that the solar system formed by a nice, orderly process. Tiny things gently coalesced into bigger objects, settling into this pleasant little arrangement of planets and moons. But now, scientists think it was probably a bloodbath, with would-be planets snuffed out in cataclysmic collisions. In some parts of the solar system, as much as 99.9 percent of the material that was once there has been completely ejected from the solar system.
Mark Hammergren, Adler Planetarium astronomer and Friend to the Apes, is trying to recover that lost history. He’s searching for traces of planetesimals, a nearly extinct race of giant asteroids that were the seeds of our planets. Their story shows just how rough of a neighborhood the early solar system was. Jupiter, for example, probably lurched around like a bull in a china shop, its gravity knocking asteroids and planetoids into each other and, in many cases, out of orbit completely.
The fate of those ejected bodies leads to one of the most evocative consequences of this model of solar system formation: interstellar space could be thick with “rogue planets,” whipping through the blackness. Some, says Hammergren, could even still be heated by their molten cores, leading to the speculative, but awesome, possibility that some could harbor life.
Second, the story of a curveball that threatened to topple some very basic ideas about space and time. Scientists, including the Adler’s Chris Lintott, started several “citizen science” initiatives, which enlist the help of tens of thousands of people at their home computers to help sort through data. In this case, they’re categorizing pictures of galaxies from the Hubble Telescope and the Sloan Digital Sky Survey. People log on, look at a galaxy and enter its shape, orientation and, if it’s a spiral, which direction the arms are moving. Before long, Lintott noticed that they were getting significantly more counterclockwise galaxies than clockwise galaxies. This was a little scary.
There’s no reason there should be a bias toward one or the other, because it all depends, of course, on which way you look at the galaxy. If there is more of one kind than the other, that would have some very spooky implications (for example, the universe might be quite small and doughnut-shaped). It would require scientists to throw out well-established axioms about the universe.
So Lintott and his team worked to get to the bottom of this crazy observation. I won’t give away the punch line, but let’s just say the answer caused Lintott to invoke this quote from Shakespeare’s Julius Caesar. Click the “listen” button above for the whole story.
Lintott, by the way, is a fascinating fellow in his own right. Besides his gig at the Adler, he does research at Oxford, hosts a long-running series on the BBC called The Sky at Night, and even wrote a book on cosmology with the guitarist from Queen.