Solar System Solved?
Those who deal in models of the origin of the solar system sometimes have to entertain themselves to overcome grief. See if you can detect this attitude in the following Stupid Evolution Quote of the Week from Space.com:
“This has been a stumbling block for 30 years,” said Mordecai-Marc Mac Low, an astrophysicist at the American Museum of Natural History in New York City, of planet formation theories. “The reason is that boulders tend to fall into the star in a celestial blink of an eye. Some mechanism had to be found to prevent them from being dragged into a star.”
The solution: Together, many boulders can join to fight a cosmic headwind that otherwise would doom them.
Surely writer Dave Mosher did not mean to imply literally that boulders were conspiring to defend themselves from doom. But the problem is evident: without some sort of ad hoc speculation to insert into the models, astronomers know that small pieces of dust and rock don’t naturally form planets. They fall into the star in a very short time. Alan Boss, another modeler, agreed with this characterization: “Overall, the calculations present an encouraging approach to understanding how something happened that we know must have happened, at least for the terrestrial planets.” (The article continued by saying that the gas giants need another mechanism to form.)
For small dust grains and rocks in orbit, the game is over in just a few hundred times around the merry-go-round with the vacuum cleaner in the center making a large sucking sound. Mac Low said his explanation was like a group of semi trucks on a highway creating “a friendly pocket of air behind it that other semis can travel in without using up as much fuel.” Still, he has to have the small rocks combine into planetesimals large enough to attract more material by gravity. The new model is far from a complete theory. At this point, it is a little more than a chuckle during the usual grief session.
This is a real-life demonstration of the Harris cartoon that shows a scientist doing a derivation with complex equations on the blackboard, with one intriguing step inserted, “Then a miracle occurs.” Titling this story “Planet Formation Mystery Solved” yields an even bigger chuckle.