Ask an astronomer

This afternoon I was the astronomer in an 'ask an astronomer' session at the observatory. This basically involved me talking about radio telescopes, the universe and everything for about an hour. I also answered lots of questions in that time.

As always, one of the best questions came from a tiny little kid. He wanted to know how gas giant planets were formed. I tried my best to explain about the best theories of the creation of the solar system; the nebula hypothesis explains why the heavy stuff collapsed into the middle - creating the inner, rocky planets - and the gas was mainly left in the outer solar system. I also got a question from an older gentleman who wanted me to justify astronomy. It is a question that comes up quite frequently and I try to answer it on several different levels. I always start out by saying that any civilized society should try to find out about the universe around it. That is part of what makes us civilized. I then moved on to the tests of physics, specifically gravity and relativity which do have practical consequences. I finished up on technological development from detectors/receivers (optical, radio, x-ray, infrarecd etc) which have lots of practical applications. In many ways it is a very important question as we should justify to the public why they fund us. I must admit that I'm in it for the sake of the knowledge though.

Now I have to come clean; I made at least one mistake in my hour. At one point, I accidentally claimed that the Sun would explode as a supernova in 5 billion years time. Unfortunately, this isn't true, as it will shed its outer layers relatively slowly (by astronomical standards) and end up producing a planetary nebula. I know this, I really do, but in the hour of rambling conversation, I got confused and was thinking of stars ten times the mass of the Sun. Sometimes astronomers make mistakes.

Posted in astro blog by Stuart on Thursday 31st Mar 2005 (16:11 UTC) | Permalink
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