Tycho's New Star
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In the next few days we will celebrate the 435th anniversary of The Event, an seemingly innocent incident which took no more effort than for one man to look up into the sky and see something new - and then act on it. That deed was one which helped change the face of astronomy forever and helped us all see the cosmos in a brand new light.
In November 1572, Tycho Brahe was just a 26-year-old Danish nobleman who had recently become interested in astronomy. He became fascinated in the discipline after seeing an eclipse (as do many people), and continued to delve into it - but especially after what he saw on that fateful day.
In Tycho's day there was a profound paradigm shift in western thought being birthed. Whether this new arrival would survive or not was yet to be seen. Tycho unwittingly made sure it would live by happening to be in the right place at the right time.
The prevailing worldview concerning the universe then was that the entire cosmos went around us, around the earth. It was the geocentric theory. There are several reasons why nearly everyone accepted it. For one, it actually does appear that way, it does seem that the entire heavens go around us like a giant starry-speckled sphere around our static planet. But, just as importantly, the philosopher Aristotle had said it was so. That Aristotelian philosophy of nature had been the great fortress in western thought for centuries.
That great imposing wall of geocentrism had begun to weaken - just decades before Tycho arrived on the scene - when a Polish monk named Copernicus had the gall to propose that the earth actually went around the sun!
There were a couple reasons why Copernicus's heliocentric ideas were not accepted right away. One was that this was before the invention of the telescope and there really was no convincing evidence proving we went around the sun. (It's tougher to prove than you think!) Another was that it was just plain asking too much. People love their worldviews, and feel safe there, unchallenged.
So how did Tycho affect it all?
Aristotle's views of the heavens included the belief that they were immutable, unchanging. For there to be a change up there implied Aristotle may have been - horror of horrors! - wrong! When Tycho looked up in that sky on the 11th of November 1572, he saw a bright and shiny new star, a "stella nova." Located in the constellation Cassiopeia it was quite literally a star not seen before.
Most dismissed the nova as some atmospheric phenomenon, not some event amongst the starry hosts. But as Tycho observed it, and took data on it, and analyzed that data, he realized that is was indeed in the distant starry heavens. There was something new over the sun.
It turns out what Tycho saw was what we now call a supernova, the intensely energetic death of a giant star. The remnants of that blast can still be seen today.
This was actual evidence needed to start the destruction ball swinging on Aristotle's universe. A few decades afterwards, Galileo, using his first primitive telescopes, got more evidence that the geocentric way of thinking was on its last legs by observing the craters on the Moon, moons around Jupiter, the phases of Venus, and even blemishes on the Sun - all evidence against Aristotle's view of flawless heavens.
Surprisingly, Tycho did not adopt a heliocentric world view. He had his own system which he felt much better explained all the observations. His universe had the earth as center, with the Sun orbiting around it, but with all the planets orbiting the sun. It wasn't true, of course, but it fit the limited facts of the time.
After Tycho's untimely death Johannes Kepler, Galileo, and Isaac Newton all helped bury the geocentric - and tychonic - systems forever.
But one might arguably say that the whole revolution really heard its first evidentiary shots when a young, ambitious astronomer saw something new in the skies - and acted on it.
Posted by Mark Ritter at 2007.11.14 01:56 PM | Comments (0)
