100 Years of the Expanding Universe
Say you wanted to find a place in Flagstaff where a scientist made a major discovery.
It would be a good bet to start at the Lowell Observatory.
“Well right now we’re sitting inside the Clark Telescope dome at Lowell Observatory.”
That’s Kevin Schindler.
He works at Lowell doing public outreach.
He also loves history….especially about Lowell.
And the story about Vesto M. Slipher is a good one.
“Vesto Slipher was a country boy from Indiana.”
He finished high school, taught for a few years, and then went to college where he became very interested in astronomy.
One of his professors called a former colleague, Percival Lowell, to see if he could land Slipher a job.
“And Lowell said, you know I’m not really that interested, but we have this new instrument called a spectrograph and we need somebody to operate it. Sure, bring him out here. This is just temporary.”
The spectrograph was a pretty important invention in itself.
It changed the way we looked at stars.
“The spectrograph will break light down into its individual parts, so you can not only tell what distant objects are made of based on that finger print of light.”
But, you can also tell if those objects are moving toward you or away from you.
Slipher got very good at that spectrograph.
He was using it to study the Andromeda Nebulae.
He wanted to see if he could learn anything about the way our solar system developed by watching another one.
And on September 17, 1912, using the Clark Telescope, Vesto Slipher made a major discovery.
“And what he found that not only was the composition was a lot different, but he realized that these objects were moving away from us at incredible speeds, some in excess of 900 times the speed of sound.”
In other words, the universe is expanding…..and it’s expanding very quickly.
Slipher didn’t know what to do with what he had found.
Schindler says there was nothing, no theory, no research that preceded Slipher’s discovery.
"it was just another classic example of serendipitous discoveries in science, where you’re searching for something else and hey, who would have known.”
And Schindler says Slipher’s work signifcantly changed the way scientists think about our universe.
“We know today that the universe is 13.7 billion years old or so. Multiply what we know about the speed these things are moving and the universe is a very large place, much more than what we thought a century ago.”
And Slipher’s discovery has opened more doors, led to more research, and prompted more theories.
“I guess some would say the obvious follow- up is, ok if it’s expanding, let’s go back in time. It had to start somewhere right? So what happened then? Maybe there was a large explosion beyond anything we can comprehend that triggered all this expansion to start. “
That’s the Big Bang Theory.
And the questions don’t end there.
“Will it keep expanding forever?”
What’s it expanding into?
Are there other universes?
“ Plus, is time expanding? Which adds another component of it. So we’re getting into sort of Einstein level questions here. “
Slipher’s discoveries actually helped prove Einstein’s Theory of Relativity and the work of Astronomer Edwin Hubble.
“And that’s the great thing about science, the more things we discover, there are a lot more things we realize we have to learn.
Slipher was a quiet, unassuming man.
And it’s probably fair to say most people don’t know his name or what he discovered 100 years ago today.
And that temporary job that Slipher got working the spectrograph at Lowell in 1901.
He stayed on and retired from the place some 50 years later.
For Arizona Public Radio, I’m Mark Bevis.