Today's Hours: 
10am - 5pm
Today's Hours: 
CLOSED
Today's Hours: 
CLOSED
Today's Hours: 
10am - 5pm
Today's Hours: 
10am - 5pm
Today's Hours: 
10am - 5pm
Today's Hours: 
10am - 5pm

COSI is now closed

From The Desk of...The Chief Scientist

"It's a big universe out there"

Written by Paul Sutter on Monday, 25 July 2016. Posted in From The Desk of...The Chief Scientist

One of my favorite things to share with people - and give me five minutes and you'll get to experience it - is the concept of the true enormity of the universe. It's really really hard to put into words. Numbers too are just filled with meaningless zeros: the observable universe is about 80 billion lightyear across, or around a trillion trillion miles. How are our primitive just-above-lizard brains supposed to comprehend such magnitudes?

They don't.

Neither can our biological muscles move a 100-ton block, but that doesn't stop us from building pyramids, aqueducts, and Target stores. Our ridiculous ingenuity has devised all sorts of clever tools and contraptions for manipulating our physical world in ways that our animal cousins couldn't imagine (because they have a hard time literally imagining anything).

Likewise, we've come up with a very nifty tool for thinking incomprehensible thoughts: mathematics. Math allows us to understand, predict, modify, and reshape knowledge of the world around us. It allows scientists to write down in a few compact equations the past 13 billion years of cosmic history, and use those equations to predict its future. With math we can think larger and more powerful thoughts. We can squeeze the staggering complexity of the universe into an easily digestible shape.

For example, we don't ever have to think directly about the size of the universe; we can just let the math do the work for us.

That's a pretty powerful tool!

"How do astronauts scratch their noses?"

Written by Paul Sutter on Monday, 18 July 2016. Posted in From The Desk of...The Chief Scientist

You're three hours into your spacewalk. Suspended 250 miles above the surface of the Earth, you can see the night-day terminator line creeping its way across the Sahara. You focus on your tasks, trying not to think too much about your circumstances. Just a few layers of synthetic fabrics separate you and the relentlessly overwhelming vacuum. Tethers that looks a lot thinner than you remember are your only connection to the space station. You can hear your own breathing inside your helmet; the warmth of the suit has begun to fog up your faceplate.

And it happens. You have an itch on your nose.

Instinctively, you bring your hand up to scratch, but succeed only in uselessly thumping your helmet. The movement unbalances you, nudging yourself into a slight backwards roll. Sigh.

Thankfully, you're not the first astronaut to experience such issues, and over the years your predecessors have come up with a few solutions. There are all sorts of things inside your helmet, like a microphone, a device to pinch your nose so you can readjust pressure in your ears, and a few controls.

But what gets the job done is a little patch of velcro, situated in just the right spot for scratching.

"Seeing in the dark"

Written by Paul Sutter on Monday, 11 July 2016. Posted in From The Desk of...The Chief Scientist

I got a great little email from Elizabeth Moody, an Outreach Educator for COSI on Wheels, a couple weeks ago, regarding astronomy and the non-visible parts of the electromagnetic spectrum (which is, you know, most of it). Our eyes are only sensitive to a small sliver of frequencies of light, so when we operate an x-ray or infrared telescope, how do they work and how do they make images that we can...see?

First it's important to note that no matter what kind of light it's observing, a telescope has two important jobs: it's a bucket to soak up as much light as possible, and a focuser to dump that light onto a sensor. The "sensor" is your eyeball if you're an old-timey professional astronomer or a modern-timey amateur astronomer. Usually nowadays the pros have gone all digital.

Think about what your eyeball does: it collects light - the iris - and dumps it onto a sensor - the retina. What gets sent to your brain is raw "data": how much of what frequencies of light and where that light came from. Lots of reds from the barnside, a good bit of blue above it, green below, etc. Your brain turns all that data into an "image", giving you a visual map of an idyllic farm scene.

So what if we have a telescope that collects x-rays? The sensor reads how much of what frequencies of light came from where, and tell it to a computer. It's just a bunch of numbers, and to make a picture some creativity is required. Maybe the high-energy x-rays should be colored purple-bluish, and the lower-energy ones we captured should be given a gentle soft red.

In the end, a computer paints a picture for us, but giving us the same kind of information our brains do with visible light. We can play the same game at any frequency, from radio to gamma-rays. In effect, modern telescopes make us all a Superman.

<<  19 20 21 22 23 [2425 26 27 28  >>