From The Desk of...The Chief Scientist

"It's Time for Time Crystals"

Written by Paul Sutter on Monday, 19 June 2017. Posted in From The Desk of...The Chief Scientist

So, time crystals. They cropped up in the news a couple months ago, and I'm just now getting around to talking about them. Despite their horrendous name - implying that they might have something to do with healing powers, energy fields, talking to your deceased relatives, or who knows what nonsense - they're perfectly reasonable physics objects.

A "normal" crystal is a pattern that repeats in space. A time crystal is a pattern that repeats in time. While we have lots of things that repeat in time (e.g., clocks), what makes time crystals special is that they do it in the minimum-energy state of the system, meaning they could do it forever.

While that sounds like some sort of perpetual motion device, it's impossible to pull energy out of the system, so don't expect these to power your smartphones anytime soon. Still, that didn't stop some press outlets from writing all-caps headlines about time crystals rewriting known physics, revolutionizing our understanding of time, or even shining a light on dark energy.

The verdict: time crystals are interesting. But that's it.

"Send Me Scripts"

Written by Paul Sutter on Monday, 12 June 2017. Posted in From The Desk of...The Chief Scientist

One of my most important responsibilities at COSI is to ensure the correctness of our presented science, from descriptions on exhibits to scripts for shows. Granted, a large fraction of the material COSI presents to the public is not in my specific domain - they don't typically hand out Ph.D.'s in "All the Science" - but that's where my connections back to OSU come in handy. If something crops up beyond my expertise, then a quick call to campus can easily resolve the issue.

So with all that in mind, I encourage all COSI team members to send me scripts. Develop a new show? Send the script. Create a new outreach demo? Send the script. Have a question about a floor cart activity? Send the script.

I hope you get the point by now: send the script!

"Great Balls of Not Fire"

Written by Paul Sutter on Monday, 05 June 2017. Posted in From The Desk of...The Chief Scientist

Some weeks ago I was chatting with a couple members of COSI's floor faculty team about meteors (they were doing a tabletop meteorite demo, so this conversations wasn't totally unwarranted), when the subject of fire came up. Meteoroids that come screaming through the Earth's atmosphere are very bright, emitting a lot of heat and light, so it naturally leads to the question: are they on fire?

When a piece of space rock intersects the orbit of the Earth at the exact wrong time, it's typically traveling at a few tens of thousands of miles per hour, and that only increases in its final moments. And even though our upper atmosphere is only a tiny fraction of the density of our surface-level air, that speed is sufficient to cause a ton of pressure and friction.

Friction from the rubbing of air against the meteor, and pressure as the rock pushes on the air directly in front of it during its passage. Both of these processes generate a lot of heat; enough heat to ionize both the air and the meteor material, ripping electrons off molecules and causing them to glow.

The air will stay ionized for a few moments after the meteoric passage, forming the familiar trail. Bits and pieces of the meteor itself will get stripped away - a process called ablation - leaving a glowing aftermath in its wake as well.

But fire is not involved here. Fire is a chemical reaction between oxygen and a fuel source, and the physics on display in a meteor shower are based on different, and far more violent, processes.

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