From The Desk of...The Chief Scientist

"What is Science?"

Written by Paul Sutter on Tuesday, 02 May 2017. Posted in From The Desk of...The Chief Scientist

Science is not a search for truth. That's not to say that science doesn't contain true statements. For example, the data returned from a measurement are facts about the world around us, and facts are generally considered true. But Truth with a capital T isn't usually encumbered by uncertainties, caveats, and incompleteness. A "data processing pipeline" sounds perfectly reasonable; a "truth processing pipeline" seems a little fishy.

So what is science? The best definition I can come up with is the following: "Science is a branch of philosophy that uses empirical techniques - and lots of mathematics - to understand the natural world."

Any statement made by scientific inquiry is falsifiable. That's what gives science its strength - the ability to be proven wrong at any moment allows the scientific worldview to be flexible enough to gain more perceptive insights about the world when new observations are made. And a statement that can become incorrect at a drop of a hat probably shouldn't be considered Truth.

"Going Negative"

Written by Paul Sutter on Sunday, 23 April 2017. Posted in From The Desk of...The Chief Scientist

Josh Kessler, COSI's Program Manager, had a quick question for me as we were driving to OSU to talk with the Astronomy Department about solar eclipse plans (more on that later). He heard in the news "something something discovering negative mass", and that seemed like a big deal.

Indeed, discovering negative mass would be a big deal, since it doesn't exist in our universe. Particles with negative mass would repel positive-mass particles, which means you could put one next to a positive-mass particle and watch as they spontaneously accelerate off to infinity. That seems...wrong.

So imagine my surprise when the headlines came rolling in recently about a "breakthrough" that is "turning physics upside down". For once, the blame isn't fully on the press release or the media. The scientists flat-out put it in the title of their paper accepted by Physical Review Letters:

"Negative mass hydrodynamics in a Spin-Orbit--Coupled Bose-Einstein Condensate"

How profound! But the very first sentence of their abstract gives the game away: "A negative effective mass can be realized in quantum systems..."

A negative *effective* mass is an entirely different beast than a negative mass. In fact, the term is really a historical artifact that doesn't mean what you think it means. It means that in ultra-cold quantum systems, there are internal forces that make a fluid move in surprising ways. In this case, when they shut off their trapping laser, the fluid expanded a little bit then stopped. That's it.

It's a totally routine operation in this branch of physics, not at all surprising, and not at all negative.

"The Calendar"

Written by Paul Sutter on Sunday, 16 April 2017. Posted in From The Desk of...The Chief Scientist

For those of you paying attention, Easter came a tad late in the season this year. But what if it got so bad it was celebrated in May?

That was the problem faced by leaders of the Catholic Church in the late 1500's. The calendar they were using, initially proposed as a reform by Julius Caesar a millennium and a half before that, didn't exactly line up with the actual length of the year. Sure, it was good enough for a couple hundred years, but over time errors crept in, and soon enough it was shorts-and-sandals weather during the big Spring party.

Pope Gregory XIII was sick of it, and so - another reform. Every 4 years would be a leap year (a feature of the older Julian calendar), unless the year was divisible by 100 (then no leap year) unless it was divisible by 400 (then leap year anyway). These changes to the leap schedule shortened the average length of the year by almost 11 minutes, meaning only minor corrections need to be made every once in awhile to keep everything synched up.

The Gregorian calendar is a little weird, but it does the job.

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