What Happens Beyond "Absolute Hot"?

Can temperature drop below absolute zero? What happens then? Does it pop out at the other end of the thermometer like Pac-Man and become infinitely hot? Well, kind of, and the seemingly wacky concept is actually surprisingly common in physics.

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The Joy of Physics: Kitchen Mysteries

As regular readers of the site know, we try to take time each week to answer an interesting or informative question that lands in our "Ask a Physicist" inbox. Part of the reason why we do this is to make sure that we're addressing your urgent questions and wild what-ifs, but it's also to demonstrate the amazing things you can do with physics. It's almost a superpower, a kind of "second sight" that lets us understand things that would otherwise be frustrating puzzles.


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Suddenly Springtime: the Nonlinearity of Seasons

Why does a change in the seasons always seem to creep up on us? Winter has a way of seeming like it'll never end, like every day closer to springtime brings only another minute of sunlight—and then, nearly all at once, you're enjoying a sunset at 7 PM in nothing more than a light jacket.


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Just What IS a "Quantum"?

Quantum is one of those words that's a godsend if you're a lazy science-fiction author in need of a plot device, or someone trying to scam people into buying your crappy, overpriced jewelry. It evokes scientific knowledge and mystery all at once; it lets things be in two places at the same time, or jump to alternate universes.

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Ask a Physicist: How Many Calories are in that Sunbeam?

Last week, Joe from Massachusetts wrote in to ask:

Life is possible through the transfer of the sun's energy, through photosynthesis, and animals eating and us eating them. Is it possible to measure how much energy a person receives from the sun in order to live an average life, say 85 years being the average? Tall order, yes?

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Wrestling the Demon: the Physics of Free Will

At the intersection of physics and philosophy, there's a question that's weighed on the minds of great thinkers for centuries: Is there truly such a thing as free will? When we make a choice, are we fundamentally any different than a calculator "choosing" which segments of its display to light up when the = button is pressed?

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Introducing the Newest Member of the PhysicsCentral Team

Allow me to take a moment to introduce myself and tell you a bit about my background. I am the new APS science writing intern. Currently, I hold four bachelor's degrees and am working on a master's.  My first bachelor's was in English from Florida Gulf Coast University. Last May (2017) I graduated from Florida State University with three Bachelor of Science degrees in astrophysics, meteorology, and biomathematics. This past fall I started my master's degree in space studies through the University of North Dakota.

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Cutting-Edge Science Applies Ancient Advice

Chemistry, in one form or another, has been practiced for thousands of years—but for most of that time, it was more akin to wizardry than the hard science we know today. The alchemists of old wielded a strange and marvelous power, to mix two substances and create something entirely new, something that couldn't be separated back into its original parts...except by more alchemy. Through trial and error, mixing up ingredients that seemed like they might be powerful—smelly sulfur, or metals like mercury—we slowly gathered enough pieces of the puzzle that clever people began to see the outlines of the whole shape: the Periodic Table.

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Ask-a-Physicist: Pulling "Juice" Out of Thin Air

This week, Andrew from Quincy, WA wrote in to ask:

I'm writing a book, and trying to think of small-scale power sources—I want the ideas to be at least theoretically possible. Is it theoretically possible to slightly compress an atom to cause the electrons to vibrate? Also could that cause heat as well, and could you harness either of those to produce electricity?

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I Want to Believe

Many physicists have a moment they can point to as the moment they decided to study physics. Often it is a teacher, or an experiment, or a demo show that made them think physics was the most interesting and fascinating subject. Others might be inspired to follow the path of a favorite author or television character. For me, Dana Scully was that character. I grew up watching the X-Files and for the first time I saw someone like me (well, not exactly like me, I'll never be that well put together or able to walk in heels) as a scientist. For many from my generation she was the first time we saw a female lead on TV that was not a sidekick and was treated as a full and engaging character. She also happened to be a physicist. This made me feel like I could do that, too.

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