Physics Buzz

When an imminent threat means troops need to move, sometimes the most powerful cover is a smokescreen. Not a figurative smokescreen, but an actual burst of smoke that hides soldiers—and even tanks—from enemy eyes. Commonly created by smoke grenades, these bursts are valuable only as long as the enemy can’t see through them.

About two weeks ago, in the coastal town of Redondo Beach, California, engineers at the headquarters of Northrop Grumman Aerospace Systems unpacked one heck of a box. Transported via the Space Telescope Transporter for Air Road and Sea , the contents were unwrapped with extreme caution by workers sporting cleanroom bunny suits. Inside were intricate pieces of the James Webb Space Telescope (JWST) —the space-bound observatory expected to revolutionize our understanding of the universe over the next decade.

As long as his ideas continue to spread and inspire people, Hawking's mind will live on.

Even Michael Jordan needed teammates. Makeshift stands selling Bulls merchandise inhabited every corner of Chicagoland after “Air Jordan” led his team to their third straight championship in 1993—and all the stands were busy. People were caught up in the excitement and inspiration of watching Jordan, Pippen, Armstrong, Grant, and their teammates take on the world.

This may be the only photo you’ve ever seen of researchers proudly displaying a university-branded potato and coconut.

I want you to try something: Find an object nearby that's made of metal, and something else made of wood or plastic. Put a hand on each. Which one is colder?

On average, about 8 million acres of land burns each year from wildfires. Big fires can reduce forests and grasslands to ash and can destroy homes and lives. Sadly, up to 90 percent of wildland fires in the United States are caused by humans’ carelessness, like unattended campfires, burning trash or waste, tossed-out cigarettes, and arson. The remaining 10 percent are usually started by lightning. Controlling and fighting fires isn’t easy. But knowing the science behind a burning blaze helps firefighters tackle the heat and flames to help save property, land and lives.

Researchers have come up with a blueprint for a small and tunable device that can control the flow of light. Because it’s much tinier than existing technology, the invention could help shrink optical equipment to the nanoscale, and even enable superfast computers that run on photons instead of electrons. The results will be published in the journal Physical Review Letters.

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.

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.

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.

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.

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?

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?

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.

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.

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?

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.

Once in a rare while, the moon turns red—because the sky is blue. That might sound like nonsense, but it's the simplest accurate way to explain what happened early this morning, when the moon disappeared from view before returning with an eerie, rusty cast to it.

Last week, reader James from Melbourne wrote in: I was having a discussion with a colleague about what would hit the ground first if it fell from a plane (let’s say 15,000 ft). An elephant (let’s say African) or a standard brick. Curious to know your thoughts. Thanks!