Asteroid Day: Reflecting on the Solar System's Past and Preparing for Earth's Future (Destruction?)

When I heard June 30 was Asteroid Day, I wasn’t sure whether I was supposed to celebrate, duck and cover, or listen to Aerosmith. Asteroids seem to be walking (okay, barreling through space) contradictions. They are simultaneously common rocks and a wealth of new information. They could destroy us, but they may have enabled life. We like them close, but not too close.

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Simulation Offers Tips on Creating Element 120

If you caught our TETRIS! post a couple of weeks ago, you’ll know that the seventh row of the periodic table is officially complete and that earlier this month the International Union of Pure and Applied Chemistry disclosed recommended names for the four elements discovered most recently. Identified by atomic number, which gives the number of protons in an atom, the new elements are 113, 115, 117, and 118.

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When Morality and Automobiles Collide

 A woman is the sole passenger in an autonomous self-driving vehicle traveling at the speed limit down a main road. Suddenly, 10 pedestrians appear ahead, in the direct path of the car. The car could be programmed to: SWERVE off to the side of road, where it will impact a barrier, killing the passenger but leaving the ten pedestrians unharmed, or STAY on its current path, where it will kill the 10 pedestrians, but the passenger will be unharmed. 

 What is the moral course of action?

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Vapor Explosions: Magic and Metallurgy

It is New Year's Eve and, somewhere in Scandinavia, a family sits around a small table, illuminated by candlelight, speaking to one another in subdued tones. On the table, an ornate spoon rests in a small silver stand, its head sitting above an open candle flame. Next to it, a stainless steel bowl of cool water seems to be full of shadow in the dim and directional light coming from the candles. As a light snow begins to fall outside the windows, an ingot of metal is placed in the spoon, and a small child stands on his chair to watch it melt while the rest of the family looks on with an air of pleasant expectancy. Before long, the ingot is a small molten pool of lead and tin in the spoon. In this family, tradition dictates that the youngest goes first. With gentle encouragement from the rest, the child reaches out to grab the spoon by its handle. His mother's hand hovers around his, not touching but following, ready to grab the handle in case he slips or loses his grip, but his hand is steady, suspending the spoon over the water basin. He begins to pour, hesitantly at first, then upends the spoon, dumping the rest of the molten metal into the water all at once. It hangs together, sliding easily and completely off the spoon as a single large droplet, but when it hits the water it deforms with a quick hiss into a pitted and bubbled structure, shaped by steam at the same time that it hardens and solidifies thanks to the water's absorption of its heat.  The child's grandmother reaches into the bowl and retrieves the tiny lump of metal, holding it up between the candle flame and the wall, where it casts a bizarre and enlarged shadow. The grandmother, well-practiced at this divination, rotates the metal piece, bringing a long protrusion into view near the bottom of the image. She pauses, shifts the shape along another axis, and its shadow takes on the vague appearance of a horse in profile.
"A horse!" She exclaims in Finnish, and the family erupts in peals of laughter.
"A new car for the little one, this year!"

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Physics Book Club: The Hainish Cycle

The Hainish Cycle, a loosely interconnected science fiction series by author Ursula K. LeGuin, is everything sci-fi ought to be. Set in a universe where humanity was “seeded” across the galaxy long ago from an ancient spacefaring homeworld, each book explores new worlds of humans and their cultures, and in doing so takes a magnifying lens to aspects of our own culture here on Earth. Some of the differences between the various worlds’ inhabitants are only skin deep, but those are the least of the differences between the Urrasti and the Anarresti in one of the Cycle’s most famous books: The Dispossessed.

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Gravitational Waves Explained: Feynman's "Sticky Bead"

With yesterday's report from the LIGO collaboration indicating that they had observed a second black hole merger event, the 'net is once again abuzz with talk of gravitational waves, but some of you might still be struggling to understand precisely what a gravitational wave is, and what's so significant about it. Fortunately, way before anyone even dreamed of building a project as ambitious as LIGO or LISA, famous physicist Richard Feynman came up with an excellent way to explain gravitational waves.

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LIGO Does it Again! Second Black Hole Merger Recorded

It’s a good day. This morning, scientists from the Laser Interferometer Gravitational-Wave Observatory (LIGO) Scientific Collaboration and Virgo Collaboration announced that late on the evening of December 25, 2015, LIGO detectors observed gravitational waves from a black hole merger that happened 1.4 billion years ago. They made the announcement from the 228th American Astronomical Society meeting, and the work was published today in Physical Review Letters.

Numerical simulations of the gravitational waves emitted by the inspiral and merger of two black holes. The colored contours around each black hole represent the amplitude of the gravitational radiation; the purple and blue lines represent the trajectories of the black holes, and the green arrows represent their spins.
Image Credit: NASA/Ames Research Center/C. Henze. Public Domain.

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Scientists Shine a Spotlight on Photons Produced in Neutron Decay

Studying decay might seem like a job for the biologists, but not so when it comes to particles. The strange, but common process through which particles decay, or change from one type into two or more other types, is fundamental to the way the universe works. After a year-long experiment and analyzing terabytes of data, a team of scientists has just published in Physical Review Letters the first precise measurements of one of the byproducts of the decay of a neutron—light.

This photo of the RDK II experiment was taken looking in the direction of the neutron beam source. The three rectangles in the center are detectors for the lowest-energy photons.
Image Credit: Herbert Breuer.

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Ask a Physicist: Phone Flash Sharpie Shock!

Lexie and Xavier, from Orlando, FL want to know:

"What's going on in this video? Our science teacher claims that the pain comes from a small electrical shock, but we believe that this is due to the absorption of light. Please help us resolve this dispute!"

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TETRIS! Seventh Row of Periodic Table Completed

What do the nation of Japan, the state of Tennessee, and the city of Moscow have in common with Russian nuclear physicist Yuri Oganessian? If you hadn't guessed, all four just had elements named after them, marking the observation and naming of all elements in the seventh row of the periodic table.

The periodic table of elements, complete with its latest additions.
If the universe is a game of Tetris, we definitely just beat a level.

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Gravitational Wave Dress = WANT!

When the LIGO Scientific Collaboration decided to make their data freely available for anyone to use, I kinda doubt they had this in mind. I'm guessing most of the collaboration members will approve, and some of them may be wearing one soon.

The Gravitational Waves dress is made by a company called Shenova. And the only thing that gives me pause before clicking purchase is the amazing array of other great designs they offer.

But how awkward is it going to be when you go to some snazzy soiree and you see someone else wearing the exact same data set? Here's hoping we have lots of new LIGO detections soon to keep the social strife to a minimum.

Do you know anyone cool enough to appreciate this dress? I sure do. Time to place an order.
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Ask a Physicist: Wormholes and Time Travel

Keegan from Normal, IL wants to know:

"I have heard a few theories about using wormholes in space to travel from one place to another almost instantly, and I have heard that by doing that you can also travel through time in a similar way. In theory, how does time travel with wormholes work?"

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LISA Pathfinder: The Freest Fall

A key component of a future gravitational wave observatory passed a series of tests with flying colors, while coming closer to experiencing true free fall than any other human-made object ever has. At the heart of the experiment is a two-kilogram cube of a high-purity gold and platinum alloy that is currently sailing through space almost completely free of any force other than gravity.

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New Terahertz Imaging Technique Reveals Tiny, Hidden Objects

In an article published today in Science Advances, a team of UK researchers revealed a new way to see small or hidden objects using a technique known as terahertz imaging. This could lay the foundation for a new kind of imaging device with a wide range of applications from studying bacteria to performing quality control in electronics manufacturing.

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Seawater as a Solar Fuel Cell Source

A team of Japanese and South Korean researchers has pioneered a way to use seawater to obtain hydrogen peroxide (H₂O₂) instead of using pure water as a solar fuel. Their paper, “Seawater usable for production and consumption of hydrogen peroxide as a solar fuel,” was published in the May 4 edition of Nature Communications. “It is highly desired to utilize the most earth-abundant seawater instead of precious pure water for the practical use of H₂O₂ as a solar fuel,” the researchers said in the paper.

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