Tag Archives: Physics

How Artificial Intelligence Is Changing Science

No human, or team of humans, could possibly keep up with the avalanche of information produced by many of today’s physics and astronomy experiments. Some of them record terabytes of data every day — and the torrent is only increasing. The Square Kilometer Array, a radio telescope slated to switch on in the mid-2020s, will generate about as much data traffic each year as the entire internet.

The deluge has many scientists turning to artificial intelligence for help. With minimal human input, AI systems such as artificial neural networks — computer-simulated networks of neurons that mimic the function of brains — can plow through mountains of data, highlighting anomalies and detecting patterns that humans could never have spotted.

Of course, the use of computers to aid … Read the rest

Galaxy Simulations Offer a New Solution to the Fermi Paradox

As far as anyone knows, we have always been alone. It’s just us on this pale blue dot, “home to everyone you love, everyone you know, everyone you ever heard of,” as Carl Sagan so memorably put it. No one has called or dropped by. And yet the universe is filled with stars, nearly all those stars have planets, and some of those planets are surely livable. So where is everybody?

The Italian physicist Enrico Fermi was purportedly the first to pose this question, in 1950, and scientists have offered a bounty of solutions for his eponymous paradox since. One of the most famous came from Sagan himself, with William Newman, who postulated in a 1981 paper that we just need patience. Nobody has visited because … Read the rest

The Universe’s Ultimate Complexity Revealed by Simple Quantum Games

One of the biggest and most basic questions in physics involves the number of ways to configure the matter in the universe. If you took all that matter and rearranged it, then rearranged it again, then rearranged it again, would you ever exhaust the possible configurations, or could you go on reconfiguring forever?

Physicists don’t know, but in the absence of certain knowledge, they make assumptions. And those assumptions differ depending on the area of physics they happen to be in. In one area they assume the number of configurations is finite. In another they assume it’s infinite. For now, at least, there’s no way to tell who’s right.

But over the last couple years, a select group of mathematicians and computer scientists has been busy … Read the rest

Prepping for a Flood of Heavenly Bodies

This is a story of getting the good out of the bad, said Mario Jurić. As a boy in Yugoslavia, he would page through an introductory physics book that belonged to his grandfather. He learned that stars came in different colors, and that these colors signified different temperatures. So for his eighth-grade science fair project, Jurić wanted to capture that spectral light. His teacher lent him a prism. Jurić connected that prism to an old-fashioned camera using a cardboard toilet-paper tube and duct tape. He planned to keep the shutter open for a couple of minutes, let starlight pass through the prism, and capture that spread-out light on film.

But Zagreb, where he lived, was home to about a million people. Under ordinary circumstances the city’s … Read the rest

Neutron Lifetime Puzzle Deepens, but No Dark Matter Seen

When physicists strip neutrons from atomic nuclei, put them in a bottle, then count how many remain there after some time, they infer that neutrons radioactively decay in 14 minutes and 39 seconds, on average. But when other physicists generate beams of neutrons and tally the emerging protons — the particles that free neutrons decay into — they peg the average neutron lifetime at around 14 minutes and 48 seconds.

The discrepancy between the “bottle” and “beam” measurements has persisted since both methods of gauging the neutron’s longevity began yielding results in the 1990s. At first, all the measurements were so imprecise that nobody worried. Gradually, though, both methods have improved, and still they disagree. Now, researchers at Los Alamos National Laboratory in New Mexico have … Read the rest

Physicists Aim to Classify All Possible Phases of Matter

In the last three decades, condensed matter physicists have discovered a wonderland of exotic new phases of matter: emergent, collective states of interacting particles that are nothing like the solids, liquids and gases of common experience.

The phases, some realized in the lab and others identified as theoretical possibilities, arise when matter is chilled almost to absolute-zero temperature, hundreds of degrees below the point at which water freezes into ice. In these frigid conditions, particles can interact in ways that cause them to shed all traces of their original identities. Experiments in the 1980s revealed that in some situations electrons split en masse into fractions of particles that make braidable trails through space-time; in other cases, they collectively whip up massless versions of themselves. A lattice … Read the rest