Menu

Blog

Archive for the ‘physics’ category: Page 263

Sep 4, 2018

“Where are they?”: SETI and modern science fiction

Posted by in categories: alien life, physics

Rather, they looked like whirlpools in space-time. In the universe, every part of space flowed, churned, trembled between madness and horror like fiery flames that emitted only frost. The Sun and the planets and all substance and existence seemed to be only hallucinations produced by the turbulence of space-time.

Read more

Aug 31, 2018

This Is A Sailboat And Those Are Sails

Posted by in categories: energy, physics

We are undeniably using up what little remains of Earth’s petroleum, and because of that, it’s getting expensive. To reduce fuel costs, shipping companies are turning back to sailboats. Yes, seriously. Sailboats. But they don’t look like any sails you’ve seen before.

You know sails – most of the time big rectangle things, sometimes big triangle things, almost always (but not always-always) made out of cloth. But while those things in the top gif don’t look like your normal sails, that’s what they are. They just don’t work like any sail you’ve ever seen before.

Most sails you’ve seen rely on the wind directly acting against them to provide propulsion. But these new types of sails, known as “rotor sails” rely on a physics principle called the Magnus Effect. Here, I’ll let the people with delightfully thick Finnish accents from Norsepower, the company that makes them, explain it:

Read more

Aug 30, 2018

Physicists Just Made the Most Precise Measurement Ever of Gravity’s Strength

Posted by in categories: physics, space

Gravity might feel strong if you drop a bowling ball on your feet, but is in fact the weakest force. Compare it to electromagnetism: the pull of all the Earth’s gravity can’t stop you from picking up a paperclip with a refrigerator magnet. That weakness makes gravity incredibly difficult to measure.

A team of scientists in China are reporting that they have now performed the most precise measurement of gravity’s strength yet by measuring G, the Newtonian or universal gravitational constant. G relates the gravitational attraction between two objects to their masses and the distance between them. The new measurement is important both for high-powered atomic clocks as well as the study of the universe, earth science, or any kind of science that relies on gravity in some way.

Read more

Aug 27, 2018

The Physics of Falling Into a Black Hole

Posted by in categories: cosmology, physics

This week, newspapers reported that a man had fallen into an art installation consisting of an 8-foot-deep circular hole painted black. It’s kinda not his fault.

Read more

Aug 27, 2018

What Is Nothing? Martin Rees Q&A

Posted by in categories: cosmology, physics

This article was originally published at The Conversation. The publication contributed the article to Space.com’s Expert Voices: Op-Ed & Insights.

Philosophers have debated the nature of “nothing” for thousands of years, but what has modern science got to say about it? In an interview with The Conversation, Martin Rees, Astronomer Royal and Emeritus Professor of Cosmology and Astrophysics at the University of Cambridge, explains that when physicists talk about nothing, they mean empty space (vacuum). This may sound straightforward, but experiments show that empty space isn’t really empty – there’s a mysterious energy latent in it which can tell us something about the fate of the universe.

Rees was interviewed for The Conversation’s Anthill podcast on Nothing. This Q&A is based on an edited transcript of that interview.

Read more

Aug 22, 2018

Physicists Think They’ve Spotted the Ghosts of Black Holes from Another Universe

Posted by in categories: cosmology, physics

Weird patches of the sky where the cosmic microwave background radiation looks funny could be signs of long-dead universes, physicist Roger Penrose said.

Read more

Aug 18, 2018

The snapback effect: Richard Feynman’s famed physics puzzle finally gets solved

Posted by in category: physics

Richard Feynman once asked a silly question. Two MIT students just answered it.

Read more

Aug 18, 2018

The Universe as We Understand It May Be Impossible

Posted by in categories: physics, space

A new conjecture in physics challenges the leading “theory of everything.” (Via The Atlantic)

Read more

Aug 17, 2018

Another way for stellar-mass black holes to grow larger

Posted by in categories: cosmology, physics

A trio of researchers with The University of Hong Kong, Academia Sinica Institute of Astronomy and Astrophysics in Taiwan and Northwestern University in the U.S., has come up with an alternative theory to explain how some stellar-mass black holes can grow bigger than others. In their paper published in The Astrophysical Journal Letters, Shu-Xu Yi, K.S. Cheng and Ronald Taam describe their theory and how it might work.

Since the initial detection of gravitational waves three years ago, five more detections have been observed—and five of the total have been traced back to emissions created by two stellar-mass black holes merging. The sixth was attributed to neutron stars merging. As part of their studies of such detections, space researchers have been surprised by the size of the stellar-mass black holes producing the gravity waves—they were bigger than other stellar-mass black holes. Their larger size has thus far been explained by the that they grew larger because they began their lives as stars that contained very small amounts of metal—stars with traces of metals would retain most of their mass because they produce weaker solar winds. In this new effort, the researchers suggest another possible way for stellar-mass black holes to grow larger than normal.

The new theory starts out by noting that some at the hearts of galaxies are surrounded by a disk of gas and dust. In such galaxies, there are often stars lying just outside the disk—stars that could evolve to become stellar-mass black holes. The researchers suggest that it is possible that sometimes, pairs of these stars wind up in the disk as they evolve into black holes. Such stellar-mass black holes would pull in material from the disk, causing them to grow larger. The researchers note that if such a scenario were to play out, it is also possible that the two merging could wind up with a synchronized spin resulting in a stellar-mass black hole that produces more gravity waves than if the spins had not been synchronized, making them easier for researchers to spot.

Read more

Aug 16, 2018

Settling Arguments About Hydrogen With 168 Giant Lasers

Posted by in categories: physics, space

With gentle pulses from gigantic lasers, scientists at Lawrence Livermore National Laboratory in California transformed hydrogen into droplets of shiny liquid metal.

Their research, reported on Thursday in the journal Science, could improve understanding of giant gas planets like Jupiter and Saturn whose interiors are believed to be awash with liquid metallic hydrogen.

The findings could also help settle some fractious debates over the physics of the lightest and most abundant element in the universe.

Continue reading “Settling Arguments About Hydrogen With 168 Giant Lasers” »