Gravity

Shorebirds “Defy Gravity” to Eat, Study Says

Publication: National Geographic News   Date: May 15, 2008   View Article

Certain types of shorebirds defy gravity to get morsels of food up their long, slender beaks into their mouths, new research shows.

The birds, called phalaropes, exploit the same principle that allows water droplets to stick on windows.

New Dark Matter Map Shows Violent Life of Galaxies

Publication: National Geographic News   Date: January 10, 2008   View Article

In galaxy clusters, the rough-and-tumble outer suburbs are where most galactic change occurs, a team of astronomers announced today.

There, galaxies harass, strangle, and strip away at each other as they are pulled from the outskirts of a cluster to the inner core by the gravity of dark matter, according to the new research.

Dark Matter Proof Found, Scientists Say

Publication: National Geographic News   Date: August 22, 2006   View Article

A team of researchers has found the first direct proof for the existence of dark matter, the mysterious and almost invisible substance thought to make up almost a quarter of the universe.

Dark matter does not absorb or emit light. So far, astronomers have inferred its presence only indirectly by measuring the effects of its gravity.

But now, by observing a massive collision between two large clusters of galaxies, astronomers have detected what they say could only be the signature of dark matter.

Supermassive Black Hole at Center of Milky Way, Study Hints

Publication: National Geographic News   Date: November 2, 2005   View Article

Astronomers are closing in on proof that a supermassive black hole is the source of mysterious radio waves at the center of our galaxy, the Milky Way.

Black holes are objects whose gravitational pull is so strong that nothing, not even light, can escape. Supermassive black holes contain the mass of millions, if not billions, of suns.

X-Ray “Vision” Unlocking Black Hole Mysteries

Publication: National Geographic News   Date: May 24, 2005   View Article

Advances in x-ray astronomy are resolving some enduring mysteries about black holes, scientists say. Black holes are places in space where the force of gravity is so strong that nothing, not even light, can escape.

In recent years scientists have learned to find black holes by sweeping the skies with space-based telescopes equipped with x-ray “vision.” X-rays are a high-energy form of light that is invisible to the human eye.

April Fools’ on Mars: Scientists Post Yearly Photo Joke

Publication: National Geographic News   Date: April 1, 2004   View Article

A pair of astrophysicists announced today that April Fools’ Day is more intense on Mars than on Earth.

To back their claim, the duo notes that Mars has less gravity (pun intended) than Earth—and is therefore sillier. In addition, a Martian day, or sol, lasts nearly 40 minutes longer than an Earth day.

Why Is Earth’s Girth Bulging?

Publication: National Geographic News   Date: August 7, 2002   View Article

This is heavy.

Something massive is moving on or within the Earth and causing the planet’s gravity field to get wider around the equator and flatter at the poles, according to a pair of scientists studying the field with sensitive satellite instruments.

© 2008-2010 Collected Writings By John Roach