Black Holes

Most black holes, regardless of their size, Canada Goose Coats On Sale are born when a giant Canada Goose Online star runs out of energy. The star implodes, and its center collapses under canada goose uk black friday its own weight. This causes an explosion called a supernova. The giant star is eventually squashed into a canada goose uk outlet supersmall dot you can’t see.

A black hole’s gravity, or attractive force, is so strong that it pulls in anything that gets too close. cheap Canada Goose It can even swallow entire stars. Nothing can move fast enough to escape a black hole’s gravity. This includes light, the canada goose coats on sale fastest thing in the universe. That’s why we can’t see black holes in space they’ve gobbled buy canada goose jacket cheap up all the light. Though astronomers can’t see black holes, they know Canada Goose Jackets they’re there by the black friday canada goose effect they have on objects that get too close.

Two types of black holes exist. uk canada goose outlet Supermassive black holes buy canada goose jacket are canada goose factory sale the largest type canadagooseonlineshop of canada goose black friday sale black canada goose uk shop hole. They’re up to one canada goose coats million times more massive than our Canada Goose online sun. This is the kind Canada Goose Parka of black hole that’s at the center of our galaxy, the Milky Way; it’s called Sagittarius A. (A is scientist code for “A star.”) The canada goose store most common type of black holes, stellar black holes, are only up to 20 times more massive than our sun.

The intense gravity near a black hole makes time behave in strange ways. If an astronaut left uk canada goose his spacecraft to explore a black hole up close, he’d see the hands on his watch ticking at normal speed. But if anyone back on the spacecraft could observe the astronaut’s watch from far away, they’d see its hands slow down as the spacewalker got closer to the black hole. When the spacewalker returned to the spaceship after an canada goose clearance sale hour long spacewalk, canada goose clearance years would have passed for cheap canada goose uk those aboard Canada Goose sale the canadian goose jacket spacecraft.

Someday humans might be able to use black canada goose holes to time travel forward. An astronaut could take a short trip near a black hole and return to Earth Canada Goose Outlet after years, decades, or even centuries had passed there. A black hole time machine could allow an astronaut to find out what the world will be like in the future. But going back in time? That’s a different challenge altogether.