red hole definition, red hole meaning | English dictionary 6 (U.S.) informal a small anchorage. 7 a fault (esp. in the phrase pick holes in) 8 Slang a difficult and embarrassing situation.
Green holes are special types of star that are so rare! Green holes form if black holes don't lose mass or only lose a ton of mass in a billion years! That happens if the star is super massive, like a hypergiant or a metagiant.
This light is shifted toward the red end of the electromagnetic spectrum, which is characterized by longer wavelengths. As objects move toward the event horizon of a black hole, they experience an infinite redshift. Hence, they appear redder in color to an observer until they become too dim to see.
Stellar black holes are very cold: they have a temperature of nearly absolute zero – which is zero Kelvin, or −273.15 degrees Celsius. Supermassive black holes are even colder. But a black hole's event horizon is incredibly hot. The gas being pulled rapidly into a black hole can reach millions of degrees.
We are in absolutely no danger from black holes. They're a bit like tigers – it's a bad idea to stick your head in their mouth, but you're probably not going to meet one on your way to the shops. Unlike tigers, black holes don't hunt. They're not roaming around space eating stars and planets.
A Q-star, also known as a grey hole, is a hypothetical type of a compact, heavy neutron star with an exotic state of matter. Such a star can be smaller than the progenitor star's Schwarzschild radius and have a gravitational pull so strong that some light, but not all light, cannot escape.
The 100 or so pink black holes we've studied to date have redshifts between 0.1 and 3. (ie. the light from them is shifted to the red, due to the expanding universe, by between 10% and 300%).
Known as TON 618, it is the most massive black hole observed so far in the Universe. NASA has revealed that it tips the scales at 66 billion times the Sun's mass!
With a depth of 12,262 metres, the Kola Superdeep Borehole in north-west Russia is the world's deepest human-made hole.
The biggest single entity that scientists have identified in the universe is a supercluster of galaxies called the Hercules-Corona Borealis Great Wall. It's so wide that light takes about 10 billion years to move across the entire structure. For perspective, the universe is only 13.8 billion years old.
Astronomers believe that supermassive black holes lie at the center of virtually all large galaxies, even our own Milky Way. Astronomers can detect them by watching for their effects on nearby stars and gas.
Astronomers announce the discovery of two supermassive black holes that are closer than any pair ever seen.
Black holes are some of the strangest and most fascinating objects in space. They're extremely dense, with such strong gravitational attraction that not even light can escape their grasp. The Milky Way could contain over 100 million black holes, though detecting these gluttonous beasts is very difficult.
If you leapt heroically into a stellar-mass black hole, your body would be subjected to a process called 'spaghettification' (no, really, it is). The black hole's gravity force would compress you from top to toe, while stretching you at the same time… thus, spaghetti.
The Great Nothing: an actual void in space
The Boötes void, often referred to as the Great Nothing or the Great Void, is an actual area of space with fewer galaxies than you'd expect. At 250 to 330 million light-years across, it is one of the largest voids that we know of.
Although the odds of Earth getting swallowed by a black hole, or any Solar System planet, for that matter, are low, it's definitely a real possibility.
In the next three years, a once-in-history astronomical event is expected to occur: two massive black holes will collide and merge to form a single black hole, with the point of convergence set to be visible from ground-based observatories. Simulation showing a pair of black holes about to merge.
In reality, they are purely theoretical. Unlike black holes—also once thought to be purely theoretical—no evidence for an actual wormhole has ever been found, although they are fascinating from an abstract theoretical physics perceptive.
We might be the product of another, older universe. Call it our mother universe. The seed this mother universe forged inside a black hole may have had its big bounce 13.8 billion years ago, and even though our universe has been rapidly expanding ever since, we could still be hidden behind a black hole's event horizon.
Black holes are absolutely silent, as they are creatures of pure gravity. But while black holes produce no sound of their own, they can generate sound waves in their environment.
The nearest known black hole is Gaia BH1, which was discovered in September 2022 by a team led by Kareem El-Badry. Gaia BH1 is 1,560 light-years away from Earth in the direction of the constellation Ophiuchus.
Cosmologists aren't sure if the universe is infinitely big or just extremely large. To measure the universe, astronomers instead look at its curvature. The geometric curve on large scales of the universe tells us about its overall shape. If the universe is perfectly geometrically flat, then it can be infinite.
The closest void to us on Earth is the Local Void (clever, right?). This guy is 150 million light years across and sits at the edge of our local group of galaxies. It is believed that the center of the Local Void is at least 75 million light years from Earth.