A white hole is the opposite of a black hole But is there cosmic evidence of its existence?

According to general relativity, a white hole is a hypothetical region of spacetime and a singularity that cannot be entered from the outside, although matter energy, light and information can escape from it.

A white hole is a strange, hyper-bright theoretical cosmic body that runs in the opposite direction to a black hole. Just as nothing can escape from a black hole, nothing can enter a white hole.

Scientists assume that white holes - if they exist - have similar properties to black holes such as mass, charge and angular momentum. It also attracts matter like any other mass, but objects that fall toward the white hole will not actually reach the white hole's event horizon.

Time reversal

Physicists describe a white hole as a "time-reversal" of a black hole, such as playing a video in reverse of a black hole, like a bouncing ball; It is a time reversal of the falling ball. While the event horizon of a black hole is the field of no return, the event horizon of a white hole is the boundary of non-acceptability, no spacecraft will reach the edge of the region.

According to the “ Space ” website , to a spaceship crew watching from afar, the white hole will look just like a black hole, it has mass and may rotate, and a ring of dust and gas can collect around the event horizon, but if the crew continues to watch, it may He notes an impossible event for a black hole, a "burp."

“Only at the moment things appear you can say 'this is a white hole,'" says Carlo Rovelli, a theoretical physicist at the Theorec Center for Physics in France.

White hole and general relativity

There is now evidence from our telescopes that black holes do exist. However, we have never seen a white hole. The reason astronomers think of white holes is Albert Einstein, and just as his theory of general relativity describes how black holes work, it also says that white holes are possible.

According to general relativity, a white hole is a hypothetical region of spacetime and a singularity that cannot be entered from the outside, although matter energy, light and information can escape from it. While the black hole can only be entered from the outside, energy, light and information cannot escape from it. “It took 40 years to understand black holes, and it was only recently that people focused on white holes,” Rovelli says.

And while general relativity describes white holes in theory, no one knows how they might actually form. What we do know is that a black hole encircles a portion of its own space when a star collapses to a small size, but that being played back makes no physical sense. The event horizon of a white hole that could explode into a star is a violation of the laws of physics.

And even if large white holes did form, they probably wouldn't stay for long. As any material emitted from it will collide with the material in orbit and the system will collapse. "I think a long-term white hole is very unlikely," says theoretical physicist Hal Haggard at Bard College in New York.

Can a black hole turn into a white hole?

According to an article published on Science Focus, white holes are often mentioned in the context of "wormholes", where a black hole acts as an entry point into a tunnel through space and time, and ends with a white hole elsewhere in the world. Universe.

But this is highly controversial, because according to Einstein's general theory of relativity, at the center of a black hole we find the so-called "singularity", a point of infinite gravity at which both space and time actually end, preventing anything from passing into The white hole is on the other side.

However, some theorists believe that a combination of Einstein's theory and quantum theory indicates a new way of thinking about white holes. Rather than being "out" of a wormhole, it may be a slow-moving remodeling of the original black hole formation.

The process begins when an ancient massive star collapses under its own weight and forms a black hole. But then, the quantum effects around the surface of the black hole stop further implosion, and instead begin to gradually transform the black hole into a white hole that spews out the original stellar matter again. But due to the effect of the extreme time-stretching around the black hole, this event would take billions of years for the slightest mass of the hole to eventually appear.

Can a white hole exist?

An article published on The Conversation website answers this question in the negative. A white hole can be accepted as an idea, but it is never possible in real life.

White holes are highly unlikely because they are something of an "inverse" type. Think of breakfast the other way around, i.e. your egg hops out of the pan and back into the shell. This is possible in one case; Which is that time has turned itself around and started to go backward, but time in our universe only flows in one direction, forward. So white holes so far, are just an interesting possibility.

According to what was published in Phys.org , another possibility for the absence of white holes is that white hole traces are already everywhere because it is one of the possibilities to explain the Big Bang, and it is one of the interesting ideas presented by physicists.

Where the Big Bang of matter and energy appears to be the behavior of a possible white hole, a huge amount of matter and energy appeared spontaneously. “The geometry is very similar in both cases, even to the point where they are sometimes mathematically identical,” Haggard says.

Source : The Conversation + Phys.org + Websites