Name: 黑洞裡面有什麼？ (What's Inside A Black Hole?)
Uploaded: 2021-01-14T08:07:42.000Z
Duration: 9 min 16 s
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關係子句

Black holes are mysterious and bizarre objects in the universe that really have no explanation.

In fact, we hardly know anything about what lies inside of a black hole?

We know and understand what we see on the outside of a black hole

But we have no way of going inside one to take a look at what is really happening.

Even if we sent a probe inside a black hole,

And there would be no way that the probe could transmit a signal outside once it had been sucked inside.

This is because a black hole is the product of mass being squeezed together, so densely and so tightly that it creates a gravitational pole.

That is so strong that not even light can escape its grasp.

Supermassive black holes with masses millions to billions of times that of the Sun are thought to lurk at the hearts of all galaxies in the universe.

You may notice that when you see a photo of a spiral galaxy

such as the Milky Way in the center of the galaxy is a giant mass of light?

Which many people would think looks like a massive Sun, but this is not light coming from the black hole itself.

Remember that life cannot escape the heavy gravitational pull.

Instead the light we see comes from magnetic fields near a spinning black hole that propel electrons outward in a jet

Along the rotation axis the electrons produce bright radio waves.

Quasars are believed to produce their energy from massive black holes in the center of the galaxies in which the quasars are located.

But quasars are so bright they drown out the light from all the other stars in the same galaxy. You're probably asking well

What's a quasar a quasar is the short name for quasi stellar object and is a very highly energetic object?

Surrounding an actively feeding supermassive black hole in more basic terms the supermassive black hole in the middle of a galaxy feeds

intermittently as it feeds gas swirls around it at incredible speeds and

Forms an insanely bright hot orbiting disc and if the black hole is swallowing a large amount of material this feeding is accomplished by gigantic jets of gas these are called quasar

They are essentially fueled by the black holes they orbit

some supermassive black hole giants release an extraordinarily

Large amount of light when they rip apart stars in devour matter and are likely the driving force behind these quasars

When material gets too close to a black hole it forms that bright hot accretion disk around the black hole

That accretion disk heats up to millions of degrees

Blasting out an enormous amount of radiation

The magnetic environment around the black hole forms twin Jets of material which flow out into space for millions of light years

This becomes what is called an active galactic nucleus

Or a GN the diet of known black holes consists mostly of gas and dust which fill the otherwise empty space throughout the universe

black holes can also consume material torn from nearby stars in fact the most massive black holes can swallow stars whole

Black holes can also grow by colliding and merging with other black holes

This growth process is what can and usually does reveal the presence of a black hole?

But supermassive black holes aren't always feeding if a black hole runs out of food the Jets run out of power and shut down

Right up until something gets too close and the whole system starts up again the supermassive black hole at the center of our Milky Way

Galaxy is all out of food or space material to consume

It lies completely dormant for the time being a sleeping giant, so it doesn't have an active galactic nucleus

And so there is no quasar emitting light however

We are on a collision course with another galaxy and in 10 billion years or so when the Milky Way collides with the Andromeda galaxy

Our supermassive black hole may roar back to life as a quasar as it begins to consume part of this new galaxy

Now it might sound like black holes are dangerous and that anything that even remotely comes close to a black hole

Would get sucked inside and be crushed and while it's true that if you manage to carefully drop an object into a black hole

You'd never get that object back, but black holes are actually remarkably bad at pulling material close to them

There are a couple of reasons for this one black holes aren't actually attractive to anything for any reason other than gravity

Much like our solar system is in a stable orbits around the Sun the vast

majority of a galaxy is in a stable orbit around the black hole with no real reason to go plunging towards the very center of

The galaxy the second reason that black holes are bad at being astronomical vacuum cleaners is that they're really?

Really inefficient at getting material close enough to them to cross the event horizon and add to the mass of the black hole

Even small black holes which exist in great numbers in the galaxy are much better at tearing a companion star apart than they aren't actually

Growing their own size by consuming the star hole so despite their reputation

Black holes will not actually suck in objects from large distances a black hole can only capture objects that come very close to it

They're more like venus flytraps than cosmic vacuum cleaners for example imagine replacing the Sun by a black hole of the same mass

But the planets would continue to revolve around the black hole at the same distance and speed as they do now

None of the planets would be sucked into the black hole our earth would be in danger

Only if it came within some 10 miles of the black hole

Much less than the actual distance of the Earth from the Sun which is a comforting 93 million miles away

So after knowing all of this do we have any idea, what is inside of a black hole?

Current theories predict that all the matter in a black

Hole is piled up in a single point at the center

But we do not understand how this central singularity works to properly understand the black hole center requires a fusion of the theory of gravity

With the theory that describes the behavior of matter on the smallest scales called quantum mechanics

This unifying theory has already been given a name quantum gravity, but how it works is still unknown

This is one of the most important unsolved problems in physics

Studies of black holes may one day provide the key to unlock this mystery

Einstein's theory of general relativity allows unusual characteristics for black holes

For example the central singularity might form a bridge to another universe. This is similar to a so-called wormhole

Which is a mysterious solution of Einstein's equations that has no event horizon?

Bridges and wormholes might allow travel to other universes or even time travel, but without observational and experimental data

We do not know whether bridges or wormholes exist in the universe or could even have formed in principle

By contrast black holes have been observed to exist and we understand how they form

What is actually inside of a black Cole is still a mystery?

So does a black hole live forever if there is nothing for a black hole to consume then no in

Fact a very surprising thing happens you might have heard of Stephen Hawking

He is a theoretical physicist in cosmologists, and is at the forefront on the study of black holes

He came up with a theoretical prediction that black holes emit radiation this of course is now known as Hawking radiation

Hawking radiation reduces the mass and energy of black holes and is therefore also known as black hole evaporation

Because of this black holes that do not gain mass through other means are expected to shrink and ultimately vanish

What it means is that if the black hole has nothing to eat it?

Eventually evaporates the energy and mass that the black hole pulled inside of itself

Evaporates back out into space in the form of radiation. It is almost as if a black

Hole is a universe recycling machine Stephen Hawking proved this in

1974 by using the laws of quantum mechanics to study the region close to a black hole horizon

The quantum theory describes the behavior of matter on the smallest scales it predicts that tiny particles and light are

continuously created and destroyed on subatomic scales

Some of the light thus created actually has a very small chance of escaping before it is destroyed to an outsider

It is as though the event horizon glows the energy carried away by the glow decreases the black hole's mass until it is completely gone

This surprising new insight show that there is still much to learn about black holes

However, Hawking's glow is completely irrelevant for any of the black holes known to exist in the universe

For them the temperature of the glow is almost zero and the energy loss is negligible

The time needed for the black holes to lose much of their mass is

unimaginably long however if much smaller black holes ever existed in the universe

Then Hawking's findings would have been catastrophic a black

hole as massive as a cruise ship would disappear in a bright flash in less than a second as

You can see black holes are incredible and mysterious things perhaps one day

We will know exactly what lies inside of a black

Hole, maybe we will find out that they are gates to another dimension such as wormholes