00:00You already know about black holes,
00:03giant space vacuums that pull inside
00:05everything in their way.
00:07But have you ever heard of a space phenomenon
00:10called white holes?
00:12And what would happen if these two met,
00:15and let's say, collided?
00:18Let's hop on a shuttle,
00:19venture into space,
00:21and get to know them better first.
00:23As you already know,
00:24you can't see black holes directly,
00:27even with fancy telescopes
00:28that detect light, x-rays,
00:30or other types of electromagnetic radiation.
00:34But we can see what a black hole does
00:36to the things that surround it.
00:39For example, when a black hole
00:40passes through a cloud of space matter,
00:43it pulls everything towards itself
00:45in a process called accretion.
00:48As the matter is pulled in,
00:50it becomes hot and emits detectable x-rays.
00:54Or something else can happen.
00:57Sometimes, a regular star
00:59comes too close to a black hole
01:01and gets torn apart.
01:03A black hole is a super-dense object
01:06with an incredibly strong gravitational pull
01:08that starts stretching the poor star out
01:11into a long and thin shape like spaghetti.
01:15You've probably guessed it.
01:16We call this spaghettification.
01:19As the pieces of the star are pulled in,
01:22they become hot and emit x-rays.
01:25A black hole can choose a different method, too,
01:28squishing the star and making it flat like a pancake.
01:33In the other corner,
01:34you have a mysterious white hole.
01:36These are less well-known
01:38because we don't have much information about them.
01:41Our knowledge of white holes
01:42is based on theories
01:44derived from the same mathematical equations
01:47used to describe black holes.
01:50To witness this battle,
01:52you would need to get close to a white hole.
01:54But don't worry.
01:55At least this one won't eat you
01:57and turn you into spaghetti or a pancake.
02:00Just like nothing can escape a black hole,
02:03nothing can enter a white hole.
02:06It's like the most exclusive club in space
02:09with no entry allowed.
02:11You can see that white hole
02:13also has a mass and even spin.
02:16There might be a ring of dust and gas
02:18around its outer edge,
02:19known as the event horizon,
02:22which acts as a border
02:23separating the white hole
02:25from the rest of the universe.
02:28While they share similarities,
02:30there is one crucial difference.
02:32A white hole can release matter and energy,
02:35while a black hole cannot.
02:37Scientists describe a white hole
02:39as the time reversal of a black hole,
02:43as if you're watching a video
02:44of a black hole played backwards.
02:48Things that are already inside a white hole
02:51can leave and interact with the outside world.
02:54However, nothing from outside space
02:56can ever affect the secretive inner world
02:59of a white hole.
03:01Einstein said that space and time are not flat.
03:05They can bend and fold,
03:07all because things like stars and planets have mass.
03:12A scientist named Carl Schwarzschild
03:14figured out how to use Einstein's ideas
03:17to describe what happens
03:18around a really heavy object.
03:21He discovered something called a singularity.
03:25It's a point of infinite density,
03:28and it lies at the center of a black hole.
03:31It's like a tiny, tiny point
03:33where everything is squished together,
03:36all the matter that the black hole has consumed.
03:39The tricky part is that the singularity is so small
03:43that it doesn't really make sense
03:45in our normal understanding of time and space.
03:49Plus, it bends space around it so much
03:52that it creates a special area
03:55that's cut off from the rest of the universe.
03:58We call this area a no-man's land,
04:01which is basically where black holes exist.
04:04Scientists still can't understand what happens
04:07at the point of singularity in black holes,
04:10let alone white holes.
04:13So let's go back to the questions
04:14we started the story with.
04:16What's stronger, and what would win then?
04:19It seems black and white holes
04:21have completely different strategies.
04:23A white hole is a mystery
04:25that we still don't know much about,
04:27but it seems more experienced at conquering space
04:31than a black hole is.
04:33I mean, a black hole swallows matter
04:35and everything it encounters, true,
04:38but a theory suggests that white holes
04:40may have once been black holes.
04:45They're purely imaginary for now,
04:47but stories say white holes can only exist
04:50if there is absolutely no matter
04:52inside their boundaries.
04:55If even the smallest particle entered a white hole,
04:58it would cause it to collapse.
05:00That's a significant disadvantage
05:03in a potential battle, don't you think?
05:05But it's also a really tough task
05:08to try to sneak a small asteroid inside a white hole.
05:12Its gravity is most likely extremely powerful
05:15and will push you away.
05:18This is where the singularity comes into play.
05:21Remember when I said scientists
05:23were not sure what really happens
05:25with this tiny, tiny dot of infinite density?
05:29It can't be that a black hole
05:31just infinitely collects matter in its center.
05:34Something else has to be happening there.
05:39What if this singularity kind of rebounds
05:41and actually becomes a white hole?
05:44Of course, it would take a really long time
05:46for this to happen,
05:48like billions of years,
05:50even for the smallest black holes.
05:54There's a special type called primordial black holes,
05:58and scientists think those probably formed
06:00right after the Universe was born.
06:03And if there were really tiny black holes
06:05created after the Big Bang,
06:07they might have already exploded
06:10and turned into white holes.
06:13Some scientists even think white holes
06:15could possibly explain the Big Bang,
06:18since both involve an enormous amount of matter
06:21and energy appearing out of nowhere.
06:24All this doesn't sound promising for a black hole.
06:27Can this be the first time ever it's going to lose?
06:30If a black hole becomes a white hole,
06:33it doesn't even matter how much it's consumed.
06:36It might throw everything back out into space.
06:40In that case, a white hole might not last that long,
06:43so it will need to make a move against its opponent
06:46really quickly.
06:49Whoa, you may have thought you were safer near the white hole
06:52because it wasn't about to eat you,
06:54but look at it!
06:55It's shaking!
06:57Oh no, it's started ejecting all the things
06:59it's been keeping inside at the speed of light.
07:02Get out of the way to not have some ripped planet
07:05catapulted in your direction.
07:08After millions, even billions of years
07:11of making a mess all around the Universe,
07:14a magnificent, spectacular, and chaotic battle
07:17is about to start.
07:19The black hole is patiently taking the attack,
07:23pulling in everything that the white hole
07:25is throwing in its direction.
07:27Asteroids, all those ripped stars
07:30that used to shine so brightly in the night sky,
07:33and even entire galaxies,
07:35it's all getting out of it insanely fast
07:38and in all directions.
07:41Both the white and black hole have managed to survive
07:44against every space object till now,
07:47but that's just because they haven't faced each other yet.
07:50It's an exhausting battle that doesn't stop.
07:53All odds were against the black hole at the beginning,
07:56but look, it seems something is changing.
07:59The white hole is slowly losing energy
08:01since it can't swallow any new things
08:04and renew its supplies.
08:07Meanwhile, the black hole is patiently collecting
08:10everything its opponent has thrown at it
08:12during this fierce attack,
08:14growing bigger and bigger.
08:17It can keep doing it for thousands of years.
08:20Its insanely strong gravity brings the white hole closer,
08:24even though it's trying to escape.
08:28And the time comes for the last strike.
08:30The black hole's gravity starts stretching its enemy
08:33until it swallows it entirely.
08:36The white hole is completely gone,
08:38and now that it has so much energy,
08:40our winner is more massive and stronger than ever.
08:45Oh no, run!
08:46Now you have this hungry supermassive black hole
08:49wandering around looking for more things to eat,
08:52until it falls apart into a white hole again one day
08:56and starts an even bigger, more magnificent battle
09:00that the entire universe will watch.
09:03That's it for today.
09:04So hey, if you pacified your curiosity,
09:07then give the video a like and share it with your friends.
09:09Or if you want more, just click on these videos
09:12and stay on the bright side.
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