We have an interesting question from an ARSE lover so let us go ahead and: Ask ARSE.
I've always been a big sci-fi fan and I was wondering what happens if you travel into a black hole?
Thank you for the question Damien, and an interesting one at that.
While we are unsure what would actually happen, we can use the data we know of and extrapolate it to create the most likely scenario.
Firstly, Black Holes are a place in space where gravity pulls so much that even light can not get out. The gravity is so strong because matter has been squeezed into a tiny space, like when a star is dying.
The outermost boundary of the hole is its event horizon, the point at which the gravitational force precisely counteracts the light's efforts to escape it. Go closer than this, and there's no escape. Quantum effects at the edge create streams of hot particles that radiate back out into the universe.
Black holes can be big or small, with the smallest black holes as small as just one atom. These black holes are very tiny but have the mass of a large mountain.
The largest black holes are called "supermassive." These black holes have masses that are more than 1 million suns together and as far as we know, every large galaxy contains a supermassive black hole at its centre.
So what would happen if you stumbled into one of these fellas?
As you are drawn into the event horizon, you begin to contort and stretch under the whims of the incredible amount of gravity focussed onto a singular spot in space.
Strangely, the closer you get to the event horizon the slower you seem to move until you freeze in place, completely stationary.
You stretch over the event horizon as a burning heat begins to consume you as no other creature has witnessed before.
Remember the hot particles we mentioned earlier?
You begin to slowly burn under the hot particles firing out known as "Hawking Radiation" after the late great astrophysicists correctly predicted theory.
It would be the equivalent of an indescribable amount of Chernobyl events, let alone trying to quantify it in how many X-rays you would be on the receiving end of.
Then you are welcomed into...
After you are stretched beyond physical limitations and are slowly burnt to ash, you then travel inside the black hole as a whisp of dust and nothingness. Pretty calmly and slowly we might add.
But what does this feel like? What are your perceptions of this event?
You might find this hard to believe, but you feel nothing.
From your perspective, nothing happens at all given the size of the hole.
If the hole was smaller than you, you would find yourself forced into a zone below your physical size and would be stretched from your head first as it tears your body away from your feet.
But given it's the size you can fit in, you basically feel nothing as you freefall through a vacuum.
This is because it is a matter of "perspective" changing not your physical makeup. Sound weird, we know.
Essentially, Einstein theorised that your contorted, burnt first scenario exists and so does your second more peaceful one. But how?
Information can never be lost, much like energy.
So when you venture into the black hole toward the event horizon, a person watching from outside would see you stretch and burn to ash while you feel nothing.
This is because Quantum Physics says information cannot be lost, ever. Your ashes would be left behind and could be collected.
Conversely, the laws of physics also dictate that you must freefall through, which Einstein named his "happiest thought".
Einstein’s happiest thought (1907): “For an observer falling freely from
the roof of a house, the gravitational field does not exist”.
Conversely, an observer in a closed box — such as an elevator or
spaceship — cannot tell whether his weight is due to gravity or acceleration.
This theory applies to general relativity, and Einstein equated it to how we currently feel about time. You see, we don't feel time, yet cannot go back in time, only forward.
This is the freefall experience within the black hole.
Only falling, never returning.
Inside a black hole, you will experience the reversal of space and time.
So how can you be in two places at once???
We don't really know and all information we base everything on in our reality points to these frustrating conclusions.
You will exist as ash and you will exist unharmed, never to return.
The only logical and commonly shared conclusion to the paradox is that because no one sees your duplicate self, it does not exist in that reality.
Same for yourself inside the black hole alive and well, the dust that was your former self does not exist to you.
This theory was made popular by Leonard Susskind, who found the only way that these two results could happen simultaneously without breaking any laws of nature or physics.
So is it an alternate reality?
Maybe, but we won't know until we know...
Thanks for the question Damien and keep spreading ARSE far and wide!