Doesn't a black hole stretch time in a really weird manner? That would mean that no sensible answer can be given to the question. It could easily be that it takes either one billionth of a second or a trillion years, depending on where you are standing when observing the occurrence.
As I understand it, the enormous gravitational force causes time and space to become inverted. Instead of velocity being defined as time to displace position, time occurs over displacement. A person on the event horizon would be apparently frozen in place until they eventually faded to nothing. Not sure how that analogy works since light doesn't escape a black hole but it's how Brian Cox explained it.
Seems that way. Physics predicts completely wild outcomes at the extrema, in this case gravity but also for things that are very small. Quantum entanglement is a very curious phenomenon seemingly transferring information over vast distances instantaneously, faster than the speed of light which is impossible.
Trick question: it's until the heat death of the entire universe. You get turned into this long spaghetti that gets absorbed at an increasingly slowing rate. So your scalp or your feet never quite make it to the inside.
This may be less than accurate because I'm not an expert.
I'm going to guess yes, the mass increases. I'm not sure about physical size because it may just be density. But I also feel like I should stop talking out of my ass now.
Hawking radiation emits energy/mass from them too so they also get smaller instead of only growing. That's believed to be the reason that micro black holes wouldn't be dangerous.
So there are two correct but very different answers to this question, then, right? One for an outside observer and another from the perspective of the black hole?
The extreme case is a photon crossing the universe. For an outside observer, it will take the photon billions of years to cross the universe. For the photon there is no time at all.
Time dilation is your subjective acceleration veering into more "time" than "space".
If you somehow were in a flat universe with parallel velocity to an object several light-years away, and somehow managed to accelerate towards it at 1 g, you'd impact at the time on your watch that pure Newtonian physics says you would.
The subjective clocks of the place you're hitting would measure your travel time as a lot longer, however. But it wouldnt be infinite at all -- a relatively small multiple of "several" years, in fact.
(Before the relativistic impact recused both you and them to an energetic plasma, that is.)
We have a physicist here ! Thanks to the universe π
(i am more like a physics' enthusiast who understood A. Einstein(s') very old book on special (= 1st draft) relativity)
Just a sci-fi enthusiast who got really annoyed by a trilogy that didn't understand what the "delta" in "delta-v" meant and so the space ships spent a lot of time getting to a very high orbital speed before each fight.
The singularity of a black hole is measured in time, not distance. The center exists at the end of time so that's where you go. So how long? -all of the time remaining in the universe.
They are classified by mass. Some are definitely bigger than others. The one in our Galaxy called Sagittarius A has as much mass as over 4 million if our suns. If it were in our solar system it would be physically as big as the orbit of Venus.
The mass of black holes is typically measured in multiples of our sun, or stellar masses. A supermassive is measured in the millions to billions of our sun, while a "small" black hole is just a few dozen suns big. The small ones, or stellar mass black holes can hang around like stars and over a galaxy but the supermassive ones are the things that create or hold the galaxy together.
"How can time end" is more complicated. Without getting too complicated with it imagine putting a drop of red food coloring in a pool. Imagine it in slow motion. The big bang is the moment the food coloring hits the water. Then the food coloring spreads out but for a while you can clearly see the red. We are at the point in the age of the universe where the red is still visible in the water. At some point the red will spread out so much you can't see it anymore. Without getting too dramatic that would be called the heat death of the universe. At that point time effectively stops because there is nothing left to change, meaning the red itself carries time with it. This is also called entropy.
So to travel into a black hole would be to fast forward to the point where the universe has become so spread out that atoms and the bits inside that make up the atoms fall apart, effectively ending time. Time itself is a measure of change. Nothing left to change means no more time. So that's when the black hole ends. It's a little more complicated than that but if you can understand what I just said you are about 90% of the way to understand everything we currently think we know about black holes.
I found this informative and mind-blowing. I know that sounds like spam, but it's relevant to the heat death of the universe and entropy and time stopping.
32 Comments
Tuuktuuk@piefed.europe.pub · 21 pts · 215d
Doesn't a black hole stretch time in a really weird manner? That would mean that no sensible answer can be given to the question. It could easily be that it takes either one billionth of a second or a trillion years, depending on where you are standing when observing the occurrence.
BilboBargains@lemmy.world · 3 pts · 214d
As I understand it, the enormous gravitational force causes time and space to become inverted. Instead of velocity being defined as time to displace position, time occurs over displacement. A person on the event horizon would be apparently frozen in place until they eventually faded to nothing. Not sure how that analogy works since light doesn't escape a black hole but it's how Brian Cox explained it.
Tuuktuuk@piefed.europe.pub · 1 pts · 213d
Does that still mean that the concept of "time" is not defined in a useful (human-understandable) manner in a black hole?
BilboBargains@lemmy.world · 2 pts · 207d
Seems that way. Physics predicts completely wild outcomes at the extrema, in this case gravity but also for things that are very small. Quantum entanglement is a very curious phenomenon seemingly transferring information over vast distances instantaneously, faster than the speed of light which is impossible.
FriendOfDeSoto@startrek.website · 18 pts · 215d
Trick question: it's until the heat death of the entire universe. You get turned into this long spaghetti that gets absorbed at an increasingly slowing rate. So your scalp or your feet never quite make it to the inside.
This may be less than accurate because I'm not an expert.
sopularity_fax@sopuli.xyz · 3 pts · 215d
Do black holes get bigger the more information they gobble up?
FriendOfDeSoto@startrek.website · 7 pts · 215d
I'm going to guess yes, the mass increases. I'm not sure about physical size because it may just be density. But I also feel like I should stop talking out of my ass now.
Prime@lemmy.sdf.org · 4 pts · 214d
The physical size is always zero. But it's event horizon can get larger with more mass
MDCCCLV@lemmy.ca · 2 pts · 214d
Hawking radiation emits energy/mass from them too so they also get smaller instead of only growing. That's believed to be the reason that micro black holes wouldn't be dangerous.
Witchfire@lemmy.world · 13 pts · 215d
Depends on who you ask
sopularity_fax@sopuli.xyz · 5 pts · 215d
Good answer. First person
A_A@lemmy.world · 3 pts · 215d
at most Ξ length / c β 6.4e6 m / (3e8 m/s)
LillyPip@lemmy.ca · 3 pts · 214d
This assumes time remains constant, though, right? But isnβt time affected by the black hole?
bufalo1973@piefed.social · 3 pts · 214d
Maybe from the POV of the person falling.
LillyPip@lemmy.ca · 3 pts · 214d
So there are two correct but very different answers to this question, then, right? One for an outside observer and another from the perspective of the black hole?
bufalo1973@piefed.social · 5 pts · 214d
The extreme case is a photon crossing the universe. For an outside observer, it will take the photon billions of years to cross the universe. For the photon there is no time at all.
DomeGuy@lemmy.world · 3 pts · 214d
Time dilation is your subjective acceleration veering into more "time" than "space".
If you somehow were in a flat universe with parallel velocity to an object several light-years away, and somehow managed to accelerate towards it at 1 g, you'd impact at the time on your watch that pure Newtonian physics says you would.
The subjective clocks of the place you're hitting would measure your travel time as a lot longer, however. But it wouldnt be infinite at all -- a relatively small multiple of "several" years, in fact.
(Before the relativistic impact recused both you and them to an energetic plasma, that is.)
A_A@lemmy.world · 2 pts · 214d
We have a physicist here ! Thanks to the universe π
(i am more like a physics' enthusiast who understood A. Einstein(s') very old book on special (= 1st draft) relativity)
DomeGuy@lemmy.world · 4 pts · 214d
Not a physicist -- they know the math.
Just a sci-fi enthusiast who got really annoyed by a trilogy that didn't understand what the "delta" in "delta-v" meant and so the space ships spent a lot of time getting to a very high orbital speed before each fight.
A_A@lemmy.world · 2 pts · 214d
πππ
ZiggyTheZygote@lemmy.ca · 9 pts · 215d
I think twelve.
sopularity_fax@sopuli.xyz · 4 pts · 215d
Units?
ZiggyTheZygote@lemmy.ca · 10 pts · 215d
Of course.
sauerkrautsaul@lemmus.org · 4 pts · 215d
psssh try 12,000
ZiggyTheZygote@lemmy.ca · 3 pts · 215d
No i did the math it's 12, don't argue with me I'm a potato.
BotsRuinedEverything@lemmy.world · 9 pts · 214d
The singularity of a black hole is measured in time, not distance. The center exists at the end of time so that's where you go. So how long? -all of the time remaining in the universe.
sopularity_fax@sopuli.xyz · 1 pts · 214d
Why are they classified by thing like supermassive etc then if they arent measured in size?
How can time end?
BotsRuinedEverything@lemmy.world · 8 pts · 214d
They are classified by mass. Some are definitely bigger than others. The one in our Galaxy called Sagittarius A has as much mass as over 4 million if our suns. If it were in our solar system it would be physically as big as the orbit of Venus.
The mass of black holes is typically measured in multiples of our sun, or stellar masses. A supermassive is measured in the millions to billions of our sun, while a "small" black hole is just a few dozen suns big. The small ones, or stellar mass black holes can hang around like stars and over a galaxy but the supermassive ones are the things that create or hold the galaxy together.
"How can time end" is more complicated. Without getting too complicated with it imagine putting a drop of red food coloring in a pool. Imagine it in slow motion. The big bang is the moment the food coloring hits the water. Then the food coloring spreads out but for a while you can clearly see the red. We are at the point in the age of the universe where the red is still visible in the water. At some point the red will spread out so much you can't see it anymore. Without getting too dramatic that would be called the heat death of the universe. At that point time effectively stops because there is nothing left to change, meaning the red itself carries time with it. This is also called entropy.
So to travel into a black hole would be to fast forward to the point where the universe has become so spread out that atoms and the bits inside that make up the atoms fall apart, effectively ending time. Time itself is a measure of change. Nothing left to change means no more time. So that's when the black hole ends. It's a little more complicated than that but if you can understand what I just said you are about 90% of the way to understand everything we currently think we know about black holes.
finallymadeanaccount@lemmy.world · 5 pts · 214d
I found this informative and mind-blowing. I know that sounds like spam, but it's relevant to the heat death of the universe and entropy and time stopping.
https://youtu.be/uD4izuDMUQA?list=RDuD4izuDMUQA
frog_brawler@lemmy.world · 2 pts · 214d
Paragone@lemmy.world · 0 pts · 211d
At the event-horizon, you're moving at the speed of light.
So, you can't have any awareness of duration, anymore.
You slam into the black-hole, from your perspective, instantaneously, then.
No machine could be "fast enough" to notice any duration pass by, between the event-horizon & the smashing-to-strings/quarks/whatever.
_ /\ _
sopularity_fax@sopuli.xyz · 1 pts · 117d
What does _/ _ mean?
Paragone@lemmy.world · 2 pts · 93d
It's supposed to be namaste, ASCII-style ( I'm old, & emojis aren't quite my thing, yet )
Sometimes my shit-keyboard-system misses ( or doubles ) keystrokes.
_ /\ _