7 ms·

Is our universe trapped inside a black hole? This JWS Telescope discovery

81 points by janandonly 2y ago

m3kw9 2y ago
Ok but then the theory of black holes are wrong because this isn’t dense at all.
- rocqua 2y ago
  Black holes aren't really infinitely dense. The matter isn't concentrated at the centre, its spread out over the event horizon. As i understand the theory, they effectively suggest you could glue another universe onto the event horizon of a black hole. From the outside that is indistinguishable from 'just a black hole'.
- jpalawaga 2y ago
  An entire universe crammed inside the event horizon seems pretty dense to me! Makes you wonder how much matter would be in the parent universe.
- ShinTakuya 2y ago
  Black holes need not be dense. The black hole at the centre of galaxy M87 has the density of air in our atmosphere. The larger the black hole, the less dense it is. So that alone doesn't preclude us existing inside of one.
  - m3kw9 2y ago
    That’s news to me, I was taught that the mass collapses into it self it creates more gravity and more matter gets sucked in because the mass is so dense. So at which point does it become less dense?
    - d1sxeyes 2y ago
      As long as it’s dense enough that light can’t escape, it’s a black hole. You can achieve that with extreme density or huge volumes of mass. The more massive an object, the less dense it needs to be to be a black hole.
    - ShinTakuya 2y ago
      Keep in mind that my own knowledge of physics is very rusty, so some of this is definitely making bad assumptions. The density in the singularity (centre) of the black hole is in theory infinite. But the event horizon (the part where light no longer escapes) is not the singularity, it's simply where the gravity becomes so strong that light can't escape. Think of it as the sun vs the planets - we're not in the sun, but we still feel its effects. The density of the solar system isn't the same as the density of the sun. This is bad analogy because the same mathematics/physics doesn't apply, but it should help you get the general picture based on your original assumption. In general, the heavier the black hole, the less dense it is when measured from the event horizon. So in theory, it's possible to have a black hole so heavy that the event horizon contains the entire universe. In fact, the known universe is heavy enough to be a black hole 3 times the known radius of the universe. But as we know from stars that turn into black holes, just because something is heavy enough to be a black hole, doesn't mean it is one yet.
- nextaccountic 2y ago
  Only the infinitesimally small singularity that is in the future of all objects inside the event horizon is supposed to be very dense. The space inside the event horizon is supposed to be normal-ish
  - Aerroon 2y ago
    If such a singularity exists at all. The thing we "observe" about black holes is the event horizon. It could be that space inside a black hole is just regular space.
    - nextaccountic 2y ago
      Yep! Generally speaking singularities only appear because the math is deficient in some way. Other areas of physics successfully got rid of unphysical singularities by employing better math, it's just that we don't know how to fix this aspect of general relativity (maybe quantum gravity will?)
jagged-chisel 2y ago
> These [baby] universes would be unobservable to us because they are also behind an event horizon, a one-way light-trapping point of no return from which light cannot escape, meaning information can never travel from the interior of a black hole to an external observer. Also meaning that “our” blackhole (the one containing us) is unobservable from the parent universe for the same reason. So where is all this extra light/energy going in our universe? Should we not have detected an increase of energy in our universe?
- flowerthoughts 2y ago
  (Complete hypothesizing from a very cursory understanding.) Perhaps that's dark energy or vacuum energy? If mass and time truly switches places when crossing into a black hole, it would make sense that the spacetime size of this universe translates into observable mass outside it. Which might tie it to the expansion of the universe.
  - nextaccountic 2y ago
    > If mass and time truly switches places when crossing into a black hole What do you mean by that?
- alabastervlog 2y ago
  I figure our whole universe so far has existed in the first nanosecond (or whatever) after the creation of the black hole in the parent universe, so very little energy or light has had time to enter. By one or two seconds in the parent universe’s time scale, our universe will have settled down to its extremely long state of being a cold, dark void of slowly decomposing subatomic particles. No good reason to think this, just feels right.
  - jagged-chisel 2y ago
    The relative time part is a really interesting thought. Thanks!
  - Aerroon 2y ago
smitty1e 2y ago
"All who dare To cross her course Are swallowed by A fearsome force Through the void To be destroyed Or is there something more? Atomized — at the core Or through the Astral Door — To soar…" https://www.rush.com/songs/cygnus-x-1-book-one-the-voyage/ https://www.rush.com/songs/cygnus-x-1-book-one-the-voyage/
rocqua 2y ago
How does this work with matter falling into 'our' black hole and hawkins-radiation leaving our black hole? Heck, Hawkins radiation means black holes can evaporate. Does that correspond to a universa collapsing? Would matter falling into our black hole come shooting out of the white-hole we see? Would time on either side of the event horizon even be related?
- Aerroon 2y ago
  Perhaps dark energy is hawking radiation. We just see what it's like from the inside. Something to consider is a possible time scale difference. Eg time could be dilated for us for being around so much density.
  - rocqua 2y ago
    It would need to be the other way around, dark energy being matter falling into our black hole. Hawking radiation should 'suck' energy out of our universe. I can't think of a satisfying source of this energy. The best I can imagine is either space contracting (but that is gravity) or entropy increasing (but that doesn't leak energy, just free energy).
- cvoss 2y ago
  > Would time on either side of the event horizon even be related? I think that's exactly the right question to ask. And ask it for space too. Perhaps the entire history of the interior universe unfolds between the black hole's formation and its final evaporation. Perhaps a heat death of the interior universe, where everything spreads out until nothing interesting is left, can fit inside this ever shrinking volume.
- cryptonector 2y ago
  > How does this work with matter falling into 'our' black hole and hawkins-radiation leaving our black hole? We would see that at the edge (if we could see it) there's new mass and energy, but that would be obscured by what appears as the CMB for us. > Heck, Hawkins radiation means black holes can evaporate. Does that correspond to a universa collapsing? No, it corresponds to stuff disappearing from our universe, until someday nothing is left. > Would matter falling into our black hole come shooting out of the white-hole we see? We'd see it as being part of the Big Bang, behind the CMB, so we wouldn't see it. > Would time on either side of the event horizon even be related? Er, not in any way that we could observe, so it's not a question we could answer. But we could receive information from the outside, except that the CMB would hide it from our prying eyes.
Sharlin 2y ago
Something something Betteridge's law of headlines.
fprog 2y ago
An alternate hypothesis which seems equally interesting, albeit for different reasons, is at the end of the article: > Another explanation for why the JWST may have seen an overrepresentation of galaxies rotating in one direction is that the Milky Way's own rotation could have caused it. > Previously, scientists had considered the speed of our galaxy's rotation to be too slow to have a non-negligible impact on observations made by the JWST. > “If that is indeed the case, we will need to re-calibrate our distance measurements for the deep universe," Shamir concluded. "The re-calibration of distance measurements can also explain several other unsolved questions in cosmology such as the differences in the expansion rates of the universe and the large galaxies that according to the existing distance measurements are expected to be older than the universe itself."
- perihelions 2y ago
  I'm utterly confused what's going on. They're measuring galaxies' rotations by looking at images of the subset that are spiral galaxies, and checking which direction the arms spiral. They describe their image processing algorithm in their paper [0]. (it's around figure 3) How can local movement of stars within the Milky Way affect which way spiral galaxy arms are pointing? [0] https://academic.oup.com/mnras/article/538/1/76/8019798 https://academic.oup.com/mnras/article/538/1/76/8019798.
  - Georgelemental 2y ago
    Read section 5.2 of the paper
    - perihelions 2y ago
      Do you or other HN commenters understand it in a satisfying way? The author writes about the Doppler effect creating a systemic bias in brightness depending on which way the galaxies are rotating. I don't understand that argument either, but it's moot, because they state categorically that that effect would be too small to explain their results. ("This explanation is challenged by the fact that the effect of the rotational velocity have merely a mild impact on the brightness of galaxies, and therefore is not expected to lead to the dramatic difference of 50 per cent in the number of galaxies as observed through JADES.") That's the only explanation I recognized as an explanation. Then I lost track of their argument following that. They refer to several speculative physics theories like MOND, but I don't understand them to be saying something that concretely predicts distant galaxies to appear to be rotating differently. I'm appealing to anyone on HN who knows enough about this field to understand the meat of this argument.
dingnuts 2y ago
at the bottom of the article the mundane hypothesis is presented that the measurement seen by JWST might be a calibration error caused by the rotation of the Milky Way making it appear that other galaxies have a preferred rotation. sadly, this is likely the real explanation, but that's not very exciting
sigmoid10 2y ago
This newsblog takes one piece of the paper [1] and blows it up like it's the most obvious thing ever and completely hand-waves away the alternative, while the paper itself actually provides some compelling evidence for the alternative explanation: This asymmetry is because of our own galaxy's rotation. It would be an insane coincidence to have the large scale structure of our universe be more asymmetric towards the poles of our galactic plane and the further you go away from our galaxy (especially when velocity blue shifts would obviously make one type of rotation for galaxies more visible in the high-z regime where JWST primarily looked). Forget black hole cosmology, if you believe what this article suggests, then special relativity itself may be wrong. The data is pretty sound and perfectly in line with earlier observations that found no asymmetry if you believe our own galaxy's rotation is the culprit. So if I had to bet, I'd say we misunderstood galaxies and not the universe as a whole. Mostly because galactic physics is incredibly complicated and has very whimsical empirics, whereas we have some really solid theories and data on the universe as a whole. [1] https://academic.oup.com/mnras/article/538/1/76/8019798 https://academic.oup.com/mnras/article/538/1/76/8019798
- specialist 2y ago
  Thanks for link. Amazing work. I'm less than noob, so barely comprehend this topic, much less this paper. ELI5: Per "5.2 Physics of Galaxy Rotation", could the Milky Way's relative movement, in addition to its spin, also effect the observed assymetry? In Figure 10, is the Milky Way also moving toward the blue and away from the red? Thanks for humouring my question. Everything about astronomy and JWST just blows my mind. Like how Figure 10 sorta resembles yinyang. What a time to be alive.
api 2y ago
It'd be neat if the universe were essentially a nested Russian doll of black holes. Our universe is a black hole with black holes inside and black holes inside them and so on, and the larger universe outside ours is also an even bigger black hole. Some of the really huge black holes in our universe might be big enough to host interesting things within, but the smaller ones probably just contain "toy" universes without much happening. I recall reading about our universe as a black hole once -- one thing posited is that everything that is happening and what we think of as space is really information processing occurring just at the surface of the event horizon. There was some possible way of explaining non-local phenomena like entanglement that way, but I forget the details. It's fascinating to think about how the actual universe might be something quite alien from our ordinary perception. It's not that our ordinary perception is wrong. What we're perceiving is just one perspective on something much larger and weirder. In this case our perspective would be from within this information substrate. It's almost universe-as-simulation, except that the simulation does not have a builder. It's a naturally occurring phenomenon. The Matrix has no architect, or if it does it's something fully outside the event horizon of this object and thus un-observable. Of course at this point we're well into physicists smoking pot territory.
xqcgrek2 2y ago
This result is a big deal, and actually seems under-hyped. None of the explanations make any sense.
bilekas 2y ago
> "The discovery by the JWST that galaxies rotate in a preferred direction would support the theory of black holes creating new universes, and I would be extremely excited if these findings are confirmed. Its an interesting theory but to be honest, given the conditions of the event horizon, I don’t see HOW it could be proven.. That said I do feel this will turn out to be a nuance of the measurement itself but maybe that’s just my mind not comprehending the scales of what’s being measured here.
vitiral 2y ago
Some confusion in this thread. I think it would help folks to know that in addition to conservation of energy, our universe has conservation of angular momentum, aka mass spin. Hope that helps!
gchamonlive 2y ago
Does this mean we could look at deep space for clues about the physical rules that govern what happens beyond a black hole's event horizon?
rvogler 2y ago
i have always been wondering if the added up velocities of a series of rotating sub-systems has a relativistic effect that impacts what we observe and measure. the moon is rotating itself, around the earth, which is rotating around the sun, which is rotating ...
rognjen 2y ago
Wow! space.com does pretty much everything you can think of to "extract max value" from each visitor. It's got a lot of ads, traffic arbitrage, floating unrelated videos and even back jacking...

81 points by janandonly 2y ago

m3kw9 2y ago

Ok but then the theory of black holes are wrong because this isn’t dense at all.

rocqua 2y ago
Black holes aren't really infinitely dense. The matter isn't concentrated at the centre, its spread out over the event horizon. As i understand the theory, they effectively suggest you could glue another universe onto the event horizon of a black hole. From the outside that is indistinguishable from 'just a black hole'.
jpalawaga 2y ago
An entire universe crammed inside the event horizon seems pretty dense to me! Makes you wonder how much matter would be in the parent universe.
ShinTakuya 2y ago
Black holes need not be dense. The black hole at the centre of galaxy M87 has the density of air in our atmosphere. The larger the black hole, the less dense it is. So that alone doesn't preclude us existing inside of one.
- m3kw9 2y ago
  That’s news to me, I was taught that the mass collapses into it self it creates more gravity and more matter gets sucked in because the mass is so dense. So at which point does it become less dense?
  - d1sxeyes 2y ago
    As long as it’s dense enough that light can’t escape, it’s a black hole. You can achieve that with extreme density or huge volumes of mass. The more massive an object, the less dense it needs to be to be a black hole.
  - ShinTakuya 2y ago
    Keep in mind that my own knowledge of physics is very rusty, so some of this is definitely making bad assumptions. The density in the singularity (centre) of the black hole is in theory infinite. But the event horizon (the part where light no longer escapes) is not the singularity, it's simply where the gravity becomes so strong that light can't escape. Think of it as the sun vs the planets - we're not in the sun, but we still feel its effects. The density of the solar system isn't the same as the density of the sun. This is bad analogy because the same mathematics/physics doesn't apply, but it should help you get the general picture based on your original assumption. In general, the heavier the black hole, the less dense it is when measured from the event horizon. So in theory, it's possible to have a black hole so heavy that the event horizon contains the entire universe. In fact, the known universe is heavy enough to be a black hole 3 times the known radius of the universe. But as we know from stars that turn into black holes, just because something is heavy enough to be a black hole, doesn't mean it is one yet.
nextaccountic 2y ago
Only the infinitesimally small singularity that is in the future of all objects inside the event horizon is supposed to be very dense. The space inside the event horizon is supposed to be normal-ish
- Aerroon 2y ago
  If such a singularity exists at all. The thing we "observe" about black holes is the event horizon. It could be that space inside a black hole is just regular space.
  - nextaccountic 2y ago
    Yep! Generally speaking singularities only appear because the math is deficient in some way. Other areas of physics successfully got rid of unphysical singularities by employing better math, it's just that we don't know how to fix this aspect of general relativity (maybe quantum gravity will?)

jagged-chisel 2y ago

> These [baby] universes would be unobservable to us because they are also behind an event horizon, a one-way light-trapping point of no return from which light cannot escape, meaning information can never travel from the interior of a black hole to an external observer. Also meaning that “our” blackhole (the one containing us) is unobservable from the parent universe for the same reason. So where is all this extra light/energy going in our universe? Should we not have detected an increase of energy in our universe?

flowerthoughts 2y ago
(Complete hypothesizing from a very cursory understanding.) Perhaps that's dark energy or vacuum energy? If mass and time truly switches places when crossing into a black hole, it would make sense that the spacetime size of this universe translates into observable mass outside it. Which might tie it to the expansion of the universe.
- nextaccountic 2y ago
  > If mass and time truly switches places when crossing into a black hole What do you mean by that?
alabastervlog 2y ago
I figure our whole universe so far has existed in the first nanosecond (or whatever) after the creation of the black hole in the parent universe, so very little energy or light has had time to enter. By one or two seconds in the parent universe’s time scale, our universe will have settled down to its extremely long state of being a cold, dark void of slowly decomposing subatomic particles. No good reason to think this, just feels right.
- jagged-chisel 2y ago
  The relative time part is a really interesting thought. Thanks!
- Aerroon 2y ago

smitty1e 2y ago

"All who dare To cross her course Are swallowed by A fearsome force Through the void To be destroyed Or is there something more? Atomized — at the core Or through the Astral Door — To soar…" https://www.rush.com/songs/cygnus-x-1-book-one-the-voyage/ https://www.rush.com/songs/cygnus-x-1-book-one-the-voyage/

rocqua 2y ago

How does this work with matter falling into 'our' black hole and hawkins-radiation leaving our black hole? Heck, Hawkins radiation means black holes can evaporate. Does that correspond to a universa collapsing? Would matter falling into our black hole come shooting out of the white-hole we see? Would time on either side of the event horizon even be related?

Aerroon 2y ago
Perhaps dark energy is hawking radiation. We just see what it's like from the inside. Something to consider is a possible time scale difference. Eg time could be dilated for us for being around so much density.
- rocqua 2y ago
  It would need to be the other way around, dark energy being matter falling into our black hole. Hawking radiation should 'suck' energy out of our universe. I can't think of a satisfying source of this energy. The best I can imagine is either space contracting (but that is gravity) or entropy increasing (but that doesn't leak energy, just free energy).
cvoss 2y ago
> Would time on either side of the event horizon even be related? I think that's exactly the right question to ask. And ask it for space too. Perhaps the entire history of the interior universe unfolds between the black hole's formation and its final evaporation. Perhaps a heat death of the interior universe, where everything spreads out until nothing interesting is left, can fit inside this ever shrinking volume.
cryptonector 2y ago
> How does this work with matter falling into 'our' black hole and hawkins-radiation leaving our black hole? We would see that at the edge (if we could see it) there's new mass and energy, but that would be obscured by what appears as the CMB for us. > Heck, Hawkins radiation means black holes can evaporate. Does that correspond to a universa collapsing? No, it corresponds to stuff disappearing from our universe, until someday nothing is left. > Would matter falling into our black hole come shooting out of the white-hole we see? We'd see it as being part of the Big Bang, behind the CMB, so we wouldn't see it. > Would time on either side of the event horizon even be related? Er, not in any way that we could observe, so it's not a question we could answer. But we could receive information from the outside, except that the CMB would hide it from our prying eyes.

Sharlin 2y ago

Something something Betteridge's law of headlines.

fprog 2y ago

An alternate hypothesis which seems equally interesting, albeit for different reasons, is at the end of the article: > Another explanation for why the JWST may have seen an overrepresentation of galaxies rotating in one direction is that the Milky Way's own rotation could have caused it. > Previously, scientists had considered the speed of our galaxy's rotation to be too slow to have a non-negligible impact on observations made by the JWST. > “If that is indeed the case, we will need to re-calibrate our distance measurements for the deep universe," Shamir concluded. "The re-calibration of distance measurements can also explain several other unsolved questions in cosmology such as the differences in the expansion rates of the universe and the large galaxies that according to the existing distance measurements are expected to be older than the universe itself."

perihelions 2y ago
I'm utterly confused what's going on. They're measuring galaxies' rotations by looking at images of the subset that are spiral galaxies, and checking which direction the arms spiral. They describe their image processing algorithm in their paper [0]. (it's around figure 3) How can local movement of stars within the Milky Way affect which way spiral galaxy arms are pointing? [0] https://academic.oup.com/mnras/article/538/1/76/8019798 https://academic.oup.com/mnras/article/538/1/76/8019798.
- Georgelemental 2y ago
  Read section 5.2 of the paper
  - perihelions 2y ago
    Do you or other HN commenters understand it in a satisfying way? The author writes about the Doppler effect creating a systemic bias in brightness depending on which way the galaxies are rotating. I don't understand that argument either, but it's moot, because they state categorically that that effect would be too small to explain their results. ("This explanation is challenged by the fact that the effect of the rotational velocity have merely a mild impact on the brightness of galaxies, and therefore is not expected to lead to the dramatic difference of 50 per cent in the number of galaxies as observed through JADES.") That's the only explanation I recognized as an explanation. Then I lost track of their argument following that. They refer to several speculative physics theories like MOND, but I don't understand them to be saying something that concretely predicts distant galaxies to appear to be rotating differently. I'm appealing to anyone on HN who knows enough about this field to understand the meat of this argument.

dingnuts 2y ago

at the bottom of the article the mundane hypothesis is presented that the measurement seen by JWST might be a calibration error caused by the rotation of the Milky Way making it appear that other galaxies have a preferred rotation. sadly, this is likely the real explanation, but that's not very exciting

sigmoid10 2y ago

This newsblog takes one piece of the paper [1] and blows it up like it's the most obvious thing ever and completely hand-waves away the alternative, while the paper itself actually provides some compelling evidence for the alternative explanation: This asymmetry is because of our own galaxy's rotation. It would be an insane coincidence to have the large scale structure of our universe be more asymmetric towards the poles of our galactic plane and the further you go away from our galaxy (especially when velocity blue shifts would obviously make one type of rotation for galaxies more visible in the high-z regime where JWST primarily looked). Forget black hole cosmology, if you believe what this article suggests, then special relativity itself may be wrong. The data is pretty sound and perfectly in line with earlier observations that found no asymmetry if you believe our own galaxy's rotation is the culprit. So if I had to bet, I'd say we misunderstood galaxies and not the universe as a whole. Mostly because galactic physics is incredibly complicated and has very whimsical empirics, whereas we have some really solid theories and data on the universe as a whole. [1] https://academic.oup.com/mnras/article/538/1/76/8019798 https://academic.oup.com/mnras/article/538/1/76/8019798

specialist 2y ago
Thanks for link. Amazing work. I'm less than noob, so barely comprehend this topic, much less this paper. ELI5: Per "5.2 Physics of Galaxy Rotation", could the Milky Way's relative movement, in addition to its spin, also effect the observed assymetry? In Figure 10, is the Milky Way also moving toward the blue and away from the red? Thanks for humouring my question. Everything about astronomy and JWST just blows my mind. Like how Figure 10 sorta resembles yinyang. What a time to be alive.

api 2y ago

It'd be neat if the universe were essentially a nested Russian doll of black holes. Our universe is a black hole with black holes inside and black holes inside them and so on, and the larger universe outside ours is also an even bigger black hole. Some of the really huge black holes in our universe might be big enough to host interesting things within, but the smaller ones probably just contain "toy" universes without much happening. I recall reading about our universe as a black hole once -- one thing posited is that everything that is happening and what we think of as space is really information processing occurring just at the surface of the event horizon. There was some possible way of explaining non-local phenomena like entanglement that way, but I forget the details. It's fascinating to think about how the actual universe might be something quite alien from our ordinary perception. It's not that our ordinary perception is wrong. What we're perceiving is just one perspective on something much larger and weirder. In this case our perspective would be from within this information substrate. It's almost universe-as-simulation, except that the simulation does not have a builder. It's a naturally occurring phenomenon. The Matrix has no architect, or if it does it's something fully outside the event horizon of this object and thus un-observable. Of course at this point we're well into physicists smoking pot territory.

xqcgrek2 2y ago

This result is a big deal, and actually seems under-hyped. None of the explanations make any sense.

bilekas 2y ago

> "The discovery by the JWST that galaxies rotate in a preferred direction would support the theory of black holes creating new universes, and I would be extremely excited if these findings are confirmed. Its an interesting theory but to be honest, given the conditions of the event horizon, I don’t see HOW it could be proven.. That said I do feel this will turn out to be a nuance of the measurement itself but maybe that’s just my mind not comprehending the scales of what’s being measured here.

vitiral 2y ago

Some confusion in this thread. I think it would help folks to know that in addition to conservation of energy, our universe has conservation of angular momentum, aka mass spin. Hope that helps!

gchamonlive 2y ago

Does this mean we could look at deep space for clues about the physical rules that govern what happens beyond a black hole's event horizon?

rvogler 2y ago

i have always been wondering if the added up velocities of a series of rotating sub-systems has a relativistic effect that impacts what we observe and measure. the moon is rotating itself, around the earth, which is rotating around the sun, which is rotating ...

rognjen 2y ago

Wow! space.com does pretty much everything you can think of to "extract max value" from each visitor. It's got a lot of ads, traffic arbitrage, floating unrelated videos and even back jacking...