It means not the creation of a black hole (like I initially thought), but an activity by the hole to blast out gas and energy.
"In late 2019 the previously unremarkable galaxy SDSS1335+0728 suddenly started shining brighter than ever before. To understand why, astronomers have used data from several space and ground-based observatories, including the European Southern Observatory’s Very Large Telescope (ESO’s VLT), to track how the galaxy’s brightness has varied. In a study out today, they conclude that they are witnessing changes never seen before in a galaxy — likely the result of the sudden awakening of the massive black hole at its core."
"Follow-up observations are still needed to rule out alternative explanations. Another possibility is that we are seeing an unusually slow tidal disruption event, or even a new phenomenon"
Unfortunately it's in a galaxy far, far away, so we couldn't see the star directly, we just saw a characteristic emission line disappear without a corresponding supernova. Given that it seemed like a large star, one possibility is direct core-collapse.
>Unfortunately it's in a galaxy far, far away, so we couldn't see the star directly, we just saw a characteristic emission line disappear without a corresponding supernova. Given that it seemed like a large star, one possibility is direct core-collapse.
It sounds like the Galactic Empire has a new super-weapon that can destroy an entire star system by causing the core to collapse into a black hole.
I mean, when you put it that way black holes as a whole are a mere theory. A theory used to explain gravitational fluctuations and the odd lack of mass in the universe (which still wasn't fully solved and are currently dabbling with dark matter to further fine tune results).
Joking aside, all of this is just inferences. They don't actually know what's going on. For all we know, it could be an alien species turning the attic light on.
Yeah the wording in this article is really vague and silly. "Transitioning from dormant to actively feeding" would be a lot more accurate than "awakening".
Maybe regional. I'm not getting a login page in the US, but I am getting the German language page. Of course, I like your link better, since my German is very rusty (non-existent, really). Thanks.
Fun fact, supernovae take only seconds to undergo extremely violent processes that typically result in their explosion.
E.g., "Within a few seconds of the collapse process, a substantial fraction of the matter in the white dwarf undergoes nuclear fusion, releasing enough energy (1–2×10^44 J) to unbind the star in a supernova."
to go from a supernova to a black hole, it takes a couple of days. For a galaxy to be rearranged by a black hole, it take a couple of millennia. (my information is not precise nor the latest, so it could have been revised recently.)
you're in good company. most cosmological "dates" are not precise. for example, the age of the universe is suspected to be about 13.7 billion years +/- 20 million years. That's a really big +/- in years, but just 0.2% tolerance. the size of milky way is estimated at 26.8 ± 1.1 kiloparsecs. again, that's a lot of miles/kilometers of a range. it's not like they can run out and "pull tape" to take that measurement.
it's one of my favorite quirks of astronomy. of course even the tolerances/variances are going to be astronomically large.
No, precision or error can measured in absolute or relative terms. In either case, the unit is irrelevant, you could say +/- "0.000001 big bang timespan." The point is that in the realm of human experience, that tracking error is quite big.
The theory behind spiral galaxies is that a black hole of considerable magnitude and time lies right in the center. Gravitational waves spirals out for millennia. They start moving towards the center but also move towards each other. Closest stars move towards the center and other stars begin following the close stars and so on. This should ordinarily end up like an octopus with multiple arms extending from the center outwards. But then the Universe must also be rotating like a disc. And so the galaxy spirals out with curved arms instead.
So, yes, we think there is a massive black hole at the center of all (or just spiral?) galaxies. And gravitational waves move at the speed of light, so if something changes the mass of the central black hole, and the galaxy has a radius of 25,000 light years, it will take 25,000 years for that wave to propagate out to the rim of the galaxy, rearranging things along the way. But:
1. The massive, central black hole did not come from a supernova. There are no stars anything like that big.
2. Even if there were a huge central mass and it collapsed, that doesn't actually change the mass distribution as far as the rest of the galaxy is concerned. There is very little change to propagate. The existence of the huge central mass would have already "arranged" the galaxy.
3. Galaxies spiral with curved arms due to their own rotation, not due to the universe's rotation. If the universe were rotating like a disk (and that was causing the spiral of galaxies), then you would expect the spin of galaxies to all be aligned. And they aren't; not at all.
What are the odds of being alive and having the technology in place to witness any galactic event, on the galactic timescale? That's just so wild to me.
So if I understand correctly the black hole was there already, doing nothing, and then some matter was passing near it and started falling inside, releasing the surplus energy as radiation in the proccess?
The only way anything "escapes" from black holes is Hawking Radiation - virtual pairs of particles that appear and disappear constantly - can be split when they happen on event horizon - and that slowly drains the energy from black hole.
Yes. If memory serves this is the first event that LIGO detected. Two black holes of 20-30 solar masses each, joining and releasing 1-2 solar masses worth of gravity.
Which resulted in the earth (and space) being stretched by less than a fraction of a proton.
My understanding is that particles and anti-particles pop into existence randomly, but quickly cancel each other out. Normally this doesn't affect anything, but if they happen to pop into existance right on the border of the event horizon, one will fall in and one will fall away. Thus matter is very very very slowly "leaving" the black hole. But not because matter inside is making it out, but rather because of some interesting quantum features of the fabric of spacetime.
What if we are quietly watching from a distance (in both space and time) as thousands of civilizations are helplessly irradiated to death by gamma rays?
Seems well within range; and yes they travel at C - there have been some LIGO observations that were successfully correlated with more traditional (e.g. optical or radio) observations.
So it's even worse: the Galactic Empire has built an even bigger Death Star which can destroy an entire star (or cause it to collapse into a black hole)?
Well, some alien species a few hundred million light years away, with a big telescope, could be currently watching the Chicxulub meteor hit earth, and all the dinosaurs subsequently starving to death.
It just occurred to me that if dinosaurs never existed here and we found them somewhere else, they’d be such an incredible discovery. We’re lucky to have such an awesome history of life on this planet.
Humans are probably unique. Intelligent life probably not and life at all is likely commonplace. It would be quite a miracle if given the size and scale of the universe Earth is the only place where life arose and also managed to evolve multiple intelligent species also emerged (cephalopods, dolphins, elephants, and primates at least)
There is a theory that humanoids aren't actually unique, if there's large animals on other planets in the universe. Our body plan has several survival advantages so it's quite possible evolution could have had similar results elsewhere. Bipedalism is really great for efficiency of locomotion (humans can walk really really far), and having two limbs with opposable thumbs is really useful for grasping and manipulating, which makes it much more likely that species will invent tools and technology.
Note I'm not claiming humanoids are all over the place, but with 400B stars in our galaxy, 1T stars in Andromeda next door, and other galaxies with similarly huge numbers of stars, multiplied by all the number of galaxies in the observable universe, multiplied by the number of exoplanets in the "Goldilocks zone", it's quite possible intelligent, humanoid life has evolved somewhere out there.
That would be a stronger claim than the one I made which is just that life exists in some form somewhere else in the universe with a relatively high abundance and it’s highly likely intelligent life exists somewhere as well.
It becomes harder to reason that humanoid life and even intelligent humanoid life must exist somewhere else without any actual data points.
>That would be a stronger claim than the one I made which is just that life exists in some form somewhere else in the universe with a relatively high abundance and it’s highly likely intelligent life exists somewhere as well.
Sure, but we're probably thinking of "intelligent life that can build a civilization", right? In that case, highly-intelligent alien orcas aren't going to meet the requirement. They just don't have a body type that allows them to change their environment and build technology. If there really are alien civilizations out there, like in Star Trek, that show might not actually be that far off with its assumption that 95% of them are humanoid. And in this case, there could very well be lots of other intelligent life, but which never managed to build a civilization.
If we’re bringing up fiction, why are we assuming Star Trek and not Cephalopods like in Arrival or completely alien morphologies like in Scavenger’s Reign. Even if there is a humanoid involved it could be as a host or slave for the intelligent life that controls it (eg dominion in Star Trek). With a sample size of n=1 of our planet (with no quantifiable way to even measure and compare intelligence), I think we’d be assuming a lot to make the conclusions you are making even if we restrict ourselves to those that can build up industry or even leave their planet. I’m also not sure why we’d care so much about leaving a planet - we’re desperately looking for any sign of life which would be a momentous discovery in and of itself. As for Orcas, don’t underestimate just how deadly humans are - we outcompeted concurrent competing intelligent hominids by killing or mating with them and regularly decimate wildlife and consume resources at a rapid pace. No reason to believe that an alien Orca with thumbs couldn’t eventually accomplish the things we did without ever leaving the water.
Star Trek used humanoids because of practical special effects at the time and because it would be easier for the audience to identify with the aliens and make the show more accessible, not because there’s some underlying scientific reasoning going on.
To make any predictions about the shape that intelligent aliens would take would require some probabilistic falsifiable model that would tell us where to look and what we’d find. Anything other than that would rely on very shaky first order reasoning which is what we’re doing to guess that there is likely intelligent life somewhere.
>I’m also not sure why we’d care so much about leaving a planet - we’re desperately looking for any sign of life which would be a momentous discovery in and of itself.
Just finding alien plant life somewhere would be a momentous discovery, but that's still nothing like finding an alien civilization that we can communicate with, trade with, etc. One doesn't diminish the other.
Alien orcas (probably) can't leave their planet, or really establish much of a technological civilization. So they'd be interesting to observe, just like alien plants or alien mice, but that just isn't the same kind of thing as interacting with an alien civilization.
>No reason to believe that an alien Orca with thumbs couldn’t eventually accomplish the things we did without ever leaving the water.
How so? How exactly are the alien orcas going to get out of the water to outcompete intelligent creatures on the land? Building any kind of technology in an aquatic environment would be incredibly difficult, if it's possible at all; if there's intelligent creatures on dry land, they'll have an automatic advantage. Sure, the alien orcas with hands and thumbs would have a much better chance than Earthly orcas that don't, but still, how do you, for instance, build a gun when you're an aquatic species? On dry land, it's really not that hard. Even smelting metals seems rather impossible underwater.
> not because there’s some underlying scientific reasoning going on.
Scientific reasoning wasn't the intention, but the idea that aquatic aliens have as much ability to build rockets and spaceships as land-based aliens is pure fantasy. The laws of physics don't change on other planets.
It depends. If simple life is common, how rare is GOE or a similar event? If GOE is not that rare, it feels like intelligent life is just a matter of time, ice ages and enough branches to grab on. Otoh if we are the result of a long domino chain, the universe life is screwed.
I have no idea what GOE is, but everything we learn about astronomy indicates that neither Earth nor our solar system is particularly unique, so “long sequence of dominoes” would be a very unlikely situation in something as large as the know universe, even ignoring the parts we could never observe.
Reminds me of "Carl's Doomsday Scenario" where they pick up a pet that happens to be an "a species seeded on all life-supporting planets, but a nasty asteroid caused them to go extinct here. I believe they are called 'Velociraptors' here."
It's not likely that life will survive long enough to form civilizations that close to a black hole. It has probably fed like this many times before already.
How close to a black hole? This isn't a common-or-garden black hole, it's supermassive. If it's (300M years ago) suddenly started producing intense radiation that we can measure here, then I assume that anyone in the galaxy that can see the central region is receiving a lot of radiation, as well as a storm of high-energy particles.
Galaxies of stars are like people traveling through the cosmos together in one group.
Elliptical galaxies have a direction of travel, that is why they are elliptical.
A galaxy gets it first massive supernova, and a black hole is formed, and it becomes a spiral galaxy, kind of like when a seismic social event happens and everyone gets in line.
You might enjoy this if you haven't already seen it: https://youtu.be/71eUes30gwc - TL;DW black hole density decreases with increasing radius, and the average density of the observable Universe is potentially greater than that of an equivalent-sized black hole, so maybe the whole Universe is inside one...
It is not hilarious, it is actually the correct use of the term.
Otherwise, you would have to contend with the fact that "real time" does not exist at all, as information about any event has to necessarily take time to travel to reach you.
So no "real time" coverage of anything -- the information always takes time to travel the distance.
What is not a correct understanding of how time works is claiming that it happened some thousands of years ago. No, from our reference frame it happened now. It is meaningless to say that it happened thousands of years ago because it happened thousands of years ago in some other, arbitrary reference frame.
This is why any faster-than-light travel must either be impossible or mean that that traveling backwards in time is possible.
I point my telescope at a planet four light years away (I have super advanced telescope that can see these details), and use a worm-hole or other plot device to teleport instantly to that spot. Where do I arrive -- at what I observed, or at some point in empty space because I've just arrived at where that planet was four years ago?
If the former, I must somehow have traveled back in time by four years to arrive at the spot I had observed.
If the latter, I suppose we could instead say our destination is where we calculate the planet will be four years from now. Except that my travel time was instantaneous, so again either I've arrived too early and need to wait around for four years, or I jumped 4 years into the future (at which point that's not really FTL travel, just kind of stepping outside of time into some nether state for four years).
>If the latter, I suppose we could instead say our destination is where we calculate the planet will be four years from now. Except that my travel time was instantaneous, so again either I've arrived too early and need to wait around for four years, or I jumped 4 years into the future (at which point that's not really FTL travel, just kind of stepping outside of time into some nether state for four years).
This doesn't make sense. If you have a wormhole teleporter, and teleport to where that 4ly-away planet is in your observation, it won't be there, since you saw it 4 years ago and it's moved. This seems fairly obvious.
Now, if you observe its motion and predict where it's traveled in the 4 years between your observation (now) and when the photons you saw started from that planet (4y ago, relative to your current position in spacetime), and set your wormhole teleporter to take you there instead, it should take you to the planet's current position. (Hopefully your calculations were accurate and you don't teleport into the planet...) I don't see why you think you'd arrive too early, or jump into the future. Your friend who stays behind would need to wait 4 years to see you arrive at the planet in your super-telescope, but that's just because it takes light that long to arrive.
I don't see how this particular thought experiment necessitates time travel.
"as it unfolded" would be more accurate than "real time"
Technically, one can argue that "real time" is relative to the time frame in which we observe something, but that's not how we generally use "real time", but rather we use it to define an event that is observed at the same moment (or very close to) the moment in which it occurs, such as a match broadcast live on TV (though there is some delay).
We say that it happened in the past, using our wall clock ideas. But you can't rush there and look back to "see dinosaurs", so it's at least as correct to say that it happens in real time. This is an event, registering now in our reference frame. Nothing else provided.
You are conflating reference frames - it determines causality in your local reference frame but not in any other reference frame. The concept of "real time" - like all time - is entirely relative to the reference frame you are using.
Correct, there's no global timeline, so it's not clear what "just" 300M years ago even means. Some RFs seen it already, and some will never see it. But in ours it happened in Jun 2024. It's 300M light years away, not ago.
But there is a global timeline. The age of the universe itself. It happened when the universe was roughly 300M years younger. Somebody might say the universe was created a year ago if they traveled through it extremely close to the speed of light. But we know how fast we travel by measuring redshift/blueshift of the cosmic microwave background and it's definitely far from any relativistic speed. There must be some effect of gravity, but that is also within a rounding error. So, I'd say we are much closer to the "truth" than somebody who travels through the universe a few percent of the speed of light or "lives" right next to the supermassive black hole. Whether something we will never see exists or happens is a philosophical question akin to "if a tree falls in the forest..."
But a distant observer could also make the same measurement of the CMW background and see themselves at rest. And yet we could be moving away from either other at relativistic velocities, due to the expansion of the universe.
Due to this relative motion we will see different ordering of events at different locations, despite both being at rest relative to the CMW background, so we can’t really say there is a global timeline.
The thing is that the CMW background isn’t global, we don’t see the same background as a distant observer. CMW photons that are passing us now will take time to reach a distant observer, and vice versa.
Another mind-blowing perspective is from that of a single photon; since time slows when approaching c, from its perspective it's eternal, and, since distance shrinks when approaching c, from its perspective it's also omnipresent.
Well, it's not exactly eternal, it's that time is not passing for that photon. It's also (as far as I can tell) only correct to say that distances shrink as speed increases when you're talking about massive objects. A photon would not experience space contraction in any meaningful way.
I’m curious if the downvote was calling us all NPCs or the entire joke being not funny. I know we all try to be serious and contribute to the conversation here but come on it’s funny, no?!
Life is too short to be all work and no play. Let’s live a little here. What’s the point of killing ourselves in tech if we can’t enjoy being nerds and having a laugh even on the message board of a VC?
"In late 2019 the previously unremarkable galaxy SDSS1335+0728 suddenly started shining brighter than ever before. To understand why, astronomers have used data from several space and ground-based observatories, including the European Southern Observatory’s Very Large Telescope (ESO’s VLT), to track how the galaxy’s brightness has varied. In a study out today, they conclude that they are witnessing changes never seen before in a galaxy — likely the result of the sudden awakening of the massive black hole at its core."
"Follow-up observations are still needed to rule out alternative explanations. Another possibility is that we are seeing an unusually slow tidal disruption event, or even a new phenomenon"