Astronomers see a black hole awaken in real time
eso.org
eso.org
"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"
It's really cool to see that we have so much instruments, we can actually monitor (a very small part) of the universe activity.
There is no direct evidence the black hole is doing anything - it's just the only theory we have.
There was a candidate for a stellar collapse to a black hole a few years ago:
https://www.livescience.com/disappearing-star-black-hole-no-...
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.
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.
I have a poor sense of when we’re talking hours, years, decades, millennia, MA, GA. Might make for a really cool static website project.
Same with geologic events, too!
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.
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.
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."
https://www.historytimeline.com/timeline/geo-time-scale/
DM if interested in the datasets.
https://en.wikipedia.org/wiki/Hawking_radiation
If 2 black holes collide - they join together.
Presumably though some of the matter "escapes" as energy released during the merger, in the form of gravitational waves.
Which resulted in the earth (and space) being stretched by less than a fraction of a proton.
And we measured it...
Doesn't Hawking radiation, since it exits a black hole, violate the idea that nothing escapes a black hole?
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.
The answer is probably the same. We would not know and continue our daily chores.
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.
With that in mind, I can imagine that millions of voices suddenly cried out in terror and were suddenly silenced.
Are you one of those people who continues to insist falsely that there was more than 1 Matrix movie, or more than 3 Star Wars movies?
I noticed that too <grin>
Is this too far away to try to detect the gravitational waves, if it made some? I forget, do gravitational waves travel at C?
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.
It is a nice thought though. That was a real rough day for Earth, but we turned out alright in the end.
We are probably lucky, to have life at all.
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.
It becomes harder to reason that humanoid life and even intelligent humanoid life must exist somewhere else without any actual data points.
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.
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.
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 must have been an incredible discovery at the time.
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.
- bubbles in water act like black holes
- the universe itself may only be a bubble among many
- the multiverse looks like foam
I tried looking for more details in https://en.wikipedia.org/wiki/Galaxy#Types_and_morphology but my conclussion is that it is a complicated topic.
Huh?
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.
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.
It didn’t happen in real time, but they did observe in it real time.
One is a measurement of the event and one is a measurement of when the photons reached us.
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).
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.
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).
In all actuality this is really really cool.
Hows it go? "Why so serious son"...