So the astronomer community imaged a black hole for the first time. It basically looks like a space donut viewed face-on. The lower half of the donut looks much brighter than the upper half, which is perhaps relativistic material moving towards us along the line of sight.
Not to understate the feat of imaging a black hole, but it is sort of underwhelming. No cool gravitational lensing effects, such as background starlight bent around the hole. Apparently this black hole does not have polar jets either. The event horizon is sort of oblong-shaped, perhaps due to rapid rotation? Too hazy to be sure.
But its cool, and I hope better images are coming.
the Veritasium channel on YouTube has the photos, with explanations of the effects. There is also a video where he explains (before the publication of the photos) what it might look like, and why.
As I say in this thread, it was immortalized in a Google Doodle – the first case I know of where they changed the Google logo to a new doodle partway through the day
I think the event horizon would be a tiny point in the middle of the photo, and the reason we see a light ring around a dark middle is that we’re seeing the accretion disk. Also, there are jets, one pointed almost at us and one pointed almost straight away from us. The jets would be perpendicular to the plane of the accretion disk.
At least, that’s how I understand the photo. Anybody who knows better, please correct me!
The thing about this that I find the most amazing is that until now, black holes were essentially theoretical, even though virtually all astronomers by now acknowledged that they existed. But history records strong undercurrents of opposition, perhaps most famously from Arthur Eddington, who claimed that no such thing could exist in nature. But if it did, it would indeed be black and absorb everything forever, but in most cases it would be surrounded by intense radiation caused by extremely hot infalling matter orbiting at enormous speeds. And this picture says: “there it is!”.
Rumor was that there was also going to be a picture of the supermassive black hole at the center of our own galaxy, but AIUI ours is relatively quiescent so there might not be very much to see or to contrast against the black disk. Apparently the hope is that as more telescopes come online, more refined images will be produced.
I think you’re right but there is a misperception many have so I’ll speak to that here:
There was already heaps of evidence for black holes, and they had been “imaged” in various ways, just not in ways that the general public would find intuitive.
And, like all good science, the black hole hypothesis has made many predictions/inferences and been verified countless times.
The data behind this image is very useful to astronomers and cosmologists, but in terms of confirmation that black holes really exist it’s another drop in a very full bucket.
40,000 people like me? That’s really not an impressive stat.
IANAS, but I’d say more like evidence that ‘event horizons’ exist. What lies inside an event horizon is hardly a settled science. Hypotheses range from quark stars / other exotic stars to regular singularities. But they would all have a black event horizon.
I am sure an actual scientist will show up shortly, but I don’t think this is correct.
e.g. we know the mass of sagittarius A from the effect on nearby stars, and if it were a quark star, say, that star should collapse into a black hole. And the energies of, say, quasars or neutron stars merging into a black hole are what the models of black holes predict, and not what we would expect from stars.
Of course we could always argue “maybe there’s another strange kind of star responsible for this phenomenon” but you can always throw out a maybe like that. But in science we gain confidence in models as they make verified predictions, and the black hole hypothesis has done that.
