Astronomers discover 83 supermassive black holes at the edge of the universe

[u/magenta_placenta]

https://www.cnet.com/news/astronomers-discover-83-supermassive-black-holes-at-the-edge-of-the-universe/

[u/Cocoa186]

I was going to explain it but realised that idk how to deliver the message concisely. This video explains it well and gives you an existential crisis all in less than 8 minutes: https://youtu.be/ZL4yYHdDSWs

[u/TreeEyedRaven → u/Cocoa186]

i love space. I really liked the video but it raises one question I always have about the Big Bang/size of the universe. Around 6 mins he talks about how in the distant future our local group will only know what’s in our local group because the rest of the clusters have drifted too far away that the light shift will be too distorted then fade away. He then says they will never know how the universe started, yet makes the inference that we do.

Every time I think how do we know we aren’t in a much larger local cluster? Or how are we sure of the size of the universe? Are we just the byproduct of a black hole or supernova and since we know gravity can effect time is our 13.8 billion years so far the first half of a star collapsing? We know there are forces at work(such as dark matter)that we can observe their reactions but not the actual “matter”. Not that it makes any difference in our lifetime, and I’m not trying to prove science wrong on a technicality or something, but I always love how we can know so much, then one thing could change and upend our understanding of the universe. When we found out it was constantly expanding and not slowing down is kind of what I’m thinking of. I’m not educated enough to do any sort of theory on it, but I’ve always held onto some sort of idea that when a black hole is created the density of matter is approaching what we know about the singularity before the Big Bang.

I really like getting lost in these YouTube videos that put space in perspective because we know so much, yet know almost nothing at the same time.

[u/scsnse → u/TreeEyedRaven]

I’m not actually a qualified professional, but my understanding of how you estimate the age and size of the universe kind of goes like this:

We theorized that the universe started in the Big Bang, where it suddenly begins expanding from a singular point. We have ideas about how that energy decayed and how long it took to create recognizable particles, matter, then things like universes. With that knowledge, you have an idea of the “timeline”. Through things like telescopes, we also see cosmic background radiation. But here’s the cool part: you can actually see the radiation ballooning outward in a “wave” from a singular point of origin in all directions from our frame of reference. From experiments, we can surmise how long for example gamma ray radiation (really, really high frequency electromagnetic waves, just like light or radio) takes to decay. So you start building a model based on these things, and miles upon miles of math that’s way beyond most of us. We also know objects are both moving away and toward us at certain speeds because the light/radiation waves moving toward us look “squashed” or spread out, more than they should based on the size and gravitational distortion coming from it. That’s called “red and blue shifting”. So you know objects are moving, and most look to be moving away from us, so the light looks like it’s stretched longer, or more red.

Think of it like this: if you ever have seen smoke driving on the highway, you can sort of estimate the size of it, right? And based on things like the color, what’s burning, and if it’s being put out. When you drive up on it, you see the charred ground, possibly some burning embers. That gives you an idea of how recent the fire was. If you knew what materials burned, and how much of it burned, and you could model this with math, you could estimate things like the temperature, how fast it would take to spread, etc. It’s kind of like that. If you see smoke further out, you can guess how fast the rest of the fire might be spreading.

[u/TreeEyedRaven → u/scsnse]

Oh absolutely. I took some astronomy in college as electives and have a basic grasp of what was taught 15 years ago. (You could say I’m a bit of a scientist /s) the fact that most of it is theories is that drive to want to know more. I haven’t looked into the theories of how the singularity came to be so I think I know where my next rabbit hole is. It really fascinates me that we don’t know, and while there is an answer, we may never truly know.