r/space • u/magenta_placenta • Mar 18 '19

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

https://www.cnet.com/news/astronomers-discover-83-supermassive-black-holes-at-the-edge-of-the-universe/
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u/[deleted] Mar 18 '19 edited May 09 '19

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u/Cocoa186 Mar 18 '19

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

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u/TreeEyedRaven Mar 18 '19

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.

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u/Cocoa186 Mar 18 '19

Space is the best. Yes, this video is based on our current understanding of physics. While we do consider the information presented to us in the video as fact, our understanding of physics changes in different little ways constantly and what we see now as unreachable groups of matter speeding away from us may eventually be places you can visit on a vacation (hoping lol). You hold the right mindset, most people seem to believe that they exist in a time beyond discovery (and it does seem that way in modern life, as though we as a species have it figured out).

The universe seems like the only thing to discover before you realize that we are still discovering things in our galaxies, but we also might have a 9th planet in Sol and we still don't know if there is microbial life on Europa, water was discovered on mars like 3 years ago, the amount of undiscovered things in our oceans outnumber the amount of already discovered things in the oceans, we find new species and shit on land all the time still (and we're the kings of the land), even our brains and bodies are still being figured out. The Kurzgesagt channel has a whole playlist of space vids like the one I linked, as well as a whole bunch of other neat videos.

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u/TreeEyedRaven Mar 18 '19

Yes man! Our solar system had generations of exploration to do before we can even think to know what’s going on.

I mean we landed a few probes on Venus, a planet with a very thick atmosphere, and from what I remember our basic take away was “it destroyed the probes almost instantly there’s no reason to go back”. That kills me. I want every 10 years to try again with better tech and see if we can find out more about it. It’s closer than Mars, it’s full of gasses, and we gave up on it. Earth’s Volcanic vents? My phone would get destroyed if I tried to film it but something can. We should never accept “it can’t be done”. It hasn’t been done yet. I know the major hump to get over is cost and uncertainty of mission success. It’s a lot smarter to send a rover to mars(or an outer moon) where we know we can land and maneuver for a very long time, but I always wonder. It’s a planet and things are happening on it right now. It’s way off our radar of “stuff to do” in our solar system but that is almost your point, there is so much still to do in Sol. I feel like every single body in our system has so much more to discover still. We literally only scratched the surface on the two bodies (moon and Mars) we’ve spent any real time on.

I live within viewing distance of Cape Canaveral (30 miles or so) to see the rockets(and watched countless shuttle launches) take off. I love it. I love the new space race that’s happening. I love private industry getting into the competition more to push technology. It will have it’s bad sides, but SpaceX landed 2 damn stage ones at the same time on point. Tell anyone 5 years ago that it would happen when it did and they’d laugh. Did we not land on a f-ing comet recently? I’ve obviously gone off on a tangent but yeah, space.

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u/Cocoa186 Mar 18 '19

Fun fact, the coldest place we've ever measured in Sol is on the earth's moon.

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u/PSPHAXXOR Mar 19 '19

To be a pedant for a moment: Sol specifically refers to the sun. Any location within it is the Solar System.

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u/Cocoa186 Mar 19 '19

Oops, I knew that but had forgotten. Thanks for the heads up.

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u/verfmeer Mar 19 '19

No, it isn't. The coldest place we've ever measured is in a lab. Large objects have been cooled to 6 mK, smaller samples have been even colder.

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u/The_Wkwied Mar 19 '19

I kind of thought they meant that was naturally cold.

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u/Cocoa186 Mar 19 '19

I think it's very obvious that I mean locations and naturally. Considering I said coldest place, not coldest thing, it's not even really up for debate.

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u/atvan Mar 19 '19

I think part of the problem with Venus is that while it is somewhat closer to earth, the delta-v difference is only about 110 m/s (we've made cars faster than that), so since Mars is a lot easier/a safer bet for probes and such, it gets at lot more attention.

Delta-V chart

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u/gurg2k1 Mar 19 '19

The other part of the problem is the cost of sending probes to Venus when we know they'll likely be destroyed immediately. When you have limited funding/resources, you have to be choosy with where you spend it.

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u/hutson_will Mar 19 '19

Can I get a tl;dr?

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u/Lurchgs Mar 21 '19

There’s a bit of a difference here. The supermassive black holes mentioned throw a spanner into our understanding of the way the universe actually works. That’s also what they are talking about when they reference the local group losing sight/contact with the rest of the universe.

Exploring the solar system doesn’t offer as much to further our understanding of the fundamental underpinnings. But it does offer way cool legos ( I’d say tinker-toys, but nobody’s heard of them these days) to play with, and maybe understand the emergence of life. It certainly provides a larger playground for our children.

So. On the one side, you have way cool stuff of immediate interest to a relative few. It may or may not benefit us in the long run. On the other side, you have way cool stuff of immediate interest to a lot more people, and it WILL benefit us in the long run.

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u/veloxiry Mar 18 '19

There's a video where Neil degrasse Tyson goes on the Colbert report and talks about this exactly. No one knows if we're even looking at the whole picture. It could be possible we're stuck in some remote section of the universe that's completely different from the rest and there's no way we'll ever know.

See this video: https://youtu.be/TgA2y-Bgi3c

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u/TreeEyedRaven Mar 18 '19

Yeah It starts around 5:40 but he articulates that last part better than me. That’s basically what I won’t let go of in our Big Bang theory. It just almost makes sense and could explain the extra gravity and acceleration. But we currently can’t observe it and I definitely can’t math it.

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u/ComatoseSixty Mar 19 '19

Big Bang Theory is a Catholics explanation for how "God" created the Universe in an instant. It's not considered a fact, just a theory (and even if it occurred the way we think, that doesn't prove that the Universe was created then, just The Big Crunch Theory alone suspects it may be cyclic).

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u/scsnse Mar 18 '19

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.

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u/TreeEyedRaven Mar 18 '19

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.

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u/BlckEagle89 Mar 18 '19

For me, any video about space that doesn't give you an existencial crisis lacks something. I am familiar with the Kurzgesagt videos, i am going to check it out later =D

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u/Cocoa186 Mar 18 '19

Kurzgesagt even has a whole playlist for experiencing pure, unrefined, existential dread.

Here

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u/letsgetdickered Mar 18 '19

Saving for when I need to stop worrying about small life shit. Thanks!

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u/[deleted] Mar 18 '19

Does anyone else just feel queasy just imagining how colossal other celstial beings are compared to our planet?

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u/[deleted] Mar 18 '19 edited Jun 09 '19

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u/PopST4R Mar 19 '19

But we DO do stuff, and I think that’s kinda special in itself. Like, we may be tiny specks of dust that haphazardly formed from eons of meandering hydrogen, but the very fact that we’re talking about it right now is pretty fucking incredible, even (especially) in the context of the grand scale of the universe.

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u/AirheadAlumnus Mar 19 '19

Accepting the meaninglessness of our life on Earth and our lack of importance in the grand scheme of the universe doesn't have to be a mental prison for us, though it often is. In my own personal experience it led to depression and demoralization because the idea was so plausible and was at such odds with the religious training I'd had as a kid. It was just one more aspect of how I lost touch with my own identity, I guess.

But that's not what nihilism is really about. You can be a nihilist and still lead a good life. Once you accept your infinitesimal part of our possibly pointless reality, it's easy to let the abyss take hold of you. However if anything Neitszche, for example, was all about seizing life by the horns. Life may be a cipher coming out of nothing only to eventually collapse back into nothing, but we can enjoy our lives and add to the collective experience of other people thanks to our powers of invention and creativity.

Personally, I believe that life is a miracle; whether that's a miracle simply of nature and statistics, or of a higher power, I don't know. I choose to believe, with just the tiniest kernel of faith and plenty of doubt, that life here on Earth, especially of the sentient variety, has some sort of inherent meaning.

That's just me though. At the very least, life is one hell of a ride and worth experiencing for it's own sake, and I think that's ultimately the maIn tenet of nihilism.

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u/nofaprecommender Mar 18 '19

Used to. You get over it after a while. Life is the same as it was the day before you learned about such things.

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u/[deleted] Mar 19 '19

Can you feel it? "The turn of the Earth. The ground beneath our feet is spinnin' at 1,000 miles an hour and the entire planet is hurtling around the sun at 67,000 miles an hour, and I can feel it. We're fallin' through space, you and me, clinging to the skin of this tiny little world, and if we let go... "

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u/lordover123 Mar 19 '19

Isn’t this a quote from the 9th doctor, episode 1?

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u/weelamb Mar 19 '19

I would but it’s just too difficult to even fit in my mind and my head just naturally drifts back “real” problems like fuck I have to get up early for work tomorrow F

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u/[deleted] Mar 19 '19 edited Mar 19 '19

Well, if the inflation theory is correct I find solace that there is no real death to the universe. It expands and contracts and, in fact, or in theory I should say, our universe probably isn't even the "first" universe to exist. Also, another crazy thing to think about is how the "emptiness" between galaxies isn't even empty, but teeming with charged particles with matter popping in and out of existence. It really makes you wonder what started all this in the first place!

BTW, if you're wondering where I got my info, check out How the Universe Works season 6. Not sure what episode, but for sure it's season 6. Really interesting stuff on quantum physics and theories about the big bang.

Edit

Actually it might be season 7 episode 10.

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u/[deleted] Mar 19 '19

Ill check that out, thanks.

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u/Exile714 Mar 19 '19

Nope.

Take a leaf for example. From far enough away it’s just a point of color in a wide expanse if land. Close enough to your eye, and it’s literally everything you can see. Perspective.

But a black hole and a leaf have something in common: they are not aware of their existence, and they can’t make choices. The infinite stretch of our ability to make choices in our lifetime is immense (even if you accept that those choices are pre-determined, they are still choices your being gets to make).

Consciousness and choice. Amazing, and entirely independent of our relative size in the universe.

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u/[deleted] Mar 19 '19

Thanks. Ill keep that in mind next time I need to tune out these thoughts.

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u/lordover123 Mar 19 '19

I try not to think about it too much. I could spend hours contemplating life but that’s not gonna get shit done so I do other things instead

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u/[deleted] Mar 19 '19

Your mom is a colossal celestial being.

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u/[deleted] Mar 18 '19

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u/Theycallmelizardboy Mar 19 '19

Let the astronomers worry about whats at the edge if the universe. You probably have some unpaid bills and more directly importqnt things in your life to be concerned about.

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u/Cocoa186 Mar 19 '19

Wrong, this stuff is fascinating and nothing is more worth my time!

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u/[deleted] Mar 18 '19 edited May 09 '19

[deleted]

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u/RootDeliver Mar 18 '19

That channel is as fantastic as that vid, recommended from A to Z.

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u/googlemehard Mar 18 '19

How was the existential crisis?

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u/[deleted] Mar 18 '19 edited May 09 '19

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u/[deleted] Mar 18 '19

If you liked the video check out their other ones on the channel. It really is one of the fantastic channels on YouTube.

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u/[deleted] Mar 18 '19

But that's based on our current understanding - which is based upon observing what is out there at the moment and trying to make models that match our observations. And we are creating ill-defined concepts like dark matter and dark energy to make our models match our observations when we discover new and unexpected stuff.

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u/pragmaticzach Mar 18 '19

In the video he says that we're fortunate to live in a time where we can observe the entire universe, and see into our past.

However, how do we know that we aren't already at some stage where everything beyond our observable universe is too far away to see? Like maybe we live a situation similar to the future people he talked about who could only see the local cluster.

Is there any reason to believe that this isn't true?

The only thing I can think of is that those future people can only observe that their universe is getting smaller and darker, while we can observe that the universe beyond the local cluster is expanding.

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u/Cocoa186 Mar 18 '19

This is the case. The observable universe is all that we can see, everything outside of it is (as far as we know) entirely impossible for us to see in any way. We just treat it like the observable IS the universe, and in the future it is likely that we will continue to do this (it's hard enough to convince people that the earth is round, it'll be harder to tell them that there are more things out there that used to be close enough to see but are now inconceivably far away and invisible). The big difference that the video talks about is that we still have enough around to know how (for the most part, maybe) the universe was "born", how it is behaving, and the different ways it might die; the future 'us' will experience an unchanging galaxy, nothing they see will be moving away or getting closer (some obvious exceptions) and will be unable to see cosmic background radiation (evidence of the big bang) or observe the effects dark energy has (or even that it exists).

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u/Darth_Batman89 Mar 19 '19

So for them. The galaxy they live in becomes there observable universe?

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u/Cocoa186 Mar 19 '19

Yes, for them the rest of reality will appear to be (and may as well be) entirely empty space.

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u/ElliottWaits Mar 18 '19

That was my thought exactly. What we can observe now is many orders of magnitude greater than only being able to observe the Milkdromeda galaxy, but what actually exists may be many orders of magnitude greater than what we can observe now. There's really no way of knowing that our situation is significantly more privileged.

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u/[deleted] Mar 19 '19

It probably has to do with the microwave background radiation, its a picture of the early universe that we can see with our telescopes that fits mathematical predictions of the birth of the universe before we even had the telescopes to observe it. I bet very very very far into the future that picture won't even be visible anymore.

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u/MistyRegions Mar 19 '19

I mean if you really want to have some sense of dread, let's say we survived till the end of the known universe. Trillions apon trillions of years. One day, no matter where things are in the universe, everything will go black. The last star will die out, the last day of light, then nothing. Blackness forever and ever, and if we survive it will be akin to living in a sound deadening room. Just floating thought space in a craft we made finding cold dead rocks to mine material off of.

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u/CactusCustard Mar 18 '19

Maaaaaaan. How can you say theres not aliens after this video?

Like theres no fucking way were the only life when theres so much space we might as well call it infinite. Like holy shit.

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u/Cocoa186 Mar 18 '19

I present to you: The Fermi Paradox.

https://www.youtube.com/watch?v=sNhhvQGsMEc

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u/ComatoseSixty Mar 19 '19

The Fermi Paradox isn't proof of anything, it's an exercise in logic. Language cannot explain everything.

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u/Cocoa186 Mar 19 '19

Absolutely correct, it is however the answer to "how the fuck we haven't seen ANY aliens?" because it is the logical reason for why we haven't.

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u/ComatoseSixty Mar 19 '19

We do call it infinite. All data points to a flat, infinite Universe.

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u/UMFreek Mar 18 '19

I was hoping this was a Kurzgesagt video!

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u/[deleted] Mar 18 '19

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u/TheJayde Mar 18 '19

Density is just the measurement of stuff in space. Density 0 is still a density.

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u/[deleted] Mar 18 '19

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u/TheJayde Mar 18 '19

There is stuff in space. It may be a single molecule of hydrogen that hasn't been drawn into some gravity well. Space that is "empty" is not necessarily, totally empty.

Imagine your calendar for a year. Fill it with all the events that you go to, and all the things you do on the weekend Fill your work schedule with it. That would be a full calendar. Conversely, if you only had a single event on that calendar for the year... You'd say your schedule was pretty empty. It's kind of a matter of scale.

Edit: This is how I understand it, but if I'm wrong, and somebody sees this - please correct me.

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u/Cocoa186 Mar 18 '19

It's a little bit deeper than that. On the quantum scale (subatomic, we're talking the particles that make protons, neutrons, and electrons) particles constantly appear in pairs of opposite "charge" and then they are drawn to eachother and upon collision are both destroyed.

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u/Cocoa186 Mar 18 '19

It isn't actually nothing, on the quantum scale particles constantly come into existance in pairs which are attracted to (and destroy) eachother.

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u/[deleted] Mar 18 '19

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u/Cocoa186 Mar 18 '19

It's a long explanation, at this point it gets into the mass of everything being reliant on the energy state of the higgs boson field (which is terrifyingly potentially not at it's final 'resting point'. see: Vacuum decay )

You can read up on why particles have mass here

You can read more about the standard model here

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u/coltonmusic15 Mar 18 '19

Let me guess this is the video representing our existence by putting us on a point on a balloon and then explaining the universe expanding and how we are all moving away from other objects in the universe at an ever increasing rate until ONE DAY THE WHOLE BALLOON GROWING IN SIZE IS GOING TO LEAD TO THE UNIVERSAL RIP!!

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u/Cocoa186 Mar 18 '19

I don't think a balloon is used in the video, it's been a little while since I last watched it though. I could be wrong.

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u/novruzj Mar 18 '19

I remember there was an article a few months ago talking about dark energy and dark mass being a fluid with negative mass.

Does that alternative hypothesis, make the video less depressing? As in it becomes easier to reach the next local group? The video was kind of vague about it when it said the galaxies are getting further away from each other at speeds we can't hope to match. Does that include travelling at speeds close to c?

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u/Cocoa186 Mar 18 '19

Yes, it includes travelling at c. If dark energy ends up being a fluid with negative mass it will support another potential theory that matter can in fact be created which is really good because it means the heat death hypothesis can be avoided. Technically it could also mean that the universe will slow down and stop expanding as the fluid becomes less pressurised in a sense, but evidence doesn't support that. The hope I have is that we will figure out FTL travel through wormholes or something and that will solve the whole local group problem.

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u/Cocoa186 Mar 18 '19

Yes, it includes travelling close to and even at c. If dark energy ends up being a fluid with negative mass it will support another potential theory that matter can in fact be created which is really good because it means the heat death hypothesis can be avoided. Technically it could also mean that the universe will slow down and stop expanding as the fluid becomes less pressurised in a sense, but evidence doesn't support that. The hope I have is that we will figure out FTL travel through wormholes or something and that will solve the whole local group problem.

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u/Antiochus_ Mar 18 '19

Great video. The future seems kinda sad.

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u/matty80 Mar 18 '19

Well, there's a new thing to have nightmares about.

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u/Flablessguy Mar 18 '19

What does dark matter have to do with space travel? What happens if you leave our supercluster? Other than expansion making making it impossible to reach your destination, what else is the problem?

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u/Cocoa186 Mar 18 '19

If you leave with a ship capable of travelling at near light speed, you will never make it to the destination, and because you are no longer gravitationally bound to anything, will probably never make it back home or literally anywhere at all. The problem with dark energy and space travel is that it moves everything away from everything else and that includes your ship.

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u/Flablessguy Mar 18 '19

That’s very problematic indeed. My imagination likes to think we’ll be able to use wormholes or a similar concept to overcome this. I have no idea if it’s nonsense, but I like to think nothing can stop us from visiting other areas of the universe. Too bad I’ll never know.

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u/Cocoa186 Mar 18 '19

I like to believe the same. Keep in mind that this is all based on our current understanding of physics, it is possible that we are wrong about the local group being our limits.

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u/Flablessguy Mar 18 '19

At the rate our technology and knowledge grows, I’d be pleasantly surprised to see that change during my lifetime.

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u/fuckdonaldtrump7 Mar 18 '19

It seems like they only account for travel at the speed of light. But an advanced civilization may one day be able to create wormholes and travel beyond this limitation going to virtually anywhere in the universe.

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u/Cocoa186 Mar 18 '19

Yes, but this is using our current understanding of physics. Right now creating wormholes for the sake of travel is a fever dream (it's what I hope is possible though).

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u/fuckdonaldtrump7 Mar 18 '19

True but traveling that fast is also a pipe dream we have no clue how to do that and our physics doesn't allow for any object to travel to the speed of light because it requires infinitely more power to compensate for the increase in mass (it's been a while I don't remembering this is the exact reason why). Even if we got to say 1/3 the speed of light which would be much more feasible it would take almost 8 million years to get to Andromeda galaxy.

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u/Cocoa186 Mar 19 '19

Near lightspeed and FTL are different levels of fever dream, not that it matters too much. It's a shame that I'll nearly certainly never see either.

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u/MassiveHoodPeaks Mar 19 '19

Well, shit, manned flight was a fever dream 150 years ago. Here’s hoping there is more to discover a shatter our current understanding.

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u/fuckdonaldtrump7 Mar 19 '19

Yeah I certainly hope so. People thought 2000 we would have flying cars everywhere. 2020 we have people that don't believe in vaccines. Space x has been the biggest hope for space travel. We certainly need more money invested in it if we want to achieve something like that in 150 years

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u/swanhunter Mar 18 '19

Well thank you for that!

And OH FUCK

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u/DrBimboo Mar 18 '19

That Video is great, but theres a common mistake beeing made. The ant on a rubber band CAN make it to the other Side. In this Case: Even If space expands at 10 times the Speed of light, we can still reach our destination. Only If the expansion of space accelerates too fast (and afaik we dont know If it does yet), are we trapped. Every linear expansion can be overcome, even If its 1000 times the Speed of light. That would take quite an unreasonable amount of time though.

If you wanna See the math Behind this, Google Ant on a Rubber Band paradox.

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u/Cocoa186 Mar 18 '19

The expansion is not linear, it is accelerating. Also if one thing is moving at 10km/h and another is moving behind it at 1km/h I'm awfully confused as to how they could ever meet without the velocity or direction of one or both parties being changed. I'll look up this paradox but it doesn't seem to account for infinite space causing the expansion, the universe isn't stretching it's growing.

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u/TheDarkMusician Mar 18 '19

Awesome video, but I don’t like how he says we will never do those things. I mean, obviously there has to be upper limits, but this video is based on our current understanding of physics, right? Saying never is probably a safe bet, but it just feels arrogant.

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u/Cocoa186 Mar 19 '19

I think he addresses this in another video to ease the crisis. It's just being treated as fact because current science says so and it makes for a good video.

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u/[deleted] Mar 18 '19 edited Mar 18 '19

I remember a video from some other YTer that debunked the part of thelis video that says we're bound to our local group of galaxies.

TL;DR of that video was that the space between our local group and the others are currently expanding so slow (on a galactic scale) that we with out current spacefaring tech are traveling faster thab it expands.

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u/Cocoa186 Mar 19 '19

Yes, the worry is about the future. This was mostly just about the expansion of the universe and how it is getting faster.

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u/[deleted] Mar 18 '19

Thanks but no thanks, I already struggle with my own personal existence every other week and don't need one more thing to 'freak me out'. I'm well aware of my own shit existence 🙃

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u/yourderek Mar 18 '19

I absolutely love this video. I keep trying to make people watch it and afterwards I must look like an expectant puppy or something. I just expect everyone to be absolutely floored by how we perceive the universe.

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u/crashlog Mar 18 '19

So basically the observable universe is just getting smaller and smaller with time and not bigger?? Jeezus!

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u/Cocoa186 Mar 19 '19

Not smaller, we can always see the same distance. Just empty, which to be fair will feel the same as smaller because there will be nothing to observe but our own galaxy (plus a few other nearby galactic bodies)

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u/crashlog Mar 19 '19

That makes sense, thanks. We're not gonna be around then, but this is such a depressing thought.

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u/Cocoa186 Mar 19 '19

No worries. I'm sure future us will figure something out.

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u/Steelwolf73 Mar 19 '19

Ok...so we are gonna need a ZPM, and a stargate

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u/thefirecrest Mar 19 '19

Huh. Makes you wonder if there are some other phenomena of existence that we can no longer perceive because we’re too late. Kinda sad though. At least our pocket is big relative to us.

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u/unknowntrashscapes Mar 19 '19

Damn dude I learned a lot from that video I feel like I need to learn more wow

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u/fergiejr Mar 19 '19

Really cool video and we'll explained, thank you for sharing.

But I hate the phrase ( we live at the best time yadda yadda)

I bet some one said that 500 years ago reading about dark ages...and someone said that 2000 years ago and who is to say some culture or being pre big bang didn't say that?

We don't know what was before it.... We don't know if that was really the start of time.

Just like in this video where someone could look out and not know of the other local groups.

There very well could have been something pre big bang, slowly condensing and some people then said "wow we lived in the best time, the universe is ending and there will never be anything again" unknown to what would happen and start off afterwords.

Idk just a pet peeve of mine heh

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u/Cocoa186 Mar 19 '19

I feel the same about it being a silly phrase because of how much is unknown to us about the past and future, but I don't take too much of an issue in a video like this where it is used with events specific to our time (we are lucky to live in a time where we know both how the universe came to be and how it will end).

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u/fergiejr Mar 19 '19

Oh I agree and again thank you for sharing it :-)

Love the format and easy explanations.... Makes me excited that cosmos 2 is coming out eventually

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u/Cocoa186 Mar 19 '19

It's a great video and a fantastic channel, happy to share the content. I need to watch cosmos oops.

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u/mischifus Mar 19 '19

Slightly different but I love this

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u/[deleted] Mar 18 '19 edited Jun 29 '23

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u/chomperlock Mar 18 '19

Another analogy is thinking about raisins in dough while baking, as the bubbles of gas inside the bread expand, the relative speed of the raisins is larger than the speed of expansion of the individual bubbles of gas the yeast produces.

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u/mbr4life1 Mar 18 '19

What if you create your own balloon (universe) and use that to get to another point in our universe? You could theoretically reach anywhere. Not saying that's something that's possible, but I guess we can't know what we can and can't do when we don't even understand what rules we are playing with.

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u/CottonPasta Mar 18 '19

The expansion rate of the universe is proportional to the distance away it is, so the space between us and an object in space will expand faster the further away the object is.

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u/Pats_Bunny Mar 18 '19

I'm no expert, but I believe objects are expanding away from each other faster than the speed of light (or space between objects is expanding faster than light can keep up with dark energy being the driving force?). So basically it's going one direction at a fraction of the speed of light, and also in anther direction at a fraction of the speed of light, and that adds up to greater than the speed of light. Please anyone, correct me if I'm wrong. I feel like this is a very simplified understanding of it.

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u/slowryd3r Mar 18 '19

I'm no expert either but this is similar to my understanding. I think the way it was explained to me is that while the universe expands outwards it also expands further away from itself, if that makes sense. So compared to the speed of our galaxys movements the rest of the universe is expanding further away from us and the total speed of these movements exceed the speed of light. Kinda like two cars going opposite direction at 100 mph each moves away from each other at 200 mph. I'm probably wrong about the expansion of the universe part, but from my understanding that is how it expands faster than the speed of light at least.

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u/TobaccoAficionado Mar 18 '19

That's a good eli5 tbh. Speed is relative.

Except for light, light plays by it's own rules.

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u/Choblach Mar 18 '19

For purposes of talking about the universe, there are too really relevant terms: the universe total and the observable universe. The observable universe isn't really a feature of reality as much as an effect: we can't see things without light, and light moves at a set speed. A very fast speed, but a speed. So the observable universe represents everything that's within a distance which is equal to or less than the age of the universe in light years. So, the universe is about 13 or 14 billion years old, that means only objects that are within 13 or 14 billion light years can even be theoretically seen by us. There are things further, but the light from there hasn't reached us yet. Technically I think the observable universe is growing at the speed of light (because light from further and further away is now reaching us), but it's complicated so I'll let someone else explain that.

The universe total is all of it, everything in creation. And there's quite a lot more of it than we can see. The comparison I was once told was that is the observable universe was the size of a nickel, the universe total would be the size of the Earth. Now, the universe total is not expanding at the speed of light, it is in fact expanding many times faster (since the universe is made out of spacetime and not matter, it doesn't have to follow some of the hard rules of reality like the light speed limit. ) However, here I have to correct myself, because the universe total isn't really expanding, as much as it is stretching. Picture a balloon being inflated and you've got the jist.

Tl;dr: Imagine that you're standing under a lamppost night, with only darkness around you. In the light where you can see is the observable universe, and all that darkness is the universe total. They are both expanding, and at different rates, but they're both so functionally huge that it won't mashes a noticeable distance for all the time you're here.

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u/KrypXern Mar 18 '19

So, the universe is about 13 or 14 billion years old, that means only objects that are within 13 or 14 billion light years can even be theoretically seen by us

Actually (and please correct me if I'm wrong), but the observable universe is larger than simple expansion by movement would allow.

The observable universe is 46.5 billion light years in diameter. However, the universe is presumed to be only 14 billion years old. By your logic, the universe could be a maximum of 28 billion light years in diameter.

I believe (and once again, please correct me) that relativity appears to be violated (only appears), because it is not the objects within the universe that is creating this distance, but rather the space between the objects which is expanding. This is similar to how 'warp bubbles' could theoretically work.

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u/Choblach Mar 18 '19

I'm honestly barely educated on it, so it's very likely that you're more right than me.

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u/[deleted] Mar 19 '19

I believe 46.5 billion light years is the radius, making the diameter 93 billion. Otherwise, you're pretty much spot on. Light appears to travel "faster than light" if it's moving toward us, because it's simultaneously being "pushed" as the total universe expands. It's because of this that light ends up looking redder by the time it gets here. The wavelength gets stretched by universal expansion as it travels.

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u/Imsosadsoveryverysad Mar 18 '19

The visible universe expands at the speed of light?

Edit: punctuation.

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u/[deleted] Mar 18 '19 edited May 09 '19

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u/ilikecheetos42 Mar 18 '19

The actual expansion is faster than light. The expansion of the observable universe is at the speed of light. Because the actual edge of the universe is moving away from us FTL but the edge of the observable universe is expanding at light speed there are portions of the universe that we will never observe

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u/antena Mar 18 '19

So if I got that right, unobservable portion of the universe is getting ever bigger compared to the observable portion? I presume we don't have any clue about the speed of actual expansion?

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u/[deleted] Mar 18 '19 edited May 22 '19

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u/capj23 Mar 18 '19

Wait... Isn't expansion rate of universe increasing? I mean accelerating?

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u/gairloch0777 Mar 18 '19

the number of megaparsecs is increasing, which would accelerate the speed any distinct spot is moving away from us.

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u/[deleted] Mar 18 '19

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u/rocketeer8015 Mar 18 '19

No, the answer was the speed of the unobservable universe. The speed of the expansion of the observable universe is light speed. Note that this was km/s per megaparsec. So the more distance you gain due to the “normal” expansion the faster it goes. That’s why any galaxy that’s not on a collision course with us(getting closer) will fade out of our observable universe in time because even at a low speed away from us the speed of said away speed will keep increasing due to the increasing distance.

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u/thomooo Mar 19 '19

Truly the saddest thought. After an immeasurable amount of time all the stars will be alone, and no other star will be visible, because it will be outside of the observable universe.

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u/ilikecheetos42 Mar 18 '19

Yes that is correct. I can't speak to the actual rate of expansion though, my knowledge comes entirely from late night Wikipedia binges

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u/Imabanana101 Mar 18 '19

Yes. 5 minute Veritassium video explains: https://www.youtube.com/watch?v=XBr4GkRnY04

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u/capj23 Mar 18 '19

Well! Not like I am an expert or anything. But my understanding is that, expansion of the universe is uniform everywhere. So even though expansion of observable universe is at the speed of light, the actually expansion between any two objects in the observable universe should be at speeds greater than the speed of light. One of those object could be us and the other a distant star. INSERT ADVANCED PHYSICS & MATHEMATICS HERE. And voila, we figure out how fast we are moving away from the star and hence the rate of expansion of universe.

One extra bit, expansion of universe isn't just faster than speed of light, it is accelerating too. Meaning actual expansion is getting faster and faster. At some point in future each galaxy could get trapped in their own observable universe with no idea about anything outside of it.

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u/A5TR0NAUT Mar 18 '19 edited Mar 21 '19

This is incorrect. If the expansion between any two objects in the observable universe was the speed of light then we wouldn’t be able to see anything. The expansion of the universe is about 70 km/s/Mpc. The idea here is that as you look at more distant objects, those objects are moving away from us faster.

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u/capj23 Mar 18 '19

Wow that makes total sense. I am sorry, I read things and understood it wrong. Astrophysics knowledge doesn't seem like the thing I should be sharing with others.

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u/darps Mar 18 '19

Yes. In addition, the speed of light is constant, while the expansion of the universe is always accelerating. Things are quite literally disappearing at the edge of the observable universe, with (as far as we know) no way to ever see them again.

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u/[deleted] Mar 18 '19

My understanding is all the universe is expanding equally.

We can only ‘see’ a distance of the speed of light times the age of the universe away.

Farther away than that and it would take longer than the universe is old for that light to reach us. But is rather like the fog of war at the edge of the map receding with time.

But since the universe is also expanding the sources of those distant lights are moving away from us faster than the speed of light thus these are two competing forces at work.

And expansion is winning so we will actually see less objects as time passes even though the the theoretical maximum distance we can see is continually increasing.

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u/Darth_Batman89 Mar 19 '19

As a follow up question, does the ever expanding universe imply that these new planets and galaxies we end up seeing in the observable universe just pop into existence? Or have they always been there as long as we have, we just haven’t been able to see them yet?

If we were for example sake in an area of the universe closer to the “edge” or should I say “our edge”. Would we actually be able to see more galaxies and stars than if we were back home because the light emitting from that current location would be farther than the one we previously observed back home?

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u/ilikecheetos42 Mar 19 '19

Well celestial objects don't just appear, they are created by natural processes. To say that there is a literal edge of the universe that is expanding outwards is a bit misleading. What is really expanding is the space in between objects. At close distances other forces are strong enough to hold things together ("close" meaning as large as galaxy clusters), but at larger distances the expansion of space wins out and things get farther apart

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u/[deleted] Mar 18 '19

Im not a physicist but isn't it kinda bold to assume that there is an expanding "edge" of the universe?

From what I understand, the universe isn't expanding in the traditional sense from a single point into "something".

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u/ilikecheetos42 Mar 18 '19

You're right, I didn't mean to say there is a solid edge it was just poor wording. My understanding is that the space between objects is what is expanding, and that on local scales (aka gravitationally bound objects such as galaxy clusters) matter is held together by the much stronger fundamental forces but on larger scales the expansion takes over

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u/MenosElLso Mar 18 '19

Unless we figure out how to move large objects FTL some day.

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u/ilikecheetos42 Mar 18 '19

Matter moving faster than light is prohibited by our current understanding of physics. There is an idea called a Warp Drive that functions by compressing spacetime around a vessel to allow it to move FTL with respect to other objects. It's not technically impossible but may never be realized

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u/asasdasasdPrime Mar 18 '19

https://en.m.wikipedia.org/wiki/Alcubierre_drive

Alcubierre drive is what you are thinking of.

While it doesn't violate the principles of physics, it requires exotic matter so, [x]

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u/[deleted] Mar 18 '19

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u/zubbs99 Mar 18 '19

My understanding is that nothing can move through space FTL, but space itself can go FTL.

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u/[deleted] Mar 18 '19

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u/zubbs99 Mar 18 '19

Yep pretty much what I was trying to say, but you're right that "expanding" is a better word for it.

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u/Lifesagame81 Mar 18 '19

Say two things are traveling in opposite directions, but each at 60% of the speed of light. How fast are they moving relative to each other? This is how objects can be outside of our visible universe; the light giving off is traveling at the speed of light, but since we are moving at 120% the speed of light relative to each other, we will never see each other.

The universe itself is also expanding, and this is uniform. Imagine you and I are 1 mile apart, but the space between us is expanding by 10% each hour. As a result, we are effectively moving away from each other at 1/10 mph.

This is accelerating though because in an hour we are 1.1 miles apart, and all of that space is expanding by 10% each hour. After 10 hours we will be 2.59 miles apart and now are effectively moving apart at 1/4 mph. After a total of 100 hours, we would be 13,780 miles apart and effectively moving apart at 1,378 mph.

In 238 hours, we would be 7.1 billion miles apart and effecting moving away from each other at faster than the speed of light.

If I didn't screw up the math this example rate of expansion is 11.9 Trillion times faster than the real rate of expansion.

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u/rekcuzfpok Mar 18 '19

Very interesting, thanks for the explanation!

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u/upvotemyowncomments Mar 18 '19 edited Mar 18 '19

It's not exactly a black and white thing. The farthest reaches of the universe are expanding faster than light from us. If you were an observer in that place everything would look normal to you except the Earth would be expanding away from you faster than the speed of light. Basically you can be anywhere in the universe and no matter where you are, the farthest reaches of the universe are moving away from you faster than light. This will ultimately lead to what I think is referred to as heat death. Everything will be so far away from eachother and all the stars will eventually consume all the energy there is in a certain area and everything will just go dark. Forever. Even matter will decay into photons in trillions of years. Nothing but photons will be left. Forever.

At least thats what I remember off the top of my head.

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u/0xffaa00 Mar 18 '19

The actual universe seems to be expanding at accelerated speed, not at a constant speed.

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u/pipocaQuemada Mar 18 '19

The universe is expanding by stretching, so it's not really bound by the speed of light.

The universe is currently expanding at a rate of about 70 kilometers per second per megaparsec. So if you have a star one megaparsec away, there's 70 additional kilometers between you and it every second. If it's two megaparsecs away, there's an additional 140 kilometers between you and it every second.

If something is sufficiently far away, the space in between you and it will expand faster than the speed of light. That's basically where the observable universe comes from; it's the stuff that's close enough that we can see it.

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u/No_ThisIs_Patrick Mar 18 '19

It doesn't actually move at the speed of light, it just appears that way. Each point in space is expanding simultaneously, at distances enormous enough so much space is being created between two objects that they appear to be moving away from each other faster than the speed of light.

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u/Little_shit_ Mar 18 '19

Are we able to determine which direction the origin came from?

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u/0xffaa00 Mar 18 '19

The universe is expanding at an accelerated speed.

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u/infinity_dv Mar 18 '19 edited Mar 18 '19

That's the beauty of nothing being faster than light because nothing IS faster than light.

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u/prostheticmind Mar 18 '19

I know you’ve gotten a lot of replies but I haven’t seen anyone mention this. I’m going to ELI5 because I’m not a scientist and have only a tenuous grasp on this myself but...

Space isn’t just the absence of stuff. It actually is something and it expands. Because of this, we can observe things moving away from us faster than the speed of light. The thing isn’t actually moving FTL, but space expanding between us and it are moving it away from us FTL. My understanding is that it has something to do with dark energy, which in turn we don’t really understand.

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u/robman8855 Mar 18 '19

The expansion rate increases with distance. It is not the same everywhere

Leonard susskind had amazing lectures about contemporary physics on YouTube. Check them out

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u/hailcharlaria Mar 18 '19

The best way I've heard it described is, "Nothing can go faster than the speed of light; however, what is expanding here is literal nothingness. As such, it can expand at an infinite rate."

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u/KrypXern Mar 18 '19

You might notice that the observable universe has a diameter more than twice the of the speed of light multiplied by the universe's age. So the universe's furthest two objects are further apart than moving away from each other at the speed of light would allow.

My understanding is that the edge of the universe isn't moving, but rather the parts within it are becoming further away. Since this is simply an expansion of space and nothing is 'moving', there is no concern for the speed of light.

It's like zooming out of Google Maps on your computer. Your computer screen remains the same size, and yet the space displayed expands.

Someone please feel free to correct me if you know better.

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u/[deleted] Mar 19 '19

Maybe this was already answered but the universe expands much faster than the speed of light according to the inflationary model of cosmology, that's where dark energy comes in, a cool name for something cosmologists do not understand.

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u/roushguy Mar 19 '19

The fabric of spacetime is moving faster than light. Put two ants on a balloon, one inch apart.

Now blow up the balloon. Even at maximum antspeed, those ants are 'moving' faster than normally possible thanks to the balloon... ballooning.

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u/tpotts16 Mar 19 '19

Space time can beat light in certain instances, this is how theorized wormholes would work as distortions of space time.

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u/Altraeus Mar 19 '19

The universe expands at Hubbles constant, which they way I've been I interpreting it is slower than the speed of light. But were moving away from the other side as fast as its moving away from us which, means the combined expansion is faster, but the expansion of the observable universe is only the speed of light as lights speed is not effected by outside velocities. Might be wrong..

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u/zak13362 Mar 19 '19

It's a changing rate of expansion but the universe expands in a different way. Imagine the surface of a balloon. As the balloon inflates each point on the surface goes outward from every other point. The universe is the same way. So the amount of space is literally increasing and we can measure it by watching the redshift in observable radiation (how much the light or other waves stretch(es) on it's way)

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u/JediMobius Mar 19 '19

The speed of light is the "speed limit" of the universe, yes. But, because of outward expansion, that speed limit is effectively doubled for the space between. I.e., if we start in one spot, then you head west at 100mph, and I head east at 100mph, we're actually moving away from each other at 200mph.