Mapping the universe: dark energy, black holes, and gravity - with Chris Clarkson
How can we map the universe and its galaxies? What's the evidence for dark matter and dark energy? And how has Einstein's general theory of relativity been proven by modern technology?
Watch the Q&A here: • Q&A: Mapping the unive...
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In this talk Chris Clarkson describes how cosmological surveys map the vast cosmic web of galaxies on scales so far only envisaged in computer simulations. Unravelling this delicate web will reveal not only the nature of the Big Bang itself, but the essence of dark energy - and with it, the future of the Universe.
This talk was recorded at the Ri on 25 April 2023.
00:00 Intro
01:58 Mapping our solar system and galaxy
8:16 Looking at other galaxies
13:08 Mapping the universe with galaxy surveys
15:32 What does the whole universe look like?
23:22 A timeline of the universe’s evolution
25:42 How do we know what the universe looks like?
27:28 Einstein’s theory of gravity
30:28 Spacetime bends and moves
33:40 Black holes predicted by Einstein
35:35 Gravitational waves
37:58 The universe is expanding - how fast?
40:02 The evidence for dark matter
41:48 The evidence for dark energy
43:35 How much is the universe expanding over time?
45:01 How can we explain the structure of the universe?
53:18 The mystery of dark energy and dark matter
56:33 Inflation at the big bang
57:39 The next generation of surveys
Chris Clarkson is a cosmologist working at Queen Mary University of London. He works mainly on the theory of large scale structure of the universe but has worked on many aspects of gravity and cosmology, including the big bang, gravitational waves and black holes. He is currently Head of the Astronomy Unit at QMUL, having previously worked at the University of Cape Town as Head of the Cosmology Group. He studied for his PhD in Glasgow a long time ago, and undertook postdocs in Canada, South Africa and in the UK.
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The way Chris described how we "see" dark matter via gravitational lensing was the first time I actually understood why we know something extra is there and didn't just have to "take his word for it" that the lensing means there's more.. many thanks for a great and simple presentation!
Another huge clue is the breakneck speed that the outer stars are orbiting the center of galaxies. At these speeds the stars would be flung out of their galaxy if not for the additional Dark Matter (and accompanying gravity).
@@georgefleming4956 right, I understood that clue... it was just the lensing that most things I've watched just seemed to say "there's lensing, so dark matter" and never explained why it meant that instead of there possibly being some other gravitational body causing the lensing
Outstandingly clear and well presented.
Excellent job as usual. However, this professor was particularly humble, yet very very clear as he presented the newest research.
I love this channel so much. There's such a huge variety of different topics that I enjoy, especially space. I don't know shit about what these people are talking about but it is so amazing to listen to these and try to learn new things. Please never stop uploading new videos, this is one of the best channels on KZhead.
Great lecture! Thank you.
Magnificent presentation!
What a great presentation! Very clear, and with a really good progression. Thanks Chris!
Some numerics even if astronomical, will help in clearifieng the subject. Enjoyed the presentation and will listen it over and over again.
If you liked this, you can watch the Q&A with Chris here: kzhead.info/sun/ataGZ8mQqGOjhK8/bejne.html
Jesus loves you all. Please turn to him and repent before it's too late. The end times described in the Bible are already happening in the world
Pin this to the top please.
@@L17_8 Rock on!
Love the speech. Great simplifications of extremely complex topics and very honest interactions and responses. RI continues to impress.
Thanks for another great video, look forward to many more!
Best lecture on the universe I've ever had the pleasure to hear! I've sent it around to my whole family--even the grandchildren.
If only it was true. lol.
@@adamk2895that’s fallacious
@@garytyme9384Thats an argument from incredulity
…but there were 3 glaring errors in this “best lecture ever” of yours I’m afraid
*In THIS universe 🤪
I didn't know Hawkeye had such an interest in cosmology.
😂
😊
He can already hit everything on earth, so he started shooting for the stars.
reach
This is an excellent summary!
Is the cmb expanding/rotating/changing or is it static/unchanged as we view it
Creepy/alarming that the large scale structure of the observable universe looks organic and familiar. My initial thought was omg the energy density/distribution looks similar to neural tissue 😅
it often makes me think of a picture I saw as a kid it's of a forest, but looking down from above and superimposed on it were the connections under the ground made by fungus. connections made from the roots to help the trees gather more water, but also the fungus itself having its own areas of greater growth and connections, flowing and fruiting. and just like the greater universe has its clearings and patches of greater growth producing its fruits
Great lecture
Well thought out and taught. Thank you.
Nice explanation about the age of the universe. But what about the new images from the JWST? There you can see that even the oldest visible galaxies are already very structured, although we would not expect that because of their age. Is the universe perhaps older than calculated? That would mean that one cannot calculate back in a linear way, which in turn would mean that the expansion did not proceed uniformly.
That beat up table changed my mind about watching the video😩👀
thank you
35:16 Correction: The right black hole image is of the M87 galaxy. Not Andromeda.
Please replace the mic with one that does not pick up so many mouth noises and sounds, pops and clicks, love the series, but some of these lectures are difficulty to listen to as a result.
RI is a wonderful institution making science available to non-scientists! Thank you RI! Professor Clarkston's visuals are stunning! Where can we get his beautiful rotating earth from! Would love to have that as an active desktop!
Excellent, thank you.
So much knowledge in the comments! I can almost see it!
Is it just me or is the image quality of this video significantly worse than average, as if it was recompressed to a very low bitrate (even the 1080p version)? I wonder if KZhead is serving lower quality proxies for some reason...
Fantastic speech!
What a wise plan to cheer us with such a splendid astronomical spectacle! Deep and big questions of almost forbidden cognizance (at least to our venerable ancestors) stunningly unfolded and narrated. The science series is scurpuosly preserved in my private account and of course in my heart.
One though that I had looking at the web like structure is, how much is time dilated in the denser regions vs the voids and what effect does that have on things. I really struggle to wrap my mind around some of the concepts. :-) The fuel of expansion is the free running clock of the void.
That is an execellent point. Jon Evans has the equation that fixes it all. Time=Energy=Mc2.
You can estimate it. Just substitute Newtonian gravitational potential for Newtonian kinetic energy in the Lorentz factor formula: 1/g**2 = 1 - 2E/c**2
The desk, that famous desk, has a new shine...
this is me being a bit silly but could dark matter anf dark energy be from muliple universe overlsppring?
I wonder if there are galaxies that rotate right & others left?
@@RayzeR_RayE 🌞 that's the answer I was hoping to get!
Illuminating 👍👍
How does a simulation form a galaxy, when our concepts of gravity are not understood, what inputs are you putting into the simulation ?
Do we know where the center of the universe is? If so, could it be that there is a phenomenon in the center that has an attractive force, and that matter/energy could have a repulsive force, that as it travels further from the center the attractive force overcomes the attraction force and thus accelerates (inverse square) away from the center? Has this been hypothesized or observed?
Not hypothesised or observed by anyone because it's wrong. There isn't a centre of the universe and the laws you state don't act in the way you've thought of.
Nice suit, very respectful
This presentation is quite magical, in terms of the images and the creative commentary. Einstein does not do away with Newton, who remains technically correct very comprehensively. Newton's view of gravity as a force needs to be understood, in context, in contradistinction to a physical act of matter. Since gravity does not wrap molten fists around our ankles to keep us on the Earth, nor do we walk in on and off terrestrial glue, the gravity that acts upon our bodies is a force, rather than a materially physical wrestle hold type of action. Likewise, electro-magnetic forces differ from handcuffs, and a magnet holds by attraction, rather than by affixing by means of structures.
Excuse my ignorance, as I'm not a cosmologist, but is it possible that the "empty" space between the quarks inside protons and neutrons is actually dark matter, and that dark matter can also exist independent of quarks? Could dark matter be what causes gravity in all things, both dark and visible?
I am a newcomer, and I was immediately drawn to the humble perspective of the announcer of this channel. We humans are susceptible to believing our own |< ool aid. Every generation before us has underachieved based on subconscious limits.
When we depict our galaxy, it looks the same from all angles. Even when the light from one end of the galaxy is traveling to us 100.000 years longer than from nearby structures. I think that's strange. Nearby, more stars should have looked older - going supernova etc -.
It’s the same reason your feet don’t look older than your nose
Then you haven't seen my feet.
The problem is the dent in spacetime is being continuously created and goes out at the speed of light, until it become unmeasurable and uninteresting, you drop it. Two merging black holes can send out a detectable the gravitation a billion years away, in a thought experiment that merge activity goes on for a billion years, it would fill a billion light year sphere with measurable gravitational activity and you can't just drop that fact like you do with the earth's gravity when it is a light year from earth. The gravitational effect by a sun sized mass every second, is still there a billion or 13 billion years in the future. Once this depleted support blends with background gravity it may no longer travel at speed of light, no one accounts for all the matter of the universe depleting space time support every second for 13 billion years.
Isn’t the expansion of spacetime stretching the galaxies so the outer edges fly off. We just can’t tell because it’s all happening so slowly. 40:49
HOW do you map Infinity ?
8:07 stars moving around blackhole looks like fireflies moving in a night sky. How beautiful yet chaotic our universe is 😅
Why isn’t he mentioning the new JWT observation?
Maybe instead of the big bang pushing galaxies out (with increasing speed), something is pulling it in?
Been working on this theory for years! 😉
It's still turtles, all the way down. The blue gravity worm proves it. LOL Great video!
so i can't quite grasp this measures, but correct me please if i'm wrong.. scientists look the CBMR identifying it as the oldest type of radiation we could ever look at, so thats it almost on the origin of the universe, but all that radiation (if we could look at it in what have become) is all the matter that we see and not see today? All the stars, galaxies, clusters etc that we observe and are spread across 93 billion light years are what this CBMR radiation has become? i don't quite get it
Is the space between every galaxy have stars? What is in the space between every galaxies?
The Warm-Hot Integalactic Medium (or WHIM.)
Interesting throw-away comment at 27:15 - "the universe is neutral". How do we know?
Because it’s not charged.
I wonder if any researcher thinks (and is pursuing) finding out what can potentially cause the expansion to slow down (imagine something that acts opposite of expansion force by dark energy) and maybe universe will end one day in either free stable expansion or maybe even collapse into singularity.. who knows..
Gravity from mass slows it down
Does the radiation at 13.4 billion light years away have mass?
21:00
Whoever editing that decided to use the zoomed out view for 19:00 apparently hit their head when doing so.
In my head spacetime is the Higgs field, gravitational radiation are waves that propagate through the Higgs. The Higgs is in condensate & as a result repulses everything else. In the case of unbound energy we call this dark energy, in the case of locally bound energy (matter) we call this gravity. Because the Higgs wants to repel the constituent parts of matter in different directions it can not because they are locally bound, resulting in the Higgs forming pustules of matter (gravity wells). The surface tension between the Higgs pustule & pure Higgs we currently call Dark Matter. The period of inflation occurred when the universe had no bound energy (matter) hence the rate of expansion was at its fastest. The Higgs predates our universe & our universe is expanding into the Higgs, resulting in the ratio of Higgs within our universe is rising, resulting in the acceleration of our universes expansion rate. - I can my theory the Condensate Flare Theory. note :- I suspect in an attempt to maintain its preference for life at ground state, the Higgs has spawned many flares, universes. Quantum fluctuations & virtual particles is this Higgs repulsion at the smallest scale.
Do all condensates repulse everything not in the condensate?
Was this recorded with a potato? It says it’s playing at 1080p “premium” (whatever that is) but looks like a hot mess.
Was good but seemed to be an ad every five minutes!
A lot of people in the comments say that in this video the lecturer made complicated concepts sounding simple, just like it happens with many other videos from this cahnnel. Honestly I have a high school diploma, I like physics and I like this kind of videos but it happens pretty often that I don't get a non negligible part of what is explained in videos form the RI channel. Maybe some concepts cannot be explained simpler than that and I am nbot saying that they could have done a better job because I can't know, but I'm sorrry, I don't think that the communication is very effective.
The reason you don't understand it is because it's 180 degrees from reality. It's mathematical nonsense, and they've had to inflate the numbers to get the model to fit the observations. Newton's F=ma. Mass has no force without acceleration. To give mass force, Einstein had to warp space. To make black holes, with lots of mass work, they had to give it lots of acceleration. Jwst is exposing their lies or their ignorance. The supermassive black holes and large galaxies. What are they doing? Giving them lots of acceleration (time) to form. The universe is 13 billion its 26 billion, then 52. Then 100. Pretty soon it goes to infinite. Sound familiar? E=mc^2. Mass increases with acceleration. Except it doesn't, and they have no evidence that it does. Their understanding of the universe is 180 degrees from reality because the models are based on mass. On Newton's Law of gravity on Einstein’s relativity nonsense. Everything to them is mathematical. The problem is that they are using mass to define acceleration instead of acceleration to define mass. They've backed themselves into a corner now and there is no way out. F=ma. You only have two options. Acceleration equals Force or Mass equals Force. Like in the movie Indiana Jones. They chose wrong.
❤❤
16:20 Dark Matter..❤
Cosmic Voids
It occurred to me that the light reaching us from the furthest objects being calculated to be traveling away faster than the speed of light equally means those objects could have actually reversed to the degree that they are traveling towards us faster than the speed of light any we wouldn't know it. If they were headed towards us now beyond the speed of light, they would arrive at us without us seeing them coming as is. Surely this would be in part due to negation of expansion/dark energy that would also prevent each object from overtaking their own photons but the compression could result in blue shift of light and brightening. Therefore maybe we would see indication that collapse is happening just before we collide with everything in the universe all at once. Whether we would recognize the visible manifestation of the phenomenon is always a big unknown.
Perhaps we could detect that it might be happening based on near galaxies having blue shift. Of course that still takes millions of years to see new light from our closest major galaxy Andromeda. I'd like to find out officially if Andromedas light is blue shifted, I have heard it is. If it is blue shifted that obviously provides interesting perspective that a collapse may actually already been going 2.5 million years ago. Not a big enough sample size for sure because there is relative movement between galaxys in the cosmic web, but it sure is that one possible indicator.
The variables in gravity are probably incidental, NOT CAUSAL. "The wheels on the bus go round and round" is not an understanding of a bus, because going round is incidental, NOT CAUSAL (Math analogy). Relativity ONLY works on paper AFTER the transform equations change your numbers to CREATE constant light RELATIVE TO THE OBSERVER (A declaration, NEVER AN OBSERVATION). So, if you move your head, the entire Universe INSTANTLY changes shape JUST FOR YOU? None of what I said is impossible, and that's science whether it hurts or not.
I didn’t know Gordon Ramsay was also a Cosmologist? ^.^
Can dark energy be effect of outside universe on our universe like Jupiter gravity effect on Europa? 😮😂
Thank God,...we Dont just Fly apart from each other at the Speed of Light....❤😅🎉
Dark Energy...❤
Velocity of S.M.BackHole
Mapping the dark matter.. Oh boy this sounds so exciting it almost reminds me of that fairy tale about emperors new clothes.. So we all know what most of the stuff is - dark matter and dark energy!
Calling 50million ly local, it's hard to comprehend.
Can't wait to see Jon Evans shopping cart of nobel prizes
The space between every galaxy and edge of all galaxies have a gravity fields causing a friction that is why the galaxy moves.
I stopped with dark matter which is only an hypothesis to explain abnormalities in gravity. Maybe it's that gravity model itself that's wrong and this is not considered.
But it is considered. All the time. Get a clue.
This is why the volume matters if you want to do the math properly
Can someone help me out here. Galaxy 10 billion years ago is moving away faster than galaxy 1 billion years ago. Looks to me like expansion is slowing down not accelerating.
Galaxies 10 billion light years away, move faster away from us than those that are 1 billion light years away. Yes, the image of them is from the past but you can ignore that.
@@MichaelOrr1984 I have hard time ignoring facts, I am not delusional that scientists got it wrong and I know better, I just cant focus on ANYTHING when they are talking about dark energy because of this. Galaxies 10 billion years ago moved away fast, galaxies 1 billion years ago moved slower, galaxy today barely moves away - universe expansion is accelerating... WTF????
@@Biskawow Well, all the info you need is open to you for free if you want to have a look.
Try removing the “T” for time out of Einstein’s equation, see if that helps.
T is mass.
2.725 Kelvin? So the Universe was very cold?
We are living at just the exact right time to see the background radiation. It can’t have been generated for long, and it’s not gone completely past us yet and it has started reaching us. What are the chances of that. Just like the chances that the moon is at exactly the right distance to form a perfect eclipse. Spooky
No word, that there are valuable alternatives to the bigbang theory? How about the Electric Universe?
The electric universe is not a working scientific theory, sorry. Plenty of debunking videos out there to watch if you are wondering why.
Anything exists because we live in everything or infinity. Don't worry at some point everything will exist all at once. It will be like when you reformat your drive. But you'll have a back up 😎
Inaudible. I can't handle the microphone crackling
How can all the matter we see around us. Be pulled into central black hole singularity and also be expanding....????
Great lecture but I wish inflation wasn't presented as factual. It's looking like dark energy may not be constant. It's too soon to say but we should know if they get 5 sigma in the next year. It's an insane experiment.
Gravity is the repulsive force between time space - the 'ether' - and mass. Electromagnetic waves are ripples in time space - ie essentially variations in gravitational strength, size of space and rate of change of time. The closer space time is together the slower time goes and the smaller the spatial dimensions are. A gradient in space time produces a gravitational force. Mass displaces space time thus creating a gradient that produces gravity. Run with that.
look to the electric universe for the true model of the universe
The electric universe is not a working scientific theory, it's there to promote a website selling electric plasma balls.
So many ads totally ruined the video experience im not watching any more
Must depend on your region. I only had two. Not bad at all for a video an hour long!
There is NO 'space-time', all directions is curved, all Motion is Spiral.
This is wrong I'm afraid.
How can You know?
@@holgerjrgensen2166 What you say doesn't agree with current best theories.
Why does any of this exist?
It’s funny, how physicists are so reluctant to accept that there is no such thing as time, because of Einstein, yet every thing, every equation from black holes to gravitational waves works perfectly fine without the insertion of time into it. It’s wacky!
If time didn't exist, every day wouldn't bring you closer to your next birthday. But they do, so it does.
Not all equations but yes some of them don't care about directional flow of time. You're still a good troll though well done.
Do you know what waves without time are called? Bumps. They are called bumps.
I don’t think astrophysics is a science of caution: I have no problem with the infinite. Raised a Christian Scientist with the emphasis on science. Visible and Invisible Quantum Oceans / Waves breaking at irregular universe boundaries. If oceans are flat, Quoceans are at minimum 3D. The universe is still creating itself. [I thought of this in 1967, and I have changed my mind very little since then. I’m not saying why or what it is, I’m just saying what it looks like. It’s gorgeous! The biggest surprise is it would need to move gasses - possibly air - some within the human hearing range]
Mn
Beautiful 🤌 Where can I get the presentation material if available . @TheRoyalInstitution
How much of this is theory vs fact?
Pretty much all of it except for dark matter/energy which are speculative.
Spacetime is fluid bh a cascade to 4th dimension
I’m told it’s best to say nothing.
:
the more I learn about it,the less I understand.
The heart of the big bang theory is a view that "We" are the center of the Universe. It's the same problem with beliving the Sun and everything revolves around us. If you investigate the theory in your mind, you will keep finding all these conclusions all over the place that could only be "True" if we were actually the very center of the Universe. lol. Jon Evans was right
It'll be nice to hear what you think after you've actually watched the video.
That is not the 'heart' of the BBT at all. As near as observation can tell us, it happened everywhere, all at once.
When he got to the "dark matter/dark energy" part, he still spoke about it like it was proven science, its not! Its philosophy being used to explain things we see and cannot yet explain. So this talk went off the rails at this point for me...
That’s because you don’t understand cosmology and the SM.
No such thing as Dark Energy. Pmsl!!! Gravity is the phenomenon of mutual mass dielectric acceleration to a null point in counter space.
I'm glad for Chris that he has three pairs of eyes, but unfortunately, I only have the one. And so could only see ⅓ of his presentation. Bummer.
I was under the impression that you are a foremost expert in this field, yet at 23:26 you show a diagram that you correctly call a cartoon. This diagram is a 2D soace by 1D time complete history of the universe. However at the supposed beginning there is s 3D flash of light that is TOTALLY OUTSIDE the universe. Further within the body of the cartoon, that can only hold long streaks built up of stack upon stack of 2D spacial slices , there are shown 3D diagrams of galaxies and galaxy clusters that clearly demonstrates the artist and the artists adviser had absolutely NO CLUE as to what was being portrayed. Please correct this delision. Then again at 31:39 you show the 2D representation of spacetime curvature that is the complete OPPOSITE of how matter curves spacetime. Matter does NOT stretch spacetime, MATTER COMPRESSES spacetime. This misrepresentation galls me beyond description.