How computer models help us understand the universe

How computer models help us understand the universe - with Andrew Pontzen

Рет қаралды 31,635

Күн бұрын

How can scientists study the past, present and future of the cosmos? Find out how computers can help.
Buy Andrew's book 'The Universe in a Box' here: geni.us/ZSw45d
Watch the Q&A for this lecture (exclusively for KZfaq Channel Members): • Q&A: How computer mode...
This lecture was recorded at the Ri on 5 February 2024.
Join Professor of Cosmology and science communicator Andrew Pontzen as he uncovers how intricate computer codes have unlocked our understanding of the universe - from galaxies and black holes to the very essence of matter itself. Simulations have also revolutionized our understanding of the cosmos, shedding new light on the universe's multifaceted complexities. They are the windows through which we peer into the hidden dimensions of space, guiding us through a journey from the phenomenon of cosmic redshift, which unveiled the universe's accelerating expansion, to the ethereal concept of dark matter, a substance that traverses solid rock as if it were a ghostly apparition.
But of course, none of these breakthroughs would be possible without the tireless efforts of scientists, whose brilliant minds persist to push the boundaries of knowledge. Join Andrew on a journey through space and time, with science, simulations and unrelenting human curiosity as your guides.
00:00 Introduction
2:20 What we can observe in the universe?
7.28 Dark matter and dark energy
9.27 Gravitational lensing
12:08 Looking back in time at the universe
14:47 The role of gravity and dark matter
16:21 The history of computing in physics
22:12 Weather forecasts, cosmology, and initial conditions
28:09 Using computers to predict the weather
35:22 Early models of our universe from physicists
42:34 Predicting our changing climate
45:02 Using computer simulations for cosmology
55:32 Are we living inside a copmuter simulation?
Andrew Pontzen is a professor of cosmology at University College London. He has written for the New Scientist, BBC Sky at Night and BBC Science Focus; lectured at the Royal Institution; appeared on BBC, Amazon Prime and Discovery Channel documentaries; and contributed to BBC Radio 4 programmes including Inside Science and The Curious Cases of Rutherford & Fry. Computer simulations are a major part of his research which spans cosmology, physics and computation.
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Пікірлер: 52

@JohnBeeblebrox 3 ай бұрын

An excellent and engaging presentation. I particularly liked the discussion regarding "limitations" of models (e.g. subgrid assumptions). No doubt there will be many comments regarding simulated universes 😊 but I found the entire talk fascinating. Thanks for posting RI - another good one

@sophiebarbara4111 3 ай бұрын

Always such a pleasure to listen to

@Silverbirchleaf 3 ай бұрын

Maybe the real universe was the friends we made along the way

@robertbritt6134 3 ай бұрын

Maybe we’re incredibly self absorbed

@alessandrobussi2545 2 ай бұрын

Good One!

@thguzzo17 2 ай бұрын

😂😂😂😂

@st0rm129 Ай бұрын

ONEEEEEE PIECEEEEEEEEEEEEEEEEEEEE !🔥

@Elena0210 5 күн бұрын

Amazing lecture ❤❤❤ Will be ordering the book!

@tizio13 3 ай бұрын

This was such a great talk! Definitely get the book!

@jonasseger 3 ай бұрын

Very interesting and informative talk! I reacted on one thing. Andrew says that gravity is caused by mass. While we do know mass affects time/space in a way that gravity is experienced. Maybe not only mass can distort time/space? At least we shouldn't assume that mass is the only thing to affect space/time, right?

@christianfloreck8347 2 ай бұрын

Great! Bring this complex topic to a "normal" consumer - that is impressiv. I'll grap this book

@thomaspittner7027 3 ай бұрын

one time I was on the East Coast of Sansibar in Pitch darkness and absolute clear sky. when I puttet my glass on it was mind-blowing. I have never experienced the night sky close to this.

@dadsonworldwide3238 3 ай бұрын

On dark matter ,we also have many different other lines of evidence in many other avenues throughout history where setting certain physical input and perimeters has a lead to many to theorize things similar to this and it should not be disregarded.

@someoneinmyhead 2 ай бұрын

Great one

@Cobiernest 2 ай бұрын

What are the requirements for attending a lecture at the RI?

@dadsonworldwide3238 3 ай бұрын

We all begin & end as machinist as the Computational plows over public sector returning us all back to the moment the light came on with cardinal direction,DX ,DY,DZ,DT as we cut the first branch, lathe off the bark,milled the edges, and grinded the tip of our spears. But now the machinist will choose the tool,app and be a roofer with an army of mathematicians ,engineers, & Saleman during the day and at night a private astronomer lol. A Computational chemist on the weekends if they don't get board of Multi skillset applications

@dadsonworldwide3238 3 ай бұрын

I'm kinda confused why he felt the need to address God though. The simulation was always the end game for my classical American puritan ancestors..they passed down knowledge to us that they knew they was going to map the code of life DNA, they knew we would follow Newton down to detect emerging actors on the smallest scales, they would not be phased at all that their hard work ethic moment and goals are happening

14 күн бұрын

The conclusion that you would need an entire universe's matter to simulate a universe assumes that optimisations are impossible. But fields make particles, quarks make protons etc., atoms make molecules and so on and most of this is somewhat static most of the time. You do not have to re-derive every molecule from the quantum fields at every tick of Planck time. And if the simulation was just made to see how the simulated humans behave (or even just one person), then you could optimise away even entire galaxy superclusters except when someone is looking at them. Then dynamically generate it and once they stop looking, store it as a highly compressed file. I think such a highly optimised simulation should be possible in 1000-10000 years.

@noneofyourbizness 3 ай бұрын

curious schoolboy/layman's Q: can anyone point in me in the right direction to understand the A to this Q/these Qs? Re: 49:42 "...it's not really spinning." what if the universe were spinning (and perhaps began doing so at big bang)? could the resulting (effectively 'centrifugal') force be of such enormity that it vastly accelerated early gravity and is now what is causing the observable universe to expand at and ever increasing rate, (flinging galaxies at its 'edge' away from each other at an ever increasing rate) ? could 'dark matter' be a form of centrifugal force resulting from a spinning universe? assuming that the idea above is nonsense: layman's Q2: what is it that allows us to determine with absolute certainty that the universe is not spinning? many thanks in advance for any/all feedback

@bambizulu5407 3 ай бұрын

Maybe it is spinning, just not in a 3 dimensional way. Maybe it's doing so in a higher dimensions 😅

@CydoniaPhysGeekGirl 3 ай бұрын

It's possible, yes, but as far as I know there's no evidence to support such a hypothesis. We would observe lateral redshift in the CMB for one thing, and as of right now, we do not. Great question though! Since all sub atomic particles exhibit spin as well as charge parity.

@GordonShuffell 2 ай бұрын

The trouble with the simulation universe is that it's a theory we will probably never be able to prove sciencetificly but I like it that scientist have these ideas anyway

@user-ju4bj6nv6z 3 ай бұрын

Пришли к пониманию, что истоки осознания материальности просто пошли по тупиковому пути. Попробуем проанализировать, а представление о процессах в материи каждому из нас даны на тарелочке, и каждый из нас эти открытия не делал. По какому пути пойти, что бы каждый мог делать открытия и осознавать свою причастность к постижениям реальных процессов в материальном мире? На данный момент, нет философского представления о процессах образующих материальную частицу и это только начало. Процессы описывающие образование локальности из материальных частиц, это конечно уже интересно до жути.

@bambizulu5407 3 ай бұрын

I exist in a real reality, even as a simulation. I am still a real thing, just not in the way I believe.

@hyperduality2838 3 ай бұрын

Forecasts = Predictions. Making predictions is a syntropic process -- teleological. Syntropy (prediction) is dual to increasing entropy -- the 4th law of thermodynamics! Teleological physics (syntropy) is dual to non teleological physics (entropy). Rational, analytic is dual to empirical, synthetic -- Immanuel Kant. Empirical measurements or perceptions are converted into ideas or conceptions (predictions). Concepts are dual to percepts -- the mind duality of Immanuel Kant. Mathematicians convert their perceptions, observations, measurements or intuitions into concepts all the time hence they are using syntropy. Predicting the weather is a syntropic process! Hence there is a 4th law of thermodynamics. Syntax is dual to semantics -- languages, communication. If mathematics is a language then it is dual. "Always two there are" -- Yoda. "The brain is a prediction machine" -- Karl Friston, neuroscientist.

@usic_imaging 2 ай бұрын

Assuming this unified dark field substance decided to be invisible? if it were to be visible it would blot out any matter and arguably it came before any atomic process also. This doesn't sound like some random thing. Imagine it could all be rendered on the desktop scale.oops!

@subhuman3408 3 ай бұрын

59:39

@cliveomahoney4096 3 ай бұрын

This was great. However, the frequency and length of the ads made me give up. It's really unacceptable and makes the whole thing annoying and pointless

@JohnChampagne Ай бұрын

49:39 "[The Universe] is not actually spinning." If that is true, it is the only thing that has no angular momentum. (It'd be easier to believe that the universe is not spinning as fast as the depiction suggests.)

@keep-ukraine-free528 Ай бұрын

@JohnChampagne You said "If that is true, [The Universe] is the only thing that has no angular momentum." That idea does not comport with our knowledge of physics. For example, electrons also have no angular momentum (this is true of many other things -- for example it's understood also for the six quarks, photons, and other Standard Model particles). Electrons are described as having a "spin" (and quarks have a "color") property, but neither is a real (physical) _spin_ or _color_. They represent special terminology, and not what we think of as spin & color. Electrons don't spin or orbit like the Earth.

@JohnChampagne Ай бұрын

@@keep-ukraine-free528 Thanks for that. The only thing we know of that is larger than a subatomic particle that has no angular momentum, then? I wonder, if any of these objects *did* have angular momentum, how would we know?

@theextragalactic1 3 ай бұрын

🖥️ 🌌 👀

@imager8763 2 ай бұрын

Skip to 48 minutes for the modeling.

@redsky1433 3 ай бұрын

I agree with you that the universe is highly unlikely to be a simulation. I don't think the 'serious people' have thought it through properly. Makes for good science fiction though as in 'The Matrix'.

@davegold 3 ай бұрын

The simulation hypothesis is not a provable hypothesis. It is using probabilities based on conjectures. I think the counter claim that "The computing power needed to recreate the universe is too large" is not properly thought through either. There only needs to be the computing power to similuate the oberservations that you, the reader of this comments, find in your reality for you to be in a simulation.

@hyperduality2838 3 ай бұрын

Real is dual to imaginary (simulation)-- complex numbers are dual. Making predictions is a syntropic process -- teleological. Syntropy (prediction) is dual to increasing entropy -- the 4th law of thermodynamics! Teleological physics (syntropy) is dual to non teleological physics (entropy). Rational, analytic is dual to empirical, synthetic -- Immanuel Kant. Empirical measurements or perceptions are converted into ideas or conceptions (predictions). Concepts are dual to percepts -- the mind duality of Immanuel Kant. Mathematicians convert their perceptions, observations, measurements or intuitions into concepts all the time hence they are using syntropy. Predicting the weather is a syntropic process! Hence there is a 4th law of thermodynamics. Syntax is dual to semantics -- languages, communication. If mathematics is a language then it is dual. "Always two there are" -- Yoda. "The brain is a prediction machine" -- Karl Friston, neuroscientist.

@snekmeseht 3 ай бұрын

I know letters are not expensive, but there is really no need to put two L's in modeling.

@dattatreyadas 2 ай бұрын

The Royal institution is in UK, not in US

@classicalmechanic8914 3 ай бұрын

This video is the perfect example of what is wrong with modern physics. Physics used to be all about the prediction followed by the experiment to prove or disprove the prediction. Modern science is all about making the measurement first and then adapting our mathematical models to the result of the measurement. Science represent predictive power of physical theories and if we don't have predictive power, we are just guessing rather than doing real science.

@hyperduality2838 3 ай бұрын

Making predictions is a syntropic process -- teleological. Syntropy (prediction) is dual to increasing entropy -- the 4th law of thermodynamics! Teleological physics (syntropy) is dual to non teleological physics (entropy). Rational, analytic is dual to empirical, synthetic -- Immanuel Kant. Empirical measurements or perceptions are converted into ideas or conceptions (predictions). Concepts are dual to percepts -- the mind duality of Immanuel Kant. Mathematicians convert their perceptions, observations, measurements or intuitions into concepts all the time hence they are using syntropy. Predicting the weather is a syntropic process! Hence there is a 4th law of thermodynamics. Syntax is dual to semantics -- languages, communication. If mathematics is a language then it is dual. "Always two there are" -- Yoda. "The brain is a prediction machine" -- Karl Friston, neuroscientist.

@classicalmechanic8914 3 ай бұрын

@uality2838 Computer can predict the weather better than any human. But computer still cannot write a new original theoretical physics paper. Physicists are in a dead end trying to solve physics by feeding the computer with equations with a hope that computer will brute force all the data and write an original theoretical physics paper. I am not saying the computer cannot understand physics but the problem is really with physicists that are unable to ask computer an original question. It is the question that precede the prediction and computer will never ask an original question the same way monkey can be taught, but it can never ask a question.

@hyperduality2838 3 ай бұрын

@@classicalmechanic8914 As I say there is a 4th law of thermodynamics or new physics. Questions are dual to answers. Thesis is dual to anti-thesis creates the converging or syntropic thesis, synthesis -- the time independent Hegelian dialectic. The synthesis of new ideas or concepts is a syntropic process -- teleological. The scientific method of asking primary questions to get answers is based upon the Socratic method or dialectic and this is a syntropic process! Hegel pinched his dialectic from Socrates. Problem, reaction, solution -- the Hegelian dialectic. Neural networks (computers) need to be designed around the Hegelian dialectic using duality! Concepts are dual to percepts -- the mind duality of Immanuel Kant. Perceptions or measurements lead to new ideas or concepts, questions. The mind is dual according to Immanuel Kant and this has been ignored for over 200 years! "Philosophy is dead" -- Stephen Hawking. Enantiodromia is the unconscious opposite or opposame (duality) -- Carl Jung. Teleophilia is dual to teleophobia. Main stream physics is currently dominated by teleophobia and eliminative materialism! If you reject teleology you are rejecting the 4th law of thermodynamics so there will be no progress and just stagnation.

@vladimirp2674 3 ай бұрын

Oh, how tribal we were some 10 years ago or so. If gloomy nooks of heaven could be reached by glimpse of AI-powered eye today, it must be regarded as huge, overwhelming upheavel of modernity. It's scientifical oddity bubbles, simmering, like flapjacks on red-hot pan. We glotted them with pleasure, like ripened fruits from grandad's orchard. Men devises robots, robots mapped the future. Someday female robots will love us.

@martinlaird9712 2 ай бұрын

I've nothing intellectual to add , so I'll just say , himley gimmlry batch botcho bing bong

@hatimgasim Ай бұрын

How can we model the Universe with almost unlimited bodies and we are not able to resolve 3 bodies problem accurately 😂😂😂

@qbarnes1893 2 ай бұрын

The statement, outside London, says enough...lightweight scientist, grown up with the belief that there is only ‘one’ place.... Please don’t be so very condescending, you have little to offer, go divulge your reasoning with true scientists who actually understand that the majority are intelligent and interested...