Decoding the cosmos - with Hiranya Peiris
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- Опубліковано 22 лип 2024
- Unravel the profound mysteries of the universe's explosive birth.
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This talk was recorded at the Ri on 26 April 2024.
Just a century ago, observational evidence established the existence of other galaxies besides our own. Soon afterwards, it was discovered that the Universe is expanding, driving a profound change in our understanding of the cosmos. In 1998, the prevailing cosmological paradigm was again upended by the discovery that the Universe's expansion is accelerating.
Since then, the remarkable progress in cosmology, spanning Peiris's research career, has been driven by the close interplay between theory and observations. Observational discoveries have led to a Standard Model of cosmology with ingredients not present in the standard model of particle physics - dark matter, dark energy, and a primordial origin for cosmic structure. The physical nature of these ingredients remains a mystery. The race to unravel this cosmic puzzle is now underway, motivating a new generation of ambitious sky surveys across the electromagnetic spectrum and using new messengers such as gravitational waves.
Peiris describes some highlights from her journey through this rapidly changing cosmological landscape in this discourse. She also discusses how laboratory experiments are helping us test new fundamental physics paradigms developed to explain cosmological observations.
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00:00 Intro
1:30 How do we know about the universe?
7:55 Tracing the light of galaxies
13:00 The Legacy Survey of Space and Time (LSST)
16:53 Mapping dark matter with gravitational lensing
22:30 How do we know how far away galaxies are?
32:03 Using machine learning to explore galaxies
35:50 Detecting dark matter in the lab
46:31 The Universe on a table-top
54:58 Condensed matter experiment and cosmology
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Hiranya Peiris holds the Professorship of Astronomy (1909) at Cambridge, the first woman to do so in the 115-year history of this prestigious chair. As a cosmologist, she delves into cosmic mysteries at the edge of our understanding, reaching back to the very first moments of the Universe after the Big Bang, often treading the path of high risk and high reward. She is noted for interdisciplinary research bridging fundamental physics with astronomical data. Peiris recently contributed to the anthology “The Sky Is For Everyone” and works to reach beyond traditional audiences for public engagement, including through science/art collaborations and live science/music events. Her work has been recognised by awards such as the Max Born Prize of the German Physical Society and the Institute of Physics (2021), the Eddington Medal of the Royal Astronomical Society (2021) and the Breakthrough Prize in Fundamental Physics (2018).
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I'm impressed by the quality of presentations from the Royal Institution. Always top notch.
Troy Nathan Thomas
Science is a role model on how to evolve as society. I am always impressed to see people talking with such a joy about what they do in live. These are the real heroes, not the people trying to spread hate and dissonnance!
That lens demo was fantastic!
Brilliant, insightful and inspiring in a second language. We are so fortunate to have such a lovely soul to learn with.
This was a great presentation of a very complex subject!
Beautiful delivery, superb lecture!
FROM BRAZIL: WHAT A GREAT PRESENTATION!!! SHE WAS FANTASTIC. CONGRATULATIONS...
Always enjoyable content. Thank you!
I grasped the concept of using gravitational lensing to map dark matter. A very cool demonstration. Thank you for this work.
I have learned much more with this videos than when I was in school
Wow!...decoding the Universe!, a very ambitious endeavor indeed, with lots of 'imagine ifs'.
This should become the standard of excellence against which all other RI lectures are measured.
I prefer mister Andrew Szydlo, but this is a very good presentation, too.
The fact this is free is. 👏👏
Good evening Hiranya and The Royal Institution
Tibetan singing bowl and energetic water simply super beautiful.
Grateful for our Universe and all the unknown yet to be discovered.
Exciting, indeed.
Thank you.
💜
I would watch this over Netflix any day! 🤓🍿
those metaphors are killing it.
Thank you 👏🏻
Anyone else watched this more than once? One of the best RI lectures ever!
What an amazing and informative video thank you Royal Institute!
I presume that the light we see is from the past but , from only one certain point of time in the past and on-going from then. Since the universe expands we are lucky to have this feature… imagine though universe if you looked out at it like it was the planet 🌎 earth. Imagine the cycle of life earth , or even a star goes through. Why discount the universe to not have similar features and processes? Maybe great extinctions, ice ages , or radiation ages that promote life ???
Astronomers can only look at the past, as light takes time to travel. Astronomers can see back in time 13.7 Billion years. As astronomers look back in time galaxies are closer together as the universe was smaller then, as the universe is expanding. Beyond is the one that brought the universe into existence.
We have studied 20 million stars, and not one can support life as they are ALL too unstable, we are alone. The Sun is the only stable star. Of the 4,100 solar systems studied, not one looks like our solar system, able to support life. Almost all the 4,100 solar systems studied have Hot Jupiters. In normal planetary systems giant planets form beyond snow line and then migrated towards the star. A small percentage of giant planets migrate far from the star. In both types of migrations, any rocky planet like an earth is lost in these planetary migrations. Most stars do not have planets. Many stars are in bi-star systems, thus no earth-type planets. Thus we are alone
She is really interesting,
So gravity; would be the measurement of pressure?
54:52 anyone who understands anything about the amount of energy water takes to change phase knows that that little, minuscule sound energy you put into that bowl changed, no phase. It caused waves that splashed, but there was no liquid water to water vapor phase change going on there.
This is bizarre indeed - could she mean something else by "phase transition"?
Is anybody else staring at what im staring at..........🫣
🪐🪐
Was the glass lens made in-house or is it available from a supplier?
The Milky Way is missing from the doctored Planck CMB maps. 😂
wow, she can explain all day in my book
Superb!
We are all star's. We just happen 2b conscious.
Well, The concept of dark matter, the elusive expansion energy and its quantifications, formation of more than 2000 isotopes of 100 elements and its systematic periodicity, the why of formation of galaxy in the way in which they are today, does the gravitational lensing is curvature created or quantum field and its grids created? Etc and thousands of things are missing in this 20th century science projected through the lense of AI based generative correlation model. We need to say, yes, thoughts are good or reaching reality only at those points where possibility of origin with BE condensate pictures (rubidium)are shown., Wishing you the best to reach real 21 st century exposition of what constitutes universe and a unified field transforming in to all these multitudes of existence.
Hmm. What has gravity but can’t be seen?
Matter that doesn’t interact with electromagnetism.
@@karagi101 matter is bound together by valences through the electron bonds. There is definitely an interaction. I was referring to black holes. Although our studies don’t have a correlation between dark matter and black holes. To the contrary it alludes to the opposite but black holes and dark matter seem to be one and the same.
@@scott-hr3hd Ordinary atoms are bound together that way. Dark matter isn’t. Dark matter and black holes are two totally different things. The dark matter in a galaxy is dispersed, it isn’t concentrated like black holes are. We know this from how a galaxy’s stars spiral.
@@karagi101 how do you know? We know very little about dark matter because we cannot detect it with all known forms of testing. We just trace its existence by the gravitational changes we are seeing. If there was a connection with electrons to dark matter it could explain the motion.
@@scott-hr3hd It is based on science. The reason it’s called dark matter is it doesn’t interact with known matter - including electrons. If it did it would be easily detected.
I'm proud that we are back to objectivism and not every object is physical.
That idealism & subjective systems can have eqaul sigma 6 measure on par with physicalism. .
And subjectivity Is not idealism or physicalism lol
96% of the universe is subjective properties like hamiltonian oscillating waves or feilds. Gravity is not idealism nor physicalism.
I understand the ease of access teaching everything is physicalism plus needs and demands of the era I grew up in but is was wrong, ugly and combative for those of us well connected to how we came to know.what we know think what we think, english orientation and direction that dictates all longitude and latitude that all the world adopted as our elusive prosperity
37:13 Super graphic! So, if one were to continue the spiral - extending behind the visible example, would a singularity be reached?
Does the 3 body problem not render the calculation of galaxy formation/collision & mutation completely impossible?
It doesn’t. We can use simulations instead of exact equations to see how galaxies form and change.
what ted talks used to be but not anymore
excellent
She looks like that gold lady from GoTG 2
Lovely presentation overall. Just a gentle note, with respect, that your Tibetan singing bowl demo shows movement of water, yes, but that is not the same thing as phase change. There is no phase change as suggested in your demo. I presume that your viewers who already have basic physics knowledge will know that, but I hope you will correct this error in notes, and in future episodes to avoid misinforming the general public further. The rest of your talk was great. Best wishes on your continued inspiring lectures!
Minkowski hyperbolic geodesics intersect only at singularities or was my proof by contradiction not clear?
Hello,
Further to my previous comment, I would very much like to offer the following to the whole team. According to my hypothesis, which can unify the various fields of physics, explain Dark Matter: Dark Energy: Antimatter, and two forces of gravity. Also, an alternative explanation for the CMBR: Redshift: The atom: and a nonexpanding universe without any Big Bang or Cosmic Inflation, the following may be of interest.
The biggest question that needs to be asked in Cosmology is, Why is it that we can only see back to the CMBR at the same distance in every direction? This presents two problems. Firstly, in a universe that is said to have a beginning in a Big Bang and Cosmic inflation within a billionth of a billionth of a second, dissipating the heat, radiation, and Matter throughout the universe, this would imply that there is a limit to how far this matter has spread.
If our Earth is situated anywhere other than the middle of this mass, we should see the CMBR at different distances in every direction. And Yes I have studied the ; Relativistic cosmological model, and what I say still stands.
And secondly, since the JWST is proving that there are fully mature galaxies so far back in time that they would have to have existed before the so-called Big Bang, It rules out that the CMBR is not what it is believed to be.
Since the only thing that supports the Big Bang is the CMBR, the only evidence for an expanding universe is Redshift and the only way that the Big Bang can be rationalized in a thermally equal universe is by the idea of Cosmic Inflation, which is a physical impossibility, Physicists are going round in circles trying to support the status quo.
I would propose that the standard model is flawed at the level of the atom.
There was no Big Bang and Cosmic inflation.
The universe is not expanding, has always existed much as it is today and extends to infinity, therefore it has no beginning and probably will never end.
There are two forces of Gravity, which I have a simple experiment that can prove this, and also proves the existence of Dark Energy / Dark matter.
Dark Matter is an incredibly small Negatively charged Monopole particle in a cloud that fills every available empty space throughout the universe.
Dark Energy, is the negative force of repulsion produced by the Dark Matter Particles trying to repel each other in every direction. It is also one of the two forces of gravity.
The CMBR is not due to the Big Bang, but is a point where electromagnetic radiation reaches saturation.
Redshift is not due to the expansion of the universe, but is due to electromagnetic radiation losing speed and energy over billions of years, If you consider over a period of around 14 Billion years, it would only have to lose 1 mile per second every 140,000 years to account for the redshift we see.
This and much more is explained in my Hypothesis, ( The Two Monopole Particle Universe ), details of which can be found by typing Tony Norman Marsh into Google
If you are interested and can provide me with an email address, I am happy to send you a copy, or it can be read instantly on kindle.. Kind regards,
Tony Marsh
How will you ever detect a red emission line when interstellar Hydrogen absorbs the same frequency light?
RI proper jammin
🤩
It just occurs to me that "Dark Matter" is a misnomer not only with respect to the "Dark" part, but also with respect to the "Matter" part.
We don't know if there's matter there at all.
The only thing we do know is that there's *mass*.
So "Dark Mass" would be a more appropriate term.
What has mass and is not matter?
@@DrDeuteron Photons, for instance.
Note that with respect to the phenomenon called "Dark Matter", we're _not_ interested in so-called intrinsic mass (aka rest mass, which photons indeed do not have), but rather so-called active gravitational mass (which photons are very much expected to have, though I'm not sure if that's been experimentally confirmed yet).
@@CLipka2373 you're right about photons, and more than one photon can have a mass, e.g., the decay products of positronium--which have total energy 2m_ec^2 and total momentum 0, in the COM frame.
But dark matter has to be "cold", which just means kT ~ Mv^2 gives a "v" smaller than the escape velocity of a galaxy cluster (idk what that is, idk guess at least twice the solar system's speed)
@@DrDeuteron I'll say just one word: Kugelblitz.
@@CLipka2373 that's not a particle. The correct answer is a right handed Z boson.
So many lunatic cosmologists come to the comment section these days!
I never believed the universe could be compressed at a point. 😂 So I didn't believe in the Big Bang.
It’s not a point, it’s a small volume, and it’s not the universe, it’s the visible universe,
Reality doesn’t care about what you believe.
The reason why some places on the galactic map are black is not because there are no galaxies emitting light behind them, but because the universe fabric that will carry the light there towards us is very weak. In other words, the tissue there (the structure called ether) has been weakened so much by large masses that it has become a kind of galactic desert
or could be a black hole between that and us in the way?
@@jonnscott4858 a possibility
I still think the expansion is actually a white hole.
It is mind boggling to see how confidently and seriuosly she presents all these speculations that don't serve any practical purpose in preventing any of the evils experienced on this earth.
Decoding the cosmos, wothout targeting PREVENTION OF ALL EVIL in it, is just another means for PERPETUATING them.
I think you might enjoy the Batman channel instead.
I listen to these talks all the time and I’m stunned that with 95% of the matter in the universe unknown yet they go on like they have a clue. If I was only 5% certain in my daily work, I’d be fired. Best they can do but they should be more up front that they effectively in the dark.
They do this because indeed they have a clue. If you do any kind of scientific researches you'd realise there's always a clue that leads you to the answer.
And second, being "up front". Yes they are up front and thus you know that 95% is unknown.
..."If I was only 5% certain in my daily work, I’d be fired..." Interesting !! In what scientific field are You working, and what phenomena/aspect are You investigating/researching ??
Best regards.
"95% of the matter in the universe unknown", this is not 100% correct, 95% is dark energy. We also have dark matter. We know in is there. We are still working out what is. Just like gravity, we know it is there, The question is what is it.
@@djsarg7451 we dont know that for certain.
It is simply maths and specualtion at this stage. Dark matter/energy are placeholders because we dont know what is going on.
We know what’s going on, there’s something cold and neutral, and there is lots of it. It’s hard to study because it doesn’t couple to any of our gauge bosons.
Still promoting LCDM simulations? Unbelievable
Ok smarty-pants, what's the alternative?
I hear a mountain of assumptions that lead to foolish conclusions. If shifted spectral lines can mean anything other than source velocity, your entire cosmos falls apart. It could be that matter produces lines differently, because space is different there. The scientific method of establishing constants and refusing to second-guess them is wasting my time. The Strong force was invented to maintain the concept of electric charge. If charge changes when crammed into a nucleus, dark matter then looks silly.
Omg. Are you an electric universer? Why do you have a problem with nuclear forces?
And I hope you’re no talking about confining an electron to the volume of a nucleus, because that is not possible,
@@DrDeuteron I thought I was clear that the Strong force was invented, because electric charge was already a "known" constant that they could not mentally change. WHY!? Electric charge may very well change when it is crammed into a nucleus, and if I were involved in that time, I would have exhausted that possibility, but I've never read one word of anything like that. I'm referring to protons and the entire cloud of particles involved, positive or negative. It is funny that neutrons are invisible. They could be huge photons of energy needed in the proton changes. You ONLY know what you were told, and that's generations of "people" on a bandwagon. I can show you how math can lie to you, look at my gyro explanation, and this is BASIC mechanics that the bandwagon missed. I remember you now, did you look at the gyro?
Oh look! A fool who thinks he has debunked all the world’s physicists over the last century.
@@karagi101 Look at my gyro explanation then come back and make fun of me. PLEASE DO THAT! A million scientists CANNOT be wrong, so you'll be doing me a favor being so smart as you are yelling from a crowd on a bandwagon.
Reading?