Gravitational Lensing

20-Okt, 2020
1 356 170 Ko‘rishlar soni

In 2015 astronomers successfully predicted the appearance of a supernova within a couple weeks. How did they do it? Win your Ultimate Tech Bundle by entering Fasthosts’ Techie Test here: (Competition now closed) This video was sponsored by Fasthosts.
Special thanks to Geraint Lewis for consulting on gravitational lensing. Check out his UZworld channel: and books:
The supernova image in the thumbnail is from my documentary, Uranium: Twisting The Dragon's Tail. Check it out here:
P. L. Kelly et al.
Predicted properties of multiple images of the strongly lensed supernova SN Refsdal
Masamune Oguri. Monthly Notices of the Royal Astronomical Society: Letters, Volume 449, Issue 1, 01 May 2015, Pages L86-L89,
Multiple Images of a Highly Magnified Supernova Formed by an Early-Type Cluster Galaxy Lens
Patrick L. Kelly et al.
"Refsdal" meets Popper: comparing predictions of the re-appearance of the multiply imaged supernova behind MACSJ1149.5+2223. T. Treu et al.
Irwin I. Shapiro (1964). "Fourth Test of General Relativity". Physical Review Letters. 13 (26): 789-791. doi:10.1103/PhysRevLett.13.789
Irwin I. Shapiro; Gordon H. Pettengill; Michael E. Ash; Melvin L. Stone; et al. (1968). "Fourth Test of General Relativity: Preliminary Results". Physical Review Letters. 20 (22): 1265-1269. doi:10.1103/PhysRevLett.20.1265
Research & Writing by Stephanie Hamilton, Ralph Crewe, Petr Lebedev, Derek Muller, and Jonny Hyman
Animations & VFX by Jonny Hyman & Ivàn Tello
Thanks to Jaime Portsmouth for his gravitational lensing simulator and help enabling it to render simulations.
Supernova simulations courtesy of Adam Burrows
Numerous hubble images by Hubble Legacy Archive, NASA/ESA/STScI
Numerous images by ESO / NASA

  • I have long waited for a mind blow like this. thank you for granting me such a treasure

    Weiss MerlinWeiss Merlin3 soat oldin
  • "Hey there's a new supernova on that galaxy! Never mind, it's just the same galaxy's lensed pic delayed due to gravity".

    AstropjAstropj5 soat oldin
  • The universal equivalent of a photo bomb

    Julian HarleyJulian Harley8 soat oldin
  • so well explained.

    9B 34 Dominic9B 34 DominicKun oldin
  • Einstein?

    RIZE RenNerdClubRIZE RenNerdClubKun oldin
  • *BeetleJuice, BeetleJuice, BeetleJu-*

    JustMoseyinAroundJustMoseyinAroundKun oldin
  • About a year to late. On astronomy I had to write a paper about Gravitational lensing. Good thing your video about Black Hole and how it looks like helped. I even linked than video in that.

    pokfenpokfenKun oldin
  • I'm absolutely goob smacked!

    ronkirk50ronkirk502 kun oldin
  • WIth this information we should be able to create a concrete equation on how much our movement is effecting redshift, why do we not see this equation when calculating the Hobble Constant?

    SutairnSutairn2 kun oldin
  • any day now ... *in the next 100,000 years*

    Jacob SawyerJacob Sawyer2 kun oldin
  • I'm on this guys wavelength so frickn happy you made this rite on man

    Bo ReedBo Reed3 kun oldin
  • Do galaxies revolves around some things?🤔

    SKM GAMERSKM GAMER4 kun oldin
  • Looks like the supernova came to bargain.

    h.s.mani deeph.s.mani deep4 kun oldin
  • 1:40 "In the next hundred THOUSAND years." :(

    Big DogoBig Dogo4 kun oldin
  • Gravitational lensing blows my mind. "Oh, those four galaxies you can see over there? Yeah, they're the same one..." Madness.

    Big DogoBig Dogo4 kun oldin
  • What I thought of this ?? Wowweee... please teach me how did they measure the trajectories and times so accurately.... what math is behind this?? If they published a paper??

    Sourav DeySourav Dey4 kun oldin
  • One of my favorites video! Thank you so much

    Alberto MalvidoAlberto Malvido4 kun oldin
  • "In 2015 astronomers successfully predicted the appearance of a supernova within a couple weeks." Technically, that was not successfully predicted a supernova(the event happened at the end life circle of the star far far away), just predicted what image(what we would see from the Earth) the Hubble telescope would get according to the video, which were two different things. Am i right?😉😉😉😉

    GplayerGplayer4 kun oldin
    • That's the actual image. Yes, it already happened and we are only seeing it now. Not exactly a prediction but it takes time for information to pass.

      Wandering DustWandering DustKun oldin
  • He said stars in nearby universe by mistake. Lol 9:31

    Makaveli ThedonMakaveli Thedon5 kun oldin
  • Where’s the universe expanding FROM?

    Diego FerreyraDiego Ferreyra5 kun oldin
  • We are so lucky to have Einsten

    a ba b5 kun oldin
  • This is incredible. I don't know what else to say.

    Unknown ProdigyUnknown Prodigy5 kun oldin
  • Makes you realize space is mind blowingly massive.

    Reuben SternReuben Stern5 kun oldin
  • A long time ago In a galaxy far far away?... Proof of Darth sidius and his death star.

    Reuben SternReuben Stern5 kun oldin
  • Einstein cross Jesus Christ!

    arnav soodarnav sood6 kun oldin
  • Soo... Does it mean that if we have a telescope sharp enough to see individual planet on galaxies far far away, and strong enough to catch light reflected from earth, we can technically see our past?

    Yuda DwiYuda Dwi6 kun oldin
  • Good hosting, not everyday i see.

    James BlackstarJames Blackstar6 kun oldin
  • A lens made of "graveity". Yeah right, what sorcery is this? Gravity doesn't even existt

    JebClangJebClang6 kun oldin
  • We can predict a supernova but not corona?

    Denzyl CasuelaDenzyl Casuela6 kun oldin
    • Maybe because universe changes but very slowly compared to it's size, when viruses mutate fast, thus we can't predict all mutations.

      Maciej CholewaMaciej Cholewa6 kun oldin
  • I wish i was not in a city so i could see this rare phenomenon

    Harish DubeyHarish Dubey7 kun oldin
  • This is the most surprising video I have seen in my life! It got me Goosebumps! Humans are incredible to have discovered this!

    klaas victorklaas victor7 kun oldin
  • The previous video title was more juicy, at least I feel

    Bhaskar BhardwajBhaskar Bhardwaj7 kun oldin
  • Amazing

    WillianWillian7 kun oldin
  • absolutely adoreable to be able to work on such topics!

    PanarborePanarbore8 kun oldin
  • So...The flat earthers are not wrong! They are right in another perspective

    Rama BandyopadhyayRama Bandyopadhyay8 kun oldin
  • Your videos are lit 👍🏻

    Mohd SameerMohd Sameer8 kun oldin
  • Thank you! Ah...I thought it will be about building a lens for a gravity laser. But this is very interesting too.

    Andrey SergeevAndrey Sergeev8 kun oldin
  • Meanwhile supernovas image giving us a creepy smile at 6:25

    Phantomrocks #phaniPhantomrocks #phani9 kun oldin
  • Can anyone tell me how light is traveling in a curved path..I have learned that light travels in straight line.

    yogesh jangidyogesh jangid9 kun oldin
    • I don't know what does really moving straight means but let's say it is moving while being not affected (accelerated) by any force. That means nothing is changing the momentum of a photon I guess. I would naively say that light indeed travels in a straight line through space but if you bend space itself then that line is no longer straight. Photons have no mass - gravity does not pull them as regular objects with mass. The gravity is bending space and time therefore anything in that space is bent too. You can draw a straight line on a paper sheet then crumple that paper - so the line will be straight relative to the paper but not to the world around it. That way path of light is curved. That means that the direction of a photon is changed - so its momentum. So I will guess you need to spend some gravitational energy on that. But what is the least possible degree of that curvature? That I don't know. If you look at curved lines on a display they are made from pixels - so any circle is in fact a sum of small straight segments. If that is the case for space curving then there are always some parts of space where light indeed travels in a straight line - because it can't be affected by any force. If not then you can arrange a bending of any degree at any place so it's not necessary to have any straight segments at all.

      Andrey SergeevAndrey Sergeev8 kun oldin
  • Wait til' the UK viewers find out that the 5000 pound Techie Bundle actually weighs 5000 pounds (

    John BerryJohn Berry9 kun oldin
  • it was Isaac Newton.

    Mahmoud MostafaMahmoud Mostafa9 kun oldin
  • when my boss catches me in a foto somewhere else..can i explain that its perhaps gravitational lensing...both time and place r incorrect..i was actually working at home ;)

    DevNDevN9 kun oldin
  • and millions of people r convinced they know it all from 1 holy book.

    DevNDevN9 kun oldin
  • It sucks

    Trying1 /Trying1 /9 kun oldin
  • amazing !!!!

    Ryan JohnstoneRyan Johnstone10 kun oldin
  • This just reinforces a question I have had for over 10 years. Using the discipline of the null hypothesis prove to me that every galaxy you see in the cosmos isn't the same galaxy seen from a different angle at a different time? The cosmos as a hall of mirrors.

    Chris MethotChris Methot10 kun oldin
    • The first answer might be how could we see galaxies merging if there were only one.

      Chris MethotChris Methot7 kun oldin
  • Gravitational lensing is one of my favourite concepts!! And this is amazing!!! Loved the way the video is made. Seemed like we are in space!!!🌌

    Kinnari BhaleraoKinnari Bhalerao10 kun oldin
  • Space has always been an inspiration for me. Hubble is fascinating my heart day by day.

    Muhammad Hamza TahirMuhammad Hamza Tahir10 kun oldin
  • Star: Betelgeuse Me: Be tel gese Veritasium: Bettle Juice

    Gabriel FerrãoGabriel Ferrão10 kun oldin
  • Its incredible how much info scientists can extract from these tiny little smears of light

    FezRezFezRez10 kun oldin
  • 1:32 beetlejuice

    Wu ChenglinWu Chenglin10 kun oldin
  • It's fascinating that how much information astronomers can get from pictures, from a normal person, not so much.

    Prince Fel Ezekiel R. LicardoPrince Fel Ezekiel R. Licardo10 kun oldin
  • And here I struggle getting a decent pic of my dog.

    Dennis DDennis D10 kun oldin
  • Is this one of the first generation stars in the universe ?

    Nae DolorNae Dolor10 kun oldin
  • Great video Derek, thank you for teaching me so many interesting things! By the way, I'm just thinking... I've been following you since 2013. Most of my closest friends I've known for less time than that. And your videos continue to amaze me! Take care Derek, and keep up the excellent work! (no pressure :-)

    David M. JohnstonDavid M. Johnston10 kun oldin
  • did you break the space time continuum? no worries, just seal it with FLEX TAPE! *slaps tape on spacetime*

    Learning UnityLearning Unity10 kun oldin
  • Only Legends Know the Title of This Video Has Been Changed

    Ninty 9Ninty 910 kun oldin
  • I love your videos! You make them entertaining and you have a catchy voice.

    Mr. Thomas A. AndersonMr. Thomas A. Anderson11 kun oldin
  • Varitasium and 3brown1 blue are best ones also PBS videos too

    Soumen BhattacharyaSoumen Bhattacharya11 kun oldin
  • Does this mean that light can «move» an object aswell? Like airflow over a wing creating lift?

    Fredrik Attila FarkasFredrik Attila Farkas11 kun oldin
    • You can push stuff with light. There's the idea of "light sails", large reflective structures that can be put on a probe or satellite of some kind and allow it to use the solar wind. And last year or the year before that the nobel prize in physics got awarded to a team who created a kind of "tweezers" with light.

      LünkelLünkel5 soat oldin
  • 3:48 Damn that looks creepy lmao

    Mohammed ShaikMohammed Shaik11 kun oldin
  • This is mindblowing sorta. Also makes me feel incredicle dumb compared to actual smart people. I knew math was important and read electronics in high school so did alot of math. But counting math that bends light by gravity and mass vs distance and time to the object and beeing able to count that far back including by my guess a ton of gravity bends/warps between stars, galaxies of the fabric of space, with an end result of different years and times to the day, which you can view the same exact thing happening. 🤯 Now thats some hardcore math right there.🧠 Also how isnt Einstein an Emoji by now. 😎✌

    Balubish TechBalubish Tech11 kun oldin
  • Oh its such crap.

    seachangeauseachangeau11 kun oldin
  • Wow, this really opens your mind! It’s like taking drugs OMG. Loved it!

    Jimmy JohnsJimmy Johns11 kun oldin
  • 6:29 Seems deep space is smiling on us!..with a cigarette in its mouth! 😵

    Mohd ShariqMohd Shariq12 kun oldin
  • What if, as the universe expands, the general speed of light increases? Meaning, if we had a window into the future we would observe everything moving faster. This does not affect the Doppler shift, which only cares about the 'stretching out' of light as it moves, since all 'parts' of light will be speeding up at the same time so there will be no differential that would be evidenced in the color shift. However it may 'speed up' other observable cosmic activity, meaning light reaches us faster than expected if it were moving at a 'constant' speed. Therefore the calculated expansion rate of some methods gives a lower result.

    Lar Wor TsomvLar Wor Tsomv12 kun oldin
  • Am I still on time to answer the question? Which is actually wrong it was Sir Isaac Newton who answered to RICHARD BENTLEY (theologian and philologist) “That gravity should be innate, inherent, and essential to matter, so that one body may act upon another at a distance through a vacuum, without the mediation of anything else, by and through which their action and force may be conveyed from one to another, is to me so great an absurdity that I believe no man who has in philosophical matters a competent faculty of thinking can ever fall into it. Gravity must be caused by an agent acting constantly according to certain laws; but whether this agent be material or immaterial, I have left open to the consideration of my readers” this was in answer to And what Richard Bentley wrote that generated Sir Isaac Newton’s answer was And as for gravitation, tis impossible that that should either be coeternal and essential to matter, or ever acquired by it. Not essential and coeternal to matter; for then even our system would have been eternal (if gravity could form it) against our atheist's supposition and what we have proved in our last. For let them assign any given time, that matter convened from a chaos into our system, they must affirm that before the given time matter gravitated eternally without convening, which is absurd. {Sir, I make account, that your courteous suggestion by your last, that a chaos is inconsistent with the hypothesis of innate gravity, is included in this paragraph of mine.} and again, tis unconceivable, that inanimate brute matter should (without a divine impression) operate upon and affect other matter without mutual contact: as it must, if gravitation be essential and inherent in it.

    raedtrabraedtrab12 kun oldin
  • Gravitational lens smears images from Hubble telescope. What is the cure for distortion? Apart from making intelligent assumptions/guesses, there seems to be no other method to give a clearer image.

    Kumar Digvijay MishraKumar Digvijay Mishra12 kun oldin
  • The Real Question: How do scientists notice a tiny dot of a star in the middle of so many blurs and other stars?!

    sokin jonsokin jon12 kun oldin
    • They don't. No, but with the power of modern technology, devoted people, and some of the smartest people on the globe many things are possible.

      A GA G3 kun oldin
    • Unstoppable curiosity does it all...I am more surprised to know that there is actually stuff like time dilation.5 years out from physics and I thought it is all theoretical.Guess that's why flat earthers still exit.Might be of my kind:)

      Aadil PeerAadil Peer4 kun oldin
    • It’s their passion... they love to do that.. isn’t that amazing??

      Sourav DeySourav Dey4 kun oldin
    • It's more like yeah there's a lot of stars. There's a lot of scientists and telescope

      jacob olsonjacob olson7 kun oldin
  • I want to live hundreds of years to observe and study all the knowledge in universe. Sadly humans life span isn't long enough for such thing. I want to discover new planets, understand what is behind this universe. I don't wanna die without knowing why I was here.

    ilkercan Kayailkercan Kaya12 kun oldin
  • Veritasium pumping out superlative quality content is one of the rare positive things about 2020 - How do they do it? That's the real mystery

    Amadley GamingAmadley Gaming12 kun oldin
  • Gravitational lensing maybe a misinterpretation, this lensing could also be produced by cosmic space, becaused *space is not completely empty-it is a hard vacuum containing a low density of particles, predominantly a plasma of hydrogen and helium.* It is the space medium itself that causes this light refraction phenomena. Then it becomes understandable that galaxies tend to form a higher density of this space medium ( Halo) , which produces the lensing effect, and has nothing to do with gravitational fields.

    Ruben Anthony MartinezRuben Anthony Martinez12 kun oldin
    • So here is a neat trick folks! This will help you understand the universe and that Big Bang everyone keeps babbling on about. Take a stone, throw it in the pool, watch the rippl

      sokin jonsokin jon12 kun oldin
  • 30 October 2020 - I started to study stars and supernova. 14 November 2020 (today) I am watching this video. 11 December 2020 is my birthday. Now skip to 2:30

    Gagandeep SinghGagandeep Singh13 kun oldin
  • I don't know why I just thought of this question weeks after the video, but if gravitational lensing can allow us to see the same light source appear at multiple points and over different time periods, how can we know a lot of what we see in the sky isn't lensed from somewhere or someWHEN else? We would be counting some of the pinpoints of light in the sky multiple times, skewing our data right?

    CyberBeast66CyberBeast6613 kun oldin
  • Space time would seem to not be homogenous in the universe thus various gravitational lensing effects.

    Ry V.Ry V.13 kun oldin
  • 6:30 creepy smiley face

    Ayoub BerradaAyoub Berrada13 kun oldin
  • My brain hurts now

    Charles RogersCharles Rogers13 kun oldin
  • He is cool🤯

    MH PromitMH Promit13 kun oldin
  • Can you please make a video that proves Universe is infinite?

    Aditya RayapureddyAditya Rayapureddy13 kun oldin
  • 6:31 oh a luck smiley

    RobloxGamezRobloxGamez13 kun oldin
  • Splendid and extraordinary video on lensing. Made me case study it intuitively. May god bless you.

    Chitra LekhaChitra Lekha13 kun oldin
  • Before I thought something else After - ohh so this is what happens!

    • able to travel the galaxy/ies but have died off millions/billions years ago?

      bilishu alissbilishu aliss13 kun oldin
  • Great video, but all this astronomy talk is so pointless really. How about giving the wasted money to buy food for the hungry.

    jake friesenjake friesen13 kun oldin
    • I hope Fasthosts got better in the last 10 years, because they used to be shockingly bad!

      bilishu alissbilishu aliss13 kun oldin
  • I'm glad we have Derek as the cosmological information lense in our time. 1000 years later, he'll reappear on an other planet

    Thinkclear BellThinkclear Bell14 kun oldin
  • can sit still through this entire video.. Well done man.

    aola wiliaola wili14 kun oldin
  • 🤔👍

    Gacheru MburuGacheru Mburu14 kun oldin
  • One thing Veritasium talks about in a future video is how currently we can't confirm the speed of light in one direction. Therefore, given that we don't know if the speed of light is the same in all directions doesn't that make our current methods of measuring universal expansion inherently flawed? They would be working upon an assumption that hasn't been confirmed, so like light, the universe could be expanding at different rates given the direction you are facing.

    SveredianSveredian14 kun oldin
  • So here is a neat trick folks! This will help you understand the universe and that Big Bang everyone keeps babbling on about. Take a stone, throw it in the pool, watch the ripples expand faster and fast and faster until they reach the edge of the pool! Did you notice how they kept getting faster and faster? No? Well guess what, I just lied to you. THINK ABOUT IT!

    Nevermore77Nevermore7714 kun oldin
    • Tony Stark: No amount of money has ever bought a second of time. Veritasium: How about the cost of Hubble telescope?

      aola wiliaola wili14 kun oldin
  • But you didn't explain how this latest method of measuring the Hubble constant works. How you get the Hubble constant by measuring the time delay between different images of a supernova? Now, I'll have to check all the referred articles in the description.

    will2seewill2see14 kun oldin
  • 6:27 the universe is smiling upon veritasium, Derrick müller is a genius, yes I put the diaerisis in last name as an understanding of observation as Derrick does for all of us. Thank you sir Derrick, your work teaching us troglodytes is appreciated

    ShabléShablé15 kun oldin
  • 1:40 "In the next hundred THOUSAND years." :(

    miko foinmiko foin15 kun oldin
  • This guy can convince me to take the blame of crimes i didn't even commit.

    victor guzmanvictor guzman15 kun oldin
  • Our mind is set to measure things , compare different objects for getting an understanding of measure. So we invent Mathematics. But in the course of human understanding of physical world and development of Mathematics , we come across a mathematical identity i.e., infinity . If we divide any number by Zero , then it is said 'INFINITY'. AND any number is divided by smallest decimal fraction, it starts increasing. It can be increased unlimitedly .If you divide 1/3 and the result is unlimited. I think here is the answer of the VASTNESS OF UNIVERSE.

    commodityHelpcommodityHelp15 kun oldin
  • The supernova might have happened 9.3 billion years ago, or - depending on the speed of light in this direction - maybe it happened yesterday.

    Daniel KuniganDaniel Kunigan15 kun oldin
    • In a few ... Me - ohhhhh yeahh boi.. Hundred thousand years.....

      miko foinmiko foin15 kun oldin
  • How do you know something happened "x billion years ago"? What if light travels instantaneously in our direction and half the speed back to the supernova?

    Ilshat AhatovIlshat Ahatov15 kun oldin
  • I hope Fasthosts got better in the last 10 years, because they used to be shockingly bad!

    mikencomikenco15 kun oldin
  • Can you explain, If we see stuff that happened millions/billions years ago, does it mean that the universe is dying, and once there could have been intelligent beings that were able to travel the galaxy/ies but have died off millions/billions years ago?

    JakubHJakubH15 kun oldin
  • The Earth is FLAT 🕳

    No ExpertNo Expert15 kun oldin
  • All these people commenting a bunch of stuff that sounds smart and I'm over here trying to figure out how to turn on the flashlight on my phone

    Nathan MaxsonNathan Maxson16 kun oldin
    • iOS or android?

      FlyingSavannahsFlyingSavannahs15 kun oldin
  • im in year 7 and i am finding this the most interesting topic i have ever learned thanks for teaching me :)

    omar 717omar 71716 kun oldin