The Absurdity of Detecting Gravitational Waves

  • Added:  6 months ago
  • A head-vaporizing laser with a perfect wavelength detecting sub-proton space-time ripples.
    Huge thanks to Prof Rana Adhikari and LIGO:
    Here's how he felt when he learned about the first ever detection:

    Thanks to Patreon supporters:
    Nathan Hansen, Donal Botkin, Tony Fadell, Saeed Alghamdi, Zach Mueller, Ron Neal
    Support Veritasium on Patreon:

    A lot of videos have covered the general overview of the discovery of gravitational waves, what they are, the history of the search, when they were found but I wanted to delve into the absurd science that made the detection possible.

    When scientists want one megawatt of laser power, it's not just for fun (though I'm sure it's that too), it's because the fluctuations in the number of photons is proportional to their square root, making more powerful beams less noisy (as a fraction of their total). The smoothest mirrors were created not for aesthetic joy but because when you're trying to measure wiggles that are a fraction the width of a proton, a rough mirror surface simply won't do.

    Filmed by Daniel Joseph Files

    Music by Kevin MacLeod, "Black Vortex" (appropriately named)

    Music licensed from Epidemic Sound "Observations 2" (also appropriately named)
  • Video CategoriesEducation
  • Runtime: 9:7
  • Tags for this video:  veritasium  science  physics  ligo  gravitational waves  wave  interferometer  black hole  black holes  interference  gravitational wave  spacetime  laser  detection  detecting  absurdity  detector  gravity  einstein  general theory of relativity  waves  

Comments: 4 593

  • eiyaz00
    eiyaz00 1 day ago

    Did we know the two black hole collided before the waves hit? Or did we find out after it happened?

  • Jane Kailey
    Jane Kailey 1 day ago


  • A. K.
    A. K. 2 days ago

    how do know what a wavelength of gravity is if it's never been observed or detected?

  • The Stuffed
    The Stuffed 2 days ago

    Yo mama so fat she caused an uncertainty in the frequency and wavelength of two beams of light at the same time and effect as another two beams of light 1000 miles away!

  • Tyler EIN
    Tyler EIN 2 days ago

    Ligo detects gravitational waves by using the Doppler effect? Light will have a change in frequency when the wave pass and their frequency will be different and there will be a signal? Is this how it works?

  • living robot productions

    Space is not a Thing it has no properties ... That is why it's called Space ... This is stupid and makes no sense.

  • David Jackson, II
    David Jackson, II 3 days ago +1

    So the next step based on detecting all of the black holes in the universe is a star map based on those black holes?

  • cubecube bean
    cubecube bean 4 days ago

    Need to do these measurements outside into the space.

  • epsilonxyzt epsilon
    epsilonxyzt epsilon 5 days ago

    min 1:23 must be 1 in 10^-21

  • Christopher Ellis
    Christopher Ellis 5 days ago

    clever stuff, at least it is not the work of clever fools.

  • Justin M
    Justin M 5 days ago

    how fast would say a basketball get up to if you put it in the tube then popped the pipe behind it

  • DannyLoveJoy
    DannyLoveJoy 5 days ago

    If the gravitational wave would come directly from the direction 45 degrees in between the 90 degrees angled arm, would there be a measurement?

  • Skeptical Dreamer
    Skeptical Dreamer 6 days ago

    a trillionth of air left.. a trillianth detected in change.. hmm.. I wonder.. 😂

  • Gus Ngregg
    Gus Ngregg 7 days ago

    I always took space as a medium for everything that goes thru it...


    How is this acuert if the mirrors are moving . These guys are faking it to try and prove gravity. Its not gravity wave its a m.p. magnetic poleses tesla already new this .

  • Gabi Mor
    Gabi Mor 7 days ago

    heyy what animation software are you using?

  • Richard Smith
    Richard Smith 7 days ago

    So the trick to detecting if the light was stretched was to make the number of oscillations of the wave on the trip static? If space is stretched it will alter the distance AND time, but also slightly shift the phase of the light, so since the distance and time being stretched is not measurable being within the same frame of reference, this instead relies on detecting the phase shift of the light from said stretching.
    Essentially this machine makes a 'virtual frame of reference' by continually firing new light, each photon having its own frame of reference, and letting that light interfere with each other, and then measuring THAT interference?

  • Louis Cypher
    Louis Cypher 9 days ago

    that guy describing the laser is probably the coolest scientist I ever seen. even cooler than DeGrasse.

  • IAmAgainst
    IAmAgainst 9 days ago

    It's sad that despite being clearly a genius he doesn't use a little bit of his intelligence to take better care of his body..

  • Rudi Simon
    Rudi Simon 9 days ago

    my question is why? Why so much effort for such a non event? They can never reproduce this.

  • Atif Rana
    Atif Rana 10 days ago

    Such a laid back scientist

  • Lui Cirocco
    Lui Cirocco 10 days ago

    if two black holes make a ripple in space time when they collide, how big do they need to be to make a big bang?

  • Sh0t
    Sh0t 10 days ago +1

    Cost to US taxpayers: $1.1 Billion

    • brownj2
      brownj2 1 day ago

      $1.1 Billion Inserted into our economy, generating some well paying jobs and revealing an otherwise unproven truth for all humans. This has more benefit to humanity than all of the worlds strategic bomber fleets combined. Quite a deal.

  • Arnold Christian
    Arnold Christian 10 days ago

    What if the expanding of the universe is just a cyclic wave-like motion? like it will start compacting and then expanding again, etc etc. Know what i mean?

  • leo001leo001
    leo001leo001 10 days ago

    the germans built these machines.

  • Jason Stokes
    Jason Stokes 10 days ago

    How do they even know that is what they are measuring, and not some other anomaly?

  • John Cloeter
    John Cloeter 11 days ago

    Somebody get this man a better shirt

  • LaserGadgets
    LaserGadgets 11 days ago

    Ohohohohoooo yeah :<

  • Vaishnavi H
    Vaishnavi H 12 days ago

    I did not understand most of the things in there but whatever these guys have achieved is just remarkable and that guy is Indian which gives me even more pride:)

  • Ti DeCoske
    Ti DeCoske 12 days ago

    Why not put one in space where it can't be disturbed by use

  • Roscoe Coltrain
    Roscoe Coltrain 12 days ago

    his shirt is an art piece

  • v a
    v a 12 days ago

    What I don't understand about this is did we just happen to build the LIGO at the right time? Are the waves still passing through? Or are gravitational waves always passing by....? It seems to coincidental that humans build the LIGO and then happen to discover GW's.

  • Brian Kerr
    Brian Kerr 12 days ago

    there is no such a thing as a gravitational wave.

  • Artur
    Artur 13 days ago

    I want that guy to say, "You may have been looking for me for the last couple of years, but I have been looking for you all my life, Neo."

  • Nikhil Dewangan
    Nikhil Dewangan 13 days ago


  • Matthew Bailey
    Matthew Bailey 13 days ago

    Now imagine how F-ing cool it will look when we can built a LIGO that is several light-minutes on a side.

    We will be able to actually "Resolve" images of the event.

    But in terms of immediate applications...

    I just want to be able to get the kind of Resolution out of Maya in terms of HSV distinction.

    Or to have eyes that can distinguish that kind of resolution.... But then I am into the Realm of John Cavill.

  • Jorge Mori
    Jorge Mori 14 days ago

    So you're certain what you think you detected was caused by a gravitational wave?

  • ranan rahim
    ranan rahim 15 days ago

    For those who love physics, this is a video that they can masturbate to. Amazingly presented, thanks @veritasium !

  • Beanshkabob
    Beanshkabob 18 days ago

    A thousandth the width of a proton. You gotta be shitting me. That's amazing.

  • He Richard
    He Richard 18 days ago

    great,so my question is , when trump is going to build the death star

  • Giovanni Stani
    Giovanni Stani 18 days ago


  • George Bond
    George Bond 18 days ago

    wow so smart to detect gravitational waves but they still can't find that elusive Oort cloud.

  • chari Muvilla
    chari Muvilla 18 days ago

    To annyone feeling stupid after watching: Well you might didn't understand some terms from physics but to be fair no scientist right now knows enough about these things.

    I mean gravitational waves, black holes, how time or space could possibly be affected by other things, all these are things we barely know about. So study them if you want to know but you will always get the feeling that you don't know enough or that many things you know could be proven wrong

  • Phil Jones
    Phil Jones 19 days ago

    a hundred and fifty years from now. we will be communicating with gravity waves.

  • titaniumslug
    titaniumslug 19 days ago

    Sounds like the most expensive example of confirmation bias ever.

  • Greg Hawkins
    Greg Hawkins 19 days ago

    This is America. State distances in inches, feet, & miles, not meters & kilometers & weights in pounds, not kilograms.

  • tuber
    tuber 19 days ago

    I got news for you genius. No matter what point in the history or future of the universe you existed, you would always feel like "nature doesn't want you to go any further". It's called technological limit.

  • VB. Jayasekara
    VB. Jayasekara 21 day ago

    So what is the last discovery ?

  • forestsoceansmusic
    forestsoceansmusic 21 day ago

    Okay, so the Heisenberg Uncertainty Principle may not apply, but the coarseness of the technology is still way too gross to measure something a thousandth the width of a proton. In fact, doesn't quantum mechanics state that the time it takes light to cross a FULL width of a proton is the shortest time there is -- that that time is the shortest tick of the universal clock. This ridiculously-minuscule scale is also the scale at which random quantum fluctuations happen, so surely you wouldn't know if you're detecting gravitational waves or quantum fluctuations.

  • forestsoceansmusic
    forestsoceansmusic 21 day ago

    And the whole experiment -- is it based on the ASSUMPTION that these supposed 'gravity waves' travel at the speed of light?

  • forestsoceansmusic
    forestsoceansmusic 21 day ago

    A trillionth of atmospheric pressure still means there will be some Oxygen and Nitrogen molecules to interfere with the beams.

  • forestsoceansmusic
    forestsoceansmusic 21 day ago

    One part in 10 to the 20th power, but you said earlier that they are trying to detect something in 10 to the 21st power, so their laser-stability is 10 times to coarse to be able to measure such a miniscule event (if indeed it does exist).
    Could you please explain how any orbit is stable if gravitational attraction only propagates at the speed of light. Surely that is too slow even on the scale of the inner solar system -- sunlight takes about 9 minutes to reach the Earth.

  • forestsoceansmusic
    forestsoceansmusic 21 day ago

    I thought the Heisenberg Uncertainty Principle said we can't measure on such a small scale without our measuring 'instruments (even if we only use photons) affecting the result.

  • plasmaastronaut
    plasmaastronaut 21 day ago

    an awful lot of resources spent chasing myths. Insanely stable lasers might have some other use though.

  • Dennis Liu
    Dennis Liu 21 day ago

    It took me awhile to wrap my around on why "more photons you use, the smaller the uncertainty gets".
    Then I realized what the short phrase after it really meant.
    The variation in terms of number of photons will increase, but when compares the numbers of photon varied to the total number of photons used, the percentage decreases, hence less uncertainty.

  • Ebenezer Olutomilayo Fagbemi

    crazy how the beginning looks like two daughter cells

  • Anubhav Yadav
    Anubhav Yadav 22 days ago

    sir you always ask the right of u 4 that

  • Metal Gear
    Metal Gear 22 days ago

    The absurdity of trying to Prove that there is an invisible HOLE punctured into Space...
    Why not just throw a Satellite as far away from Earth as possible actually Testing. How far does Earth's Gravity go beyond Earth's Atmosphere?...

    A simple Scientific test rather than a 300 trillion dollar "We found SIGNS of the Loch Ness Monster's Existence guys!" fiasco...

    Are you fkn kidding me w/ this BS blatant Confirmation Bias of so-called 'Science' charade? gtfo here w/ this nonsense

    Black Holes are like Falling off a Flat Earth except now you're falling into a gd fkn Hole..
    Wtf is the Difference. Neither 1 is REALITY

  • metalko koma
    metalko koma 23 days ago


  • Scawsome
    Scawsome 24 days ago

    I say we take the uncertainty, and *push it somewhere else!*

  • Remi Stardust
    Remi Stardust 25 days ago

    We have to apply some Baysian Theorem here: Having read a long article on this and watching vidoes, I can't give 100% certainty that they ACTUALLY pulled this off. The measurement requirements are absolutely nuts!

  • Morris The Cat
    Morris The Cat 25 days ago

    1MW infrared laser would vaporise your head? WTF?

  • Omartini
    Omartini 25 days ago

    what if Time was shifted, and not space? Meaning the measurements are happening at slightly different times.

  • Karol Palazej
    Karol Palazej 26 days ago

    how do they know the data they get is truly from gravitational waves? what if theres some other signal causing it?

  • Miriam Moore
    Miriam Moore 26 days ago

    the other guy said 10x the energy of the rest of the universe. hmmm

  • Jaime Monsalve
    Jaime Monsalve 26 days ago

    If being close to the black holes (at a "safe" distance lets assume), we would be able to percibe with our own senses those gravitational waves?

  • Simon Stebbins
    Simon Stebbins 26 days ago

    I'm not sure I trust him, because he appears to be wearing crocs.

  • J Kinney
    J Kinney 26 days ago

    Just because you worked hard, with the best equipment, advanced degrees and achieved some result doesn't mean you have proven what you think.

  • guy anello
    guy anello 26 days ago +1

    is this man wearing crocs...?

  • Martyn2473
    Martyn2473 26 days ago

    Is it just me or is one hell of a coincidence that that wave went pass earth just after we'd built this device. 10 years earlier and we would have missed it?

  • Dheeraj Bhaskar
    Dheeraj Bhaskar 26 days ago

    I like how chilled out that scientist guy is (not the host). Is he an Indian btw?

  • Mario Jost
    Mario Jost 27 days ago

    The next obvious step from my perspective would be to create a third tunnel to get a sort of 3D measurement. How can they detect gravitational waves if they are coming from directly above? These waves would then have the same impact on both arms rendering the measurement useless. A third arm would solve this problem. I just ask myslef who pays for this stuff? What do they gain by the knowledge based from these measurements? I'd like to beleive there are selfless companies or people that do this for the greater good. In the end, this has to give some kind of payback, i think.

  • Benjie Urbina
    Benjie Urbina 27 days ago

    the guy's white shirt is loaded with gravitational waves

  • mouaj
    mouaj 27 days ago

    can he detect the gravitational ripples with the wrinkles in his shirt too?

  • Duncan Gray
    Duncan Gray 27 days ago

    So, the LIGO detectors work because the gravity propagates at the speed of light. So, why doesn't the mass inside the event horizon of the black hole become hidden from all objects outside of the event horizon ... thereby making the black hole "not heavy?"

  • Omero Diaz
    Omero Diaz 27 days ago

    understandable have great day

  • Sabeer Abdulla
    Sabeer Abdulla 28 days ago

    So, the light itself is being stretched by the waves as a result of space time being stretched. To counter which, they send in new light to check the difference to the old light. By the time the new light is being made, the wave would've stretched the source of the light, right? How's that factored in?

  • rushabh m
    rushabh m 29 days ago

    how do we know that collision occured ,it took information and gravitational wave same 1.3 billion years?

  • Hank Jagt
    Hank Jagt 1 month ago

    Neutrinos cannot be removed from the detector so my question is, what impact will this have on the result you see?

  • Ken Kall
    Ken Kall 1 month ago

    does a falling apple create gravity waves?????

  • Me Not You
    Me Not You 1 month ago

    How do they know ?

  • Movie Spoiler
    Movie Spoiler 1 month ago +1

    got asked about this in my a level exam today🙃

  • Ferris Vueller
    Ferris Vueller 1 month ago

    When 95% of gravity is unaccounted for (dark matter 27% and dark energy 68%), call me a skeptic.

  • Max Lindner
    Max Lindner 1 month ago

    You should show this video to Bill Gates and ask him why my PC necessarily needs to install updates for HOURS every now and then.

  • Nic Morales
    Nic Morales 1 month ago

    Beautiful video man, one of your bests! Keep doing this good material!

    With this quality of videos consider entering into a new platform called Steemit, where you may find a lot more of earnings per post and a whole new community rising up. If you do, find me there, I'm @anritco and as a concept designer and illustrator, my hand is yours in case you need it =)

  • Craig Mackay
    Craig Mackay 1 month ago

    thanks for a great channel! always leaning something from your videos.

  • Patrik Bergenholt
    Patrik Bergenholt 1 month ago

    Fascinating, but what does it cost and how are the results helpful?

  • Anatole Sokol
    Anatole Sokol 1 month ago

    wow, holy ONE MEGAWATT!!! is about 1300HP or so... ?

  • Luke Brog
    Luke Brog 1 month ago

    I WANt those Glasses 👓 cool AF!

  • Nick Loz
    Nick Loz 1 month ago

    This megawatt is singlehandedly causing global warming. Totally worth it.

  • semmering1
    semmering1 1 month ago

    It would be so wonderful, to get translation's of this videos, so bad not to understand all of this.....

  • Squidward1314
    Squidward1314 1 month ago

    at 8:09 what is the "other thing" where the uncertainty gets crammed into? They measure distance with high accuracy, then what value has high uncertainty and how does that play out in this experiment?

  • Kumar Abhishek
    Kumar Abhishek 1 month ago

    Please, I beg not distort the names. Indian names carry a lot of meaning as with many other cultures, so kindly respect that @Veritasium. Very informative video though, nicely explained too!

  • Microawesome
    Microawesome 1 month ago

    "the whole thing is bogus, shut it down!!" 😂😂

  • Microawesome
    Microawesome 1 month ago

    That guy was wearing crocs 😂😂

  • Max Lake
    Max Lake 1 month ago

    also stop saying things will not go faster than light or that nothing escapes black holes as clearly black holes have jets on the axis and the big bang prove this statement to be nonsense. When a black hole hits a critical mass it's gravity can no longer win against it's mass and since light is being sucked in and we are about to see an explosion then it follows that in a big bang event (a black hole explodes) then that matter must exceed the speed of light. It's just logic. And stop saying light has no mass and that the event horizon had infinite mass.If you can add to something and make it more powerful it clearly was never infinite.
    It is mearly very small or very large. It serves no purpose to round up to infinity or round down to nothing. This only confuses students that then have a giant logic hole and it makes a nonsense out of all other physics. Light bends because it has mass and it was obvious it would it we don't forget that. it can also be slowed, stopped and speeded up precisely because it has mass. Might not be practical but it happens in nature I guarantee it.

  • Max Lake
    Max Lake 1 month ago

    I wish people would not draw literal waves in digram. The wave is nothing more than a graphic visualisation of an expanding and contracting orbital shell as this is the only geometric movement system I know that can create a frequency wave. Light particles move in straight lines not literal waves due to the law of physic that states an object can not change direction without a force being applied. for a literal wave to occur this would require an outside force nothing to do with the light particle. It we say that it is like a water wave involving compression then would would also say light also has currents due to traffic jams and compressions and it does not.

    Just draw particles and straight lines -light is not a wave. This is a issue that most physics teachers do not seem to understand or the vast majority of the scientific community it seems as I have never got a straight answer and come to this conclusion that the information they keep giving me was wrong. Other than the actual people making new science and not just parroting it. I mean there are really only a very few real scientists in the world- perhaps only one in each field over decades. They all bumble along saying what the last great scientist said before the next scientist comes along and actually gets it.

    Computer brains and scientists. I prefer scientists. They have the passion for curiosity and won't accept nonsense like literal light waves. You kind of need both these days.

  • Joel Ayoub
    Joel Ayoub 1 month ago

    What was needed to detect gravitational waves? A LOT of money....

  • betaneptune
    betaneptune 1 month ago

    What about the beam splitter? How smooth do _its_ surfaces have to be? What keeps it from moving? Is it also suspended by silica wires? And what keeps _it_ from disturbing things, when a few air molecules in the pipe would ruin things?

  • jonrox24
    jonrox24 1 month ago

    gravity is not the speed of light, if you calculate the planets orbit around the sun with gravity as the speed of light, the planets wouldn't orbit the way they do, if you make the speed of gravity infinite, then the math works and it shows the planets orbiting as they do.

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