Would Headlights Work at Light Speed?

  • Published on Feb 25, 2015
  • If you were driving at the speed of light and turned on your headlights, what would happen?
    Twitter: twitter.com/tweetsauce
    Instagram: instagram.com/electricpants
    Sources and extras below!!
    Thanks to Jude for asking me this question on twitter! twitter.com/stefanikj5/status/550865272895447041
    “The Life of the Cosmos” by Lee Smolin: www.amazon.co.uk/The-Life-Cosmos-Lee-Smolin/dp/0195126645
    “In Search of the Multiverse” by John Gribbin: www.amazon.co.uk/In-Search-Multiverse-John-Gribbin/dp/0141036117
    “The Pig That Wants to be Eaten: by Julian Baggini: www.amazon.co.uk/The-Pig-That-Wants-Eaten/dp/1847081282
    Relevant MinutePhysics videos:
    light slowing down in glass: thexvid.com/video/FAivtXJOsiI/video.html
    a different perspective from Sixty Symbols about light slowing down: thexvid.com/video/CiHN0ZWE5bk/video.html
    Why is “c” the speed of light?
    Car at light speed:
    Light speed is the same in all inertial frames of reference:
    Relativistic addition of velocities:
    doppler shift:
    Light speed and catching-up to light.
    Other good relativity resources: newt.phys.unsw.edu.au/einsteinlight/
    Light echo footage: www.spacetelescope.org/videos/heic0617a/
    “fine-tuned” universe:
    Irrational numbers: mathworld.wolfram.com/IrrationalNumber.html
    a million digits of pi: www.piday.org/million/
    Vsauce2: thexvid.com/user/Vsauce2
    Vsauce3: thexvid.com/user/Vsauce3
    animated drawings by Guy Larsen twitter.com/guylar
    rocketship animation by Eric Langay twitter.com/ericlanglay
  • Science & TechnologyScience & Technology

Comments • 20 855

  • ruba rabania
    ruba rabania 15 minutes ago

    seriously go use your knowledge for good things your hypotheses are worse then hitlers XD

  • Joseph Torres
    Joseph Torres 10 hours ago

    As he is the same a me

  • Anthony Bartolomei
    Anthony Bartolomei 15 hours ago

    Doesn't it take an exponentially increasing amount of mass of computer to simulate more mass? So theoretically if you were to simulate the universe you'd need to have a computer with the mass of the universe to the power of the mass of the universe? Correct me if I'm wrong

  • matt duncil
    matt duncil 18 hours ago

    So if I build a space ship traveling at 99.999999999999999991% C , and fire a gun out front of ship, the bullet wouldn't go faster then light, even though speed of ship and bullet add up to faster then light? How?

  • Gordon Ramsay is Savior Yaks are back

    I know you didn't just say "a instant"
    I'm getting seriously triggered lmao

  • 🅱️eelon 🅱️usk

    This is a really good explanation of special relativity

    ENDER RIST Day ago

    WAIT scientist founded the end of Pi😱

  • Flapjackpants 23

    How did this video go from car headlights to simulated reality???

  • Caméra Prod
    Caméra Prod 2 days ago

    Irrational numbers... Keepin' it real since 2015

  • AstralDimensions
    AstralDimensions 3 days ago +1

    Has anyone tried to find the last nr. of PI?

  • SurfyDragon
    SurfyDragon 3 days ago

    The most simple question and thoughtful does light have a limit on how far it goes does it dim out after 1 trillion light years

    • Anthony Flagg
      Anthony Flagg 2 days ago

      No. That we can't see every other star in the universe is basically only a function of the fact that the light hasn't reached us yet (or is so small that it's imperceptible to the human eye). At least that's my understanding.

  • Eli Tagle
    Eli Tagle 3 days ago

    Vsauce is created his new,he is how to basic

    LOLXDEEZNUTZ22 5 3 days ago +1

    My brain just oofed

  • TI Bayonex
    TI Bayonex 4 days ago

    What if...
    This is a simulation, just far in the future, we can pay to go through a simulation, that we pay to enter? We are able to live a lifetime in just a few seconds in reality as an escape from life? Like what if we die, and we wake up in this futuristic environment, "Where the hell am I?" you exclaim. Then it's explained to you that you were simply in a simulation over the past few seconds, and that over the course of a week, your memories will come back to you?

  • Chris
    Chris 4 days ago

    It's actually easier to believe there is a God that created everything, which is a valid theory.

  • Pablo Rodriguez
    Pablo Rodriguez 4 days ago

    maybe that's why black holes need to suck in matter so fast it needs the "materials" to make it maybe its just like that or it needs them fast because if it takes too long the universe will collapse

  • Pablo Rodriguez
    Pablo Rodriguez 4 days ago

    why is life the way it is? :O

  • Pablo Rodriguez
    Pablo Rodriguez 4 days ago

    i think the light wouldn't come out or collect. it would be in the same position the whole time because they are going at the same speed.

  • Pablo Rodriguez
    Pablo Rodriguez 4 days ago

    is that why when your walking and you stop
    everything looks stretched and then in a way shrinks

  • Evan Verburg
    Evan Verburg 4 days ago

    What would it look like if we would travel in a spaceship with an alcubierre drive?

  • iman fox
    iman fox 4 days ago

    what if there is something faster than the speed of light 🤔

  • MC AV
    MC AV 4 days ago

    Yeah... From 10:05 Mystic Messenger is flowing inside my head and now i cannot sleep great

  • Ryan Toomey
    Ryan Toomey 5 days ago

    So time travel would be possible by traveling near the speed of light?

  • Saswat Sarangi
    Saswat Sarangi 5 days ago

    it's night here, but your video isn't horror category but i'm afraid because of all the simulation part

  • Saswat Sarangi
    Saswat Sarangi 5 days ago

    hence if there's god beyond , he can't do anything because he doesn't have time to do anything,,,just kidding

  • Saswat Sarangi
    Saswat Sarangi 5 days ago

    1:21 as long as you're not accelerating? means accelerating would change speed of light??????????????????

  • RogueEvasion
    RogueEvasion 5 days ago

    *Oh no.. There are getting smarter.. They are realizing this is a simulation..* *DELETE WORLD**

  • Benjamin Joshua Beggs
    Benjamin Joshua Beggs 5 days ago +1

    -Vsauce 2015

  • Zak-Attack
    Zak-Attack 6 days ago

    A photon with a light that projects photons that have lights that project photons that have lights...

  • Bigfriendly15
    Bigfriendly15 6 days ago

    I don't have the educational background to totally understand this. I still find totally fascinating though.

  • allcomando lol
    allcomando lol 6 days ago


  • Dorian Radosevic
    Dorian Radosevic 6 days ago

    wanst it proven that photons have mass?

  • MGsquared
    MGsquared 6 days ago

    What if the simulation is more like an AI constantly improving itself and pugging numbers into gaps so that when we find more pi it’s simply adds more pi.

  • Meghajit Mazumdar
    Meghajit Mazumdar 6 days ago

    8;42...Best question so far. It feels so good when he starts questioning the laws of Physics as to why they behave the way they do. Great going Michael :)

  • Omega Henry
    Omega Henry 7 days ago

    But photons have energy and E=mc^2 so E/c^2 = m I think so they have like, effectively none, but still some. Please let me know how what I said is wrong.

  • LxuisIX
    LxuisIX 7 days ago

    M A T R I X

  • AcidMist
    AcidMist 7 days ago

    Traveling at light speed is a scary speed. Think about it. It takes 8.3 minutes for light from the Sun to reach the Earth. Imagine you and a friend are communicating from that distance with a special phone. You are at the Sun and your friend is back on Earth. You tell your friend you be there at light speed and they say okay. To you, as soon as you hung up you were right there with your friend. Your friend however, did other stuff for 8.3 minutes waiting on you to arrive. That is crazy....imagine if we could create a device that could see what light "sees" or what is around light? What would we see?

    • AcidMist
      AcidMist 7 days ago

      11:00 His faicial expressions scared me omg..I thought he was going to say who are real.His face was like yeah...you buddy

    • AcidMist
      AcidMist 7 days ago

      If you believe in infinity then at some point we will reach the speed of light and see what is going on with this universe. Imagine however many billion of years in the future our ancestors reach this speed and a congratulations pops up infront of everyone. You get up in some other form or maybe still human and be like man that was a good game. Like it was at a convention or something and the game was about however many years in the past human civilization was like..i.e. us. Like it's a history lesson or something. Imagine...really how are people like really smart and think up these inventions? Inventions that keep human civilization going. Is it really concidence or are they hacks? Seems like a lot of geniuses always had a 'defect' or not what we consider 'normal'. Maybe that is the glitch. If infinity is real than anything is possible.

    • AcidMist
      AcidMist 7 days ago

      They say the universe is always expanding and then say nothing can move faster than light...but that rule only applies to what's inside the universe. The edge of the universe is moving faster than the speed of light because that's the speed it gave it. So the real question is what's the universe expanding into? What is there before the universe? This stuff is scary...I'm HAF

    MAKSIMS TARASOVS 7 days ago

    This hurt my brain..

  • Mathies
    Mathies 7 days ago

    It must be terrifying for simulators that we are starting to speculate of being in a simulation, coming closer and closer to discovering the truth... But maybe they all died a billion years ago and the simulation has managed to survive on itself and has been evolving to the point that we exist.

  • Mathies
    Mathies 7 days ago

    If an object travelling at the speed of light would not experience an instant of time, how does light from the sun take 8 minutes to get here? The sun could have exploded 7 minutes ago and we would not yet have noticed... Yet it's the same exact moment?
    It's not that it experiences no time, it's just that no light is able to catch up to an object travelling at the speed of light, so you don't *see* time changing. But time is more than what you can see and even if you can't see things changing because of your velocity, they're still changing.
    I thought of a simpler way to explain the problem with the stationary and moving spaceship. The lightbeam of the moving spaceship appears to not yet have travelled a lightsecond after one second, because the spaceship has been moving with it. The light most in front of the beam was emitted from where the spaceship was at the start, next to the stationary spaceship, and from there it has travelled a lightsecond.

  • Cheese Burger
    Cheese Burger 7 days ago

    Does anyone else hear that ticking? It’s actually quite annoying

  • Mac cat
    Mac cat 7 days ago

    Han Solo disagrees smart man! 👍

  • NJgamer
    NJgamer 8 days ago

    Vsauce: Nothing that has mad could travel of the speed of light
    Me: The millennium falcon

  • noah smith
    noah smith 8 days ago

    WAIT your earth doesn’t have 2 suns??? V-Sauce are you in a different universe are you being dead serious about you not having 2 suns?

  • noah smith
    noah smith 8 days ago

    Does light travel in the fourth dimension above time and space? Because if things were to go at the speed of light (which light does) then they would slow down time so much that time wouldn’t be moving for them, so if light travels at the speed of light which obviously it does is light itself then wouldn’t it be frozen in time it’s self, but then how does it move, it goes in the timeless dimension until it reaches a space then we see it, is this why we can’t ever see light with our own eyes? Or can we see light move and all this is wrong and yeah I’m just throwing a theory out there👍

  • Smartistic
    Smartistic 8 days ago

    *_lEt’$ bUiLd A c@r OuT oF LiGHt_*

  • Electric_ mohawk
    Electric_ mohawk 8 days ago

    Answer in short:no

  • Aniket Maurya
    Aniket Maurya 8 days ago

    And as always, thanks for raping my brain.

  • - -
    - - 8 days ago

    someone could make a microverse to power a car

  • S H I N Y
    S H I N Y 9 days ago

    But if the photon experiences no time but we do, does the photon seem to itself like it’s staying still or moving?

  • Breezy Mods
    Breezy Mods 9 days ago

    Photons are like gods dandruff

  • Yashsvi Dixit
    Yashsvi Dixit 9 days ago

    *_Hi from a parallel universe_*

  • yoshi32!!!
    yoshi32!!! 9 days ago

    00:54 That face

  • GamerBros
    GamerBros 9 days ago


  • Kate pro
    Kate pro 10 days ago

    That transition at 9:30 with music is simply perfect . Our universe is amazing isnt she ? :)

  • Hasan Shirazi
    Hasan Shirazi 10 days ago

    All our theories break down at the speed of light. Hence strange concepts like time standing still and inertia becoming infinity etc. crop up. We need a better theory than Special Relativity to understand what really happens at the speed of light.
    Multiverses are just a fairy tale for the adults.

  • GandalfGaertner
    GandalfGaertner 10 days ago

    Who says there aren't simulations created by us already? Imagine the Pokemon Characters exist in a simulation, and everything we tell them to do in the games is what they actually experience?

  • Aakash Shah
    Aakash Shah 10 days ago

    2.45 which earlier video??

  • MikotoX
    MikotoX 11 days ago

    Song at 2:10? Does anyone have a link please ?

  • Norbert Sós
    Norbert Sós 11 days ago

    Music at 11:20 ??

  • Aquaholic
    Aquaholic 11 days ago

    But what if Pi is only a process, not a stored number>

  • Myishen Haines
    Myishen Haines 12 days ago

    I was just watching another serial killer documentary when I noticed this video and though: hmmm....I feel like this video would be healthier for me to watch. Lol

  • Ron Kreike
    Ron Kreike 12 days ago

    Q: Lightspeed is constant in water and in glass and in vacuum, so why not also in Earth’s atmosphere?
    And: As lightspeed in Earth atmosphere is constant also when the lightsource is at different velocities,
    that should be different when observers at different velocities would measure the light-speed?
    Or not?

  • Warhawk 837
    Warhawk 837 12 days ago

    I think my brain melted

  • Daniel Øystrøm
    Daniel Øystrøm 12 days ago +10

    Why did youtube decide to translate this title to norwegian for me?

    • Fox Life
      Fox Life Day ago


    • iutubby
      iutubby 5 days ago

      Its in spanish for me, it sucks

    • Slydaa7
      Slydaa7 7 days ago

      yeah, it sucks. I hate it.

    • bare veesh
      bare veesh 12 days ago +3

      Same for me but only vsauce

  • Rian Richardson
    Rian Richardson 12 days ago

    1:50 what music did he use...?

  • StellaMatutina
    StellaMatutina 12 days ago

    Time is on my side yes it is....?

  • Tenly2009
    Tenly2009 13 days ago

    What I don’t understand about the speed of light is: If I leave earth in a spaceship travelling at 75% of the speed of light, and you leave earth in a spaceship travelling at 75% of the speed of light in the opposite direction... to an observer on earth, we are each travelling at 75% of the speed of light - but to me, would it not appear that you were travelling at 1.5 times the speed of light? If we each travelled for 2 earth years and then stopped, we would each be 1.5 light years from earth - and 3 light years away from each other, right? But if we don’t stop, and I think of myself as stationary in my frame of reference, then the earth would have been moving away from me at 75% of the speed of light while you were moving away from the earth at an additional 75% of the speed of light - which means you were moving away from me at 1.5x the speed of light - which is supposed to be impossible. So where did I go wrong?

  • Abin Joe
    Abin Joe 13 days ago

    Whatever happens, you can't see it as the light will not reach your eye.

  • Rowan Lloyd
    Rowan Lloyd 13 days ago +1

    Wait if universes are inside blackholes and there are blackholes in univeres that are inside blackholes then there are universes inside universes inside universes, *universeception*

  • Julie Stenberg Andersen

    I am confused. I clicked on a video to see if headlights would work at the speed of light and now I'm living in a simualtion

  • Singh Anmol preet
    Singh Anmol preet 13 days ago +5

    Haha I like the joke at the end there 12:02 get it? Cause irrational numbers are the opposite of real numbers! Funny

    Oh wait... irrational numbers are still real tho...

    • Sonnetica _
      Sonnetica _ 12 days ago +2

      But irrational numbers are still real numbers

  • Marisa Kirasame
    Marisa Kirasame 14 days ago

    Yeah that would be weird, I wonder how life on earth with only one Sun would look like 🤔. Would we constantly have to travel with the Sun in order to not freeze?

  • reniel fanini
    reniel fanini 14 days ago

    Do you know the definition of mindf@ck? it's watching Vsauce over and over, and think your brain will be the same afterward...

  • 龘鱈鍵
    龘鱈鍵 14 days ago

    "Thank you irrational numbers for keeping it real"
    **Mic explodes**

  • Fabian Runkel
    Fabian Runkel 14 days ago

    I always thought that propability argument about our life being simulated is stupid. What's more likely, that every event that has ever happened, with concious beings expressing their free will (to an outside observer) completely random, occured exactly the way it happened, or that some tiny thing along the way didn't happen the way it did? And still, the less likely thing happened. With a propability of, according to our current knowledge of existence, basically 0%.

  • BenjerminGaye
    BenjerminGaye 15 days ago

    Wouldn't it suffer from the doppler effect like sound?

  • Alpha Centauri
    Alpha Centauri 15 days ago

    *Vsauce video*
    1. Good Title
    2. Get Math
    3. Talk about Shoes
    4. Create a meme

  • Alpha Centauri
    Alpha Centauri 15 days ago

    this guy on the camera never met Donald trump

  • Minky Manky
    Minky Manky 15 days ago

    We live in a society

  • Joe O Sullivan
    Joe O Sullivan 15 days ago

    Is light called light because photons are very (infinitely) light?

  • [ ZootNoison ]
    [ ZootNoison ] 16 days ago


  • John USA
    John USA 16 days ago

    150k flat earthers liked this video

  • kylesplinter1
    kylesplinter1 16 days ago

    *Angry Moth Noises*

  • Niels Daemen
    Niels Daemen 16 days ago

    Mind Blown!

  • Cherry
    Cherry 16 days ago +2

    Am I the only one with a german title?

  • Sima Nova
    Sima Nova 16 days ago

    photons are not affected by time, they are timeless - perhaps only mass objects can experience time

  • Parikshit Thakur
    Parikshit Thakur 16 days ago

    wtf wow. My mind is fucked.

  • Doodle Squad
    Doodle Squad 16 days ago

    They work at light speed I’ve tried it
    TRUST ME☹️

  • Roar Variant
    Roar Variant 16 days ago

    Light has a source, be it a chemical reaction or otherwise
    So it has a b e f o r e
    Light we observe is due to a chemical reaction
    So it has an e n d , an a f t e r
    So assuming we are talking about light we observe, and the time we are talking about is our time, and the mass-less vehicle arises from a chemical reaction at some time, our time, then giving that mass-less vehicle a headlight that works is not that far fetched
    The "headlights" "switch on" before the mass-less vehicle arises, so when the vehicle "turns on" and "starts" to move at c, the photons would already have traveled some distance, and encountering some reflecting plane, would strike back, and since both photons and the mass-less vehicle would be traveling at the speed of light, there will be a constant distance between the "end" of the headlight illumination, and if we're talking about a space where photons could scatter, light would be "visible" to an observer, but that would cause interference in the path of the mass-less vehicle as well
    Well, I guess?

  • Iam Vikk
    Iam Vikk 16 days ago

    This is the kinda question no one has ever thought of... except Vsause..

  • Atul Badgujar
    Atul Badgujar 16 days ago

    What are trying to say?????

  • Stofzuigerzak
    Stofzuigerzak 17 days ago

    Why is the title and description in the language of my country?

  • Mikki Hintikka
    Mikki Hintikka 17 days ago

    we can build a car which goes faster in a fluid than light goes in the same fluid

  • Powder
    Powder 17 days ago

    youtube is translating these titles and descriptions .. or is this a german channel? i cant search for your videos because their title is now translated into german ... wtf

  • eSKAone
    eSKAone 17 days ago

    Everything is real.

  • Marjolein Krol
    Marjolein Krol 17 days ago

    Can some one explain Why the title of this video is translated ? It is only this video and I think its very weird 😅🤔

  • eSKAone
    eSKAone 17 days ago

    First of all: Define 'real'.

  • eSKAone
    eSKAone 17 days ago

    You and Yuval Noah Harari.

  • Memesis
    Memesis 17 days ago

    Oh no the title got translated