WSU: Special Relativity with Brian Greene

  • Published on: 01 September 2020
  • Physicist Brian Greene takes you on a visual, conceptual, and mathematical exploration of Einstein’s spectacular insights into space, time, and energy. In just 11.5 hours, using nothing more advanced than high school algebra, journey from Einstein’s earliest musings on the speed of light to his startling realization that time can tick at different rates to his revolutionary discovery of the world’s most famous formula, E = mc2.

    This is a more in-depth and mathematical version of the WSU Master Class “Space, Time, and Einstein.”


    Watch the class in full or view in segments via the chapter links below.

    Experience the associated free online course at World Science U:

    0:00 - Introduction
    01:43 - Scale
    05:46 - Speed
    18:19 - The Speed of Light
    27:39 - Units
    33:28 - The Mathematics of Speed
    44:24 - Relativity of Simultaneity
    54:25 - Pitfalls: Relativity of Simultaneity
    1:03:32 - Calculating the Time Difference
    1:18:42 - Time in Motion
    1:28:48 - How Fast Does Time Slow?
    1:46:32 - The Mathematics of Slow Time
    1:57:11 - Time Dilation Examples
    2:10:51 - Time Dilation: Experimental Evidence
    2:19:58 - The Reality of Past, Present, and Future
    2:34:01 - Time Dilation: Intuitive Explanation
    2:37:57 - Motion's Effect On Space
    2:55:11 - Motion's Effect On Space: Mathematical Form
    3:00:47 - Length Contraction: Travel of Proxima Centauri
    3:07:46 - Length Contraction: Disintegrating Muons
    3:12:00 - Length Contraction: Distant Spaceflight
    3:18:54 - Length Contraction: Horizontal Light Clock In Motion
    3:27:17 - Coordinates For Space
    3:36:37 - Coordinates For Space: Rotation of Coordinate Frames
    3:48:36 - Coordinates For Space: Translation of Coordinate Frames
    3:53:10 - Coordinates for Time
    4:07:12 - Coordinates in Motion
    4:26:08 - Clocks in Motion: Examples
    4:35:02 - Clocks in Motion: Length Expansion From Asynchronous Clocks
    4:38:42 - Clocks in Motion: Bicycle Wheels
    4:45:01 - Clocks in Motion: Temporal Order
    4:54:35 - Clocks in Motion: How Observers Say the Other's Clock Runs Slow?
    5:08:50 - The Lorentz Transformation
    5:16:52 - The Lorentz Transformation: Relating Time Coordinates
    5:26:10 - The Lorentz Transformation: Generalizations
    5:33:18 - The Lorentz Transformation: The Big Picture Summary
    5:47:37 - Lorentz Transformation: Moving Light Clock
    5:54:39 - Lorentz Transformation: Future Baseball
    6:02:35 - Lorentz Transformation: Speed of Light in a Moving Frame
    6:08:43 - Lorentz Transformation: Sprinter
    6:10:44 - Combining Velocities
    6:17:46 - Combining Velocities: 3-Dimensions
    6:27:45 - Combining Velocities: Example in 1D
    6:30:23 - Combining Velocities: Example in 3D
    6:36:34 - Spacetime Diagrams
    6:50:35 - Spacetime Diagrams: Two Observers in Relative Motion
    7:01:16 - Spacetime Diagrams: Essential Features
    7:11:42 - Spacetime Diagrams: Demonstrations
    7:15:23 - Lorentz Transformation: As An Exotic Rotation
    7:27:26 - Reality of Past, Present, and Future: Mathematical Details
    7:39:00 - Invariants
    7:43:55 - Invariants: Spacetime Distance
    7:54:25 - Invariants: Examples
    7:59:19 - Cause and Effect: A Spacetime Invariant
    8:12:40 - Cause and Effect: Same Place, Same Time
    8:22:37 - Intuition and Time Dilation: Mathematical Approach
    8:29:46 - The Pole in the Barn Paradox
    8:43:51 - The Pole in the Barn: Quantitative Details
    9:04:43 - The Pole in the Barn: Spacetime Diagrams
    9:08:25 - Pole in the Barn: Lock the Doors
    9:20:50 - The Twin Paradox
    9:29:28 - The Twin Paradox: Without Acceleration
    9:46:34 - The Twin Paradox: Spacetime Diagrams
    9:53:12 - Twin Paradox: The Twins Communicate
    10:06:34 - The Relativistic Doppler Effect
    10:19:00 - Twin Paradox: The Twins Communicate Quantitative
    10:30:17 - Implications of Mass
    10:40:06 - Force and Energy
    11:00:12 - Force and Energy: Relativistic Work and Kinetic Energy
    11:07:24 - E=MC2
    11:26:28 - Course Recap

    Official Site:
  • Runtime : 11:29:
  • Brian Greene Special Relativity Albert Einstein e=mc2 Mass energy equivalence the speed of light Free online course Special Relativity course What is Special Relativity? physics best physics course space and time Relativity of Simultaneity Time Dilation Past Present and Future Length Contraction Coordinates For Space Clocks in Motion Light Clocks Lorentz Transformation World Science U WSU World Science Festival


  • Mark GTMA
    Mark GTMA   1 days ago

    Thank You Dr Green. Such passion is unequaled.

  • TheOneWhoWas
    TheOneWhoWas   2 days ago

    i cannot believe my comment being a huge compliment, gets deleted.. wow.. thanks youtube censorship!!

  • TheOneWhoWas
    TheOneWhoWas   2 days ago

    You know Brian Greene is 100% legit.. cause he isn't all the time saying uhhhh.. ummmm... uhh uhhh umm... and all that crap... He's just af.. and actually knows wtf he's talking about!!! He isn't trying to indoctrinate, he isn't trying to influence.. he's just teaching what he knows, and he's 100% legit.. No fakeness here folks!!! and you can tell he loves what he does here as well!!

  • A Merlin
    A Merlin   3 days ago

    Just started and already a little turned off by the Einstein worship. Einstein wasn't the first to propose Mass Energy equivalence, nor did he provide a proof that his equation was correct. Plugging in kilograms, meters, seconds provides the corresponding units for Energy represented by Joules, but what about an alpha constant, for example E = 3/4 m c^2 or E = 5/4 mc^2 (both of which have been seriously considered).

  • Mile Gedojzna
    Mile Gedojzna   4 days ago

    Sir, I am really sure thinking that we are inside a simulation, inside a simulation, inside a simulation, inside a simulation of base reality. And then realized that we are actually inside the emulation. Unless I find a way how to pass that "nothing" where nothing are something and that something is nothing. xD

  • spalje vina
    spalje vina   4 days ago

    why would anybody be interested in this 100yrs old stuff, this is like almost babylonian science from baked tables

  • T2
    T2   5 days ago

    Incredible presentation. Superb. 55:50 I believe Prof. Greene could have avoided some discrepancies with neuroscience in his example. I would (humbly) suggest for future presentations this example be remodelled using two instruments that measure light and sound. If you use human sensory perception to pick up the data you will have a very surprising result. You will probably (depending on the distances) hear the sound first BEFORE you actually see the event. This is because of the way our brain works, it takes longer processing optical information, we process sound FASTER than light in our brains. So this example would work well on larger distances (when for example you see lightning then you hear the sound) but actually works the other way around on relatively small distances.

  • Barask Paras
    Barask Paras   1 weeks ago

    The same idiocracy that brought nearly a million Covid19 deaths to the USA promotes a bending of space and time to solve something Einstein couldn't solve legitimately because he was too stupid. Clocks can be slowed but not time- the average kinetic energy of all the elementary particles in the universe. There is no such thing as length contraction, snake oil salesman.

    KASST TIEN   1 weeks ago

    You are a beast of best explain everything better

    KASST TIEN   1 weeks ago

    How can they cancel sir!! Wrong (38:45) You should take c² on numerator from denominator of denominator, I. E (c-wc²)/1-cw Then taking common C(1-wc)/1-wc then These guys get cancelled each other and then we will left with 'c'. ................. 🤗................... Hence corrected myself

  • Mr Goldie
    Mr Goldie   1 weeks ago

    Special relativity - isn’t that just the manipulation of the right side of the general relativity formula {G = ((8.pi. G)/C^4) T} ?

  • Sinha S
    Sinha S   1 weeks ago

    Thank you so much sir this was so helpful and a great experience to learn from you. Your way of teaching has always been very easy to understand even the complex concepts to me. Thanks for this amazing lecture. I wish I will be able to learn more from you in future.

  • Dhruv Jain
    Dhruv Jain   1 weeks ago

    I am an economist and I still find listening to these lectures worthwhile and fascinating

  • G Randolph
    G Randolph   1 weeks ago

    Too bad you can’t do an example with Team Democrats and Team Republicans, that would explain everything!

  • iven nostrodamus
    iven nostrodamus   1 weeks ago

    special relativity is a byproduct of quantum physics. ie. while trying to understand if light 💡 is a particle or a wave 🌊 - they hit a conundrum where lightspeed was a weird cosmic constant. neither a particle nor a wave 🌊 behaves this way. so btw - what is light 💡 ?

  • Mike
    Mike   1 weeks ago

    Mind = blown !What?! Why is this so easy to understand? What an amazing lecture!Thank you so much professor.

  • Maksims Ivanovs
    Maksims Ivanovs   2 weeks ago

    4:33:33 I'm infuriated by this. It makes an absolute absence of sense.5:07:23 t george divides d and v, the expression in the START multiplies them, what's going on?

  • Geo. Perry
    Geo. Perry   2 weeks ago

    About 525s in, "... the Earth itself is going in orbit around the Sun", which is depicted rotating clockwise viewed from North, which would be a drag, especially upon Mercury. - That is, thanks to the graphic typo, and thanks to an internet-search, I have a phrase to define what I'd thought must exist: rotational frame dragging. I suppose there's linear frame dragging, and that these two are related. That is, when some thing massive's rushing at us, and we're sorta' falling in towards it, we might feel less gravity; and when it's whooshed by and rushing away, it may be extra-disappointed that we're not falling, and pulls harder.Yes, that's more hand-waving than sound science (... and, hey: speaking of waving, if one could get some thing really-really massive oscillating on a really-really taut spring, could one generate gravity-waves?) and I'm not even paying proper respect to spacetime-geometry; but until I can see spacetime actually bending, and I /can/ feel mine own weight, I'm going with Newton. I'll leave to generations hence to luxuriate in a more-cosmic scale: we're individually puny and brief; but if we make it out into our solar system, and can loot the joint, our descendants may enjoy an inter-stellar future. - That is, we might grow past a search for habitable planets altogether. - Gravity, after all, /is/ a drag.

  • Leïla
    Leïla   2 weeks ago

    Thank you!!!!!! <3<3<3<3

  • wdilks
    wdilks   2 weeks ago

    I'm wondering about the human physical aging effect of time dilation beyond clocks. Seems to me that standing still or moving with the clock, the bodies would age the same, unaffected by which "time" one is in. I know there are theories. But I cannot find anything proving the theories. Yes, we have proof of the clocks in space. But human aging is chemical based, not clock based. The differentiation is chronological aging vs biological aging. Apples & oranges.I haven't seen actual human bio-measurement proof, and don't know if that proof can actually be found today. To my unscientific knowledge, the aging process is set at a specific biological pace, and doesn't care about "time". It moves at its own pace. Examining a chronological time divergence, if I travelled out near the speed of light and returned home, sure, time-dilation says you've been away a month but earth is a decade ahead (No, I'm not doing the math). But regardless of "time", I assume there is no biological divergence, as the constant pace of biological aging has not changed. You return home the same age as your twin. Timewise, only a month has passed for me in space, but 10 years have passed on earth. So it appears I age chronologically faster in space, 10 years in one month in my example. In a space station astronaut example, an article talks of the astronaut being .01 seconds younger that his twin. I posit that it's merely a chronological time divergence, not a physical divergence. Time-wise he's been around .01 second less, but physically they're still equal and the astronaut's actual biologic process didn't slow down.Does anyone have a link to the biological proof? Please share if you have it.Excellent presentation, and awesome food for thought. Thank you Brian and WSF.

  • Tony Stone
    Tony Stone   2 weeks ago

    The gentleman below and this entire community shares my own admiration and appreciation of Dr. Greene and the treasures he shares so willingly and freely. I couldn’t help but respond to the person who cited the profit possibilities of running such a series on Netflix. Think of the downside however. Imagine the possibility of having one of Prof. Greene’s lecture being followed by an Adam Sandler movie! The cultural shock could be lethal! Incidentally, he’s also published a great many books intended for the same audience to whom these talks are directed. Not only are they extraordinarily instructive but he laces them with language that approaches the poetic. At one point, he contemplates the inescapable finiteness of the universe and ourselves quoting Emily Dickinson’s phrase admonishing us to enter into “The eternity of now.”

  • Ranindu
    Ranindu   2 weeks ago


  • Robert Eric Wagner
    Robert Eric Wagner   3 weeks ago

    Sometimes I feel like this is the only stuff worth talking about.

  • Review Freak
    Review Freak   3 weeks ago


  • Abdullah Khatib
    Abdullah Khatib   3 weeks ago

    OK I'm 90 minutes in and I understand the reasoning however it all hinges on that the speed of light must be constant and he hasn't explained why is that? Anyone knows?

  • sujith lal s nair
    sujith lal s nair   3 weeks ago

    NO MATHEMATICIAN WOULD BE A PHYSICIST, but A PHYSICIST would be a mathematician 😘😘😘 proud to be a physicist

  • Azalea Jane
    Azalea Jane   3 weeks ago

    please at least there be auto subtitles!

  • Dan Mihaesi
    Dan Mihaesi   3 weeks ago

    Who on earth could dislike such an admirable endeavour.Many thanks WSU and Mr. Greene for this gem!

  • Jhon Connor
    Jhon Connor   3 weeks ago

    antes que siga con su relatividad especial analice el experimento de Michelson-Morley para conocer la verdad y comprender que la transformación de coordenadas de Lorentz dice la monstruosa mentira que ' todos los observadores inerciales miden la misma velocidad C para un fotón

  • nocontrol06
    nocontrol06   3 weeks ago

    I understood everything except the alien on the bike's now slice seeing our future.... if our future hasn't happened yet then it doesnt exist. and cannot be on the aliens now slice.. because the alien cannot see something that does not exist