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Do You Know What Time It Is?

2008 ,    »  -   62 Comments
Ratings: 6.11/10 from 9 users.

Do You Know What Time It Is?Particle physicist Professor Brian Cox asks, 'What time is it?' It's a simple question and it sounds like it has a simple answer. But do we really know what it is that we're asking?

Brian visits the ancient Mayan pyramids in Mexico where the Maya built temples to time. He finds out that a day is never 24 hours and meets Earth's very own Director of Time.

He journeys to the beginning of time, and goes beyond within the realms of string theory, and explores the very limit of time.

He discovers that we not only travel through time at the speed of light, but the experience we feel as the passing of time could be an illusion.

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62 Comments / User Reviews

    Saptarshi Auddy
  1. Saptarshi Auddy

    I spent an hour without realizing the TIME spent.
    Must see

  2. Der Oberst
  3. Der Oberst

    Nice little documentary about Time, addressing several aspects of what time can be perceived to be.

    ***(3 Stars out 5)

    Der Oberst

  4. curioustimer
  5. curioustimer

    marvelous! a great help in figuring out my own ponderings of time.

  6. Lilly
  7. Lilly

    Really interesting

  8. Sarah
  9. Sarah

    Wow! I never thought about this before Very Interesting.

  10. Alicia
  11. Alicia

    This Really Helped With my homework :)

  12. tscheer
  13. tscheer

    Wonderful! Informative, interesting and easy to understand. A must see.

  14. sophia
  15. sophia

    Thank you Prof Brian Cox you are an inspiration! Keep up the good work.

  16. Epicurean_Logic
  17. Epicurean_Logic

    You clearly explained that,

    'Barbour theorizes that time is nothing more than a product of human perception. “Copernicus, Galileo, and Kepler taught us that the Earth moves and rotates while the heavens stand still”, Barbour says, quote, “Now I think we must go further, to a deeper reality in which nothing at all, neither heavens or Earth moves. Stillness reigns”.

    The crux of Barbour’s view. Every possible configuration of the Universe, past, present and future, exists separately and eternally. We don’t live in a single Universe that passes through time. Instead we– or many slightly different versions of ourselves–simultaneously inhabit a multitude of static, everlasting tableaux that include everything in the Universe at any given moment. Barbour calls each of these possible still-life configurations a “NOW”!'

    Three reasons why we will consider Barbours time model:

    1.Because Greater minds than ours seem to think its important.

    2.To see if we can derive any corroborating concepts.

    3.Because we can. (i hope so anyways)

  18. Epicurean_Logic
  19. Epicurean_Logic

    Achems Razor. Does Barbour back up any of his ideas with maths? are there any equations in his book? if not how did he develop these ideas?

  20. Achems Razor
  21. Achems Razor

    @ Epicurean_Logic:

    Yes , there is some maths/equations-physics in his book "the end of time".

    I studied his book about 2 years ago, got it out of the library, If you want the maths you will have to get the book.

  22. Epicurean_Logic
  23. Epicurean_Logic

    After seeing the doc posted above, i fear that this may be way out of our league Achems. But in saying that there's nothing i like more than a tough challenge.

  24. Saif
  25. Saif

    If time slows down by massive mass then probably there are time/ lights exists that we cannot see or didn't reach us or the telescopes. Because its' stopped somewhere at a point.May be the universe is much older....

  26. Novi
  27. Novi

    Yes Saif, this question popped up in my mind just after Einsteins theory was explained. Too bad he didn't address this problem

  28. gothnate
  29. gothnate

    I love the Doctor Who music at the beginning. Very fitting.

  30. gaby
  31. gaby

    great doco, thanks for your presentation and thoughts

    it still plays on my head, i think time could be just as much our perceptions and trying to take away the link from the link can pull the puzzle apart

    the very nature of time is one of the most fundamental mysteries, all the quantative analysis has taken us nowhere and the real questions are qualitative. which takes us the the very nature of ourselves and the limits of our thinking

  32. Doc
  33. Doc

    Interesting, but Prof Cox's damn talking smile haunts me

  34. Dick from Brisbane
  35. Dick from Brisbane

    so, all my future decisions have really already been made, and everyone else's too? Like a movie reel being screened - we're only aware of what's on the screen this instant, but the whole film has already been recorded? Not the best analogy, but is that the gist?

  36. toddy
  37. toddy

    very interesting, but nothing on how the Langoliers fit into the puzzle(lol just joking of course) on the past.

  38. UsUala
  39. UsUala

    Blew my friggin' mind aaah.

  40. Satish
  41. Satish

    Good Doc on Space and Time

  42. Other Ryan
  43. Other Ryan

    Theoretically, technology can be developed to make entire events disappear from time, by creating a 'shell' of sorts that keeps light from passing through at it's true rate. Basically, if you had one of these theoretical shells, you could commit murder in front of a man and he wouldn't see it because you would slow the passing of light. He would see what was happening moments before. Once it sped back up, the observer would see the aftermath, but not the act itself.

  44. Delcio Delboy Henjengo
  45. Delcio Delboy Henjengo

    The wiser we get the closer to God we become. That's because we start asking the right questions and becoming wiser as result, and God is The Supreme Intelligence.

  46. Guest
  47. Guest

    The wiser people get the more they distance themselves from all the make believe fairy tales as in your gods.

    No upwards mobility in all the etched in stone stagnant circular logic books from the bronze ages.

  48. M/B
  49. M/B

    dont be f***ing ludicrous,c´mon!!!! its f--kin 2011 and you still think theres an all powerful,all mighty lord who created everything....srsly give it a thought,tonight you go to bed and and think bout it,ask yourself this impaled (yeah cos in case you havent informed yourself properly,roman soldiers impaled criminals,cucifiction was considered an insult to god,the cross you know,funnily enough) nazarene who died for our sins....came back to life...oh but wait,he is coming again,which actually sounds quite strange,cos....isnt he...omnipresent???....I mean srsly???? not even gravity is omnipresent,its just bananas and it sounds like fairy tales and fables to me not even that perhaps,and it frustrates me to see how people really believe in such a thing,im no expert but I think you should really let your mind evolve,open it and realise that the concept of God is the greatest lie ever in yourself,the human kind and its achievements,thats actually what the world needs,faith in the human kind.

    heaven,hell,good,bad,resurrection,divine conception,miracles,levitation...GROW UP FOR F*** SAKE!!!!!!!!

  50. Andrew Preston
  51. Andrew Preston

    @ Delcio

    Really? ever read Nietzsche? He makes a cracking argument about how the more we shun God, the wiser we become. This is due to the fact that there is no God, never has been, never will be.

  52. DeAndre Miiler
  53. DeAndre Miiler

    And you, kind sir, should open your mind. Your so caught up in bashing religion that you failed to make a sensical argument. Besides, all the information this universe has to offer will neither prove or disprove the existence of a higher power. Of course modern religion is nothing but piss, but you can't honestly say, with 100% certainty, that there is no god. In so doing, you would only be lying.

  54. g isaac
  55. g isaac

    I would really like to watch the full video but I am always cautious when it comes to downloading unknown/unfamiliar software. I came close to downloading a VEOH player until I read this online:

    "April 7, 2010, it was announced that Israeli start-up company Qlipso acquired Veoh for an undisclosed sum. Qlipso aims to use the acquisition to add users and revenue to its multi-user content sharing service.

    Included with recent installations of Veoh is a program called OpenCandy, which some security programs, including Microsoft Security Essentials, class as adware."

    I'm not downloading that to my computer and I wish that I could enjoy watching a documentary on this site without having to do so. I REALLY DO LOVE THIS SITE AND WHAT IT OFFERS. I just don't trust downloading things like that.

    P.S. I can recall watching a documentary on this site that shared the possibility that one day, people working in another country like Israel might actually use spyware and computer technology as an act of terrorism on the US. It was said that they have a great deal more control over telecommunications than we think. I don't know how far-fetched that idea is, but, I'm just saying...

  56. Guest
  57. Guest

    Just finished watching the doc suggested by Epicurean_Logic, by Julian Barbour. In my favour it wasn't technical as Epi noted.
    I have done a lot of my thinking in the last three years while experimenting with photography. I was using myself as a subject and taking shots in movement, calling them moving energy. Some of them are on my photo site under autoportrait, i added a few tonight (i have many many more). Those photos were taken with a digital camera on mid speed (shitty camera with few options) while i am moving or while moving the camera. I was curious as to how many different me that could come out of a split second shot. Anyway...Barbour's doc reminded me of that.
    I haven't watched the main doc yet...but i am about to do that unless something else grab my attention in time.
    edit; i would have to download some program in order to watch this doc on TDF, i found it on a chinese site so waiting to stream (appropriate term for time).

  58. Guest
  59. Guest

    at 30:37 when Neil Turok shows the two membranes i got to think why does he draw these membranes square and not round like two finite circles. If they are finite circles* when they bumb on each other one brakes ex: OO like two eggs that collapse together, only one egg brakes and subsequently releases a universe as in a big bang. The bang causes the round membrane to form into a |(straight line) then the membranes are shaped this way |O for eons until the one | bends continuously until it reforms a circle (like a snake bitting it's own tail) and goes on to collapse together again. This would explain infinity.

    10th dimension, the 11th would be when they reform

    again see Nassim Haramein when he talks of finite circles as universe.

  60. Achems_Razor
  61. Achems_Razor

    Don't know why he draws them square, does not matter what shape is drawn, just gives an idea. The Branes don't break, they just release energy from the collision causing a big bang.

    I am not particularly into Haramein, don't think he is even a PHD, I believe not much of his stuff is even peer reviewed. His agenda is basically spinners, everything spins.

  62. Guest
  63. Guest

    Haramein's finite universe hypothesis is interesting.
    I don't like to hear him talk though...kind of annoying.

  64. Guest
  65. Guest

    @Epicurean_Logic @Achems_razor
    Woke up in the middle of the night with the pain in the knee, couldn't sleep started thinking about this membrane thing.
    Why does he draw it square? I do think it is important although i don't know why.
    Is it that he thinks the membranes are 2 infinite flat surfaces(*1), or that they are finite square shapes, or that he is showing them as two patches of two bigger finite circles?
    What do you think? Don't tell me it's unimportant, you certainly don't just eat what you're fed. When i read, question arrises...i may still be like a child though!
    You say the branes don't brake. How do you know that? And if they were finite circles, isn't it possible that in the collision one would explode in a big bang? I have no doubt my resulting little drawing "|O" may be wrong but why could it not be right? The| could be a sort of popped balloun and have a black hole on it's membrane and over time refill itself and reshape into an O next to the other O.

    The problem for us non scientist is that our thoughts would never be accepted as a possibility until a "well regarded" scientist (2*) was to say it's possible. In my opinion the double membranes could have been thought by a chinese peasant working his fields on a sunny day.

    Also since i still coulnd't sleep i got to think what is math? Isn't math a language that has been expending as much as any other language. They say if the math works then it is possible but would the math from 200yrs ago work for the hypothesis of today? Or has the math grown like english has grown? and will Math continue to grow?
    Is it that something exist and it is compared to a finite Math or is it that expanding math explain expanding thoughts?
    "Mathematicians resolve the truth or falsity of conjectures by mathematical proof." ???????

    I hope you are patient with me. I imagine it is more interesting to have someone talk about what you seem to be passionate about than to have someone argue about religion.
    I copied this to Epicurean_Logic ...because i would love his opinion on this....and i would very much enjoy watching a scientific tennis match between two good players such as you and him.

    1*reminds me of a flat earth
    2* i am still waiting to hear the answer to my question What makes a scientist a real scientist. I often read here on TDF: He is not a real scientist.

    I know i'll have to edit some of this as i reread it. I always do

  66. Achems_Razor
  67. Achems_Razor

    Az...I do not think it is important how branes are drawn, impossible to visualize.
    It is good to question everything as you say, but it seems you are trying to complicate all this, forget which scientist said when we find the answers of TOE we will probably say to our selves why we never thought of that before, because it is so simple.

    To further your quest of scientific knowledge I recommend a real great doc here on TDF..."parallel universes"...with Michio Kaku and other great physicists.

    They go into "Branes, string theory, et al...might answer some of your questions.

  68. Guest
  69. Guest

    Then i'll keep hoping Epicurean_Logic brings something more interesting as a response.
    Ya it is important how one draws a thought, always has been, always will be, even if the answer is that they have no clue what this membrane could be and they thought drawing it rectangular represent a patch of it only, but then a patch of what? Is the membrane non corporeal?
    Sorry to bother you with my complication but i thought the whole thing was suppose to be complicated.
    OK i drop it for now.
    waiting....any one else?

  70. Achems_Razor
  71. Achems_Razor

    Az, I was not discounting you, I did give you something very important, watch "parallel universes" I cannot say it better than what is said on that specific doc, and then we can talk more about your subject, I am leading you in the direction of further knowledge if you want, if you do not want, that is fine also.

  72. Guest
  73. Guest

    Dear Achems, could you spread yourself a little bit on this white sheet and show me your manhood brain about membranes. ;) lol
    Lady Gaga

  74. Guest
  75. Guest

    What about the question concerning math? and the question what makes a scientist a real scientist?
    Yes just about to start the parallel Universes. Learning is what i like best in life, when learning is over for me, i'll be either transformed or gone.

  76. Guest
  77. Guest

    I watched the Parallel Universes. I don't see why they think they got ride of the singularity. It looks to me more like they replaced it with multiplicity. I think eventually someone will ask what contains the membranes? And if the answer is nothing than the membranes are incorporeal which pleases me to no end at the moment. It is my opinion that the world humans understand is contained inside themself. We went from singularity (or the representation of a power so far named GOD) to the incorporeal, the power of the non physical self energy within. This may prove that we are not. To be or not to be?
    It may be right to say that we are incorporeal being who visit for a very short time a corporeal world and the possibility of visiting this world at will may not be such a crazy idea. These universes offer all possibilities. I kind of think, if we can think something, it is bound to happen if we think it long enough even if it is for millions of year which in the scheme of being could represent a fart of air.
    As i have often written lately; God is in the making as long as we throw out the window every single old thought that comes to mind when the word GOD is pronounced.
    edit: never read me right away, i always need 4-5 or 10 edits

  78. Guest
  79. Guest

    I just sent Vlatko a doc suggestion for tomorrow...or later(depends on him). It is also called Parallel Universes but this one is by the History channel.
    It show that (they think) the membranes are round not square, it also shows how they think that when they hit together a universe is created out of the collision but not the way i had imagined.
    But wait! there is the level three type and the level four...even more interesting!
    I am still watching it...wish someone was here discussing all this stuff, but no...i am by myself with two dogs in a German castle often times sitting by the wood stove. Life is good!

  80. Achems_Razor
  81. Achems_Razor

    Okay, I think disqus was down for awhile couldn't comment, love the ending of parallel universes when it is suggested you can create a universe in a lab, that would on its own accord grow up to be just as viable as the one we are in.

    On another doc a few years back Stephen Hawking said you can make universes from soap bubbles and said universes can come from absolutely nothing, drove some religee's nuts! had major battles with them, one in particular, we called him religious Alex I believe.

  82. Guest
  83. Guest

    Now onto an other doc called Limits Of other very good one.
    I am starting to accept that this accident (falling through a trap hole) that happened to me was good timing. A lot of process since then. And plus, i end up having a quiet place with internet and hours of nothing else to do but think, watch, write, rethink, watch and write some more.
    A sort of portal hole into defining in a sharper way the unknown.

  84. Achems_Razor
  85. Achems_Razor

    Well just to show, what if you did not fall through that trap door? then would be a different chain of events that would be unfolding leading to new directions, not necessarily the ones that are transpiring in your life right now.

    That is probable actions in progress unfolding from your probable now's, and the thing is, that the actions that did not transpire or you did not take are just as viable as the ones you are living now in alternate realities with alternate you's or multidimensional selves, those other actions are also happening.

  86. Guest
  87. Guest

    So you are saying, in an other dimension you are sitting with me having Bengal Spice tea.

    I agree with what you write, but also we have to remember that we are imprisonned for the moment in this dimension(actuality), until we find a way to go through a portal we are stuck here. Every night we escape this actuality and enter the sleeping stage. I always say the portal is right between the two. Those are the two membranes we do live in. The awake and the asleep, we are so used to take the "elevator" between the two that we lay there unaware.

  88. Guest
  89. Guest

    What???why?? my comment is flagged for review?

  90. norlavine
  91. norlavine

    But but but but ....he needed soap and he needed water! This is not a 'religee' comment either. Once you commence an experiment in a lab,or anywhere - even within the space of a vacuum,you can be sure that all bets regarding 'starting from nothing' are off.
    PS There are so many docs now, I can find good ones more readily by looking first at the 'recent comments' list, that's how I found this. xx

  92. Guest
  93. Guest

    and i just suggested two in the last two comments. The other Parallele Universe is also very interesting and newer. With this one you have to download some program, i found it on a different site Chinese or Japenese...can't tell the difference in writing but the streaming was extrememly slow.

  94. Guest
  95. Guest

    where is my comment

  96. Achems_Razor
  97. Achems_Razor

    Yes I know, I found that strange also, soap and water is not a nothing.

    But as I recall maybe someone else said that on the same doc, but Hawking said the universe came from absolutely nothing. Actually in his book "The Grand Design" he goes in more depth about that.

    The docs name is..."How did the universe begin?" is a short doc, think 1/2 hour. You want another good doc? this is it. Very interesting.

  98. Achems_Razor
  99. Achems_Razor

    Have found it Az, and you are welcome again.

  100. Guest
  101. Guest

    With all this mess in Africa coming out with the Kony2012 doc all over the States...we better find that portal soon. The frog is bathing in a very warm water and things will only get hotter.
    Thank you Mr Moderator.

  102. norlavine
  103. norlavine

    I feel that 'nothing' is the most difficult concept to grasp, because the very act of thinking about it causes it to become 'something'.

  104. Achems_Razor
  105. Achems_Razor


    Nothing is difficult to grasp? Yes, and also very difficult to grasp is there is no past present and future, everything happens at once, and already happened, everything is static, say a lot of physicists, especially Julian Barbour in his "end of time" theory.

    The only way that the "act of thinking about it causes it to become "something" is only if our thoughts are entangled with matter "quantum entanglement" do you think that is so?

  106. Guest
  107. Guest

    The thought of nothing must have arised from seeing death, but it could be that in death everything is, every thing at once and at the same time nothing of this matter.
    So i do believe than "quantum entanglement" is something we live as we are taught from the first minute a reality imposed, a reality we hold together as a mass, a reality we think is real because we were all brought to mold ourself to it. It is as if i say: "I am therefore they are" but it may be in reality, "i am not and neither are they".

  108. Greg Gauthier
  109. Greg Gauthier

    I swear Brian has a painting of himself hidden somewhere.

  110. Eddwin Rodri Rodriguez
  111. Eddwin Rodri Rodriguez

    time is there and always will be... only humankind is not there forever.. when a child born , brings with him/her time in of his/her life...let´s say 83 years that child must live = 727562hrs 27.63 min......
    so when your time is over...your time is gone, you are gone from this world.. but time of a planet still there ,and the time of the universe will be there at least more than 500,000,000 years...means that its time could be at least 4,382902388888 hours and 53.3 min of life for the universe...

    so , when somebody mention,,,you are wasting time...the real meaning is,,your life is getting wasted.. your time is getting short every day...

    cruel reality.

  112. Minh Vinh
  113. Minh Vinh

    The best wedside but why i can't find subtile or reading when i listen!

  114. James
  115. James

    If you have an idea of what time is, in that moment "time" is a thought taking place in your head. What we forget to notice is something is aware of change taking place. That awareness is always right now, or "timeless". If you just focus on awareness, you would realize "time" is just a human thinking a sequence of thoughts.

  116. Shay
  117. Shay

    I believe one of the problems we as humans face when trying to solve the mysteries of time is our inherent narrow minded-ness. Almost all theories regarding time make allot of assumptions. For example, that time is required for motion.
    Also people tend to want to measure time in "length or duration"....but what if time is say, a particle or a wave? If that were the case you would need to measure it by density or frequency. What we perceive as time might be an illusion, but time itself might be very real and tangible....who knows...My point is maybe we should start thinking a little more outside of the box bc the current thinking is getting us basically no where

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