Is time travel possible? - Colin Stuart
-
Not SyncedHave you ever daydreamed
-
Not Syncedabout travelling through time,
-
Not Syncedperhaps fast-forward in the centuries
-
Not Syncedand seen the distant future?
-
Not SyncedWell, time travel is possible,
-
Not Syncedand what's more,
-
Not Syncedit's already been done.
-
Not SyncedMeet Serge Krikalev,
-
Not Syncedthe greatest time traveler in human history.
-
Not SyncedThis Russian cosmonaut holds the record
-
Not Syncedfor the most amount of time
-
Not Syncedhe's been orbiting our planet,
-
Not Synceda total of 803 days, 9 hours, and 39 minutes.
-
Not SyncedDuring his stay in space,
-
Not Syncedhe time traveled into his own future
-
Not Syncedby 0.02 seconds.
-
Not SyncedTravelling at 17,500 miles an hour,
-
Not Syncedhe experienced an effect
-
Not Syncedknown as time dilation,
-
Not Syncedand one day the same effect
-
Not Syncedmight make significant time travel
-
Not Syncedto the future commonplace.
-
Not SyncedTo see why moving faster in space
-
Not Syncedaffects passage of time,
-
Not Syncedwe need to go back to the 1880s,
-
Not Syncedwhen two American scientists,
-
Not SyncedAlbert Michelson and Edward Morley,
-
Not Syncedwere trying to measure the effect
-
Not Syncedof the Earth's movement around the Sun
-
Not Syncedon the speed of light.
-
Not SyncedWhen a beam of light was moving
-
Not Syncedin the same direction as the Earth,
-
Not Syncedthey expected the light to travel faster.
-
Not SyncedAnd when the Earth was moving in the opposite direction,
-
Not Syncedthey expected it to go slower.
-
Not SyncedBut they found something very curious.
-
Not SyncedThe speed of light remained the same
-
Not Syncedno matter what the Earth was doing.
-
Not SyncedTwo decades later, Albert Einstein was thinking
-
Not Syncedabout the consequences of that never-changing
-
Not Syncedspeed of light.
-
Not SyncedAnd it was his conclusions,
-
Not Syncedformulated in the Theory of Special Relativity,
-
Not Syncedthat opened the door
-
Not Syncedinto the world of time travel.
-
Not SyncedImagine a man named Jack,
-
Not Syncedstanding in the middle of a train carriage,
-
Not Syncedtraveling at a steady speed.
-
Not SyncedJack's bored
-
Not Syncedand starts bouncing a ball up and down.
-
Not SyncedWhat would Jill, standing on the platform,
-
Not Syncedsee through the window
-
Not Syncedas the train travels through.
-
Not SyncedWell, between Jack dropping the ball
-
Not Syncedand catching it again,
-
Not SyncedJill would have seen him move
-
Not Syncedslightly further down the track,
-
Not Syncedresulting in her seeing the ball
-
Not Syncedfollowing a triangular path.
-
Not SyncedThis means that Jill sees the ball
-
Not Syncedgo further than Jack does
-
Not Syncedin the same time period.
-
Not SyncedAnd because speed,
-
Not Synceddistance divided by time,
-
Not SyncedJill actually sees the ball move faster.
-
Not SyncedBut what if Jack's bouncing ball
-
Not Syncedis replaced with two mirrors
-
Not Syncedwhich bounce a beam of light between them?
-
Not SyncedJack still sees the beam dropping down
-
Not Syncedand Jill still sees the light beam
-
Not Syncedtraveling a longer distance,
-
Not Syncedexcept this time Jack and Jill can't disagree
-
Not Syncedon the speed
-
Not Syncedbecause the speed of light
-
Not Syncedremains the same no matter what.
-
Not SyncedAnd if the speed is the same
-
Not Syncedwhile the distance is different,
-
Not Syncedthis means the time taken will be different as well.
-
Not SyncedThus, time must tick at different rates
-
Not Syncedfor people moving relative to each other.
-
Not SyncedImagine that Jack and Jill have highly accurate watches
-
Not Syncedthat they synchronize before Jack boarded the train.
-
Not SyncedDuring the experiment, Jack and Jill would each see
-
Not Syncedtheir own watch working normally.
-
Not SyncedBut if they meet up again later
-
Not Syncedto compare watches,
-
Not Syncedless time would have elapsed on Jack's watch,
-
Not Syncedbalancing the fact
-
Not Syncedthat Jill saw the light move further.
-
Not SyncedThis idea may sound crazy,
-
Not Syncedbut like any good scientific theory,
-
Not Syncedit can be tested.
-
Not SyncedIn the 1970s, scientists boarded a plane
-
Not Syncedwith some super-accurate atomic clocks
-
Not Syncedthat were synchronized
-
Not Syncedwith some others left on the ground.
-
Not SyncedAfter the plane had flown around the world,
-
Not Syncedthe clocks on board showed a different time
-
Not Syncedfrom those left behind.
-
Not SyncedOf course, at the speed of trains and planes,
-
Not Syncedthe effect is minuscule.
-
Not SyncedBut the faster you go,
-
Not Syncedthe more time dilates.
-
Not SyncedFor astronauts orbiting the Earth for 800 days,
-
Not Syncedit starts to add up.
-
Not SyncedBut what affects humans also affects machines.
-
Not SyncedSatellites of the global positioning system
-
Not Syncedare also hurdling around the Earth
-
Not Syncedat thousands of miles an hour.
-
Not SyncedSo, time dilation kicks in here too.
-
Not SyncedIn fact, the speed causes the atomic clock on board
-
Not Syncedto disagree with clocks on the ground
-
Not Syncedby seven millionths of a second daily.
-
Not SyncedLeft uncorrected,
-
Not Syncedthis would cause GPS to lose accuracy
-
Not Syncedby a few kilometers each day.
-
Not SyncedSo what does all this have to do with time travel
-
Not Syncedto the far, distant future?
-
Not SyncedWell, the faster you go,
-
Not Syncedthe greater the effect of time dilation.
-
Not SyncedIf you could travel really close
-
Not Syncedto the speed of light, say 99.999%,
-
Not Syncedon a round-trip through space
-
Not Syncedfor what seemed to you like ten years,
-
Not Syncedyou'd actually return to Earth
-
Not Syncedaround the year 9000.
-
Not SyncedWho knows what you'd see when you returned?!?
-
Not SyncedHumanity merged with machines,
-
Not Syncedextinct due to climate change
-
Not Syncedor asteroid impact,
-
Not Syncedor inhabiting a colony on Mars.
-
Not SyncedBut the trouble is,
-
Not Syncedgetting heavy things like people,
-
Not Syncednot to mention space ships,
-
Not Syncedup to such speeds requires
-
Not Syncedunimaginable amounts of energy.
-
Not SyncedIt already takes enormous particle accelerators
-
Not Syncedat the Large Hadron Collider
-
Not Syncedto accelerate tiny subatomic particles
-
Not Syncedto close to light speed.
-
Not SyncedBut one day, if we can develop the tools
-
Not Syncedto accelerate ourselves to similar speeds,
-
Not Syncedthen we may regularly send time travelers
-
Not Syncedinto the future,
-
Not Syncedbringing with them tales of a long, forgotten past.
- Title:
- Is time travel possible? - Colin Stuart
- Description:
-
View full lesson: http://ed.ted.com/lessons/time-travel-and-einstein-s-special-relativity-colin-stuart
Time travel is a staple of science fiction stories, but is it actually possible? It turns out nature does allow a way of bending time, an exciting possibility suggested by Albert Einstein when he discovered special relativity over one hundred years ago. Colin Stuart imagines where (or, when) this fascinating phenomenon, time dilation, may one day take us.
Lesson by Colin Stuart, animation by TED-Ed.
- Video Language:
- English
- Team:
- closed TED
- Project:
- TED-Ed
- Duration:
- 05:04
Krystian Aparta commented on English subtitles for Is time travel possible? - Colin Stuart | ||
Krystian Aparta edited English subtitles for Is time travel possible? - Colin Stuart | ||
TED edited English subtitles for Is time travel possible? - Colin Stuart | ||
Jessica Ruby edited English subtitles for Is time travel possible? - Colin Stuart | ||
Jessica Ruby edited English subtitles for Is time travel possible? - Colin Stuart | ||
Jessica Ruby approved English subtitles for Is time travel possible? - Colin Stuart | ||
Jessica Ruby accepted English subtitles for Is time travel possible? - Colin Stuart | ||
Andrea McDonough edited English subtitles for Is time travel possible? - Colin Stuart |
Krystian Aparta
The English transcript was updated on 2/13/2015.