00:04 i still lose sleep over
00:09 okay i still lose sleep over it and i
00:11 want you to lose sleep too i don't want
00:12 to be the only one staring at the
00:14 ceiling at night i'm going to tell you
00:17 a lot of things already beat you to that
00:20 sure i mean the asteroid strike that
00:22 could happen or the exactly right or the
00:26 so here it is you may remember or you
00:28 may have heard that einstein's
00:31 relativity right more more specifically
00:35 you learn this in special theory of
00:39 the faster you move
00:43 slower time ticks for you right
00:46 as others view it relative to the
00:49 observer relative to the observer
00:51 correct you don't know anything's
00:54 your clock still ticks as far you still
00:56 got your your heart beat all of this
00:58 okay so this is not a physiological
01:00 thing is an actual property
01:04 of the fabric of space and time under
01:07 those conditions wow
01:09 okay that is fascinating it is it's
01:12 completely fascinating it's completely
01:14 i watch you fly by and the faster you go
01:18 the slower time ticks for you okay but
01:22 my time stays the same to you to me to
01:25 you so not only does speed do this also
01:28 the strength of a gravitational field
01:30 will have the same effect on you the
01:32 stronger the gravitational field is the
01:34 slower time ticks for you and that
01:36 wasn't formulated until his general
01:38 theory of relativity um uh ten years
01:41 later that took a lot more math and
01:43 and and deeper insights
01:45 into the universe but once again it
01:47 makes sense because you're dealing with
01:49 the fabric of space time it's the fabric
01:51 of space time correct but initially when
01:53 formulated you're thinking it's just
01:55 because you're moving right but it's
01:56 it's actually way deeper than that and
01:58 that's why that one oh by the way his
02:00 original special theory of relativity
02:01 was not called that
02:03 the title of the research paper was on
02:05 the electrodynamics of moving bodies
02:07 what okay that was that was the title we
02:09 would later call it the special theory
02:11 of relativity because it was a special
02:12 case of what would later then be called
02:14 the general theory of relativity oh oh
02:17 while we're there let me just slip this
02:18 in the gps satellites
02:21 orbit higher than our
02:25 then like the space station and right
02:27 and other things that are what we call
02:29 they're in like mio the middle earth
02:31 orbit there's leo mio and geo okay
02:33 if you have kids maybe you name him that
02:40 lowest ortho middle earth orbit and uh
02:44 geo orbit okay so the the geosynchronous
02:47 satellites are are like middle orbit
02:50 that is far enough away from earth's
02:54 for them to have a difference a
02:56 measurably different space-time
03:02 so that their clocks tick faster than
03:05 our clocks on earth's surface
03:07 because they're farther away
03:09 and so remember i said the the more
03:12 intense the gravitational gravitation
03:13 slower the slower time ticket so they're
03:15 farther away their time ticks faster
03:20 wow but we get precise timings from
03:24 geosynchronous satellites
03:27 so how does this work
03:32 the time signal from the gps satellites
03:35 to compensate for einstein's general
03:38 theory of relativity so that by the time
03:40 the time reaches us where it's been
03:42 properly corrected and it matters to us
03:45 and our space-time continuum not the one
03:48 that's in middle-earth orbit oh my
03:52 so gps couldn't work as accurately as it
03:54 does however wait a minute what i'm
03:58 you would have to have
04:02 in order to pre-correct something
04:06 you know the rate at which its time is
04:08 speeding up because you can calculate
04:12 what the gravitational field is up there
04:14 there you go there you go okay okay and
04:16 once you calculate that then you do and
04:18 you say oh my gosh we the the the
04:20 formula works einstein was right
04:23 right right this is not just something
04:25 on a few high theory but hypothesize
04:28 that may or may not be true it is true i
04:31 just want to be there when that phrase
04:34 is uttered oh my god
04:42 yeah these aren't just cult heroes that
04:44 we wish they were right right these are
04:46 real this is real okay this is the real
04:48 universe we're talking about here okay
04:51 let's keep going faster and faster let's
04:53 go half the speed of light three
04:55 quarters of speed 90 the speed of light
04:58 99 the speed of light time is ticking
05:01 slower and slower and slower
05:03 for you you will watch the whole future
05:06 history of the universe
05:08 unfold in front of your eyes
05:11 as fractions of a second go by for you
05:14 as you go 99 there's a formula for this
05:16 of course but 99 99.9 99.99
05:21 the speed of light because you're the
05:23 observer of that but for you
05:26 your time has slowed to the point
05:29 where as you observe
05:31 the things that are not
05:33 moving at the speed of light
05:37 speeding correctly you see them unfold
05:40 correct boom correct that is insane so
05:43 now watch oh my god wait no watch okay
05:49 i didn't even get to the part where i
05:52 okay that's what happens by the way by
05:57 there are particles that decay you've
05:59 heard of like radioactivity right yes
06:01 yes one part it decays and becomes
06:02 another point it releases the often
06:05 deadly energy yes okay radioactivity all
06:07 right some particles let's take for
06:16 one of these uh decays in like six
06:18 minutes when it's left out in the in the
06:20 wild okay when it's not part of an atom
06:22 okay when it's not in captivity i forgot
06:25 which of these it doesn't matter for my
06:26 example decay isn't like six minutes
06:30 what happens if you take that particle
06:32 and speed it up in a particle
06:35 so you take a a a community of these
06:37 particles speed them up
06:39 calculate wait a minute the internal
06:41 wrist watch on these clocks says they
06:44 should live longer and sure enough
06:46 their decay time takes longer wow
06:49 that's oh my god yes yes oh wow yes and
06:54 that becomes that becomes living proof
06:56 of what einstein said yes because we
06:58 can't go half the speed of light right
07:00 you can accelerate a particle to do that
07:02 yeah it's an internal built-in clock
07:04 that decays after a certain amount of
07:05 time and there they are taking longer to
07:07 decay in the exact amount that einstein
07:10 predicts that's genius so we don't make
07:13 this stuff up okay it yes it is genius
07:16 it's like triple genius all right
07:18 now let's take this to an extreme
07:23 right let's go so fast
07:26 that we're going the speed of light
07:29 right well we can't do that because
07:31 we're made of material substance and
07:32 that's there's no way to do that but
07:34 there are things that travel at the
07:36 speed of light and what is that
07:39 those would be photons yes
07:49 what travels at the speed of light light
07:50 does yeah okay i was about to say light
07:59 the clock would never tick
08:04 which means when i go to a mountaintop
08:07 as i did in graduate school
08:10 to observe the center of the milky way
08:16 that emitted their light 30 000 years
08:20 ago traveling through the gaps of
08:22 interstellar space and they moved
08:25 through space come through earth's
08:27 atmosphere they come down into the
08:29 telescope they reflect go back to my
08:31 detector and land on my ccd chip
08:36 that photon when it was born
08:40 at the star that emitted it
08:45 was detected at my telescope
08:48 in the same instant
08:52 according to the photon itself
08:59 knowledge of that trip
09:01 right because time did not exist for it
09:05 oh that's great and i'm saddened that's
09:08 many of these photons like hit people's
09:10 tanning on the beach you know and and to
09:13 how they're imagining 30 000 years and
09:15 land on someone's buttocks
09:18 with the telescope i collected i'm now
09:20 decoding the nature of the universe not
09:22 and some photons go right on by earth
09:24 and are still moving but they have no
09:26 internal time clock
09:30 and they're just traveling through like
09:31 i hope when i'm born i hit a telescope
09:33 bam you're you're born a telescope
09:39 yeah yeah that would be an interesting
09:41 but when i what i want to be when i grow
09:42 up or you know or the instant i am
09:45 admitted where am i going to be where i
09:47 like to be right right right and so just
09:50 the idea that light can move across the
09:52 universe and have no
09:55 uh and not age this is a fascinating
09:59 wow so yeah that is that is more than
10:02 fascinating yeah yeah i mean that's
10:04 mind-boggling yeah yeah so that is light
10:06 the age of light it's like it doesn't
10:07 age at all i am convinced that all of
10:10 you guys secretly micro dose and smoke
10:15 i'm just that's another
10:21 all right chuck we're calling it quits
10:22 there all right all right mysteries of
10:25 light and time uh neil degrasse tyson
10:28 here keep looking out
