Neil deGrasse Tyson Explains Time Dilation
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- čas přidán 10. 05. 2024
- Is time relative? On this explainer, Neil deGrasse Tyson and comic co-host Chuck Nice explore facts about Einstein’s theory of relativity that keep them up at night. Does time always move at the same rate?
Discover fascinating properties of the fabric of space and time. Is it true that the faster you move, the slower time ticks for you? What other variables affect the passage of time? Find out about the passage of time on objects orbiting Earth and how we compensate for that here on the surface. Does time dilation affect satellites? What is time like for an object traveling at the speed of light?
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Science meets pop culture on StarTalk! Astrophysicist & Hayden Planetarium director Neil deGrasse Tyson, his comic co-hosts, guest celebrities & scientists discuss astronomy, physics, and everything else about life in the universe. Keep Looking Up!
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0:00 - Introduction
0:27 - Neil deGrasse Tyson explains Relativity
2:16 - GPS satellites run on different time...
4:51 - How time moves at 99% the speed of light
5:55 - How particles decay in an accelerator
7:19 - Time at the perspective of a photon
10:21 - Outro - Věda a technologie
"If you can't explain it simply, you don't understand it well enough."
Neil does it effortlessly. Amazing video.
Well, either that or your language skills aren't very good.
You call that explaining it simply?
I mean granted he broke it down pretty good anyone here watching this I think is a niche audience and is probably able understand it a bit better tho. But I'd say even this breakdown is far from simple for everyday folk.
@@satisfiedcustomer yes and no. it is for a specific audience but he broke it down in simple terms RELATIVE to that audience. you could even say to anybody with his particle accelerator example that the faster u go approaching the speed of light the slower your time is relative to others
Time is LOCAL.
That was explained very poorly.
To me, the craziest thing about this is how Einstein conceptualized these theories in his time. I wonder how much different things would be today if he had never lived and we had to wait 50 years for someone to come up with these in say the 1950's or 1960's. Einstein is the GOAT in science without a doubt.
Its really crazy how much stuff he predicted so long before it could be physically proven
It's actually easy. If you use the Pythagorean theorem and compare two reference frames, and then allow the speed of light to be constant, you get time dilation. Einstein didn't even invent this, but Fitzgerald and Lorentz did.
What Einstein did was to have the courage to see how this could affect everything - nobody wanted to go there or think about the implications. In fact, they used all their energy to come up with some alternative explanation that did not seem so insane.
cough isaac newton cough
Maybe today he would just be playing videogames...
It helped a lot that he wasn’t scrolling through CZcams comment threads.
What? Oh! Oops!
I said this to a friend some years ago. On a hypothetical world moving much faster than we are through the universe, if they were to look at us through a telescope, they would see the whole of human existence has already passed by. On a hypothetical world moving more slowly, it hasn't even begun.
If you take that concept and stretch it out, you see that because of the way time works in our universe, it preserves a perfect copy of our lives. In a very real sense, each of us has always existed, and always will exist.
so someone x light years away will see us and someone 2x light years away would see our ancestors this is amazing to think about
light emitted preserves our image throughout space n time
u dont even need a hypothetical world moving faster than us u just need them to be at a greater distance
@@chunkyboi4526🤯🤯🤯
These two need a show. A REAL show like late night.. Absolutely insane. And this is why I love science..
No matter how many times I hear this explanation I still can't wrap my brain around it.
The closer to the speed of light an object moves, the slower it appears to be moving through time (aging) to outside observers... and the faster the outside observers seem to be moving through time (aging) to that object. Another way to look at this, if you looked through the window of a spaceship moving near the speed of light, the outside universe would seem to be moving on fast-forward like a VCR. And if outside observers through a telescope peered into the window of that space ship, you would appear to moving in slow motion.
Now light (photons) move AT the speed of light, so to outside observers photons are frozen in time. They don't age, they are the same age the moment they were created as when they have traveled 1 billion light years. And from the photons' perspective, the universe moves through time at infinite speed, so in the instant the photon is created and then destroyed, the universe ages instantly. A photon created shortly after the Big Bang and flung into deep space experiences the birth and death of the Universe in the same instant.
Basically, photons are outside of time, time doesn't seem to apply to them in any meaningful way.
whats about the heartbeats? Does that remains same?
@@sleepwith4098 From the perspective of outside observers the heart would beat in slow motion, the heart beats of outside observers would seem faster.
Great!!! It's not just me. I start off paying close attention to every word and detail. About 4 minutes in and I'm lost.
Okay, I've heard that explanation umteen tumes before. Still no aha moment.
Chuck Nice is smarter than all of us think he is. He really understands and questions things we wouldn't. I love it
I think he is smart so that must mean I am not part of all of us! 🤔
He’s annoying and ruins the videos
Deadass … he is keeping up with the convo meanwhile idk wtf they even talking about i keep having to rewind it lol
czcams.com/video/1BCkSYQ0NRQ/video.html
Chuck's a beast
I consider myself to be smarter than the average bloke, but I am constantly impressed by Chuck’s lines of questioning AND his snappy comedical quips. His contribution is what makes the format of Star Talk so succesful. Fascinating and entertaining at once!
There is no real "dumb" person actually. There is no smart or smarter imo. Personally i think we all live in our own world and we try to express that with own views.
@@semiramisubw4864 LMAO
@@semiramisubw4864uhhh ok… get em son
I think both Neil and Chuck together....
Oh and btw its alr been proven that people can be genetically smarter than others and you can also inherit the intelligence from say for example your dad.
I understand why Flash sees things in slow motion
A good example of time traveled, to him it's very slow, to everyone and everything, he is fast. A prime example for traveling in space but not as much on earth
I remember as a teenager learning that time travel is definitely possible, but only going forward in time. It's just a one way trip. Gives new meaning to "I'll hit you into next week".
It also boggles the mind that if a photon has no time, then a light-year really is extremely large.
large ?
@@geog26 you know what he meant.
Only those that don't hit a telescope are extremely large hence relativity
Yah well 9.5 trillion kilometers. Extremely large. Wanna know what's even larger? A 105,700 lightyears. That's the diametre of our galaxy, The Milky Way. So theoretically speaking, a photon born at one point on the edge of our galaxy would take 105,700 years to reach the opposite point, while travelling 9.5 trillion kilometres/5.9 trillion miles per year. Gives you a headache just trying to fathom the vast expanse of just our own galaxy doesn't it? We're nothing in front of it. Then there are 200 billion galaxies and that too is limited to the spectrum of what we call the observable universe.
I didn't understand the correlation there between Photon not experiencing time and then light year becoming extremely large. Hypothetically a spaceship is travelling at the speed of light from our perspective we can see its travel albeit very fast but still observable for us.. but from the perspective of traveler in the spaceship he would not experience the travel itself and from Point A to Point B as soon as he starts he would reach his destination and time would not pass from him between the two points so basically for him he teleported there maybe would not have aged in his travel but for us we saw him moving from Point A to Point B that's what I understood here.
really cool to see chuck’s aha moments, and the depth of his questions. Thanks chuck for translating for us!
Learning is actually really cool.
@@StarTalk yeah it is, my 6 year old daughter is learning that everyday:)
You know Chuck meant business with the fewer than average quips in between.
Yes. I was thinking the same.
Chuck loves the subject as much as us watching and does a brilliant job of translating (as you said) and saying the genuine "wows" as we are. 👍
I really enjoyed this. He's genuinely intrigued, as am I.
I feel so privileged to be able to enjoy the ramblings of our greatest minds at any time. TY Universe, Chuck, and Neil.
Agree!
But thought time slows down the faster you go
Mind blowing stuff. I recently watched "Interstellar" and so many references are made to Einstein's theories such as time dilation and gravitational effects. Great film!
more mind blowing facts:
Let's consider the hypothetical journey to the Alpha Centauri star system, which is located 4.3 light-years away from Earth. If time is measured in years and distances in light-years, then the unit acceleration (a) = 1 light-year/year², is close to the acceleration due to gravity and approximately equals to 9.5 m/s². Let's assume that the spacecraft accelerates with unit acceleration for half of the journey and decelerates with the same acceleration for the second half. Then the spacecraft turns around and repeats the acceleration and deceleration stages. In this scenario, the flight time in the Earth's reference frame will be approximately 12 years, while on board the ship, it will be 7.3 years according to the ship's clocks. The maximum velocity of the ship will reach 0.95 of the speed of light.
In 40 years of proper time, such a spacecraft will reach the center of the Galaxy, and in 59 years of proper time, a spacecraft with unit acceleration potentially can make a journey (returning to Earth) to the Andromeda galaxy, which is 2.5 million light-years away. On Earth, during the duration of this flight, approximately 5 million years will pass. By developing twice the acceleration (which a trained person can adapt to under certain conditions and with the use of certain adaptations, such as hibernation), one can even consider an expedition to the visible edge of the Universe (approximately 14 billion light-years), which would take astronauts about 50 years. However, upon returning from such an expedition (28 billion years according to Earth's clocks), the participants risk not finding alive not only Earth and the Sun but even our Galaxy. Based on these calculations, in order for astronauts to avoid future shock upon returning to Earth, a reasonable radius of accessibility for interstellar expeditions with a return should not exceed a few tens of light-years unless, of course, fundamentally new physical principles of space-time travel are discovered. However, the discovery of numerous exoplanets gives reason to believe that planetary systems are found around a sufficiently large fraction of stars, so astronauts will have plenty to explore within this radius (for example, the planetary systems of Epsilon Eridani and Gliese 581).
One point in this film interests me. It is known that when approaching a black hole, time slows down (for an external observer), but when crossing the event horizon, time stops altogether (for an external observer). The question is: how was the main character able to cross the horizon of events? After all, for any external observers this moment will happen in the infinitely distant future. That is, when it crosses the event horizon, by this time an infinitely large amount of time will have passed outside the black hole, and the universe surrounding the black hole will have long since perished.
@@NamemaNSl so, you're not bothered by the fact that after crossing the event horizon he sees the freakin bookshelves in his daughter's room, but you're bothered by the lack of sufficient time dilation for an external observer?
@@NamemaNSl I'd say this is where the "Fiction" part of Science-fiction comes in...
@@IamGroot786 In fact, this question interests me even without reference to the film. How can black holes grow if the lifetime of the universe is not enough for anything to cross the event horizon? It seems that it is believed that the event horizon still intersects in a relatively short period of time from the point of view of an external observer, but I have never seen an explanation for this.
After seeing how much Chuck figured out and understood on his own, it's starting to look like he should be in line for an honorary degree! He has had the best teacher... it was really fun watching Chuck realize he knew what was going on and paraphrasing/explaining with glee. This was fun to watch.
...absolutely - couldn't agree more.
He's become such a well educated dude.
Calm down. Intelligent people exist, don't be surprised and threatened by them.
Chuck always impresses me
His "live fast die young" was perfect. 😂
If you spend ** hours with Neil you should just get one …
Even though science wasn't my thing in college, Neil breaks this down in a way that I can understand. Mind successfully blown.
©€€° J™udah D™avid ®€€°
On other topics, Neil DeGrass Tyson is a scientific sellout and should not be taken seriously. He has lied on several counts and pushed SCIENTISM (the abuse of science for the sake of pushing a narrative) for his own political gain in certain arenas. Buyer beware.
Thats like not being able to count and hiring someone else to do your books. How would you know if you are not being cheated out of money? You won't because you can't count. Taking something at face value is just the same.
Imagine having a teacher like Neil for all of your school and university stages.
I would’ve probably graduated
I would then believe there are 500 genders.
Why is that ? @@porterwake3898
All the people who made it in life, became their own Neil to teach themselves. All the losers like you blamed not having a good teacher.
One major problem is, teachers that WOULD be like NDT can’t be like him because their class sizes are too big for individual attention as kids need, as well as overwhelmed with the amount of work and not enough resources. 😢
I am always obsessed with space and future tech type concepts. Time Dilation has been something I could never really grasp much until this video. Explaining how the photon from 30,000 years ago doesn't experience any time itself made so much sense, it's a good comparison to show why people experience less time when traveling near that speed.
"The photon has no knowledge of that trip." I can never un-hear that. Now, I too will lay awake, staring at the ceiling... knowing the light from my neighbors porch light, the light from the moon, the light from Saturn, the light from the center of the Milky Way and the light from the edge of the known universe all reach my eye in exactly the same amount of time (relatively speaking from the photon's perspective)...
Wait until you hear about Feynman's work. It's perfectly possible for subatomic particles to travel back in time. Happens all the time in fact.
Sounds/seems almost spiritual in nature
@@Y_M1967 From a spiritual perspective, it would seem this description of travel from the photon's perspective (timelessness) seems like the closest scientifically observable thing we can compare to the nature of God. I mean if all the photons in the universe collectively travel throughout the universe instantly (at least from their own perspective) then they are basically omnipresent which has always been one of the key attributes of God.
@@skyhawk_4526 omnipresence was not always attributed to god(s). Even within christianity: according to the bible, god only knew that Adam and Eve ate the fruit when he saw that they were covered.
Also, humans are sentient, and god has always been attributed sentience. This, among other attributes of god shared with humans, means that we're the closest thing to gods (which makes sense, considering we made it up).
How did the explanation of the travel of a photon turn into commentary about spirituality and god? That makes no sense to me. People's opinions about spirituality and implying them in science boggles my mind
I’ve honestly never wondered if light aged,or not. But finding that out that it does not,is a mindblower.
Apparently it has a pretty short life span once it stops woving fast enough to freeze in time, hence turning out a light in a room and it going dark right away. A photon is literally an instant frozen in time, never succumbing to its extremely short lifespan
then how come the light from a star goes out or it dies and turns into a super nova?
@@cocolove9916 that’s because the star runs out of fuel
@@aaronmiranda1312 is there a reason behind why ?
if the photon does not age then how come it stretches?
thank you Dr Neil and Mr Chuck,
Im a huge fan of science and you by far are my favorite Astro Physicist! I love learning. Thank you for your contributions in science
‘Time Trap’ is an underrated movie with a nice plot based on time dilation.
Even though I understand time dilation, it still blows my mind every time.
Yeah it's completely counterintuitive.
Sounds like something a lot of kooks talk about in a psych ward.
It's actually impossible to understand.
The faster you try to understand it, the slower your mind travels until it stops completely.
@@valueofnothing2487 haha!
@JFQ uhmm not really
This is the first explanation of this theory that I actually now can comprehend the "relative" part. Thank you Startalk.
Love these videos as these extremely complicated topics are made understandable ! Thank You for Posting 🙂
@@StellarFacts12 ok buddy
@@StellarFacts12 ok😭lmaoooo
Thankyou for the explanation. After two years of watching CZcams on time travel, now I understand.
Stunning. I had read about this so many times, but I hadn't realized that light is, indeed, eternal. Thanks Neil and Chuck.
Doesnt look too eternal when i hit the light switch and the room goes dark lol
"Light is eternal"
Blackhole/dark spots on the universe: "Are you sure about that?"
Same realization lol
Lets say I have the whole universe in a snowball and I am some giant being observing. One person in the snowball is wizzing around at the speed of light, the other is stood still. Both have watches on, then the one who was wizzing around stops. Why would their watches then be different? Because it moved? Does not make sense to me and I'm trying.
@@mattball420 We dont know if light disappears when they get soaked in actually. It could actually live on.
OMG! Einstein was right! 😱
.
.
Love you guys, can't tell you enough how grateful I am for making content like this accessible and comprehensible for all ❤️
I wish I had this in school.
Yea 😐in fact think about it what do you remember before you were born you don’t remember anything 😐you could have had a life before but you were dead for a very very long time in fact when you die you go to the same place as if you were not born 😐and eventually you will loose track of time it’s self 😳in fact we could be somewhat repeating our lives and we don’t even realize it 😳after all how would we know earth would form? How would we know it will happen ?we don’t 😐live is very strange 🤔
Nuc med tech here. Love that I knew most of this, but you explain it so well that my mind is reconfiguring how I look at my surroundings!
I am so late to this series but so excited to get started in it
The duo of Neil and Chuck is perfectly matched. I love to learn these concepts in such an easy way!
How long can a can phone reach
@@ericparrish1515 Their maximum range was very limited, but hundreds of technical innovations (resulting in about 300 patents) increased their range to approximately 0.5 miles (800 m), or more under ideal conditions.
Chuck is kinda annoying tbh
These two need a show. A REAL show like late night.
Thank you for explaining it so well
Amazing democratisation or vulgarisation of knowledge. Well done sir 🙂
thanks 1000 times.
Man my brain got a workout following along. Unbelievable the knowledge built over years. Thank you so much for simplifying it for the rest of us to follow along 🙂
T=0 for the photon the entire distance travelled towards earth from its frame of reference earth is travelling towards the photon at light speed but hits earth at present time?
That was fascinating! Keep up the good work guys❤
Wow, that's just mind boggling.. I just found this channel and it's like I can't get enough.. love the knowledge that you have and thank you for sharing it with us!
I have a lot of admiration for Chuck's comprehension and quick articulation of scientific knowledge. I believe if he had the opportunity to pursue physics he could have been very good at it and probably a brilliant educator.
This is really wonderful. Thank you for explaining the concept of time in this way.
This is the most fun Science Show out there! It's a wonderful show to have middle-schoolers & perhaps High Schoolers watch as part of their curriculum, to first engage them via the curiosity aspect, but keep them via the entertaining manner it's presented. Wonderful segment, wonderful duo Neil & Chuck !
If I’d had this presentation in school, I may have had a clue, and possibly an interest, rather than staying confused entirely in the weeds, and memorizing instantly-forgotten random facts. At 60 now, I’m finally having fun learning some science!
Watching this reminded me of a poem I wrote about art two years ago.
How the light would long to die in consciousness..
Art!
Yes, it's just seven notes,
There's just so many songs!
To think that all of it will be sung,
Not tomorrow, but one day!
Surely, quite a few are sung away by now.
Maybe in the cosmos's formative years,
As we all crushed, smashed into each other,
We sang like the tap of rain drops on a metal roof, aloud, with none listening,
For they weren't carried through to infinity.
Or in ours, when we gurgled in the fluids,
Inside the soft embrace of her tissues,
Listening to her heartbeat infused with the sound of her laughter.
A song of life, of birth, that was lost right as it was sung,
Maybe locked away somewhere in our primitive cerebral corner; a tragedy!
There's also a song sung in absolute solitude,
Possibly left for dead, tinged in pain and loneliness,
Unheard, never to be sung again.
And a song that could resuscitate the fallen; forgotten.
There's a song that evolved over time,
Its artistry distinctly pointed out,
Revitalised as it was sung over and over,
Mothering other forms of art.
And one that devolved,
A poem washed into abysmal wails; intense!
Maybe some songs are meant to be sung once,
Just once!
What ecstacy would the universe vibrate in, in that brief moment it plays,
Brimmed in the awareness that it would never replay in its long long existence.
Imagine how each song would long to fall into a human ear,
Just to be remembered and resung,
For as much as we deny divine things aren't "human",
There's this inherent will in nature to live on, and that's beautiful!
Just like the photons cooked in the core of a star would long,
To fall into "your" eye.
After making it through the quantum tunnel over millions of years,
To die in consciousness!
Embrace them, embrace them all!
For only the likes of you can
Poem inspired by music: Max Richter "Written on the sky"
Dated: Oct 26 2021
So proud of Chuck he learned so much.
I love this man. His Charisma and enthusiasm is just so astoundingly entertaining and hilarious, and at the same time compelling and fascinating.
This was the best episode I’ve seen from you guys ever in time!
Chuck tries a bit too hard to unlearn what he learned from Neil over the last couple of years to act surprised. I think it's time for Chuck to graduate from the Tyson Academy and become an equal conversation partner!
When I was doing network engineering and we need to sync the routers clocks with satellite clock, nearly monthly we'd loose a few thousands of a millisecond. If you ignore it too, much after a year the router clock would be off by at least 20mins.
Great talk & subject as always
I look forward to the days when i get to listen to you guys
Me too
Love these episodes! I always love to get a different spin on things I know (or learn about things i don’t). Never considered that time means nothing to a photon…
I love the way this stuff is explained to make it understandable. Thanks Neil.
Amazing .. thank you Neil and chuck !!! My mind is officially blown 😀
Neil blows my fing mind every time I see something by him.
On other topics, Neil DeGrass Tyson is a scientific sellout and should not be taken seriously. He has lied on several counts and pushed SCIENTISM (the abuse of science for the sake of pushing a narrative) for his own political gain in certain arenas. Buyer beware.
How you met your lover?
No kidding. So true.
neil is a big dummy dumb dumb
Same.
This is actually an observable phenomenon. It's use case is understood in machining on machines like mills and lathes. The easiest place to observe it is with an analog clock that has a second hand. The outer most tip of the hand moves faster according to its relative position in relation the axle it sits on. The relative notion here is because the whole hand moves at the same time but the outer most tip has to travel a further distance over that one second. The force generated on the tip is also heavier as a result. Essential it can be used to think of gravity in relation to time. It's not that a clock will tick faster for you or slower for you the faster you move. The tip of the clock is not transcending the passage of a second relative to the axle and the gears that push it along. The moment of that second is the same. For everyone. The passage of time relative to 2 people, one driving and one walking. The one driving will get to the end of the block fast than the one walking though the arrival of 2 o clock is the same for both. Just as the direction of that second hand's tip and center pointing to 12's arrival happens in the same moment
Man, for the longest time, I was asking myself what the gravitational pull of a planet has to do with time dilation and you finally answered it for me. I was watching every video on this search and not one mentioned a planet's gravitational pull. I'm telling myself, there has to be more to this story. Then bam! Out of nowhere, you began to explain that it wasn't until ten years later it was formulated that the stronger the planet's gravitational pull the slower time tics. Thanks for clearing that up for me and now I'm left wondering why this isn't mentioned more in any of the other videos. Go figure!
Neil? You blow my mind and stir my Soul! Thank you!!!
I LOVE your videos! I wish I would have started watching them a long time ago. I guess it’s never too late to take a new path.
I love these short explainers, and Chuck is brilliant
You guys make me smile. Such passion.
I love watching these because it gives my mind a little twist every now and then.
I love watching Neil and Chuck. Such a great duo! Thank you for making these videos!
I had to watch this 3 times to get it. Thanks
Legendary podcast by tyson
Just LOVE Neil’s passion!
Love your humor and incredible smarts!
Love watching this and knowing I knew some of this before, only to remember that I learned it from him growing up and now still learning the se things but more details
man, this was a trip. Loved every second. Now I am gonna hit the spliff again
I just discovered this channel and I'm a bit surprised. When being interviewed he comes across as so unpleasant, talking over his interviewer to the point of extreme rudeness, but here he comes across as more conversational and respectful of the person he's speaking with. In other words, it's a give-and-take, as it should be. I've seen so many interviews where he's positively insufferable. It's nice to be able to listen to him nowadays without that distraction.
This concept (photons experiencing their life history simultaneously) has fascinated me for 50 years. It makes one view the double slit experiment and in particular the delayed choice variants “in a different light” :-)
The fact is that BTC symbolises the future of cryptocurrency, and traders are wondering if now is the best moment to trade, I feel you should examine the situation more closely before jumping to any conclusion. BTC's price has been fluctuating over the previous days, signaling that the market has become unstable and that is it impossible to anticipate whether it will go bearish or bullish. Others are patient, while others continue to trade with no risk. It all depends on the pattern you're trading and the source of your signal;
Great video, I feel the same about surf and travel.
There is no time,there is no past no future only Endless now .
Love this man! He has taught me SO much about the universe
I would like to see a longer explainer on this topic. I'm pretty sure Dr. Neil has even more facts in his mind. I love it!!! And also who doesn't love Chuck reactions?:D You always make me laugh and I'm not even native english speaker.
Excuse me, that's Dr Neil and Lord Nice to you (and all of us).
Fixed, i'm so sorry. Didn't wanna disrespect doctor Neil deGrasse Tyson and Lord Chuck Nice.
Thank you so much, sir. Very informative.
There is a ‘Present’ that is everywhere at once. Right now it is the Present. But if I wait a few seconds it is still the Present. And if I wait a Thousand Years, it’s still the Present. What divides the Past & Present yet retains so interconnected?
Once upon a time I’ll pass on to the next
For as soon as I am here I’ve left.
However this is merely how you perceive.
For I never really change and yet still continue to weave.
I am reminded of that old poem from long ago:
“Has it ever struck you that life is all memory, except for the one present moment that goes by you so quick you hardly catch it going?”
Tennessee Williams
That Was An Amazing Topic
When I was a kid, This guy had a loud stereo in his car, When he came into hearing range, the sound was distorted, but got clearer the closer he came to our position. Then as he moved away from us, his sound, again went distorted. So I said to myself, that the speed of sound, or the time it took for that sound to reach my ears, changed according to the cars speed. That was my first scientific breakthrough. Science is badass!
The muffle isn't caused by any change in the speed of sound, or the time taken for the sound to reach you. It is because of an inverse square law due to the wave-like nature of sound (so it spreads out over an area that has the same curvature as the surface of a sphere). If you're referring to a change in pitch, that is caused by a relative frequency change of said sound, measured by an observer (which indeed is a direct consequence of the distance of the sound source changing relative to you). If the source moves towards the observer, the frequency (pitch) increases; vice versa for a source moving away from the observer.
Imagine someone honks their (stationary) car horn for 10 seconds at a distance of 100m away. Say we get z complete cycles of the sound wave in that time.
Now assume the same car is travelling towards you at 10m/s, also honking its horn for 10s. As the amount of time is the same, and it's the same horn, you must also observe z complete cycles (oscillations) of the sound (the speed of the sound wave does not change).
But as the distance to you is decreasing, then that must mean that the frequency of the oscillations must have increased, as the horn has honked for 10 seconds so the number of oscillations remains the same as earlier (also note that as the frequency increases, the wavelength decreases). Its this increase in frequency that you hear as the higher pitch, and vice versa, as the source passes you and moves away. That is the Doppler Effect.
@@blueboy189 Well, as the car comes closer, in motion, the speed sound, although constant, does change because the car speeding up and slowing down. The only way that it wouldn't, is if I were moving at the same speed as the car. Don't you just love this?
I've been a fan for years and have bought all your books. I don't know if this is the episode where you cover GPS but one of the things I love about what's necessary for accuracy is the combination of general relativity to account for the satellites being farther from earth's gravity and special relativity because they're traveling so fast, so the adjustment has to be both backward and forward.
Agreed. I am a civil land surveyor and I use a GPS unit almost daily. It's very cool to hear something That corresponds with the work I do and how it interacts
my conclusion on everything I've learned on quantum/relativity over the years: If you don't get it, that means you get it. The math points at their implications, but our minds halt at comprehending/visualizing "how."
So, for interstellar travel, the further away from gravitational bodies the astronauts go, the faster they age. But the faster they go the slower they age. And as they pass by massive bodies, their clocks slow down again. So the rate that they age will depend on the route and their speed. I suppose if you know the route, you could calculate the average rate of aging. Not me however.
Omg, I'm binge watching this right now. I always failed and hated science, but no one explained it this way. If they did, I would probably choose the path of science. I can't put it into words how much I love Star Talk!!¡!
StarTalk keeps me sane in an otherwise crazy world; I appreciate you guys!
Times slows down when one:
(1) Moves near the speed of light.
(2) Gets towards strong gravitational field strengths.
Now this thing is keeping me awake at night
How I love Neil and Chuck describing science!
6:16 The neutron is the one decays when it's freed from an atomic nucleus. Has a half life of about 10 or so minutes before splitting into a proton, electron, and antineutrino (this is called Beta decay).
I was looking for the exact term over the internet and indeed it seemed to be the neutron with a different lifetime than the one indicated in the video. Thanks for confirming it!
perfekt ! thank you
God bless this man, his last covid video had me on point talking to my kids pediatrician 👍🏾🙌🏿
@StarTalk by far my favorite episode, I always knew that photons didn’t experience time but I was awestruck when you put it from the perspective of the photon itself. The underlying beauty of our universe is poetic.
Maybe the best video I have ever exspierenced
Entertaining and informative
Imagine that we proved that we live in an infinite cyclic universe. If we one day sent a being the speed of light, (assuming they could live through big crunches and bangs) what they would experience. they would simultaneousely go through every single possibility, every timeline, and all that could be. all possibilites at once, all within the smallest possible timeframe.
*mindblow*
Or, if they could travel faster than light, they could theoretically travel back in time. Imagine a society where said person (or group) could witness what you've described but then speed up and return back with this knowledge to the instant they left.
Crazy to imaging that, that is the perspective of parts of the universe. Although not living, parts of space are experiencing that acceleration, therefore skipping through our perspective of history in less time than we can imagine
They wouldn’t experience anything, because no time would pass for them.
They would only experience anything once they decelerated back below lightspeed. While at lightspeed, they would have no experience because no time passes.
An individual might see some cool things at near lightspeed, but at lightspeed, they wouldn't be able to perceive a thing. Even at near lightspeed, things would probably happen too quickly around them to make any sense of it (like watching a movie at 10000x speed).
Whoooshhhh!!!!!! This all went over my head but not sure faster or slower. I am glad you explained all this that I didn't understand. I guess I need to go back in time relative to now and watch this video again while the current time moves on. As we say, it is all relative. Have a great day whatever time you are traveling at.
Keeping in mind all the endless possibilities/phenomena in our universe, I wonder if there’s something even faster than the speed of light? How fascinating!
I believe something similar applies to thought process, the faster you think the slower time seems to pass.
Chuck is amazing. He truly loves learning and I love it when he gets quiz and surprises Tyson with correct answers.
no he just says wow to everything
You're doing great Chuck. Love his humor. Both of you're great.
My first trip on l S D this come up and it keep being there during my travels I never thought about that in the past, I also was taken to the moment when I was born and have flashbacks that I completely forgot about.
Never had a video where I had to go back 10 seconds every 10 seconds to grasp what he’s saying and enjoyed every bit of it.
Same
Every time I watch these episodes, I come out with more questions than answers. I teach science and love to learn what they talk about.
Seems like that's how most things work with science. I hope you're a fun teacher that does experiments and makes learning fun rather then a strict teacher that just hands out home work. Seems most science teachers in my experience are pretty cool.
Dr Tyson, I just had a thought about the photons being at their creation and observation at the same "relative" time. It's probably a dumb question, but I'm far from being a physicist.
What if, somehow, two separate observers are able to see the same photon at the same time, but at different locations? Since that photon of light is arriving at their "eyes" at the same time, does that mean that photons can be omnipresent?
Neil is so entertaining to listen to....and Chuck is funny. Good duo.
I always learned something new every time I watch Neil's videos. Thank you, Neil. Love from India, Pune.
I can listen to Neil all day talk about everything apropos of astronomy and astrophysics. Time Dilation really fascinates me. It boggles my mind, you could, in principle, travel far into the future from everyone else's perspective on Earth (assuming you could travel a substantial fraction of the speed of light or if you could hover above the event horizon of a black hole).