WSU: Special Relativity with Brian Greene
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- Опубліковано 31 тра 2024
- 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 = mc^2.
This is a more in-depth and mathematical version of the WSU Master Class “Space, Time, and Einstein.” • WSU: Space, Time, and ...
#WorldSciU
Watch the class in full or view in segments via the chapter links below.
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
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I love that:
6:08:28
"Space and time conspire, in just the right way, to keep the velocity of light equal to the speed of light (c),"
The one reason I like professor Green's teaching professor Green makes it very understandable.
Brian is without a doubt the most eloquent theoretical physicist on UA-cam. His words are a steady flow that paint a picture in your mind.
He’s a string theorist not an astrophysicist
@@muttleycrew
Yes, technically you're right. But the fields are closely related to one another.
Theoretical physics, astrophysics and cosmology use relativity and quantum mechanics to explain how the Universe was formed and it's current behavior.
At Columbia, Greene is co-director of the university's Institute for Strings, Cosmology, and Astroparticle Physics
Alex Castro a string theorist is a theoretical physicist interested in the foundations of physical law and tracing that back to a single class of theories. An astrophysicist is not so committed to a specific class of theory, being more interested in any physical process as observed in an astronomical setting. The two fields are quite distinct. It’s like saying a physiologist, who does medical research, is the same as a radiologist.
@@muttleycrew
Ok.. Thanks. But I still think we are splitting hairs...
From what I understand, there are debates with some who believe theoretical physics, especially string theory, have become detached from the realities of experimental science and don't accept it as a branch of true science... Things are a little fuzzy.
I'll go with Theoretical Physicist for now....But I'm going to try and send a comment to Brian and ask what title he likes to refer himself with. He has a podcast where you can ask questions...
Alex Castro I would be one of those people who considers string theory deeply troubled. I feel the same about cosmology. And it’s not splitting hairs imo, theoretical physics is a study of what Feynman called the fundamental processes. That’s utterly distinct from all applied physics of which astrophysics is a branch. You can have theoretical astrophysics but this means the application of fundamental processes to develop models of astrophysical processes. What it does not mean is the development of a new theory of fundamental processes
How am I the first person to throw this epic lecture a like???? Well done Brian. I've watched this multiple times over the last few weeks.
You are not. Just there is no counter.
@@gsyamsri8122 of course there isn't. It seems so obvious now. vanity/science
Dr. Greene - I just can’t believe how wonderful a teacher you are! Thank you so much. You have no idea what a difference these lectures make to us.. Thank you.
Brian Greene is among my favorite present-day "pop" scientists. He has a zeal for helping people understand these concepts, and you can tell his own understanding of both the science and the art of teaching evolve thru that process. Genuinely personable, he's never condescending and it feels more like a discussion than a lecture. Bravo.
Simply the best explainer by far margin... it’s a blessing to have him around...
Just can't get enough physics with Brian Greene. All science teachers, especially university level should take his courses. Comprehensible and incredibly interesting. Unlike the college classes many of us were forced to endure. You know what I'm talking about. Thanks Brian and WSU.
I found a copy of Einstein's Relativity at a unsorted goodwill center two years ago. It was steadily opening my mind until I hit Lorentz transformations. I am a punk rocker with a GED. This video is invaluable. So thank you!
Don't bring yourself down, you're as smart as anyone, just takes a great teacher like Brian for us to realize how much we actually love physics lol
You’re amazing.
What edition
I suppose it wasn't as native language though so maybe that doesn't matter if you find a book that you know that everyone likes look at what edition number it is if it's number one then you have a lot of money on your hands
Especially too I would imagine with great scientific minds if you find one of their books that they had first written with misspellings I mean the price would be astronomical people who want that book not to ridicule but to humanize the author
All the examples that are supposed to show that there is no such thing as simultaneous events are all based on simultaneous events. And the results from different POV that do not experience the events as simultaneous are due to the fact that the events were simultaneous. So, we could say that those results from different POV are actually a confirmation of the events being simultaneous.
It's so bad find videos like these late in the night, if you know what I mean... BG does a really great job to make it as entertaining as it is informative. Awesome!!! As always
It took me 3 weeks to watch this. Truly a crowning achievement of our species. Dr. Greene’s ability to effortlessly pour this complex information into palatable bite sized portions is an achievement of its own. Bravo.
Love this so much and it's so counter to the modern day world where the attention span has shrunk to a few minutes and here we have an 11 hour video!! Brilliant, love It!!
B uhh &bbhhuguugh bbhhuguugh && & Hbo b. Bbh be sure bbnb you b b b. Bbn b bbnbb. By all this bbh b b b suo that I don't really By. 7. 7 I in. 7
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keep making these long lectures, they are simply amazing!
This is called happiness 😍
I put this video on right before I started cooking dinner. An hour and a half later , I decided to pause the video so we could eat, and then I realize that this video is 11 and a half hours long. Still, it's great content.
I always believed that teachers influence whether a student will continue to have interest in a subject. Even for students who are intellectually superior, they still need good teachers. What more for me (and for most of us) who are average or slightly above it, who needs teachers who can teach with clarity and simplicity to draw our interests and make learning fun. This is important for a technical (and sometimes abstract) subject such as applied math (as oppose to abstract) where physics, engineering, computer science, etc. belong. I get lost or discouraged when the teacher "talks", but doesn't teach. I'm not surprised that Dr. Greene is one of the best. With a warm, friendly demeanor a smile, a calm voice and not to mention fairly good penmanship and possessing great technical knowledge and skill to teach a subject in Physics, he made me understand (or at least it got clearer for me) the subject of why time is relative.
Thank You! You are a gifted teacher.
Best teacher of science ever, well up there with Feynman 😊
Woah, woah, woah. Let's not go that far. Greene doesn't play the bongos, after all.
23-hour General Relativity master class, when?
i want too
Yes please
Yes Please, we beg you! You are the best! And a thousand thanks for this exceptionally good presentation. And all this knowledge for free! Let's count our blessings, thanks to you, Professor Greene. I hold you in the highest esteem!
Professor Greene: How long would you like the course to be?
Everyone: Yes.
I'm as dumb as dog shit, but I really enjoy listening to Dr Greene 😊
Thank you thousand times to make so easy to comprehed something so much difficult. I’ve really enjoy every minute of the vid.
Brian Greene, you are
a master teacher par
excellence. I bow to the
divinity in you my brother 🦁🔯👑!!!
Thank You so very much.
The duration of this video is no matter whatsoever against the realisation of reality that it offers.
I am literally doing all the mathematics of this video as it goes along.
Thank You Thank You Thank You
This is a gem. Thank you so much Brian.
Thank you, Dr. Greene. You are a master educator. It means a lot to me that you were able to give me an intuition for this subject where reality is so preposterous. Hopefully, gravity has a reasonably simple explanation too, because it seems ridiculous that two distant objects would pull on each other.
Amazing professor. Lucky for us he's out there
This is absolutely brilliant Brian. Thank you for taking the time to do this. thank you so much
Best teacher I've ever come across! Thank you so much Dr Greene!.
Notice that Brian is in the same attire for the whole course which explains how hard working his is and how helpfully he finished the whole course in just a day!
You might be right but most likely is that he is doing what they do on a lot of reality shows on TV which is to wear the same clothes (or look-a-likes) for the entire duration of the episode to make editing and post editing easier. I think it's highly unlikely that he video taped this all in one day. Especially since you can see how the entire video was many, many little lessons strung together.
Thanks for the Upload, I always like stuff like this!
Time does not seem to exist as a constant force or value. But I think, "time" does not exist at all in the way that we normally describe it.
Clocks do not "measure time" clocks measure distance at a certain speed. So regardless if you use the "tic toc" clock (Light clock), or a mechanical clock, the internal works (system) is working in a way that is counting a distance, not (a) time. if you would change the internals of a clock, we know that the dial will go faster, or slower, but it does not mean that "time goes faster of slower".
Therefore, in the "time dilations calculations at light speed", you are not calculating time, you are calculation (obeserved) distance.
I think that that "time" is an effect of motion of a mass, we can calculate when an object will be "where" when we know the direction and the speed. Time is a required characteristic in a 3d space when objects are moving (or actually where they have a mass) it is in essence a part of the directional force of an, (and all) objects.
Philosophical is time only important for "living matter", because for "dead objects" entrophie is more then enough to indicate a state in which an object holds up.
maybe we can see it like this,
If I put a pencil point, on a blanc piece of paper, then nothing happens, only when a directional force is applied, then a line can be seen. If no "force is applied, then "no time for that situation" passes, and nothing will happen.
Only when the pencil tip moves, we allow changes in position of the pencil tip (a change in position), and that requires time, but time only is applicable as long as the tip is moving.
This is what I think, am I close? hahah :)
Best regards, and thanks for the upload again, comments welcome
Can Mr.Greene do another full stack course for string theory? It'll be a great help for us. Thank you.
Tq and Tq WSU and Prof Greene. Someone who is 12 hours away could also learn.
This is an incredible lecture. I love it so much. Thank you!
E = mc2 =bollocks
Thank you, Professor Greene.
The whole thing about getting different results from different points of view reminds me of quantum mechanics where observation can influence a quantum event. Observing a quantum event can change its outcome. And Gracie's stopwatch observation seems to change the length of the train. I would say that the train has a length independent of anyone's POV. The different lengths that Gracie gets from George's measurement, as BG points out, is all about light. The faster the train goes the shorter it gets because the light coming from the rear of the train is closing in on the light coming from the front. The light from the back and the front of the squished taxi is very nearly simultaneous.
I can't believe I am binge-watching this video. The last series I binge-watched was GOT. Brian you are an awesome teacher! Great examples and illustrations. Hats off to you.
Carl Sagan and Brian Greene… True pioneer of Science. They made science understood by common people
this lecture is precious....
Excellent thankyou for this !
Hey Brian, can you do more of such 11 hour lectures on other physics regimes? Like classical physics, electrotomagnetism, thermodynamics, general relativity? Thanks!
Agreed bro he explain so well
ok i will do
@@neutrinos2478 🧐🧐🧐
@@gabbarisback6052 🤔🧐🧐
Nice if he would explain quantum physics.
Thank you 😊
My God, This was an amazing lecture. Thanks for all the hard work this must have needed.
I am at 5 hours and this is brilliant!!!!!
Wow , really amazed the way science moves, this is the difference between the perspective of Einstein and common man.
Thanks alot for such a useful video, revealing the secrets of science.
An amazing and invalyable presentation..)))..
Amazing lecture!! I would like to contribute with a comment in @ 3:17:55 is missing in the denominator C^2, it should be 10^18+C^2
What a wonderful teacher!!! Thank you so much Dr. Greene for making these most useful lectures available for free for general audience. So clear and simple - even a dumb surgeon like my self ( no pun intended, I really know nothing about Physics) can so easily understand what this enigmatic special relativity is all about! Can’t thank you enough.
Watching this for the third time... in a row haha
You got some TIME my guy.
For some reason my eyes did not see that this was an 11 hour lecture and I put it on in the evening before i went to bed, bad idea because i stayed up way to late as he is a very energetic speaker but fell asleep eventually and now Im not sure where i was haha, Time to watch it again I guess lol.
I'm not sure WHAT time is,.... but I sure am grateful for 4:20
🤘😆🤘
Thank you thank you thank you. The multiverse will take care of you. Blessings.
Dr. Greene, your enthusiasm for science is rather contagious. I've always been intrigued by astronomy and the other sciences but when I read your books and listened to your talks, you really made it far more fascinating more than what I previously imagined.
What a treat to watch a marathon session from Dr Greene, can't get enough, big fan! Wish we had more gems like this on YT. #DrBrianGreene, @1:25:50, is it correct to show the times in the two clocks the way you've shown? Since the clocks are in relative motion, either clock can be assumed to be at rest and the displayed values should change depending on the frame from which the two clocks are being observed. Also, @1:57:40, in the time dilation example, I think it's important to highlight that the calculated time elapsed in the spaceship clock IS WRT THE EARTH. How can we claim that the clock in the spaceship recorded lesser time, because this time is supposed to be wrt the earth frame and since the spaceship is moving at a constant velocity, it can never return to earth?
Thank you. ✌
amazing video i enjoyed it for the past whole month sir.BUT AT 10:52:7 I DIDNT GET THE VELOCITY COMBINATION OF Vy=V'y/rVx. How that Vx come to that equation?Can someone explain me?pls
I rechecked the whole video but i stil dont get it
Ha, I have the same question (at10:52:17). I was looking through all of the comments to find if it was already answered. All the examples of velocity-combination seem to be in one dimension (x).
please next lecture on "Quantum Computing"
The idea that units are "random," while mathematically correct, disregards a significant reality: in physics: That the metric system is designed such that a single meter, when multipled by 12/C, gives the volumetric circumference of Earth with 99.997% accuracy. Equally, it then disregards how this scale factor is quite near to a 1 to Phi ratio with plancnatural units (which are not random, but represent the pixelation of the universe in a certain sense), and that light travels 1 planck length per 1 planck time. Given this has implications for information transfer and all physical equations, it becomes apparent that the units themselves are not "random," and do hold certain specifics within the scale at which we have come into existence, which certainly proves that we live within a set of conditions that exhibit relative orbital and energetic stability within our solar system and home planet.
The result at 1:11:01 assumes that the length observed by the stationary observer. tb - tf = vL(c^2-v^2). But this L is not the rest length of the train. L = rest-length/gamma
Exceptional ❤❤❤🎉🎉
#BrianGreen - Hello Professor, my question is this: when we move our clock move at different speeds, since that is the case how am I able to see a moving car while I am standing still? if a car's clocks move slower then mine since I'm standing, shouldn't that car move into another dimension of time or something similar?
Love this
I wonder how much of this is new material by Brian. I'm gonna be busy regardless, I can tell...
I love it!
My dream is also the update on the status of the order and weekend and I believe that I'm going to Costco today and tomorrow.
To the Patience Brain Greene 🙏
3:25:13 it's not so obvious for me so fellow nerds
Where does the velocity of the clock (-v^2) goes?
How does the gamma end up in the denominator with the L when they're in multiplication in the RHS?
Thank you
hello everyone, is the formular at 3h17minute correct? I get to a different result ... thanks !!!
Professor Greene: How long would you like for this physics lecture to last?
Me: Yes.
Dr, Greene - You are freaking incredible. Thanks for taking the time to stretch our mind.
I thought the math version was not free but wow!
Internet lecturer Brian are you in it for the love of the game.
Great stuff m8.
@ 9:27:40 - I can understand that stop and reverse, but what about constant speed in circular motion?
Constant speed in a circular motion also means constant acceleration. In that case the acceleration is used to change the direction of the speed.
As far as I currently understand it conceptually is: if you let two twins move away from each other at nearly the speed of light, each of them can claim the other to have time ticking more slowly along the journey (and therefore be the younger one). Whenever one of them accelerates to get back to the other twin, that acceleration enables him to go back to a frame in which he has constantly been measured. In other words, the twin that has not accelerated has a right to claim that his light-clock was really ticking vertically with respect to the one that has accelerated, because he saw the force/acceleration that was needed to get the other twin back into his frame and he knows he has not been been changing his speed (accelerating) in between.
The circular motion can be understood in the same way: a force is constantly being applied by gravity to a satellite orbiting earth, so that it doesn't fly off into the distance, both the satellite and we know that that force is what keeps it in our reference frame, so we can claim that the satellite is really the one that is moving fast with respect to our time. Suppose gravity would stop attracting the satellite? The satellite would fly off with a constant velocity and would have as much right to claim that earth's time is slower by as much as we see the satellite's time being slower. In fact if we choose to rocket boost the earth to catch up with that satellite, it would have been right about our time really having been slower.
haha...v.good question.Finally someone reason! Already A.einstein in his 1905 got into trouble/conclusion at the end though few verses earlier he argues RIGHTLY on Symmetry! Thie lecture is a total BS (Ball Shit) but I found by accident in his examples a super argument for a physical change of the "rate of a clock" for total conclusion idiocy in almost every textbook also by Deans of Warsaw and Jagiellonian University(Wroblewski,Sokolowski).A.Eisntein finally "smelled" sth wrong before his death but ..still could not resolve it though he rejected the argument "from acceleration" (in R.Schlegel, his friend). M.Sachs tried to correct this BS but he made a little mistake not seeing the mistake of Tolman and C.Moeller (ignoring the equivalence of acceleration and gravity)
Like taking a physics class with a master professor.
How many has seen the whole video??
*I am now seeing the video and seen it till SPACE TIME DIAGRAMS **6:36:34** and I will comment as a reply when I will complete it. By the way, I am typing this comment on 28th December 2020.*
@ 2:10:38 you gave an example of braking symetry, what about starting from the earth surface with 100% light and maintaining that speed in a circle like travel and landing back on the starting spot? Then no symmetry was broken, there was no speed change - what then would happen?
i think there is acceleration involved to keep the motion in circle. centripetal acceleration
Change in direction...
Could someone explain at 10;52 please ? For my understanding the speed of the grenade should never changed unless we consider external force. If we don't consider external factors, speed remains constant. Distant increase, time also increase.
If the grenade is thrown at 5m/s and she runs towards it at 3m/s, from her perspective the grenade isn’t traveling at 5m/s it’s traveling at 8m/s. Her speed, 3m/s plus the grenades speed, 5m/s equals 8m/s. Remember it’s all relative to the viewer’s perspective.
I want mathematical version of this what should I do? Pls tell me
I know it's irrelevant, but after the grenade incident, I don't understand why Gracie is still allowed to hang out with George.
Woah that's 11 hours.
YEP :D
have they sent a message to voyager 2 to see how much time has elapsed on it's internal clock?
What if the light clock is oriented horizontally, how will time dilate?
Its just really got interesting at 2hrs 25m (in my now slice)
Can anyone suggest me a Best book for general theory of relativity
Is this really 11 hours? He stands there talking for 11 hours. Because that’s great
He's doing the speech near a black hole so time is all crazy.
#BrianGReen - can you update me on 1 thing, @ 2:06:10 you talk about 2 ways, A)from Earth to some star, B) From Earth to some star and back, that's fine examples, but what about a ship orbiting earth with speed equal to light speed - what happens then?
How something can be completely subjective if it is a constant? It is contradiction and if someone creates a program, which analyses the language many inconsistencies would rejected without knowledge of physics.
I'm not sure why people don't notice the fact that precisely because of the "twin paradox" the Universe can't be a sphere of a 4-dimensional ball. If it were, then you could leave Earth in a spaceship, maintain a constant velocity and return to Earth without taking any turns. But this would mean the paradox would become a fact. There would be a perfect symmetry of the two observers and hence both could truly claim the clock of the other observer had to be going slower. But that's not possible, of course. I don't know how such a simple fact has escaped the attention of so many physicists until this day... Or am I wrong?
Why would normal clocks slow down when in motion? Wouldn't that only apply to light clocks to due the speed of light being constant?
I don’t know what kind of ships you’ve been on, but you can definitely tell if it’s in motion.
"In May and November, the Earth is moving at "right angles" to the line to Algol. During this time we see minima happening regularly at their 2.867321 day intervals. However, during August, the Earth is rapidly moving towards Algol at about 107,229 km/hr as explained on my How Fast Are We Moving? page. (The Earth moves approximately 202 times its own size in one day.) So in 2.867321 days the Earth moves about 7,379,039 km closer to Algol. _But the varying light from Algol doesn't know this - its light waves left Algol 93 years ago and are travelling at a constant speed._ The result - we "catch a bunch of minima early" during August as shown on Chart 2. Exactly the opposite happens during February - the Earth is moving away from Algol that fast and it takes longer for the group of minima to reach us so we see them taking longer between events. How long? 7,379,039 km divided by the speed of light 299,792.458 km/sec is 24.61382 seconds. So in May and November when we are not moving towards or away from Algol - the period seems constant. It is our rapid movement towards or away from the events in August and February that causes the timing differences."
I assume that light is passing the earth at c when the earth isn't moving towards or away from Algol.
In February the earth is moving away from Algol and the time between the eclipses is 2.8675875347 days and the light is passing the earth at 186,265 mi/sec.
In May and November the earth is not moving towards or away from Algol and the time between eclipses is 2.867321 days and the light is passing the earth at 186,282 mi/sec.
In August the earth is moving towards Algol and the time between eclipses is 2.8670608912 days and the light is passing the earth at 186,299 mi/sec.
I love his passion, he’s a lot of fun to watch
The relationship between time and distance is curious. What is the time it takes for the earth to rotate 15 degrees? It would take an hour. And what is an hour? A 15 degree rotation of the earth. Comparing the distance that the hand of a clock travels around its face to the distance traveled by some object in motion is to compare one distance to another distance. And we call that time. So, the movements of a clock are geared to the rotation of the earth. Clocks are energetic systems and like any other energetic system their operation will be affected by things like altitude and speed. But if a clock slows down does it mean that the time it represents slows down? Say there is a clock placed at the base of a skyscraper and another clock on top of it. They would register different times. But according to the rotating earth it would be the same time for them both.
Brian Green is the Carl Sagan of our day
I voted down because of enormous respect I have for Carl Sagan. Carl was the most humblest genius. He ignited search in many many people of his time thereby producing more scientist and explorers.
I know im stupid. Sadly now I realize how much stupid resides in me. Awesome lecture
Time is a structure. You cannot describe by numbers. Just structure is a number of time.
But if approach speed is added from both directions, doesn't that mean that any movement in the direction of a light source, is faster than light? I am an idiot, please help.
Afraid to ask, but what is the "math version" (btw, mr green is so awesome!)
Believe it or not, his actually is the math version. The other version is only about 2 and a half hours long
If Constant velocity motion is so from one reference point isn't it accelerated motion from another one ?
Reupload?