minutephysics
Go to http://brilliant.org/MinutePhysics for 20% off a premium subscription to Brilliant!
Mark Rober’s youtube channel: https://www.youtube.com/markrober
This video is chapter 5 in my series on special relativity, and it covers how things that are moving (that is, moving relative to an inertial reference frame) at different speeds appear to be shorter in length… and longer in length. And shorter in time, and longer in time. It all makes sense, I promise, and is clear when you use the Lorentz transformation of coordinates of the events in question, enacted with a mechanical minkowski diagram, aka mechanical Lorentz transformation, aka spacetime globe.
Support MinutePhysics on Patreon! http://www.patreon.com/minutephysics
Link to Patreon Supporters: http://www.minutephysics.com/supporters/
MinutePhysics is on twitter – @minutephysics
And facebook – http://facebook.com/minutephysics
And Google+ (does anyone use this any more?) – http://bit.ly/qzEwc6
Minute Physics provides an energetic and entertaining view of old and new problems in physics — all in a minute!
Created by Henry Reich
Source
thanks, but could you speak faster?
But wouldn't the cat be dead if we changed it's length? Than why is it still alive? Actually why do we have different realities anyway, how is that even possible? Does this mean there are infinite realities and we pass through them when we move to different perspectives?
You should sell this space time globe. I certainly would buy it.
mmmmmmmeeeeeeeeeeooooooowwwwwww
Aaaaaand you lost me
Why is there no guitar background music, you cant do that
I just want to know if you go back in time at x3 speed of sound?
Let me try n grasp spacetime n share with u.
Spacetime can't be fitted together as a dimension unless space n time are on the same reference platform. As time is in progress, moving forward every moment, then, space must be same, for spacetime to be. If so, then space is not absolute, as we currently think so. It can be considered absolute only when refered at a given time.
At zero time, space was also zero. At 1 second after beginning, space was absolute at 300k km across. As energy was the first substance of beginning and is bursting out at 300k km per sec. So, space is growing in tandem with time at the speed of light.
Space is to be taken as the volume of expanse that's engulfed by light or em energy. Or, we call this space, lighted space. And lighted space is that relevant component of spacetime. This engulfed volume, lighted space, grows by 300km across per second. Such that, the current expanse of lighted space now is 14 b light years across, if the universe is taken to be 14 b yrs old.
Unlighted space is yet to be a component of space time. It s a domain yet to be occupied by light. So, space is of 2 parts. Lighted space and Unlighted space.
This is not to be taken as same to the expansion of the universe. That is another issue.
In essence, for every second of time , while appearing stationary, we are moving at light speed.
Now, this is how time dilation comes about.
If someone is travelling at the speed of light relative to us, his lighted space is not growing. But ours is. So, his spatial reality is experienced differently to us.
His moments are slower than our moments. N the proportion of time dilation is relative to his speed against the speed of light. Similarly, his measurements are shortened to our view, proportionately to his speed against the speed of light
Thus explains, time dilation and lengths contraction.
Henry, I think I maybe found a contradiction. In this video, you say "Your 3 is my 2." But in your other two videos, you say "my 5 is your 4," and "My 2 is your 1." I actually think this video is wrong and your other two videos are right. With 1100 comments, this may have been mentioned a few times already. Could that be? If I screwed up, please let me know how, thank you.
I teach highschool physics and I approve this message. (Showing this to my students today) Thanks!
At 1:25 when you say you have another video on that. Where is that video? I am having trouble finding it.
That stretched out cat though
what if you attach a string to 2 points on that in stead
There is no natural measurement of time in the universe , it is only measured by our technology , Does the decomposition of Cesium slow with gravity ? Altering time in atomic clocks .
Again BS(of textbooks)! Does your clock period time depend on …velocity????
His explanation going through my head:
➡️
➡️↗️😐↘️➡️
So now I know, I learned a little in my high school . That was how to solve maths with equations, this is how to feel physics.
I downloaded the game slower speed of light which helps to observe these relativistic effects nicely
However, I couldn't understand why while moving forward everything lengthens and while moving backwards everything contracts
3:57 Based on the equation, length of the moving cat is greater than the length of the cat that is not moving. Shouldn't be the opposite?
Length contraction; If I tilt a pole lying horizontally on the ground twenty feet away from me perpendicular to my line of sight, through 45 degrees in the horizontal plane it will look shorter. It doesn't get shorter, it just looks shorter. If It is rotated a further 45 degrees, it will look like a dot – but its still a full length pole. We don't need an incomprehensively complex toy to tell us that.
Time is an arbitrary measure of rate of change. As you can't give me an inch, you have to give me an inch of something; as with time you can't give me a second, you have to show me a second's worth of change in something – like the finger on a clock face.
Time dilation and length contraction are how things look, not how they are – especially at .near-light speeds.
http://psd1.us/spacetimeglobe to see a spacetime globe in Desmos and play along with the video.