Einstein's Twin Paradox (& Why Your Head is older than your feet)!

In this video, we talk about how the Twin Paradox is actually not a paradox, but rather a Thought Experiment that can help us understand the idea of Time Dilation. We also explain how GPS satellites counter time dilation, and why your head is a bit older than your feet.

0:00 Is 1 second always 1 second?
0:27 Why time dilates
0:39 Time Dilation due to Special Relativity
0:52 Time Dilation due to General Relativity
1:50 Twin Paradox (or not!)
2:44 How old are the Twins now?
3:56 GPS satellites and Time Dilation
5:36 Your head is older than your feet

[joesmith]

Hands down the best explanation of the Twin Paradox on youtube. I watched the TED-ed video on Twin paradox and 4-5 others. But this one is the best. Quite impressive!

[berrybhoy]

I watched this with my 6th grader. Swear to god, he explained it back to me with such ease I couldn't believe it. Just brilliant!

[ryoujiichihara]

The height of GPS satellite is related with its speed.
That makes sense!

[ceotec]

Now I understand why my head is older than my toe. It’s verified by scientists. Wow!!!

[meryad]

So, basically it's not a paradox, but everybody calls it a paradox. What a paradox!

[ujjwalbhattarai]

What was outside singularity?
You are quntam singularity before bang.
Now,
Imagination what was outside singularity or you ?

In outside singularity there was dark empty place.

Time was boths inside and outside singularity.

Do you think so our head is older than our body ?

For me no.
No our head is not older than our body.
Our body is as old as time.
There is no place in Universe where there is time.

For to thik I want to give you example.

Race between to people A and B is staring at 3 pm.
Race is of 500 meter.
Now race is started and A completed and won race.
When A had completed and won race the referee the clock has show 3 pm of 3 hours 20 minutes and 30 second.

A has completed 500 meter race 20 minutes and 30 second.
Now In Same time B racer has completed his race one second after A. In 21 minutes and 20 second.

While A Had completed his race B person clock has also shown 3 pm of 3 hours 20 minutes and 30 second,
The rest audiences clock has also shows same time 3 pm of 3 hours 20 minute and 30 second too.
Now, while racer B had completed his race the clock has shows 3 pm of 3 hours 21 minutes 30 seconds in everyone clocks including racer A too.

If you get example you will understand our head is not older than our body.

While In race our and awhile we walk our one leg is always move fast than ours body it doesn't mean time is slow for one leg and fast for another leg.

Speed has nothing to do with time.

First phd holder of earth was taught by non phd holder.
First person who has got education was taught by uneducated.

Who is brilliant in between non PhD holder and PhD holder? and uneducated and educated?

Simple I want to say that time is same and fundamental constant.

Time is not different body and speed is different all thought we measured everything in time.

We are not measuring time we are measuring speed in time.
Time has nothing to do with speed.
Time is same and fundamental constant time is not floating like wave ans same everything.

Our head is not older than our brain.
Yes true in birth process our head becomes out first than our body but
Inside and outside body experience time same time.
Time don't care body of inside or outside of stomach.
Time has no dilation.