There is no time

/
>>>>>>/u/sLAYdemHOE:
Giải thích theo cách này nè.
Tưởng tượng có một con tàu đang di chuyển với vận tốc ánh sáng.
Người A ở trên tàu.
Người B đứng ở trạm và nhìn người A.
Người A lúc này thảy một quả bóng lên và chụp lấy nó. Nó bay thẳng lên và cũng rớt thẳng xuống tay A.
Người A sẽ thấy quả bóng bay lên và đi xuống theo một đường thẳng |.
Còn người B lúc nhìn sẽ thấy quả bóng bay lên theo hướng / và rơi xuống theo hướng \. Quả bóng trong lúc bay sẽ di chuyển theo hướng của con tàu, nhìn từ góc độ của người đứng ở trạm.
Quả bóng là thời gian, nó di chuyển bình thường so với A, nhưng đứng ở ngoài nhìn vào sẽ thấy nó di chuyển châm hơn.
Thực tế thời gian không tồn tại, thời gian chỉ là cảm tính thôi. Chúng ta dùng nó để đo, nhưng thời gian không nhất quán.
Dựa vào rất nhiều yếu tố như vận tốc và trọng lực mà thời gian có thể bị bóp méo.

Link Reddit: https://redd.it/6rx0q3

Speed is equal to distance over time.

Gravity increases the distance light travels as it curves space.

The speed of light is constant no matter where you are and no matter how fast you're going.

So, if the speed of light is fixed and the distance increases due to gravity then time has to slow to make sure the equation still balances.

The more gravity there is the more space is curved and the slower time moves.

Well that right there is the heart of Einstein's most famous contribution to science; his theory of relativity. It's a beautiful one, really, because it unifies three things that always had been a bit of a tricky subject to wrap your head around: * Space, Time, and Gravity* .

You might have heard the pair "space-time" thrown around, and if that confuses you, you have Einstein to blame. In his theoretical views, time and space are intimately intertwined, both acting as two ways to describe the landscape in which all of matter and energy takes place. Gravity is basically what this landscape looks like!

As for why time slows down, is difficult to explain without going into the [detailed mathematics](https://en.wikipedia.org/wiki/Gravitational_time_dilation). If you do take a shot at the formulas, my suggested take away from it is that *light speed* here is the culprit for this funny phenomenon. Whilst space and time turn out to be variable, curving and twisting depending on the conditions, *light speed* always needs to be the same. Speed relative to what though? Relative to someone chilling at the surface of the sun, or relative to us looking from a distance? If you think about it, these two scenarios *must* be different. Perhaps you could say it's all a consequence of time and space having to accomodate to the stubborn speed of light, and impracticallly large celestial bodies messing up the environment.

Finally I just need to repeat how silly and strange the concept of time and space is. Time doesn't slow down for *you* if you'd be the one dancing close to a Black Hole's embrace, you'd just be surprised to see everyone so much older if you get back to Earth. In other words, it's not that time slows down to be honest, it's that apparently time itself is relative to the space-time landscape you're in. There is no absolute clock, but we can however, compare how fast our clocks are running *relative to each other*. That's why Einstein called it the theory of relativity ;)

Put it this way.

Imagine there is a train traveling the speed of light.

Person A is on the train

Person B is off the train, stationary observing it.

Person A tosses a ball up in the air and catches it. Straight up and down back into their hands.

Person A would have observed the ball travel just up and down |.

Person B who was watching would have observed the ball travel up at and angle \ and down at a angle /. The ball would be moving forward with the train to the outside observer.

The ball represents time, it'd be traveling normal to person A, but outside observers would see it's traveling slower.

Realistically time doesn't exist, time is personal. We use it as a measurement but time isn't consistent.

Depending on a lot of other factors like speed and gravity time can be distorted.