Time and flies - part 2?

Question

Okay, I think I have a better description of what I was getting at before now. When you read about the perception of passing time at light speed, there are descriptions of, for example, something moving at light speed observing something that isn't and vice versa and their perceptions being different to reality. BUT, in these cases, the people at light speed are actually passing through time at a different rate, I know this is to do with the fact that they are travelling but... Oh dear, I am confusing myself more now! Somewhere in that is something to do with flies perceiving things as faster than we do but I don't know if i am making enough sense for anyone to explain it to me!

Answer 1

There's a big difference between you vs. real time vs. the fly, and you at home vs. you traveling relativistically.
Your and the the fly's perceptions of time differ; you react, move, metabolize and age more slowly. Your perception of time may also be affected by mood (e.g., boredom, excitement). It is reasonable to say that you and the fly operate on different time scales simply because of inherent physical differences in your construction.
In relativistic travel, the traveling you will age slower than the stay-at-home you, but both will experience the same apparent rate of aging. When you reunite you will notice the relativistic effect as an age difference. You are operating on different time scales, but you don't perceive a difference and your timepieces don't show you that. These differences are not due to biology (you two started out identical) but due to Mr. Einstein.

Answer 2

I had a go at the last answer so I'll take a stab at this, too. First off, time DOES stop at lightspeed contrary to what one of the earlier answerers claimed and 'light is time' can be safely ignored as the nonsense it is.

Einstein's special relativity did more than bring lightspeed in to infamy as that annoying cosmic speed limit, it showed it as the 4th dimension - part and parcel of the others. Everyone it seems has heard of spacetime but I dont think many people think of the consequences. When you're moving, fast, you are experiencing less time. Now you could say then if you sprinted all your life would you live longer - the answer would be you might get an extra microsecond from relativity and minus 40 years from your organs wearing out from the exercise, at speeds approaching c which is 300,000 km per second the effects become non-trivial. Admittedly nothing with mass can be accelerated to lightspeed but photons have no REST-mass (It would be simple to say they have NO mass but as mass = energy I have to state it this way) as you get closer to the speed of light you will experience time dilation. You might think you're going much faster as planets and stars whizzed past but when you stopped you might find thousands of years had gone by. You'd be experiencing less time, but your perception of time would be normal to you. I fear there's not room to cover it here!

When you really see how spacetime is a unified fabric in the cosmos you'll have something of an epiphany but I dont think there is room to go over it in this forum. I'd recommend you read Stephen Hawking's a Brief History of Time, Brian Greene's Fabric of the Cosmos to start with.

Put it this way, if a photon could experience anything, then travelling at the speed of light it would experience its whole journey of how ever billion years in one infinitesimal instant. Over as soon as it had begun.

Answer 3

Well, you're saying something about "perception being different to reality", but each person's "reality" is as valid as the other's. Someone moving at close to speed of light will see time outside go much faster than time inside the ship. Conversely, a person outside will see time inside the ship move much slower. So who is right? The answer is both.
So as your speed gets closer and closer to the speed of light, time for you slows down, and distance gets shorter (time dialation and length contraction), therefore time and space are interchangeable and in a way compensate for each other.
Hope this helps.

Answer 4

The fallacy is that at the speed of light, time stops. It slows down dramatically as we near the speed of light - 98% and faster.
No one knows the characteristics of what "time stops" may actually be - but one thing is for sure, you are not going to perceive it or make any observations because even a thought takes time - and you won't have any.

Flies, on the other hand, are in the same time reference as we are. They may well perceive things differently than us - but that would be more in the realm of a biology question than a physics question.

Answer 5

Time is relative.

When the speed of an object increases, the time dilates, it moves slowly.

But for ordinary speeds like the speed of a fly, this time dilation is insignificant. Only when the speed of an object is somewhat near to the speed of 3x10^8 m/s, the time dilation becomes significant.

Even in that case, the observer in the flight will not feel this. It is because, with respect to his frame of reference he is at rest and the other frames of references are moving.

Answer 6

I think these are two separate things.
If you travelled close to the speed of light, time to you would travel just as fast as usual. Your observed time (to you) is unchanged. Seeing five minutes pass on yor watch would feel like any five minutes to you. The amount of time passed to different observers is different, so someone watching you might only see two minutes pass on their watch and it would feel like two minutes to them. Time is not absolute in space - it is relative to the observer, just like spacial dimensions and speed.

The fly question is a biological one. Flies process information much more simply and rapidly than humans. So they spot changes around them more rapidly than people. This is a perception thing, like time seeming to go slower when you have nothing to do or you clock watch.

Answer 7

You must approach the speed of light before you will notice any time difference.

Just like you cannot doppler shift the radio frequency you're listening to in your car by going fast.. You're just not able to go fast enough.

Answer 8

Light IS time.