Travel to the future and time at speed of light

[awanderer]

Hi all, newbee member here and just want to say that no matter what you do, we just cannot have enough fascination with our universe and its science.

I have a question I just want to know. It's stated that if we can travel at the speed of light time will slow down compare to time on earth and so say we go 1 year and return it's 10 years on earth have passed. This means we are comparing time with two different time clocks? One on the time machine and one on earth. The fact that time slows down at lightspeed is fascinating, but still, I believe it is more of a physical reactions of subatomic particles and they way they behave when they are moving at the speed of light.

To me, time is mental and it is not physical. You cannot physically alter time so how can we say we can travel to the future based on a clock that slows down at light speed??

 

[orionrider]

Welcome on SDC

Well, the 'Space Science and Astronomy' answer involves the relativity theory which cannot be easily explained on a forum (not even in the appropriate 'Physics' forum).

Then there is the 'I believe' and 'To me' part, which qualify your post for the 'Unexplained' forum.

Since you seem to not accept the relativity theory, don't expect too much replies to your post here. :?

 

[MeteorWayne]

It will wind up in one of those fora. The decision will be made based on followup posts

 

[orionrider]

awanderer, the effects of relativity are very real, even in your everyday life. GPS satellites for instance have to take relativistic effects into account in order to generate a correct time signal. If time dilation was not taken into account, the GPS would not work:

http://www.astronomy.ohio-state.edu/~po ... 5/gps.html

 

[ramparts]

Yep - that whole conception you have about time not being physical is wrong, and that's a fact of the Universe you should probably get used to

I'd add that if you were to actually travel at the speed of light, you wouldn't experience time passing slowly... you wouldn't experience any time passing at all! Luckily no massive object can ever reach the speed of light. The effects you're talking about are for objects traveling very close to the speed of light.

 

[crazyeddie]

The fact that time slows down at lightspeed is fascinating, but still, I believe it is more of a physical reactions of subatomic particles and they way they behave when they are moving at the speed of light.

To me, time is mental and it is not physical. You cannot physically alter time so how can we say we can travel to the future based on a clock that slows down at light speed??

As other posters have implied, we have atomic clocks that are so accurate that they can measure the difference in the rates of time passing from the speed of orbiting satellites.....even the differences from the speed of a traveler on a jet airplane circumnavigating the world. So the changes are certainly not a mere mental or perceptual manifestation.

 

[awanderer]

Thanks all and sorry if this is in the wrong forum. I understand time is extremely important and its representations and accuracy are what make things work around us for our daily survival. With that said, how can we claim we have traveled thru time with two different reprenstations of time?? The way I see it, we travel at the speed of light to influence the clock and its subatomic particles more than to claim we can travel into the future.

I know a lot of you are smarter than me, but it's just something I'm still puzzled with.

 

[MeteorWayne]

Nothing with mass can ever travel at the speed of light...

 

[crazyeddie]

With that said, how can we claim we have traveled thru time with two different reprenstations of time?? The way I see it, we travel at the speed of light to influence the clock and its subatomic particles more than to claim we can travel into the future.

Could you try to clarify these statements? They don't make sense the way you've phrased them. Who is claiming to "travel thru time"? We move along with time at a rate that is for all practical purposes, constant. Nothing with mass can travel at the speed of light, so what is the meaning of that sentence?

 

[awanderer]

What I mean is the 10 year to 1 year difference. As from theory that if we could move at the speed of light time slows down. One year at light speed will be 10 years on earth.

 

[EarthlingX]

Travelling at 0.9 c, would make 1 year 2.294157338705618 years on Earth.

Relativity Calculator

At 1c it goes to infinity.

 

[orionrider]

One year at light speed will be 10 years on earth.

As already said, nothing with mass can travel at the speed of light. You could maybe travel close to the speed of light, but not at the speed of light.

Check the link above, the calculator is easy to use, no fancy math required. You will see that to have a one in ten dilation of time, you would have to travel at 298,289km/sec. Actually, that is quite close to the speed of light.

At the more mundane speeds our space probes travel, you could think it makes no great difference but then again, space is HUGE and even a small difference can have a big effect. Say our next Mars probe leaves us at a moderate 30km/sec, the relativistic effect is only 1.000000005. If you don't take this effect into account, after 1 year of travel the probe will have cumulated an error of 4km. More than enough to fail orbital insertion on Mars...

Travel to the future is a fact, we do it all the time...

 

[Solifugae]

Saying that time is based off particle motion isn't at all anything astounding, because space and time are one and the same, but if you were to slow down all motion right down to the smallest level on a spaceship, relative to motion on Earth, by traveling close to the speed of light, then yes, that is time travel, because when you returned, Earth's calendars would be at much later dates than the one you hung in the spaceship.

There's no absolute time as Newton thought, but it doesn't stop us traveling to Earth's future by changing our flow relative to Earth.