Are we travelling slower than time?

[cmsdaker]

It may sound strange but someone told me we (Earth I guess) are travelling slower than time. I thought it sounded ridulous and thought she was testing my gulibility but the more I thought about it the more I considered it could be true.

She told me we are losing 5 days a year of time, although, she was just passing on information she had heard and didn't really have any understanding of what she was saying.

Is this true and if so how is time (on a universal scale) travelling faster than us and why don't we notice?

I hope I'm not being really stupid here!

Thanks!

[loudickson71]

There is no such thing as independent, objective time. It simply does not exist.

[Clanad]

To flesh out loudickson's response... our measurement of time is completely arbitrary. Did you ever wonder why, in a mathmatical system that is base 10, why time keeping is base 12? Historically, man had the ability to only measure time, at its smallest increments, in days and nights. When we gained the ability to measure smaller "slices" of time we assigned a name to that small slice and eventually we've ended with 60 seconds, 60 minutes, etc. But it could be anything... So your friend simply hasn't thought very clearly, in my opinion, about her statement, since the loss of 5 days per year would be readily apparent to anyone... We have to jump through hoops to account for an extra day every 4 years as it is, and everyone is quite aware of that.

I will add, however, that the Earth, since early in its nearly 4.5 billion year history, did spin at a much higher rate in the past than it does now, but that has nothing to do with timekeeping...

[loudickson71]

sorry, but that's not really a fleshing out of what I said. The problem of the lack of an independent, objective time, is not one of measurement. If I take the radioactive decay of certain elements, e.g. caesium, it will decay at the same rate here on the ground in the UK, as on the ground in the USA. However, when it is in the plane going to the USA, it is not decaying at the same rate. This change is not due to a change in the caesium itself, but in time itself. Time is passing at a different rate in the plane, just by virtue of the fact that it is travelling faster than I was, stationary on earth. Thus, for example, atomic clocks need to be recalibrated when they finish such an in-air trip.

[Clanad]

So, which way is then? On one hand you state there is no such thing as independent, objective time and then you say the change in caesium is not due to the decay in itself, but time... time is passing at a different rate... Sounds like a measurement problem to me....as I stated. When the clocks flown by Haefel and Keating in 1971 were returned from the aircraft, the only way to know the clocks were different than ground based clocks was by comparison... or again, measurement. The amount they differed (although quite small) was a matter of calibration, as you say, which again, is a matter of measurement... as I said...

[jake-the-peg]

to

[jake-the-peg]

Oooh ghosts in the keyboard this morning - I'm sorry I'll say that again.

To be honest it doesn't sound as if she had any real understanding about what she was saying either! Was there any liquid refreshment involved?

a year is the of the number of times the earth spins on it's axis in a single orbit of the sun and as Clannad says this has changed.

And as louddickson71 says relativity tells us that there is no such thing as a universal clock that we could measure by.

So really there is no such thing as Time in that sense - the statement doesn't really mean anything so no you're not being really stupid

[loudickson71]

Clanad> you're right, I did say there is no such thing as independent, objective time. But the emphasis is on independent, objective. This is what relativity means: there is such a thing as relative time...the caesium decay occurs at a precise rate for me here. But if I put it on a plane, that rate is preserved for the person beside it on the plane, but at a different rate for me here on the ground. Not a measurement problem. Measurement will demonstrate the phenomenon...

[jenstar]

"Slower than time" doesn't mean anything. It's like saying "shorter than length" or "lighter than weight".

[cmsdaker]

There was no liquid refreshment involved unfortunately this is every day in my office! The way I thought it might work is if time worked like a river and different areas travel at different speeds, like currents. So, if I were to stand outside my front door and you (x) were to stand 5 light years away would we live/age at a synchronised rate?

[loudickson71]

jenstar is dead right as far as correctness is concerned (;-p), I guess the questioner meant 'time going slower than the time we're used to'. Which, when you think about it, is totally legit.

[jake-the-peg]

Ah in this case you're talking about the relative nature of time.

This can be different for people travelling at different speeds relative to each other. (Special relativity) - although things have to be travelling at an appreciable fraction of the speed of light before they're noticable.

Or they can be different depending on how strong gravity is where you are (General relativity)

Now this all sounds quite arcane and otherworldly but the most dramatic proof of this is muons.

These subatomic particles are created when cosmic rays hit the upper atmosphere. But they are very short lived. Even at the incredible speeds they move at less than 1 in a million should reach us. But they do or at least 49,000 in every million do. and the reason is that they move so fast that time is "slower" for them than it is for us.

[cmsdaker]

Correct-a-mundo! Apparently 'the source' now tells me it's five 5 hours a day we're losing! It'll Christmas 2010 before you know it!

[cmsdaker]

The corect-a-mundo was for the re-definition of the question by loudickson not the next response. Thanks!

[MrPahoehoe]

This is just a guess, but could she mean that we loose time relative to an imaginary 'stationary' Earth: e.g. an Earth which is not spinning and not rotating round the Sun?

[loudickson71]

Maybe. But that would be like .0000000001 seconds every billion years.

I think she means that 365.4x days per (nominal) year is not the earth's orbital time round the sun no more.