Hi just for a laugh here's a question I've just stuck on a physics forum, this is what happens when work gets quiet…

Anyone here got a good solution?



Hello,

This might be an old question by now, though I have never seen any mention of it yet.

I was considering all the fictional time machines and even theoretical the laser time tunnel idea. When it occurred to me that all have a certain flaw, in that they are all based on a stationary destination.

For example if I was going to send a particle down Ronald Mallett’s laser tunnel or use a Delorean like machine. Rather than appear in the past or future in the same location as they originally were, they would most likely end up in empty space.

Why? Because of course the planet is moving along with everything else in the universe. Go back a half a year and not only is the planet on the other side of its orbit, but the whole solar system and the indeed the galaxy it’s in has moved millions of miles for when you left, even light years if you traveled far enough in time.

To be able to send a particle down a time tunnel you would have to keep all the other time frame tunnels stationary in space. Or if you were in a Delorean, go rather faster than 88mph.

Just my thoughts on the matter.

Cheers.

FECK ME SCOTT
Another busy day in the office is it

Mr Whippy, if we ignore the blah blah blah boring tedious physics that makes time travel difficult I think you have made a more problematic assumption.

You assume a time machine is stationary or at least has a very very low displacement in space when it operates (i.e. the delorean just needs a few hundred feet).

If time travel is allowed, then your time machine is going to have to either be going faster than the speed of light (so youll be pretty far from origin once you make the leap) or its going to have to travel through a stationary (in real terms) blackhole/wormtunnel.

so yes, there is a flaw in the films, but not a flaw in future methods for time travelling... at least not with the "where ill end up" issue

N.B. I'm purposefully ignoring the quantum gravity/mechanics issues for a laugh.

sweat is pouring from my brow.....not

Of course you are in theoru correct BUT if I were to design such a machine it would have all the planetary movemnt calculations in place to avoid such a mishap.

Spacetime is a 4 dimensional meduim; up - down, left - right, fore - aft, forwards in time - backwards in time. Although I've never tried the time dimension, I can happily navigate one of the others without being distracted by the remaining 2. For instance, I know that the earth moves round the sun along the east - west axis. If I walk due north, despite the earth moving away from me, I never seem to fall off. So I can assume that if I had a flux-capacitor equipped delorean, I could happily drive along the time dimension without finding myself appearing in the empty void of space directly in front of a speeding comet.

This does assume that you "travel" through time rather than the convenient sci-fi "teleporting" through time. I have no experience of teleporting upon which to build a hypothesis.

One would assume, though, that if you invented a machine that teleported through time, you could also teleport through space. The user would have to enter a 4 dimensional destination, taking account of the position of the earth in the universe at the time of arrival. And its speed. You wouldn't want to appear precisely on the surface of the earth at a speed 1,000,000 MPH slower than the planet or you would end up as a red smudge at the bottom of quite a deep crater. Details though.

Traveling through time would be fun because you could stand in a street and the world around you would slowly move into the past or the future.

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Originally posted by cd.thomson
Mr Whippy, if we ignore the blah blah blah boring tedious physics that makes time travel difficult I think you have made a more problematic assumption.

You assume a time machine is stationary or at least has a very very low displacement in space when it operates (i.e. the delorean just needs a few hundred feet).

If time travel is allowed, then your time machine is going to have to either be going faster than the speed of light (so youll be pretty far from origin once you make the leap) or its going to have to travel through a stationary (in real terms) blackhole/wormtunnel.

so yes, there is a flaw in the films, but not a flaw in future methods for time travelling... at least not with the "where ill end up" issue

N.B. I'm purposefully ignoring the quantum gravity/mechanics issues for a laugh.

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Invalid question since I don't believe in
time.

google for Kantian time, Kant's theory on time as opposed to the classiic Newtonian propostion.


FYI Kant said:
One of Kant’s major revolutions was to show that time and space are not primary qualities, but exist only in relation to the subject of science. Where previous philosophers and scientists thought of time and space as being real and independent of humans, Kant argued that time and space only exist for humans and do not belong to things themselves. Newton, for example, believed in the existence of absolute space.

Is time something fundamental or something we as humans can experience and therosie about?


Oh, and if time travel was possible, we would be innunadted with tourists from the future; but we are not therefore it is a load of bolox.

[Edited on 3/9/09 by 02GF74]

I too have heard of this concept that time and events do not exist unless there is someone to observe events happen. Tbh I consider it a very naive belief that humans have even a remote significance on such a huge universe, which for all but its briefest of existence, humans have even existed themselves. There are many theoretical concepts of what time is, none of which have been proven to be correct.

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Originally posted by 02GF74
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Kant argued that time and space only exist for humans and do not belong to things themselves
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Time travel is possible. I bought a time machine next year and it broke down which is why I'm stuck here now waiting for it to be invented so I can buy parts to fix it I knew I should have taken out the recovery insurance, the extended warranty was a waste as I went past the end of it next day so it was invalidated.

I think that it will act a bit like a ball on a windless day - if you throw it straight up into the air it lands right back on your head despite you having moved a few feet to the east as the earth spins - i.e. time travel is like a ball - you end up where you started never mind how long it takes.

Yeah OK - I know the above makes no sense whatsoever - but it makes just as much sense as any answer you might be given, seeing as there are only about 2 people in the world at any one time who could answer a question like Mr W's, and even they wouldn't agree with each other.

All this positioning lark is irrelevant anyway.
If I were to make a time machine, I would make it suitable for space travel, fully armed, and able to survive for a long period with no outside help.
So no matter where and when It ended up, It would be safe and able to carry on with whatever tasks were to show themselves.

The way I see it is that time travel is that far away that we may very well have fully functional space flight by the time we are able to travel through time.

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Originally posted by Mr Whippy
I too have heard of this concept that time and events do not exist unless there is someone to observe events happen. Tbh I consider it a very naive belief that humans have even a remote significance on such a huge universe, which for all but its briefest of existence, humans have even existed themselves.

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If God really does exist then we would never be able to screw up something that big.

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Originally posted by 02GF74
My belief, & pretty sure I posted it on here before ... and before I came across the Kant concept, is that it is because humans have a memory that time has any meaning.

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Originally posted by MikeRJ
For example, a lump of uranium has no conciousness or memory, yet it's radioactive decay is intrinsically linked to time.

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this is like the tree falling in the forest type stuff.

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If a man says something in a forrest and there is no woman around to hear him, is he still wrong?

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MikeRJ - 7/9/09 at 08:33 AM

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Originally posted by Peteff

Only because a person linked it, the uranium has no sense of time as it has no consciousness as you say and then go on to directly contradict that. Also we say that the half life of uranium-238 is 4.5 billion years approximately but how can we know that unless someone has a time machine to go forward and check that half it's atoms had decayed in that time.

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We know that radioactive decay is exponential from measuring decay in materials with much shorter half life, so you can predict half life quite accurately without actually waiting for it.

My point being is if time only exists because we have conciousness, then if we as a race ceased to exist would radioactive decay stop happening? I somehow doubt it.

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Peteff - 7/9/09 at 08:56 AM

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Originally posted by MikeRJ
We know that radioactive decay is exponential from measuring decay in materials with much shorter half life, so you can predict half life quite accurately without actually waiting for it.

My point being is if time only exists because we have conciousness, then if we as a race ceased to exist would radioactive decay stop happening? I somehow doubt it.

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I think someone is taking this thread far too seriously If we cease to exist would the uranium decay matter and what would be measuring the time ?

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MikeRJ - 7/9/09 at 11:25 AM

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Originally posted by Peteff

I think someone is taking this thread far too seriously

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This is serious stuff! If I can convince my boss that time is simply an artefact of his conciousness, and does not exist in reality then maybe I can go home early

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If we cease to exist would the uranium decay matter and what would be measuring the time ?

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Does time have to be measured to exist?

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Ninehigh - 7/9/09 at 06:08 PM

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Originally posted by MikeRJ
Does time have to be measured to exist?

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And there's the rub

Time, along with height, distance and wieght will still exist. Gravity existed for millions of years before Newton wondered why we haven't fell off yet. What we invented were the measurements.

Incidentally when did football fields, elephants and double decker buses become units of measurement?

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02GF74 - 10/9/09 at 09:08 AM

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Originally posted by Ninehigh

quote:

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Originally posted by MikeRJ
Does time have to be measured to exist?

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And there's the rub

Time, along with height, distance and wieght will still exist. Gravity existed for millions of years before Newton wondered why we haven't fell off yet. What we invented were the measurements.

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... but all of those are observed by humans who then give names to them.

imagine if we lived in a 2D world, then height has no meaning to us so would height exist or not?

We would see a 3 D object passing through are 2 D universe as something whose width is changing.

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Mr Whippy - 10/9/09 at 10:03 AM

Considering man is just a smarter than average ape, so no more significant than any other animal on the planet i.e. would this apply then to even fly’s or bacteria? Would time exist if just one beady little insect eye was there to view events happening?

If so, then how did the planet form in the first place for the bug to crawl across, or for that matter all the many violent and inhospitable events leading up to the formation of the planet in which life could not exist , which as scientist feel has only been around for a third of the universes age.

Of course this is one of those far out (probably drug fuelled) theory’s that no matter compelling it may sound, simply doesn’t solve anything and falls down to any kind of scrutiny whatsoever.

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02GF74 - 10/9/09 at 11:58 AM

Mr W, how many flies have you seen wearing a watch?

Does that not answer your question?

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cd.thomson - 10/9/09 at 12:22 PM

i cant tell, are you guys just trying to wind up whipster?

next youll be arguing that mathematics isnt universal

The thing about philosophy is its basically nonverifiable science, i.e. a waste of "time", whether it exists or not

Q. does a tree that falls in the woods still make a sound if there is noone there to hear it?

A. all evidence suggests that a tree falling in standard earthly conditions will produce a pulse of compressions and rarefactions in the gas that makes up our atmosphere. The longitudinal wave is described as "sound" in our native tongue. No matter what word you use to describe it or even if this occurs where there are NO words (i.e. no humans exist) it still happens and the action/reaction would still be described as a sound if by any chance there was someone nearby!

How we describe something does not prevent or allow it to exist, thats the whole point of scientific base principles.

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02GF74 - 11/9/09 at 10:30 AM

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Originally posted by cd.thomson
How we describe something does not prevent or allow it to exist, thats the whole point of scientific base principles.

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yeah, but the scientific base principles are described by us.

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cd.thomson - 11/9/09 at 10:58 AM

the description doesnt change whats described.

the earth would still orbit the sun whether it was habited by us who can talk about the nuances of "gravity" or it was an uninhabited lump of condensed space dust. The earth would still reflect the wavelength of the electromagnetic spectrum we detect as "blue light" from its oceans wether there are eyes to see it or not.

Although scientific theories change historically, the base truths that science seeks to describe do not. Thats why all this rubbish about science being a social construct is nads. A scientific theory oscillates round a core truth as more evidence is collected, complete paradigm shifts are extremely rare!

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