h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

The idea is certainly not bad. A possibility would be that the process of time-travelling somehow takes away the same amount of energy from the destination-moment as is added by the time-traveller, and dissipates it as heat at the origin-moment. In this way the total energies at both sides can stay the same.

so a man travels back in time from time a to b. what time would the heat be dissipated to?

Even though the energy is lost as heat it would still be added to the total sum of the energy of the universe at that time thus increasing (or you could say creating) extra energy at that time.

So universe at time b would still have 1 + man energy and universe at time a would have 1 - man energy (or some variation on that)

Or you could just say that it's the same universe so there is the same amount of energy in the universe its just in a different place (or time).

Tango

As nobody has travelled as yet in time, it is difficult to be certain.
I would say, If a man, or a thing is moved from a to b, the machine will remove from a the same amount of energy as the man represents.
In fact it would be an exchange of energies, so that both times keep the same total energy.

But of course there is also a question of entropy, momentum, angular momentum and some more conservation laws. We can only speculate.

If time is a single dimension, then it is perfectly possible to move backward in time. However you would have no memory of moving backwards as those memories would now be in the future! (Is this the origin of deja vu?)

This entry has been updated with more information by the way.

Where? It might be that my computer isn't reloading properly (I'm using Netscape, which has the propensity to reload every 30 sec. whether you want it to or not), but I'm not sure what has changed.

It was merged with this from Frump:
http://www.bbc.co.uk/h2g2/guide/A340048

What if you were on the edge of not moving forward in time at all, and someone handed you a cup of hot tea. Might not the brownian motion send you back in time?

I think it's more likely that the tea would transfer some of its heat (and therefore motion) to you, and since motion spacially would likely encourage motion chonologically, you would start going into the future at a faster rate. Of course, this could be completely untrue.

You're not messing with the theory of energy conservation if the universe is a Schroedinger model Multiverse. The energy is already there - it always was - kind of like the electron in the electron cloud bit. Check out my post on the Schroedinger Multiverse towards the end of this thread here: http://www.bbc.co.uk/dna/h2g2/classic/F49284?thread=166402 It's far too long to go into again.

I like the idea that it's all one Universe and so energy is conserved even if you move it from now to then. By saying this is a problem you are saying that energy conservation is a 'now' thing but surely it is a 'now' to a 'moment later than now' thing. D'you know - I think we night be getting somewhere with this line of thought?

Yeah he is right. Or is the mass tied to the place it came from? Maybe you wouldn't be able to interact with anything in the past because your matter is different and is still tied to the place you came from? What really would happen if the matter just went into the past? Then would the matter gap try to be filled with the matter around it, creating a black hole somewhere? It's making me dizzy already.