4 ms·
Third law of the thermodynamics has to be false for that to be possible. It is still a paradox.
by rightbyte 6y ago
Third law of the thermodynamics has to be false for that to be possible. It is still a paradox.
- littlestymaar 6y agoWould you mind expanding on that?
- rightbyte 6y agoIf you send an apple back in time the conservation of energy is broken. The energy sum of everything increases in the past.
- littlestymaar 6y ago1. Not necessarily: nobody said the time-travel couldn't pump energy at your destination to compensate for the energy the future is sending. 2. What does it have to do with the third law of thermodynamics (which is about the impossibility to reach a temperature of 0K)
- ricardobeat 6y ago> pump energy at your destination What does that even mean? This is the kind of hand-waving the OP was pointing out. He probably meant the first law.
- littlestymaar 6y ago> What does that even mean Any variation on this: “sending this item in the past, will grab the same amount of mass from the past, taken at random in a way that preserve the energy on both ends”
- 194765 6y agoSo like the gate of truth from Fullmetal Alchemist?
- rightbyte 6y agoI think I messed up the number.
- Contax 6y agoI know next to nothing about all this so excuse my ignorance -and limited English-, but I've always thought that if you send, say, an apple (as in GP's comment) to the past... wouldn't that apple's atoms already exist there in the past -in the same apple if it already existed (you are sending it just some minutes back) or elsewhere like in the tree, the tree's soil... animals that later died and nourished the soil/tree... in rocks... wherever- and so you are duplicating them and hence creating energy/mass and breaking the law of conservation? Either it's impossible to travel back in time in this universe or it is not an isolated system... or the law of conservation could somehow be broken... do my thoughts make any sense?
- tremon 6y agoThe conservation of energy only applies to a closed system. If we can "create" an apple at any given point in time, that only means that "the universe at a given point in time" isn't a closed system.
- d1sxeyes 6y agoOnly if you consider conserving the energy sum of all possible spatial locations to be the rule we need to keep. If instead the rule is that we need to conserve the energy sum of all possible locations in space-time, then no law is broken.
- diggernet 6y agoThat's an interesting point. I'd even go a step further and say that which of those two definitions is true determines whether time travel is possible. Put another way, conservation across space-time (instead of a single point in time) is necessary for time travel to exist, and the existence of time travel is the only reason conservation would be across space-time.
- d1sxeyes 6y agoI'm not sure that time travel is the only reason - it might turn out to explain some other peculiarities in the universe (spooky action at a distance jumps into my mind as something that could potentially have an explanation linked to this). It also would seem to be impossible to calculate energy at a specific moment. Energy = mc^2, or expressed differently, e = m * d^2 * t^-2. If t = 0, then t^-2 is not calculable.