@Patches,
If time travel were possible we would be up to our asses in time travelers by now. Then there is the science fiction tale of the time travelers (Sound of Thunder) who crushed a butterfly when hunting a dinosaur and with that one mistake altered the future negatively.
teleportation
Well, a group of physics students from the University of Leicester just burst that bubble. They took a scientific look at the feasibility of teleportation and found it to be a highly impractical form of travel. Not only would it not be instantaneous as promised, it would take a really long time—300,000 times longer than the history of the universe.
The students calculated the time and energy required to teleport one human from the Earth to a space in Earth’s orbit directly above it, going with the strategy of translating a human into tiny bits of transferable data, at the molecular level, and putting the person back together on the other end in an exact replica.
Breaking down a person by the DNA pairings in each cell, they found the total data for a human genome is 6x109 bits—billions of tiny particles. But what really slows the teleportation process down is the human brain—all those facts, memories, song lyrics, Spanish verbs, and the rest of the information stored in the average person’s head. The brain added another 2.6x1042 bits that had to be beamed into space.
Assuming a beaming speed of 30 gigahertz—the fastest speed manageable using the maximum power physically possible to transport that mass—the students calculated it would take about 4.85 quadrillion years to teleport a human into orbit.
Philosophical questions aside (What about the soul?), not to mention safety questions (Does the original person die?), it's simply not practical. In their somewhat understated conclusion the researchers wrote, "Our results indicate the time scales to complete a full teleport of an individual are a little too lengthy at this time. Current means of travel remain more feasible.” They added, "It would probably be faster to walk.”
The findings were published in the latest volume of the university's annual Journal of Physics Special. In case you hadn't guessed, the research was somewhat tongue and cheek, meant to teach students about the process of publishing scientific works. But physicists are studying quantum teleportation in all seriousness, a feat scientists once thought was impossible, until someone successfully did it 10 years ago.
Quantum teleportation isn't teleportation as we imagine it in sci-fi terms. It isn't actually moving the particles, it's recreating their quantum state. This is possible thanks to a mysterious phenomenon called quantum entanglement, which Einstein famously called a "spooky action." Here's the gist, via How Stuff Works:
Photon A: The photon to be teleported
Photon B: The transporting photon
Photon C: The photon that is entangled with photon B
If researchers tried to look too closely at photon A without entanglement, they would bump it, and thereby change it. By entangling photons B and C, researchers can extract some information about photon A, and the remaining information would be passed on to B by way of entanglement, and then on to photon C. When researchers apply the information from photon A to photon C, they can create an exact replica of photon A. However, photon A no longer exists as it did before the information was sent to photon C.
Now scientists have successfully quantum-teleported atoms several times, and are working to go greater distances. Last year, a group of Chinese engineers broke the previous distance record by "teleporting" entangled electrons nearly 90 miles.
Using this phenomenon to beam people from one place to another is another thing altogether. To accomplish this on the human scale you not only have to recreate the quantum state, but the exact location of every atom. Quantum teleportation isn’t actually moving mass, it's transporting the information that's encoded in the matter. Scotty can beam up data, but not humans, atomic physicist Christopher Monroe explained in the Aol video below:
What Star Trek got wrong in their teleporter, in their transporter, was that to move Captain Kirk from one place to another there has to be a substrate of him—his atoms have to be at the receiving end. These atoms would not look very pretty because they not would be recognizable as Captain Kirk. The act of teleporting Captain Kirk would be moving the information from his body into these atoms and forming Captain Kirk from scratch.
So, while human teleportation is theoretically possible, it's so improbable experts have written it off as impossible in this universe, relegating teleportation to the "forget about it" realm of science fiction, along with time travel and worm holes. I'm still holding out for hoverboards though.
http://motherboard.vice.com/blog/it-would-take-quadrillions-of-years-to-teleport-a-human-into-space
