It is the same for pretty much all the narrative hand waves that are used to push the story forward. This is not knocking SF but to temper expectations.
Deep sleep/human hibernation.
FTL travel of any description, including FTL communication.
Directed energy weapons already exist today. They're mostly experimental, but the US and Germany (and possibly others) are both investing millions into R&D and have working prototypes.
That's quite the question to ask, but as far I can tell it only works with quantum information. Sending a body would be like you trying to fit into a fiber cable to be bounced inside of beneath the Atlantic to avoid the otherwise long flight.
From what I know of sci-fi, teleportation is often a machine that scans, destroys, and replicates the particles in your body at a secondary location.
So if we could figure out scanning and printing at the atomic scale, with zero defects, and pair it with sending information at near instant speeds via quantum teleportation, we could have a teleporter.
You just made me curious and we're not alone in wondering
To have a scanner that can record the position of every atom in the body to an accuracy of the order of the size of a hydrogen atom would require position accuracy of about 10-10 meters. To get that accuracy over a distance of order 1 meter, this would require 30 decimal digits, which would be about 100 binary digits per atom. However, there would be a lot of redundancy in this data, so let’s be optimistic and assume you could compress this down to 1 bit per atom, so we still need approximately 1027 bits of data to just specify the positions of all the atoms in a human body. According to Wikipedia (Exabyte), the approximate data storage capacity of all the computers and storage devices in the world today is roughly 1 zettabyte = 1021 bytes = 1022 bits. Therefore, the data for the scan of one human would require at least 10,000 times the total storage of all the data stored on Earth right now.
I was getting incredibly confused because the copy/paste didn't copy the superscript for the exponents. I was like, "there's definitely more than 1027 atoms in the body.. wait, how are there supposedly only 1021 bytes of storage in the whole world? Oooh.."
Now I'm wondering how long it would realistically take for that to become a not-insane demand. I know data storage multiplies pretty rapidly, but not that rapidly, so are we talking decades or centuries?
Quantum “teleportation” is not capable of sending information FTL. Quantum entanglement means that the wave functions of two or more particles (in essence, the information possessed by the particles) are correlated, but the information must be encoded by a device at the midpoint between the two observers and sent to the observers at a speed not exceeding the speed of light.
Teleportation in that term means “make a thing disappear in one place and appear in another”. No “immediate” is ever implied.
Wikipedia article has a great diagram on the topic. Add an article on “no cloning theorem” to understand why “teleportation” is a fitting term. I recommend reading both without expectation, just read through the steps as if you’re learning a new math tool.
In short, quantum teleportation is a way to take a quantum state (which are fundamentally unforgeable - you can’t simply create a clone of a particle), destroy it, extracting classically communicable data, and they recreate it in another location.
Speed of light is a singularity in a special relativity theory. Singularities usually indicate model limitations, not reality fundamentals.
The theory happily describes behaviours below and above this “speed limit”, but insists on it being unapproachable from either side, which is weird already. At the same time our other models tell us that matter loses a finite amount of energy when it gains mass and stops moving at the speed of light.
Problem is, we don’t seem to have a vocabulary to discuss ways around this singularity and universe is not so forthcoming with any clues.
It’s a general crysis of physics lately. We know our models have limitations, we often know where they break exactly, and universe just giggles along.
But yeah, it’s highly unlikely that any SF will correctly guess a viable FTL, even if it is possible. Especially considering how seemingly every author thinks quantum entanglement is it.