Traditioanlly, travel at the speed of light is believed impossible for corporeal beings. The energy required to accelerate mass to the speed of light is infinite, and it causes all sorts of bizarre problems like time dilation, length expansion, & so forth and so on. Sort of the existential equivalent of jet lag, only instead of being due to the day/night cycle being messed up for the airplane traveler, it's being due to the fabric of the universe being messed up for the time traveler.
But consider this.
Take a 3d-printing machine like the MakerBot, that can create physical objetcs based on computer data. For example, you can go to thingiverse.com, download a file for a teacup, and it spits out millions of little plastic droplets that, after an hour or two, form a teacup.
Now, let's say that instead of in your bedroom in Kazhakstan or New Jersey or Hokkaido, you are, instead on mars. You have a makerbot, and you live on mars.
You go to thingiverse.com, and after a few minutes, you download the information about the teacup to your computer on mars, and you print one out.
Did the teacup travel from Earth to Mars in 3 minutes? No, it took an hour or two to print out on your Makerbot on Mars.
Ok, well, let's say that 40 years from now, we have Makerbots that can print things in 10 seconds, like laser printers do now compared to line-printers from the 1970s. What then?
Ok, you are on Mars, you got a teacup, and it only took you a few minutes. But that's not travel! !! !!
How do you know it's not travel? Can you prove it?
If I gave you two teacups printed by makerbots, and said one was created on Earth and shipped to Mars on a rocket over several months.... and another teacup that was printed out on a Makerbot on Mars in a few minutes...., could you tell me which teacup was which?
Perhaps it is like Einstein's remarks about gravity and acceleration. If you are in an elevator, you have no idea if the elevator's motion is from gravity or from some super-quiet rocket engine on the outside. In fact, there is theoretically no way you can figure it out. Acceleration is acceleration is acceleration.
I this case, a teacup is a teacup is a teacup.
Oh, but what if you had a microscope, you say? Or a special isotope meter? Or some other whiz-bang tricorder gadget? Then you could figure out which teacup was made on Earth and which on Mars, by some tiny discrepancy in alignment or patterns of plastic molecules.
But in some distant future, imagine the perfect Makerbot, that can replicate, down to the atom, the arrangement of a teacup. Perhaps it would be a never ending race - betwixt the machines that can transmit information and reconstruct objects, and the machines that can detect minute differences in objects to distinguish which one was made where.
Here is the problem. When you transmit the information to Mars, you are not getting rid of the original object. Here, we have 'travel', but travel in the sense that an identical object is created in another place, and it has been transferred there at light speed.
Now, imagine the replicator machine that can transmit human beings?
Do you really want a copy of yourself floating out there in the universe? Even if it meant that "you" could travel at light speed? To distant stars? If it only takes a few light years to reach Alpha Centauri, would you wish for a 'copy' of 'you' to go there? The new 'you' could talk back to the old you... but it would take the message several years to reach original 'you'.
Now consider if a copy of 'you' could travel, say, another part of the milky way? What if it took 1000 light years to get there? By the time the information-copy of 'you' got there, original 'you' would be dead. Would 'you' then live two lives, one on Earth, one in some distant planet? Which 'you' would be 'you'?
Yes, we can travel at light speed. It just means changing the defintion of certain things. Starting with the word "we".