[Mr. K]

you’re sure of that?

any other scientific theories you can prove impossible for us?

should we close the patent office?

[FredZarguna]

All known physical processes are subject to a limitation that they are timelike in all equivalent Lorentz frames. This makes superluminal travel an impossibility.

Evidently, you are of the opinion that there are time-travelers. I ask the same question of you that Fermi asked, mutatis mutandis:

"If there are time-travelers, where are they?"

[FredZarguna]

should we close the patent office?

First, your use of that statement betrays that you don't know what you're talking about. Charles Holland Duell, the head of the patent office who supposedly said this, never made such a statement. In fact, he said EXACTLY THE OPPOSITE: "In my opinion, all previous advances in the various lines of invention will appear totally insignificant when compared with those which the present century will witness. I almost wish that I might live my life over again to see the wonders which are at the threshold."

Second, neither Duell nor the various others to whom this claim is attributed are/were physicists. At one time, long ago, I was one.

Third, what I would urge you to "close" is your office at the Flat Earth Society, because we have roughly as much evidence that superluminal travel is impossible as we have the the Earth is round.

[SgtHooper]

These people are infuriating and have been saying “no” since the beginning of humankind.