Faster spacecraft and faster than light travel.

[don]

Oh, FTL travel is certainly possible, as tachyons do it all the time, if the theory behind their existence is correct.

"Things can travel FTL if particles defined to be able to travel FTL exist"?

No, I didn't say "things" (meaning a physical object of some sort to me), I just said that "travel" at FTL speeds is possible <smile>. Adding "mass" would make it a "thing". I suppose as long as a tachyon's mass remains "imaginary", then it would not be restricted to c speed. But, since it is classified as a "particle" and not something else (force, wave, etc.), then to me this means it *does* have mass. Confusing.

a) There's no reason to believe that they interact with tardyons (slower-than-light) particles, so there's no reason to believe that converting a ship into them or sending a message using them is possible.

Agreed.

b) Even if you could send a message or ship through converting it into tachyons, the message/ship would not travel FTL. ... Although the carrier particles (tachyons) are FTL, the modulated wave they carry (the message) is not.

Yes, this is absolutely correct.

Tachyons have imaginary mass (fittingly).

But of course.

In other words, it's completely arbitrary as to whether the tachyonic object is travelling forwards or backwards in time.

Good point.

[Cormoran]

As I said when I posted, I'm a layman. To be frank, I think FTL is an entertaining concept, even if science predicts that it is improbable.

As for my assertions in relation to past predictions, I would reply by saying that, the predictions were made based on the underlying scientific knowledge of the day (apart from that daft old sod who said spaceflight was impossible), just as the assertions that 'Guest' makes are based on the scientific knowledge of the present.

Present science is just that. Present. It will expand. Some ideas will be disproved, some reinforced, some broadened or modified. I did say I hoped I was wrong about FTL being unlikely. I stand by that. Its a hope, more emotional than strictly rational, and while some may think that it lacks validity, I'll just keep on hoping

That's my two cents, for what they are worth

Regards,

Cormoran

PS: Maybe you should register, 'Guest'. Your knowledge of physics is undoubtedly better than mine, and there are LOTS of very knowledgeable people here. I'm sure you'd have some interesting discussions.