[scott113341]

> such as around Proxima Centauri, the nearest star to Earth, or TRAPPIST-1, a star about 40 light-years away...

I don't think they are asserting that the laser beam travels faster than the speed of light. I think they are referring to Proxima Centauri being about 4 light-years away from Earth [0].

[0] https://en.wikipedia.org/wiki/Proxima_Centauri

[Johnny555]

That may be what they meant, but that's not what they said, they mentioned 2 systems, one is 40 light years away, and said "...If the signal is spotted from either of these nearby systems..."

[jessaustin]

They're talking about interstellar communication, not how long you've lived in your house. 40 years is just a few years.

[Johnny555]

"Few" has a specific meaning when applied to something countable. 40 is not "a few" in any common use of the word.

You don't say "It took the settlers 180 days to ride a wagon across the country, but today it only takes a few hours to drive across the country" when you meant "40 hours".

If you want to use "few", you'd use a different unit like "and now it only takes a few days". Or "And you can send a signal to that star system in a few decades".

[jessaustin]

Your example sort of fell apart there. It took 180 days at some hypothetical moment in history. Now it takes a few days.

There are a few words in English the meaning of which is absolute, regardless of context. "Few" is not among those words.

[Johnny555]

Few doesn't have an absolute meaning, but it does have a consistent relative meaning.

You could take a handful of sand from a sand dune and say "I took only a few grains of sand home with me"

You could say "only a few of the thousands of visible stars are close enough to send a signal to" even if that means hundreds.

But you wouldn't say "it takes 40 light years to reach the star, so the laser can reach it in a few years". You might say "It would take 1000 years for a spaceship to reach the planet, but a laser can do it in a few years" even if a "few" meant 40.

[jessaustin]

Now you've got it! Yes, "few" in this case is 40, just as in the sand example you've given it is maybe a few hundred thousand. Just as interstellar communication might take thousands of years, the sand dune might have contained billions of grains. Context is important!

NB: The light-year is a measure of distance, not of time.