3 ms·
I don't think it's accurate to say that light is slow on any timescale. It's literally the fastest thing, no matter what scale you're on. The issue at hand, an
by kokanee 5y ago
I don't think it's accurate to say that light is slow on any timescale. It's literally the fastest thing, no matter what scale you're on.
The issue at hand, and the reason that we can make light look slow, is that we can't comprehend the distances we're talking about covering. No one said anything about restricting the search for life to our galaxy, so let's set that aside. Given the distances involved, the odds that evolution has gone complex in more than one galaxy are high, but the odds that we might find evidence of this are low.
- jjoonathan 5y agoYes, it's true, to define a velocity scale you need to plug in a spatial scale and a temporal scale. A human lifetime defines the temporal scale, but I technically didn't mention a spatial scale. However, we were talking about Fermi paradox and galactic colonization -- so a reasonable spatial scale would be that of the galaxy, and then we have defined a velocity scale and can make comparisons: c << (galactic diameter / human lifetime) c >> (galactic diameter / billion year evolutionary lead)
- dhosek 5y agoThe end of the gif with the distances between the sun, Mercury, Venus and Earth to scale is kind of informative and then you look at the fine print that indicates that with that scale the planets are all represented at 50x and the sun at 2x and it really makes the distances that much more amazingly large. And I have to confess that my mental image of the distance from Mercury to the sun was way off—I'd always envisioned it as being close enough that the sun would fill the daytime sky but really it would just look about 2.5–3 times bigger than it does on Earth.