[itishappy]

Nope! We can detect individual photons (and measure their properties) and a mirror can (nearly) perfectly focus and collect every photon that hits it. The frequency of detection events would change with the distance, but the frequency doesn't hugely matter, one photon per week is enough for science!

[bee_rider]

It is definitely possible that I’m missing something here.

But, for example, if we are trying to get an image of a dinosaur, and we’re only getting one photon per week, how’s that work? The dinosaur should have moved before the second photon is sent off, right?

[itishappy]

You're totally right, it's me that's missing something. If you had something that moved predictably, say a whole planet, you might be able to get results by accumulating over a long period of time, but single photons would not be useful for imaging a dinosaur.