The 14 Dumbest Things In Star Trek IV: The Voyage Home
6. The Whale Horizon
Zooming in on something on something hundreds or thousands of kilometers away in space is easy, because there’s effectively zip between you and almost anything you want to look at. Down in the Earth’s atmosphere, that’s something else.
UHURA: Affirmative. Contact with the whales.
KIRK: Bearing!
UHURA: Bearing three two seven, range six hundred nautical.
KIRK: Put them on screen!
GILLIAN: How can you do that?
How indeed, Gillian.
Unlike in space, the trouble with looking at things far away on Earth is that the Earth itself tends to get in the way. The farther away something is, the higher above the surface you must be to get a line of sight on it over the horizon.
600 nautical miles is 1,111 km, and to even see the whales just on the horizon at such distance the Bird of Prey would have to be at a minimal altitude of 96,179m (315,548ft), which is up in the suborbital range where the X-15 rocket plane flew. Up there the sky is black. That’s 9x as high as our familiar fluffy clouds go, but moments earlier, before Uhura reports the distance, we get a POV of zipping through clouds under bright blue skies.
Down where the clouds are anything over 200–280k away would be invisible over the horizon.
And the lower you are in the atmosphere the denser it is and the harder it is to see through the atmospheric haze.
That’s definitely a science dumb.