system
Given the following post, respond as if you're commenting on Reddit:
human
[Independence Day] How do the ships reach their target cities so quickly?

Throughout the movie, the City Destroyers are shown to be traveling very slow, yet in some instances, they are shown to arrive in a a city only a short time after they were said to be very far away.

One instance of this is when the President and his staff are watching coverage of a fireball (which contain the ships) near Novosibirsk, Russia, and the female news reporter says that the fireball is headed right for Moscow, around 2,000 miles away.

When David briefly watches some coverage of the ships over cities across the world, Moscow is shown with a ship. This was not long after the aforementioned scene above, probably not even an hour. If this was the same ship that was spotted in Novosibirsk, then it had to have traveled the 2,000 miles in the span of around 30-45 minutes.
gpt
They look like they're moving slowly when seen from the ground, but in fact they're moving very quickly, possibly at near-sonic speeds, or even supersonic.  

Ever looked up at the sky while a plane flies past?  The plane looks like it's pretty slow too, doesn't it?  You can visually track the movement of the plane without any problems.  And yet airplanes fly fast enough to traverse continents in a matter of hours.  Similarly, the alien ships appear to move slowly to observers at ground level because they're high up and far away.  In actuality, they're moving fast enough to rival the fastest airplanes.