Plane Stopped in Midair

In article ,
Dylan Smith wrote:
Especially the giant Antanovs - they look like they are barely moving on
approach, despite really moving at 150 knots or so. By comparison,
a C140 approaching at 55 knots looks like it's just racing along.

I remember reading something about this. The conclusion was that we
perceive speed as a function of aircraft lengths per second. So a large
jet, such as a 747, seems to be crawling, while a smaller aircraft, such
as a Lear, will seem to be moving much faster while actually at the same
speed. Recalculate their speed in terms of aircraft lengths per second,
and you can see the correlation, since a 747 is several Lears long.

I would imagine you'd experience the same thing if you were to compare
the visual perception of the speeds of an Amtrak train and a fast car
travelling at the same rate.

- Nathan