Flea speed only 4.25mph?!

[Commander Kinsey]

This page claims fleas jump at 4.25mph, surely we'd be able to see them then? When a flea jumps it vanishes, your eye can follow an object at a brisk walking speed surely?

[alan_m]

4.25mph = 6 feet per second A human brain can process an image in perhaps 100ms so the flea has moved 7 inches in a random direction from where you were looking before you could possibly register it again.

With walking you are predicting where the walker will be in 100ms.

[Commander Kinsey]

Are you saying we only see 10fps? Then why does 10fps look shit in computer games and videos?

I guess the walker is also much bigger and easier to spot.

[Brian Gaff]

Have you considered persistence of vision and the fact that the eye is a very noisy and inaccurate device often cleaned up by the brain, so something so small would vanish if you have no way to predict its direction. Brian

[Commander Kinsey]

You may be correct. But have you considered that fleas might be breaking the speed of light? We should base spacecraft on fleas.

[whisky-dave]

No I haven't but I do believe they think quicker and more accuratly they you do. which could be why you don't see them.

[Commander Kinsey]

They certainly are fast at breeding.