Galilean relativity rules! (At speeds much less than the speed of light)

The Mythbusters team looked at what happens when you fire a soccer ball at 50 mph backwards out of the back of a truck that is moving forward at 50 mph. The result would have come as no surprise to Galileo.

But if instead of a soccer ball, you fired a beam of light out of the back, it would still travel at the speed of light, however fast the truck was moving. (The truck can never travel at the speed of light, of course.) You would have to use the Lorentz transformations, not the Galilean ones, when you have objects traveling at close to or at the speed of light. You could use the Lorentz transformations for the soccer ball case also (since the GT are an approximation to the LT).

1. Pierce R. Butler says

The truck can never travel at the speed of light, of course.

They’d have to do that experiment on the autobahn -- and rather quickly.

2. sonofrojblake says

I misread that at first as “Galileean relativity”, and pondered for a moment what that could be. “I am the way, the truth and the always-travels-at-the-speed-of-light, sayeth the Lord”, or something.

3. robert79 says

of course… someone is going to come along and claim they didn’t fire the soccer ball backwards, but simply dropped it with no velocity…

4. Rob Grigjanis says

You would have to use the Lorentz transformations, not the Galilean ones, when you have objects traveling at close to or at the speed of light.

Not at the speed of light -- the transformation becomes undefined;

(1 − v²/c²)^(-1/2) goes to ∞

5. John Morales says

Ah yes, Mythbusters. In their first season, they lived up to their name.

But the rot set in pretty quickly, much like Top Gear with Jeremy Clarkson.
Pretty soon it was all about the badinage between presenters, and pointless explosions.

I gave up on it early in the second season. No regrets.

(Seriously, each episode could be distilled into a 3 minute segment without losing any info)

6. Jazzlet says

I thought the headline said Gallifreyan …