think thank thunk

This actually makes an interesting point, sort of. Why don't you recoil when you shine a beam of light? The answer is -You actually do! But not at the same SPEED as the light - with the same MOMENTUM as the light. The momentum (p) of a single photon of light is equal its energy divided by the speed of light (E = c p). So how much momentum does a beam of light carry? Well, suppose we shine a 100 Watt spotlight - we are producing 100 Joules of light energy per second (a Watt is a Joule of energy per second). So every second we are giving that light a momentum of (100J) / (300,000,000m/s) = .00000033 kg m/s.

To give a sense of how hard of a push that is, let's assume that the stupid troll thing in the wagon weighs 50 kg. To accelerate the wagon up to a speed of 1 m/s (around 3 feet per second... which is still pretty slow) would take (33 million * 50) seconds, which is 52 years. And that's assuming no friction!

(In reality, it would never move at all because of friction, so we'd have to do it in space. In fact, even though this seems like a feeble form of propulsion, NASA has plans for prototypes of a "solar sail" to push space probes out of the solar system using no propulsion other than that provided by reflected sunlight!)

Just moving straight up into the air ("making the jump to the third dimension") doesn't get you from Rome to Buenos Aires.

That's the annual cost to fliers when planes don't run on time, according to researchers who delivered a report Monday to the Federal Aviation Administration detailing the economic price of domestic flight delays.

The total cost to passengers, airlines and other parts of the economy is $32.9 billion, according to the FAA-commissioned report. More than half that amount comes from the pockets of passengers who lose time waiting for their planes to leave and then spend money scrounging for food and sleeping in hotel rooms while they're stranded, among other costs.

Much of what medical researchers conclude in their studies is misleading, exaggerated, or flat-out wrong. So why are doctors—to a striking extent—still drawing upon misinformation in their everyday practice?