The physicists tested their idea with satellite images of boats and ships from the website Google Earth, measuring the wake angle and length of the boat from the pictures and inferring the boat's speed from details of the wake.
Discovered only 10 years ago by physicists testing a low-light video camera from an observatory, the eerie red sprites, streaks of light called blue jets, and related phenomena are now being studied intensely to figure out their role in the planet's electrical circuitry.
It could also enable physicists to test whether some properties describing atomic forces, now believed to be constant, are slowly changing as the universe expands.
Rather than making precise predictions for features of the universe the anthropic principle gives a vague range of values so it is difficult for physicists to test, he added.
Some suggest, for example, the rate of the passage of time could depend on a clock's orientation in space, an effect that physicists hope to test on the space station.
(In one test, physicists measuring gravity by means of deep boreholes in the Nevada desert found a two-and-a-half-per-cent discrepancy between the theoretical predictions and the actual data).
More relevant to the Massively Open Online Community courses (MOOCs) being piloted in higher education, a team of researchers from that replacing a physics teacher with lectures from a Nobel Prize-winning physicist nearly doubled test scores [PDF].
Some physicists have been testing whether Newton's law of gravity remains correct at distances shorter than a millimeter or so; the delicate experiments can be muddled by extraneous electromagnetic effects.
If enough radioactive residues seep out of the underground test area, physicists might eventually be able to give us the answer.
Physicists still need to test whether the observed particle has precisely the properties that the standard model predicts it should, stresses John Ellis, a theorist at King's College London.
