Word: fractional
(lookup in dictionary)
(lookup stats)
Dates: all
Sort By: most recent first
(reverse)
...comet Hale-Bopp was one) are usually not spotted until they begin to flare somewhere out near the orbit of Jupiter or closer, only a few to 18 months before they pass Earth's orbit. That doesn't leave much time for defensive measures. Then, too, only a tiny fraction of the more numerous and smaller NEOs, some of them potential city killers and tsunami producers, are yet known...
Polls show that 54% of Americans are convinced that there are aliens out there, to say nothing of the significant fraction (30%) who suspect we've already been visited by them...
Since 1965, astronomers have had powerful evidence that the cosmos began with a Big Bang and that everything has been expanding outward ever since. But in the 1970s and early '80s, U.S. and Russian physicists (including Guth) realized that powerful energy fields dominating the cosmos when it was a fraction of a second old could have turbocharged the expansion, forcing the universe to fly apart--or "inflate"--at a rate many times faster than the speed of light. (The light barrier can't be broken by things moving through space, but space itself is exempt from this universal speed limit...
...problem with wormholes is that the openings are microscopic and tend to snap shut a fraction of a second after they're created. The only way to keep them open, as far as we know, is with matter that has negative density. In layman's terms, that's stuff that weighs less than nothing. This may sound impossible, but the Dutch physicist Hendrik Casimir theorized in 1948 that holding two plates of electrically conducting material very close together in a vacuum actually does create a region of negative density that exerts an inward pressure on the plates. The force predicted...
...would be terribly convenient to circumnavigate the earth in a fraction of a second, to make a round trip to the sun in just over a quarter of an hour, to go to Neptune and back in a workday. Modern life is too busy to waste time getting from here to there, and flitting around at the speed of light--about 186,000 miles per second--would take a lot of the drudgery out of travel...