One-way plunge into black hole takes 200,000 years: “The one-way journey from the heart of a galaxy into the oblivion of a black hole probably takes about 200,000 years, astronomers said on Monday. By tracking the death spiral of cosmic gas at the center of a galaxy called NGC1097, scientists figured that material moving at 110,000 miles an hour would still take eons to cross into a black hole.” (Yahoo! News)
Mysterious lightning characterized three powerful hurricanes this season. I was actually surprised to learn that lightning is unusual in hurricanes, although the reason makes sense once you understand what makes lightning in the first place:
Within thunderclouds, vertical winds cause ice crystals and water droplets (called ‘hydrometeors’) to bump together. This ‘rubbing’ causes the hydrometeors to become charged. Think of rubbing your socked feet across wool carpet–zap! It’s the same principle. For reasons not fully understood, positive electric charge accumulates on smaller particles while negative charge clings to the larger ones. Winds and gravity separate the charged hydrometeors, producing an enormous electric field within the storm. This is the source of lightning.
A hurricane’s winds are mostly horizontal, not vertical. So the vertical churning that leads to lightning doesn’t normally happen.”
A NASA flyover of Hurricane Emily measured electric fields comparable to those seen over massive land-based thunderstorms. While flyovers were not done of Rita and Katrina, electric discharges were detected by remote land-based sensors. The investigators dismiss the tempting concept that the sheer violence of these three category 4 and 5 storms was responsible for the generation of the electrostatic fields, since the phenomenon has not been observed in other equally violent storms. They conclude that they have alot to learn… (NASA)