"On January 4, 2008, a reversed-polarity sunspot appeared—and this signals the start of Solar Cycle 24," says David Hathaway of the Marshall Space Flight Center. Solar activity waxes and wanes in 11-year cycles. Lately, we've been experiencing the low ebb, "very few flares, sunspots, or activity of any kind," says Hathaway. "Solar minimum is upon us."
It’s well known that black holes can slow time to a crawl and tidally stretch large objects into spaghetti-like strands. But according to new theoretical research from two NASA astrophysicists, the wrenching gravity just outside the outer boundary of a black hole can produce yet another bizarre effect: light echoes.
