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kottke.org posts about Dennis Overbye

A tour of our solar system’s eclipses

posted by Jason Kottke   Aug 16, 2017

In a meditative video for the NY Times, Dennis Overbye takes us on a tour of eclipses that happen in our solar system and beyond.

On the 21st day of August, 2017, the moon will slide between the Earth and the sun, painting a swath of darkness across North America. The Great American Solar Eclipse. An exercise in cosmic geometry. A reminder that we live on one sphere among many, all moving to the laws of Kepler, Newton and Einstein.

Humans have many more vantage points from which to observe solar eclipses than when the last solar eclipse occurred in the US in 1979. I had no idea that the Mars rovers had caught partial solar eclipses on Mars…so cool. (via @jossfong)

Supernova reruns

posted by Jason Kottke   Mar 05, 2015

Astronomers have been able to view the same supernova in a distant part of the Universe several times due to the gravitational lensing effect of a cluster of galaxies in-between here and there. From Dennis Overbye in the NY Times:

Supernovas are among the most violent and rare events in the universe, occurring perhaps once per century in a typical galaxy. They outshine entire galaxies, spewing elemental particles like oxygen and gold out into space to form the foundations of new worlds, and leaving behind crushed remnants called neutron stars or black holes.

Because of the galaxy cluster standing between this star and the Hubble, “basically, we got to see the supernova four times,” Dr. Kelly said. And the explosion is expected to appear again in another part of the sky in the next 10 years. Timing the delays between its appearances, he explained, will allow astronomers to refine measurements of how fast the universe is expanding and to map the mysterious dark matter that supplies the bulk of the mass and gravitational oomph of the universe.

Scientists expect the supernova to reappear in the next few years. Gravitational lensing was predicted by Einstein’s general theory of relativity and as Overbye writes, “the heavens continue to light candles for Albert Einstein.”