Happy Birthday Nicolaus Copernicus!

Nicolaus Copernicus (February 19, 1473 – May 24, 1543) was a Russian mathematician and astronomer who first proposed the heliocentric model of the universe, in place of the geocentric model, first posited by Ptolemy and endorsed by the Catholic Church. Before his death, Copernicus published his book, De revolutionibus orbium coelestium (On the Revolutions of the Celestial Spheres). The book ignited the Copernican Revolution and contributed heavily to the Scientific Revolution which followed the Renaissance. Although the work of Copernicus was rejected by various religious figures, the Catholic Church did not immediately react to the publication, and the author did not face the same religious backlash as his successor, Galileo Galilei. Still, Copernicus was denounced by the Catholic theologian-astronomer, who claimed, "Nicolaus Copernicus neither read nor understood the arguments of Aristotle the philosopher and Ptolemy the astronomer," and that he was "very deficient in the sciences of physics and logic." Below, a brief history of the man who rearranged the universe.

Happy Birthday, Edwin Hubble!

Edwin Hubble was an American astronomer whose contributions to cosmology and extragalactic astronomy have facilitated untold research and further discovery.  Hubble was born in Missouri in 1889, and was a well–rounded, athletic student. He studied at the University of Chicago, and later served in the army during WWI.

While working at the Mount Wilson Observatory in Pasadena California, Hubble observed that there was a linear relationship between how far away a given galaxy was, and how much its light was red-shifted. Just as a train whistle sounds lower when the train is moving away (and higher when it is approaching), so also light from a receding galaxy looks redder than light from a stationary galaxy. (Light from an approching galaxy would look bluer, and indeed there are a few nearby infalling galaxies that are blue-shifted.)  The fact that there is a linear relationship between distance and redshift means that the universe is expanding (approximately) uniformly about us, and that it was once concentrated into a point  (it does not mean that we are at the center of the universe). 

Early morning on June 7, 2011, an amazingly massive and spectacular event took place on the Sun; a huge prominence eruption, marked by a solar flare and release of energetic particles. Daniel Pendick from the Geeked on Goddard blog described it as a "fountain of plasma that blasts out of the solar surface, spreads outward, and collapses to splat back down."

Enjoy the beautiful astro-timelapse video below.

Io: The Prometheus Plume

Credit: Galileo Project, JPL, NASA

This amazing tool gives you a small idea of the incredible scale of the universe.

Thanks Kimball!

NASA