Apr 19, 2011

Unequal weights fall with the same speed in a vacuum

"In his 1638 Discorsi Galileo's character Salviati, widely regarded as largely Galileo's spokesman, held that all unequal weights would fall with the same finite speed in a vacuum. (...) Galileo proposed that a falling body would fall with a uniform acceleration, as long as the resistance of the medium through which it was falling remained negligible, or in the limiting case of its falling through a vacuum."

Source: http://en.wikipedia.org/wiki/Galileo_Galilei

Apr 18, 2011

Wonders of the Universe

No APOD de hoje está um vídeo muito interessante que nos leva numa viagem pelos objectos celestes do nosso Cosmos. O vídeo foi criado pela BDH e a música por Timo Baker.
Today's APOD is not a picture but it is an amazing video which takes us in a journey throughout the Cosmos. The video was produced by  BDH and the music was composed by Timo Baker.
Link to APOD:  http://apod.nasa.gov/apod/ap110418.html

Apr 7, 2011

AAPOD 07/04/11: Biggest Moonrise in almost 20 years

É com agrado que vejo mais uma foto minha como AAPOD!
Link permanente:
I am glad that "my Super MoonRise" is today's AAPOD!
Permanet link:

Mar 31, 2011

NASA Announces 1235 Planet Candidates

NASA's Kepler mission has discovered its first Earth-size planet candidates and its first candidates in the habitable zone, a region where liquid water could exist on a planet's surface. Five of them are Earth-like. The findings increase the number of planet candidates identified by Kepler to-date to 1235. 170 stars show evidence of multiple planetary candidates 

Source:  http://kepler.nasa.gov/news/nasakeplernews/index.cfm?FuseAction=ShowNews&NewsID=98

Mar 20, 2011

LPOD: 20/Mar/2011 - Supermoonrise

LPOD: 20/Mar/2011

I am glad to see that my image sequence of the supermoonrise was selected to be today's LPOD (with Damian Peach's image too). It's "my" second LPOD (this was the first). The aparent diameter of this (almost) perigee moon (only 1h05min apart) was about 33.5'! Very impressive!

Here it is the permanet link to LPOD of 20/Mar/2011:

PS: Check  also Supermoon Photo Gallery from APOD's forum!

Biggest Moon in almost 20 years!

This animated (click in the pictures to start the animation) GIFs shows the "biggest moonrise" in almost 20 years! The moon had reached the perigee just 1h05min before I took the pictures. Prime focus in 8" f/5 reflector and Canon 1000D.



Color inverted

BW inverted

This video from NASA explains the phenomenon: