More astronomical information or links to websites you can find on my page Usefull Links.
An interesting website with the most recent and latest astronomical news is Astronieuws.nl.
The information shared is in the Dutch language, but they reference the original sources.
Sunday, November 23, 2014
Thursday, October 30, 2014
Double rainbow explained and Alexander's dark band.
A rain droplet functions both as a mirror and prism.
As the first, primary, rainbow is caused by refraction and reflection of sunlight within rain drops, the secundary rainbow will show up when sunlight is reflected twice within the droplet. This also explains the reason why we see the reversed order of the colors. Because of the extra reflection and thus light gets lost, we see the secundary rainbow less bright than the primary rainbow.
Another phenomenon is the area between the primary and secundary rainbow. This area is typical darker and called Alexander's band or Alexander's dark band. This optical phenomenon was the first time described by Alexander of Aphrodisias, 200AD.
As the first, primary, rainbow is caused by refraction and reflection of sunlight within rain drops, the secundary rainbow will show up when sunlight is reflected twice within the droplet. This also explains the reason why we see the reversed order of the colors. Because of the extra reflection and thus light gets lost, we see the secundary rainbow less bright than the primary rainbow.
Another phenomenon is the area between the primary and secundary rainbow. This area is typical darker and called Alexander's band or Alexander's dark band. This optical phenomenon was the first time described by Alexander of Aphrodisias, 200AD.
Wednesday, October 29, 2014
Saturday, October 18, 2014
Startrail Summer triangle
Startrail of the summer triangle. This triangle is made by the brightest stars Vega, Altair and Deneb of the constellations Lyra, Aquila and Cygnus. Picture taken using by Nikon D60 and pictures stacked using Startrail.de and final modified using CS4.
Record High Temperature
Today, October 18 2014, a record high outside temperature was registrated in Belgium. The previous record was recorded 100 years ago. In Averbode a temperature of 25,5°C was measured around 17h08.
Friday, October 17, 2014
Eclipse August 21, 2017
The eclipse of 21 august 2017 in the US will be a unique opportunity to experience a total solar eclipse combined with a visit to the US.
Interesting websites : see usefull links on this blog
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