Minute Physics
#AstronomyTermOfTheDay @MinutePhysics
Astronomy Term of the Day
Prior to this epoch, the electrons weren't captured by the nuclei. These electrons scattered the photons causing them to have a very short mean free path. Thus the universe was opaque.
Once the neutral atoms formed, the photons were free to travel with a longer mean free path. This gave way to the "first light" of the universe at 4000 K. Using Wien's law, we find that this temperature corresponds to infrared-orange wavelength. Thus the universe was of orange color. With time, due to expansion of the universe, this radiation got redshifted and now, after 13 billion years, it lies in the microwave spectrum. This is the reason why we see nothing in the background of the universe with the naked eye. The radiation is invisible to the naked eye. It is now known as the "afterglow" of the big bang.
Prior to this epoch, the electrons weren't captured by the nuclei. These electrons scattered the photons causing them to have a very short mean free path. Thus the universe was opaque.
Once the neutral atoms formed, the photons were free to travel with a longer mean free path. This gave way to the "first light" of the universe at 4000 K. Using Wien's law, we find that this temperature corresponds to infrared-orange wavelength. Thus the universe was of orange color. With time, due to expansion of the universe, this radiation got redshifted and now, after 13 billion years, it lies in the microwave spectrum. This is the reason why we see nothing in the background of the universe with the naked eye. The radiation is invisible to the naked eye. It is now known as the "afterglow" of the big bang.
Minute Physics
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ISRO will launch Cartosat-2 and 30 other satellites on January 12, instead of its earlier tentative date of January 10, a space official announced on Monday.
ISRO’s first space mission of 2018 aboard the Polar Satellite Launch Vehicle (PSLV-C40) is exactly four months after a similar rocket failed to deliver India’s eighth navigation satellite in the earth’s lower orbit on August 31 last year.
ISRO’s first space mission of 2018 aboard the Polar Satellite Launch Vehicle (PSLV-C40) is exactly four months after a similar rocket failed to deliver India’s eighth navigation satellite in the earth’s lower orbit on August 31 last year.