Friday 17 March 2017
coolfactsabouttheUniverse: The universe is so vast it’s extremely difficult t...
coolfactsabouttheUniverse: The universe is so vast it’s extremely difficult t...: The universe is so vast it’s extremely difficult to know the full extent of its complexities. Humans can only scratch at the surface of it...
Thursday 16 March 2017
1. A recent anomaly observed in its orbit has made scientists highly skeptical about the existence of an alien megastructure lurking out there around the star named KIC 8462852 situated 1,480 light years away. Data from the planet-hunting Kepler telescope has shown that this particular star's light has dimmed by about 20% for up to 80 days at a time, and at irregular intervals and that, there’s no planet around, nor is it likely to be a clot of dust and rocks.
Edit 1 : Here’s a pretty informative TED talk by Tabetha S. Boyajian, best known for her research on KIC 8462852 : The most mysterious star in the universe Thanks Hassan for mentioning it in the comments!
2. Roughly 68% of the universe is Dark energy, the rest 27% being an invisible Dark matter and all the normal matter that we see comprises the remaining 5% content. The speciality of dark matter is that it does not interact with any known matter and is thus invisible to the entire electromagnetic spectrum while dark energy is responsible for the ever-accelerating expansion of the universe.
3. There is this famous Drake equation which gives the probabilistic estimate of the number of active, communicative extraterrestrial civilizations in the Milky Way galaxy.
where,
R* = the average rate of star formation in our galaxy,
fp = the fraction of formed stars, fp, that have planet
ne = the average number of planets per star, that can potentially support life,
fl = the fraction of those planets that actually develop life
fi = the fraction of planets bearing life on which intelligent, civilized life has developed,
fc = the fraction of these civilizations that have developed communications, i.e., technologies that release detectable signs into space, and,
L = the length of time over which such civilizations release detectable signals.
This gives an astonishing result indicating the average distance we should expect to find any alien intelligent life form may be 2,670 light-years from Earth and that, there is a 75% chance we could find ET between 1,361 and 3,979 light-years away. Thus, our failure in finding any ET yet has been perfectly normal!!
Edit 2 : However, the variables used in the equation may vary from scientist to scientist, and even a slightest change can result in vastly different answers. Also, the equation assumes a sort of cosmological uniformity rather than a dynamic and ever changing universe, since it does not take into account the age of galaxies, the time at which intelligence first emerged ,etc. Also not to forget that after a certain time, a civilization may be advanced enough to stop releasing unintentional signals into the space and that some might undergo Technological singularity, ie. civilizations which have passed through the radio-signal ages, if so, we can never know what these civilizations might be capable of, and detecting them through our present-day technologies would be next to impossible. Finally, our rapidly changing of understanding of cosmology and astrobiology leaves a very little consensus amongst the values of the variables used and hence, Drake equation might not be that reliable and scientific, as of today. Thanks Scott for bringing in the topic!
4. There are five such points around the Earth where the gravitational pull of the Earth and the moon is exactly balanced by the centripetal force due to the moon’s circular motion. These spots are known as the Lagrangian points. In addition to stability, these points also provide stable thermal environment, i.e. any satellite placed at one of these points would be far away from the sun’s heat and light and thus, would be much more sensitive to measuring infrared radiations.
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