Category: Space Science


Are We Alone


Are We Alone?

Are we truly Alone?

“The large-scale homogeneity of the universe makes it very difficult to believe that the structure of the universe is determined by anything as peripheral as some complicated molecular structure on a minor planet orbiting a very average star in the outer suburbs of a fairly typical galaxy.”
– Stephen Hawking

The universe is a pretty big place with about 80 billion galaxies and 10^24 stars. Humans have lived on this earth for millennia’s. We have always thought that are we the supreme beings in this cosmic junction are we the only sentinel beings in such a vast place. If it were only us wouldn’t it be an awful waste of space? I have always, as a child been interested at the enormity of our universe I have always wondered “are we alone?” We are just mere dust fleck in this vast cosmological sea. We are just a pale blue dot, the third rock from the sun lucky enough to sustain life.

We have heard of UFO sightings and of alien abductions all our life and we discard them as hokum or fun. We have all heard of little green men coming in ships to observe or annihilate us.

There have been numerous stories about contacts with extra-terrestrial life forms ranging from aliens abducting cattles to humans themselves. The most famous UFO incident ever dates back to July 8 1947 in place called Roswell, New Mexico. On that uneventful night a huge crash was sounded in the middle of the desert on the next day a huge army encampment was found and the headlines given by Walter Haut an army official read “RAAF captures Flying Saucer”, this led to huge hysteria among people.

At that place where the crash happened a farmer, W.W. “Mack” Brazel lived who saw what had crashed and he diatribe’s them as silvery-purple objects with certain humanoid forms inside. In the next week the army took back its statement saying that there weren’t any flying saucers but it was just a weather balloon.

Well there is another connection to Roswell incident and alien conspiracy theories and it is said that and secret US military base in the middle of the Mohave desert in Las Vegas Nevada called Area 51. It is said that the three alien life forms encountered at Roswell and the debris from the spaceship was taken to this site where it is till date being studied and deciphered. The movie independence day and the TV series 7 days even are based on such dogmas itself. Outside of area 51 a warning states that violent force will be used if anyone tries to enter within the radius of the facility and photography is strictly prohibited. The US Govt. denies that area 51 is even a base of operations.

Stephen Hawking believes that if ever we encounter alien life it won’t be better for humanity. If they travel so far from outer space they won’t go without making contact. Probably a civilization which is so developed to travel hundreds of light years, it could probably have expired its resources and plans to attack earth. It might be possible such an developed civilization can even annihilate us if it found us. For them we must be like vermins infesting a planet full of resources and nature’s bounty.

Some scientist believes that we don’t have to go looking for alien life in the far reaches of the universe; we might find it in our very own solar system. Our own neighbor Mars has shown the prospect of life; it still has frozen water, scientists believe that any number of bacteria or virus can live at the depths of mars craters. Although this life might be primitive but would surely qualify as extraterrestrial contact. Films like Mars Attacks and Andromeda strain to the classic book by HG Well War of the World have depicted as mars having life and its inhabitant’s invading us. Europa one of Jupiter’s moon has a 6 foot of frozen ice layer on its’ surface but inside has flowing water and scientists believe that maybe marine life might exist there and aphotic bioluminescent bacteria might exist there.

SETI search for extra-terrestrial intelligence was started by one scientist Frank Drake in around 1960 where he pointed all his auditory satellites up to look for outer audible signals and thus began an intensive search of space for electromagnetic radiation which are the best source if aliens contact us. Project Orion started by US deals solely with SETI and listening to outer space is heard.

The Wow! signal was a strong narrowband radio signal detected by Dr. Jerry R. Ehman on August 15, 1977, while working on a SETI project at the Big Ear radio telescope of The Ohio State University. Delaware, Ohio.[1]The signal bore expected hallmarks of potential non-terrestrial and non-solar system origin. It lasted for the full 72-second duration that Big Ear observed it, but has not been detected again. The signal has been the subject of significant media attention. Scientists believe that WOW signal was of alien origin probably sent by an intelligent life form. . Only about 15% of the know space is known to us.

There is a famous quote from X – Files which I love that is “The truth is out there” these lines have a profound meaning just as CIA agent Fox Mulder passionately keeps on trying to find clues to extraterrestrial life forms in the same way humanity must itself keep on striving to find our cousins light years far away from here. And maybe then we could answer one of the question that haunts humanity from time immemorial and that “why are we here? And what is our purpose?”

By Ali Akbar
(A Minerva-M Writer)
Read more articles at www.minerva-m.com

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A few hundred million years after the Big Bang, the universe was a soup of ionized H (Hydrogen), He (Helium) and D (Deuterium) with trace amounts of Li (Lithium), B (Boron), Be (Beryllium) and H2 (molecular Hydrogen). With little amount of metal and H2, the conditions were far from ideal for star formation.

For star formation to begin, a sufficient amount of cold dense gas has to accumulate. But in the early universe, the primordial gas could not efficiently cool radiatively because atoms had excitation energies that were too high, and molecules, which had accessible rotational energies, were very rare and only trace amounts of molecular hydrogen (H2) were formed.

Under proper conditions, the formation of molecular hydrogen  allows the gas to cool. The cooling of the gas lead to thermal instability and a local density enhancement, which resulted in the fragmentation of the gas cloud. In the primordial gas clouds, the thermal instability took place at higher temperatures compared to leading to the formation of massive stars with mass of about 100 solar masses.

 

Primordial gas clouds undergo runaway collapse and forms a protostar when sufficient mass is accumulated at the centre. Then, the protostar starts to grow by accreting the surrounding gas to become a massive star. The ultimate mass of the star is determined by the mass of the cloud out of which it forms and by a number of feedback processes that occur during the evolution of the protostar.

The protostellar feedback processes affect the formation of primordial stars quite differently from the contemporary stars. First, primordial gas does not contain dust grains. As a result, radiative forces on the gas are much weaker. Second, the amplitudes of magnetic fields generated in the early Universe are so small that they never become dynamically significant in primordial star-forming gas. Magnetic fields have at least two important effects in contemporary star formation: they reduce the angular momentum of the gas out of which stars form, and they drive powerful outflows that disperse a significant fraction of the parent cloud. Third, primordial stars are much hotter than contemporary stars of the same mass, resulting in significantly greater ionizing luminosities.

The feedback processes affect the formation of individual stars also influence primordial star formation on large scales. The enormous fluxes of ionizing radiation and H2-dissociating Lyman–Werner radiation emitted by massive population III stars dramatically influence their surroundings, heating and ionizing the gas within a few kiloparsecs of the progenitor and destroying the H2 within a somewhat larger region. The effect of radiation from the first stars on their local surroundings has important implications for the numbers and types of population III stars that form. The photoheating of gas in the minihaloes hosting population III stars drives strong outflows, lowering the density of the gas in the minihaloes and delaying subsequent star formation by up to 100 Myr.

Abhinab Paul

(A Minerva M Writer)

Read more articles at www.minerva-m.com