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Showing posts from August, 2020

Alone or not?

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  Image taken fron pixabay The search? Maybe because we are social animals by nature, we are afraid of being alone. Even though there are billions of us on this planet, not to mention all the other incredible creatures that we share this planet with, on the cosmic scale we feel quite lonely. The instinctive search to look for life elsewhere has been driving humans to develop new and more powerful telescopes some of which are mainly used to find habitable planets. Even landing on Mars multiple times and conducting experiments and sending out other probes to take a closer look at the other planets in our solar systems and even their moons. Who knows, we might find something as new and improved probes and sensors are developed.  Are we really? I would like to clarify that I do not believe that earth is the only planet with life. Looking at the sheer number of planets that are out there and then seeing the diversity of life on our planet that is thriving in almost all kinds of env...

Quasars and Direct collapse black holes.

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  Image taken fron pixabay. Some of the most distant objects discovered till now, powered by super massive black holes millions to billions of times the mass of the sun, quasars (or quasi-stellar objects) are some of the brightest objects in the known universe. Quasars are generally found in galactic centers with highly dense clouds of gas and dust and these are extremely luminous active galactic nuclei. Black holes appear black because even light cannot escape it's gravitational pull. When matter from these clouds is sucked into the black hole some particles are flung outwards at high speeds (nearly the speed of light) and these jets can be seen above and below it. Due to this, they are among the brightest objects known to us. Credits: NASA, ESA, and X. Fan (University of Arizona) B ut  there is another mystery at the heart of this. As they are also one of the most distant objects it means that they are among the oldest objects too. The quasar  J0439+1634, shown above, i...

Galactic Collisions

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NGC 1614 Image Credit: ESA/Hubble & NASA, A. Adamo What happens when 2 objects collide? Well it depends on various things, what is the size/mass of the objects, what are their respective compositions etc. If the objects are of considerable size and mass then the results can be incredibly spectacular and even destructive. Now imagine 2 galaxies, hundreds of thousands to millions of light years across, hurtling towards each other at hundreds of kilometers per second. Thanks to hubble we don't need to imagine. The image above is not the first time hubble has captured such an event and this is not a recently discovered galaxy either but this image is new. NGC 1614 was discovered in 1885 by American astronomer Lewis Swift. This is the result of the merger of 2 galaxies, a trail arm of stars can be seen in the upper side of the image and by the looks of it the merger is not complete yet. A few other examples can be seen below: UGC 2369 Image credit: ESA/Hubble & NASA, A. Evans...

Milky-way's long lost sibling? SPT0418-47

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Gravitationally Lensed view of SPT0418-47. Image taken from www.eso.org Credit: ALMA (ESO/NAOJ/NRAO), Rizzo et al. SPT0418-47, this is the "catchy" name given to the above galaxy. Located about 12 billion light years away from us this galaxy seems to be very similar to ours. I know that we do not have any direct images of the Milky-way galaxy, for that we will have to go outside our galaxy at a fair distance and then take a picture, I'm sure that is not possible for the foreseeable future. But we know that it is a spiral galaxy and we have pictures of many other such galaxies for reference.  Reconstructed view of SPT0418-47. Image taken from www.eso.org Credit:ALMA (ESO/NAOJ/NRAO), Rizzo et al. At first glance it looks nothing like a typical spiral galaxy like ours. It is disc shaped but there are no beautiful spiral arms like the ones we see in images from the hubble telescope. So what makes this galaxy so simlar to ours? Well at this stage it may not look like it but it...

Planets orbiting Black holes

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  Image taken fron pixabay The first planets we learn about as children are the ones in our solar system. So as children, a concept is developed that planets orbit around stars no matter how big or small. But planets can exist without stars, rogue planets are planets that wander through the cosmos without a star. Such planets are hard to spot as they are not illuminated by a star. But they can be found using infrared light and according to some estimates there could be billions of them in our galaxy alone. I thought that was amazing but for the past few days I have been reading posts about planets that may be orbiting black holes, even super massive black holes. Now when we think about black holes it is hard to imagine a planet orbiting it safely. If that is the case then what would such a planet be like and could it be potentially habitable? Also, what about time dilation on such planets? We may never get the answer to these questions during our lifetime, but I hope that we do, so...

Black holes - Destroyers or Recyclers

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  Image taken fron pixabay More than a century ago Albert Einstein presented his theory of relativity. Through this theory objects like Black holes were thought to be theoretically possible, even though Einstein himself had reservations about such objects. Finally photographed in 2019 (Super massive black hole at the center of Messier 87 galaxy), black holes are still mysterious. Maybe because we still don't know much about them. They are known for devouring everything that gets too close to them, even light. I'm sure that you know this already. But what if they play a much bigger role than this? The prevailing theory is that the universe started with a big bang and the expansion of the universe is accelarating and the universe will keep on expanding. There is another theory known as the Cyclic theory which gets attention from time to time. According to this theory the universe does not have a start or end point and that the current big bang is just one of many. If we look at n...

Aliens - What can we expect?

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Image taken fron pixabay We have a strange concept of alien life mainly due to Sci-fi movies. But in reality, if we do find alien life, what can we expect? I think that we can imagine, if we take a look at the diversity of life on earth throughout the history of this planet. We can find all manner of life forms, from single celled organisms to all the life we see now. As the planet evolved so did the life forms and we can use that information to imagine what may lie out there.  For example, we know that there once existed giant insects due to the oxygen rich environment that once existed on our planet, there were once giant snakes due to higher average temperatures, who can forget the dinosaurs which pushed the upper limits of size that can be achieved on land and not to mention all the strange aquatic life. We might find life at any of these stages and that is only assuming if things are similar to earth. What if we find life on a planet with stronger gravity than earth? It may ha...

Time travel

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Image taken fron pixabay I think everyone is fascinated with time travel. It might be due to popular Sci-fi movies which show different kinds of time machines with clocks sticking out of them or too many lights that attract our inner child. Or maybe because we make so many mistakes in our lives that we really want to go back in time and fix all of them. No matter what the reason for this attraction is this will always be a fascinating as well as controversial debate, at least until it is proven to be possible or impossible definitively.  But for now we might not be able to go in the past but due to the speed of light we sure can see in the past. Because when we start looking farther and farther away the speed of light, as fast as it is, does not seem to be fast enough. Even in the case of our own solar system which is not that large when we consider things on a cosmic scale. We know that we can only see something when light from that thing reaches us. Whether that thing is the sour...

We are stars???

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Ever since childhood one of the most eye catching things for us are stars. Whether they have 5 points or twinkle in our nursery rhymes or even when we see them in the night sky, they have a strange attraction like someone you have a close connection to. Maybe that is not so wrong as everything we see around us even inside our bodies were formed inside the cores of these stars. Of course I don't mean that rocks, plants or arms, legs or kidneys were formed there. Rather all the elements that make up these things were and there is strong evidence to support it. Almost everyone knows about the big bang. But the interesting thing is that not everything was created then and there. It's not like all the elements were created right after this event. Even Hydrogen and Helium that make up most of the matter in the visible universe were formed after a few minutes, once things had cooled down a bit. All the other elements that we know about took quite a bit longer and we can thank the star...

Life on other planets

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Image taken fron pixabay Everyone must have heard the news by now that there are an estimated 6 billion earth-like planets in our milky-way alone.  So that means that there is a very good chance of life on other planets. This is exciting news but is it that shocking? If we consider the vastness of our galaxy not to mention the entire universe and the fact that elements like carbon, hydrogen, nitrogen, oxygen etc are some of the most abundant elements in the universe, life seems inevitable. The possibility of intelligent and technologically advanced life forms can be debated but I'm sure that simple life is abundant and thriving. There is good proof of that even on earth. We can find life even in the most inhospitable places on earth. Earlier this year a parasite called "Henneguya salminicola" was discovered that does not need oxygen. If life like that can exist on earth then why not on other planets. In my opinion it is just a matter of time. As our technology advances we...