Monday 16 November 2015

Week 7 [16.11 - 22.11.2015] Black Holes

Black holes

Recently I have watched a TV documentary about black holes and their significance in the universe. Generally speaking, there are more questions than answers, what makes it even a hotter topic of discussion. So what do we now or rather assume we know in regards to the  laws of mathematics and physics? A black hole is a region, where exists so strong gravity that nothing even light can escape from it. Most likely they are created by great mass gathered in certain space-time. How to get such mass in relatively small capacity? At the end of life cycle a star collapses. If it is big, the mass compressed during its collapse creates a black hole. Around them exists space called event horizon. Does anything cross it, it will never be able to leave it. A detailed course how they work is available here (12m): https://www.youtube.com/watch?v=qZWPBKULkdQ.

Illustration showing star being eaten by black hole.

In the documentary there was information about the discovery of black hole in the center of Milky Way (our galaxy). Although there were predictions that it exists, it was extremely difficult to locate it and prove its existence, but thanks to Chandra X-ray Observatory it was possible. Right now scientists are trying to create a virtual telescope by aiming the biggest telescopes on Earth at the same location to get more data about it.  It was named Sagittarius A* and from latest computations it its radius is 13 times bigger than our Sun, with mass equal around 3.7 billion mas of Sun (quite a lot, don’t you think?). Observations are difficult not only due to distance, but as all every other object  moves in space. It is hard to calculate proper orbit of it, because it keeps expanding, and it’s mass changes all the time. Numbers hardly give a clear view how big black holes are, I recommend watching this short (4min) video for better perspective: https://www.youtube.com/watch?v=QgNDao7m41M.



Is there any threat to Earth? There is no theory that black holes explode, plasma that leaves them cannot affect us, it is barely noticable, so we are safe. For now, because after some bilions of years it would expand so much it could just suck us in. Right now its gravitational field range is about 100 000 000km, what gives us approx 0.00001 light year, where our distance to is 25368 ly.
At the end there were some theories about what can be behind event horizon. As told in the course video, there are many basic things still unclear for scientists, what gives a wide variety of what can be observed inside.  Have you watched Interstellar movie? Yeah, perhaps time travel is possible. But it would be to easy just to jump in, what is on the other side? From mathematical point of view if you put all data into equations and think how much matter black holes take into themselves maybe after getting there you would jump out right into Big Bang? What do you think? According to such technology development will we live long enough to see time travels? Or there is no such thing and going there will mean certain death?

More information for interested here:
https://www.youtube.com/watch?v=JcD6Ia6o78I National Geographic 1h30m documentary video

21 comments:

  1. The thing that we have already created so well-developed society, we, as a mankind, have achieved so much, we travel to the space, we get deep into Earth, but still there are so many questions we can't answer. It perfectly illustrate who (or what) has the power in this world. It is not us. It's nature. With one caprice it could ruin our world in less than a second. Who knows how many suprises does it still have?

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    1. People underestimate power of nature. Considering surprises, we still know less about oceans, than about space!

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  2. I've seen Interstellar and Event Horizon movie. Both great!
    Black holes, astronomy, UY Scuti, sci-fi. Interesting topics. I like to listen about, how small we are in comparison to the entire universe. Is our universe is the only one etc.
    That's why, with such enthusiasm I've read your presentation.
    I think if we could somehow penetrate into a black hole (with life). This could change our look at the world.

    There still many surprises... waiting to discover them.

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  3. I think I'm no scientist, therefore it's no use for me to wonder "what might" on the scientific basis. Having no conclusive proof, all we can do is treat it as sci-fi, which is awesome and all, but there's just too little data for anything more.

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    1. Looking at the fact how much we don’t know about space and black holes itself, I think that reasonable assumption is enough to start research in that area. Everything that is not impossible is worth checking.

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  4. Informations about black holes are as useful as informations about planets containing rare resources. They exist, but we can do nothing to leave the planet if it starts to destroy Earth.

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    1. Well, thankfully we don’t have to bother about abandoning earth to rescue ourselves from black hole, it is not going to suck us soon.

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  5. Black holes is a really abstract topic for me. I have never read much about it. I watch some movies like Interstellar but I'm aware that it's mostly fiction. I just hope they won't destroy Earth to soon :D

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  6. Black hole, people little they are talking about her, nothing about her is heard.
    He exists, is expanding, but nothing else.
    Most probably because I isn't interested in.

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  7. I'm curious where things appear(if they appear) on the other side of the black hole. Probably we don't have technology and science can not explain what exactly black hole are. It's very interesting, but we probably will need to wait to find out more about them.

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  8. Michał Stankiewicz22 November 2015 at 21:11

    Seeing movies like interstellar in the popular cinematography makes me sick. Because there are so many stupid people out there, that totally believe these movies. There are many people that after seeing all these pseudoscientific movies believe that the facts presented there are based on scientific facts. Some year ago We don't really know a lot about the black holes itself, we only know they are black spots somewhere there, there is ultra strong gravitation near there etc. But trying to guess what exists on their other side sounds just plain funny. Like the people living on Earth long ago, trying to guess why the sun is rotating with all the planets around Earth. And how are the turtles capable of carrying whole known world.

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  9. I would like to say that INTERSTELLAR IS CRAP and it showed really baaaad image of black holes, spacetime and its curvature.
    Black holes are one big mystery, nobody can tell what would happen if somebody went there, probably you would break into pieces.
    Tbh, black holes theory was almost disproved few times. It's only a theory, and bringing it to proven theory is a long way and guess we won't live to see it.

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  10. Like you said: "there are more questions than answers". We know almost nothing about black holes. In the sci-fi movies black holes usually leads to another dimensions. They are "gates" to other worlds. Personally, I would prefer to avoid contact with black hole.

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  11. Let's first at least get to Mars before we start talking about jumping into black holes, shall we? Or build a space elevator already! We know nothing, we see nothing, we may keep speculating about this, but please stop talking about time travel, teleportation, etc. While this *might* work in some weird way, the only thing that'll be going back in time are your finely ground remains.

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    1. Why not? There are scientists trying to make it possible to go to mars, and there are also scientists trying to get as much data about black holes as possible. In this article time/space travel is just a theory, there are many other more important things that may be discovered while observing black holes.

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  12. It's definitely interesting topic, and it's always great to learn something new, especially when it's that interesting and is one giant mystery.

    Personally I think that we know too little to even consider time travels, or anything connected with it. In fact, we barely know anything about space to be honest, like, we know just enough to claim that we're more or less "safe" in space, but it will take hundred of years to even think about colonization of other planets, and I don't consider an actual human life there, but at least evaluating them to search e.g. for new unknown resources which would benefit and help us to save the earth.

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  13. For most people on the subject of black holes is to put it mildly abstract. Everyone knows that such a thing exists, that is growing, that often they are increasing it. But it would be enough.

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  14. I really don't know anything about black holes but a friend of mine is fascinated by them. He watches movies on yt made by professors of MIT and even write articles about them.

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  15. I really like issues related to astronomy, but the black hole is constantly fascinating topic (but very little-known) for me. Just like time travel, although I have to admit that the "interstellar" was not convincing for me the film, because there were several fairytale scenes, which meant that I had not picked up the film too seriously.

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  16. It's hard to say something on that topic, it's very wide and not fully-discovered. I remember some things from science lessons about this but it's not really much to comment and there is discussion going on about interstellar but I didn't watch it :(

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  17. Would be pretty awesome if time travelling would turn out to be possible. Nevertheless, I'm sceptical that any of us will live long enough to see that.
    By the way, Interstellar was great, but a bit contrived, I think.

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