Black Hole

How is black hole formed? Explain 2Β  important features of black holes (in 100 words)

17 responses so far

to “Black Hole”

  1. gizemgokceron 01 Nov 2010 at 5:13 pm

    Black hole is formed by collapsing of a massive star. When the giant star?s fuel finish and star stops burning, they get crushed into a single point which is called a black hole. Black hole is a place where gravity is so strong that when something gets within a certain distance nothing can escape from it, including light. People need to be faster than the speed of light to escape from it. It is impossible to see a black hole directly because they don?t shine, they are black. Singularity and event horizon are important characteristics of black holes.Finally, astronomers find ways of detecting black holes. These are X-rays, rotating stars and gravity lenses.

    Comment:
    Gizem you started well, but towards the end the coherence is lost. You cannot simply give the names of singularity and event horizon, but you need to explain them. You need to give the names when you are explaining them not just at the end.

    Thank you
    Meltem

  2. selenyon 01 Nov 2010 at 6:14 pm

    Black hole is a kind of celestial thing that is like a dead star.When star?s fuel finish, it stops burning.A starwhicg is mass greater than 3 times the sun?s gets crushed into a single point,which human call a black hole.At a single point time and space stop.There is no volume and time doesn’t pass.It’s like the centre of a black hole.The point at the centre of a black hole is called a singularity.In a certain distance of the singularity, the gravitational pull is strong ..Many people think that nothing can escape the intense gravity of black holes.Astronomers find 3 ways for seeing them.These are X-rays, rotating stars and gravity lenses.

    (Word count:110)

    Comment:
    Coherence is maintained πŸ™‚
    Only give the name of the distance you are talking about before starting to talk about ways of detecting them.

    Thank you
    Meltem

  3. alibodurogluon 01 Nov 2010 at 6:54 pm

    Black holes came into existence by death stars. When a star is dying, if it is big and if its energy for burning went out, there is a mass left and it calls into being black hole. So a star, only if it?s three times bigger than our sun, can make exist black hole. Since a black hole comes into being, star’s all of the mass gets together on centre point which named singularity point. It causes an incredible gravity. Because of this gravity black hole can absorb huge stars. Actually all black holes have an event horizon. If something in it, cannot escape. There is only one way for escaping in event horizon of black hole, travelling faster than light speed so it?s impossible.

    105 words 124 words

    comment // Eren ;
    When a star which is big enough dying , it s burning energy went out,in addition there is a mass left and it calls into being black hole.If a star only it s three times bigger than our sun make black hole.The center point which named singularity point all of the mass gets together and it causes an incredible gravity.The gravity causes absorb huge stars.

    Comment by Meltem:
    Your first 2 sentences are problematic. Please try to write short but correct sentences. Coherence is affected from the mistakes in this part.
    There is some missing or wrong information in the following part. E.g. Black holes could only swallow stars when they are within the event horizon; not all huge stars are swallowed.
    Event horizon needs to be explained well.
    I’m afraid you cold not maintained the coherence because of the problems mentioned above.

    Thanks
    Meltem

  4. senaaksoyon 01 Nov 2010 at 6:55 pm

    A black hole is the formation which happens after the death of a star. If the star spent it?s fuel and stop burning, there?s no heat which can counteract to the energy of the gravity. With this energy the stars crushes into a small point which is called black hole. Black holes so powerful if something isn?t faster than a speed of light or doesn?t have enough safe distance, cant escape from it. The fact of they don?t shine, it?s impossible to see them without gravity lenses, detecting rotating stars and emiting x-rays. (93 words)

    Comment:
    You mentioned almost everything about the black holes and maintaind coherence (flow of ideas)
    However, it would be better if you also mention about the terms lile singularity and event horizon

    Thank you
    Meltem

    Comment 2:
    I just want to repeat the feedback given above. Why haven’t you changed anything? Such a writing won’t get a high grade in the exam πŸ™
    Meltem

  5. erenkaymazon 01 Nov 2010 at 6:59 pm

    Black holes occur when a star,which with mass greater 3 times Sun,dies.Since the stars fuel spent,as a result of that condition star burning no longer.Thus,in the center of star consist a single point ; where mass has no volume and time doesnt pass, which called singularity.Due to the star death,it was formed a event horizon.Since anything has fallen into the event horizon,consequently can’t escape.There is one way to get out of that event horizon is travelling faster than light.However,black hole has same mass as stars.On the other hand stars and planets orbiting also around the black hole.For to detect black hole,we should use some special solutions : Trap intense gravity,x-rays,rotating stars and gravity lenses.

  6. serselon 01 Nov 2010 at 7:28 pm

    Black holes appear when stars die.there are 2 important feature of black holes.these are event horizon and singularity.the point at the centre of a black hole is called a singularity.it’s very hard for us to imagine a place where mass has no volume and time does not pass but that’s what it is like at the centre of a black hole.The other feature is event horizon.within a certain distance of the singularity,the gravitational pull is so strong that nothing can escape.that distance is called the event horizon.it is has a very large velocity.and it is the point-of-no-return for anything that crosses it.(102 words)

    Comment:
    It is very straight forward and direct πŸ™‚
    All ideas are correct and given in organized manner πŸ™‚
    Only transition between the formation of a black hole, sinularity and event horizon could be done more smoothly.
    And please capitilize the letters at the beginning of a new sentence.

    Thanks
    Meltem

  7. oguzhanuon 01 Nov 2010 at 7:55 pm

    Black hole forms when the stars fuel is spent it stops burning, there is no heat left to counteract the force of gravity.Black hole is a place where the gravity is very strong if something’s speed is less then speed of light it cannot espace from it furthermore the point at the center of a black hole is called a singularity.Mass has no volume, time doesn?t pass and light cannot escape. Singularity and event horizon are important characteristics of black holes.Astronomers can find black holes by observing the gravitional effects on other objects.Lastly it is hard to see the black hole because it bends into light rays and also astronomers will find them out in 3 different ways which are ;x-rays,rotating stars and gravity lenses.

    (word count 118)

    Comment:
    Puntuation is very problematic. Since I do not know where your sentences fnish it is difficult to comment on the language mistakes and his affects the coherence in the paragraph.
    You need to explain event horizon as well as singularity. Just giving the names is not enough.
    Easy way of maintaining coherence is using transition signals. This will also help you to determine where to put a full stop.

    Thanks
    Meltem

  8. ytekinalpon 01 Nov 2010 at 9:50 pm

    Black holes are formations which form when stars die. Once a giant star dies and a black hole has formed. The point at the centre of a black hole is called the singularity. The mass has no volume and time does not pass here. Also both space and time stop in a singularity. A certain distance of the singularity which people call event horizon. The event horizon is not a physical boundary but there is no return for anything. The more mass the singulariy has ,the larger the event horizon. If human’s vehicles were faster than light, human’s vehicle could escape from event horizon but human’s vehicles can’t be faster than light.

    word count:105

    Comment:
    Ideas are all correct and almost everything is explained πŸ™‚
    However, there is no flow (coherence; unity) in the paragraph. Pay attention to connect each sentence to each other and all sentences to the topic

    Thanks
    Meltem

    Comment 2:
    Generally coherence is maintained and information is well presented πŸ™‚
    However, in some parts you have unfinished sentences:
    Once a giant star dies and a black hole has formed _ you need to use “once” like “when”
    A certain distance of the singularity which people call event horizon – not a sentence

    Thanks
    Meltem

  9. berivanbrknon 01 Nov 2010 at 10:29 pm

    Black holes compact into giant dead stars.When a star’s fuel finishes,it was explosed,because there is no heat left to counteract for gravity.Stars which are going to transform to black holes have to be bigger than 3 times the Sun.When a black hole existed its mass squeezed into a tiny point.This single point which is named singularity,which is centre of the black hole,both time and space stop.Within a certain distance of the singularity,which is named event horizon,nothing can escape.Only things which are travelling faster than light could be escaped.There is intense gravity here.Finding black holes is too difficult.Black holes bend into light rays,in fact astronomers can find them in 3 different ways which are x-rays,rotating stars and gravity lenses.
    word count:115

    Comment:
    All the necessary information is given πŸ™‚
    However, pay attention to grammar mistakes and especiaaly passive and active use of verbs.
    There is no smooth transition between the sentences and/ or ideas (Coherence problem)

    Thanks
    meltem

    Comment:
    It is a good job, well done!

    Thanks
    Oğuz

    Comment by Meltem
    I agree with Oguzhan it is a good job . Welldone πŸ™‚ πŸ™‚
    Thanks
    Meltem

  10. bortecinebon 01 Nov 2010 at 10:35 pm

    When stars die, black holes form. Heat in the star pushes out and balances force of gravity, while star is burning. The mass of the star determines what it will be when it died. If a star has a mass greater than three times of sun, becomes black hole. There is no volume, time doesn?t pass and it?s like the centre of a black hole which is called singularity. In a certain distance of singularity, the gravitational pull is strongly that nothing can escape. It is impossible to see black holes because they are black. There are three ways of seeing them such as X-rays, rotating stars and gravity lenses.

    word count: 110

    Comment:
    Information is there except event horizon; however, there is a serious coherence problem. Sometimes you provide details before even mentioning whose details you are giving and it makes it difficult to follow your writing.

    Thanks
    Meltem

  11. okyildirimon 01 Nov 2010 at 11:03 pm

    When a big star’s (almost 3 three times bigger than Sun) fuel is spent, it means that the star died and when it dies the star becomes a black hole. Black hole’s mass is squeezed into a single point which is called a singularity. Nothing can escape from singularity, only way to escape from this hole is exceeding the speed limit of light, so this is impossible in this century because our technology cannot succeed it yet. It is hard and even impossbile to see the blackholes with your eyes. So scientists use X-rays, gravity lenses and rotating stars to observe the black holes.

    Word count: 97

    Comment:
    Almost all important details are given (except event horizon) πŸ™‚
    Ideas are connected to each other well and coherence is maintained πŸ™‚
    Only definition of black hole could be improved because not all stars that die become black holes

    Thanks
    Meltem
    Comment:
    Great job(=

    Comment by Meltem:
    Great job Kaan πŸ™‚
    But one comment I forgot to make before is that you should not be using “I, you, we, our, your” in your writings
    Thank you
    Meltem

  12. mertkahvecion 01 Nov 2010 at 11:42 pm

    When energy of a star finishes, its mass forms a black hole. Black hole is a form which has powerful gravity and there is a single point in it which called singularity.Within a certain distance of singularity nothing could escape.This distance called event horizon.Actually even light can not escape,your speed have to be faster than light for escape from event horizon. Lastly black holes can not be detected easily if they are not able to absorb. However scientists are working on detected it.For example they are trying to use gravity lensing to search for black holes.

    Word count:96

    Comment:
    Coherence is generaly maintained πŸ™‚
    Coherence is only a problem in the the part you said “if they are not able to absorb”- I could not form the link between this idea and the previous idea

    Thank you
    Meltem
    Try to avoid using “your”

  13. mertbocnakon 02 Nov 2010 at 12:12 am

    Black holes are formed when stars which are 3 times bigger then the sun die. After a burning giant star finishes its fuel it gets crushed into a single point. The point at the center of a black hole called singularity. In the center of a black hole time is not pass and there is no volume here. Black holes are so powerfull because of the gravitational pull. nothing can escape from here, not even light. that distance is called evernt horizon. Humans can not detect black holes with naked eye but they are bend lights so if we are going to shed light we can detect black holes.

  14. emrebilginon 02 Nov 2010 at 1:59 am

    Black hole is formed by a vanished star. Over time stars fuel run out and it stops burning, there is no heat left against to the force of gravity. After that star dies and black hole occurs. For transform into the black hole, star?s mass must be greater three times than our sun?s mass. The center of the black hole called singularity. Close to the singularity the gravitational pull is very powerful because of this nothing can?t escape. The other property of black hole is event horizon that is not a physical boundary it is the safe distance to the black hole.

    Word count: 102

    Comment:
    Ideas are fully given πŸ™‚ and combined to each other well πŸ™‚
    Only you need to pay attention to punctuation and using some linkers to connect the sentences to each other from time to time could be good.

    Thanks
    Meltem

  15. elifmutluon 04 Nov 2010 at 12:51 am

    When a star ,which is three times bigger than the sun ,spent all fuel that means this star is died and becomes a black hole.Black hole?s mass is squeezed into a single point which is called a singularity where mass has no volume and time does not pass.In a certain distance of singularity, the gravitational pull is strongly that nothing can escape only way to escape from this hole is exceeding the speed limit of light, so this is impossible in this century because our technology cannot succeed it yet.Also black hole can absorb everything in it.However we cannot see the black holes.But three way to see them . These are x-rays,rotating stars and gravity lenses.

    word count:116

    Comment:
    The beginning is good, but you do not talk about event horizon which is an important feature of black hole.
    Coherence is lost starting from the sentence “Also black hole…”

    Thanks
    Meltem

  16. rbaranaltunon 07 Nov 2010 at 10:54 pm

    Black holes from when stars die.When a star’s fuel is spent all then it stops burning like before. However every stars wont be a blackhole . Because stars have bigger than the Sun three times for be a black hole. If it has suitable properties which we call a black hole.
    Black holes mass is squeezed into a single point. It’s really hard for us to imagine this happen. The point at the centre of black holes is called a singularity. Also black hole is very dangerous and special thing for world or other planets. Then lastly,lots of people think that impossible can escape from the intens gravity of black holes.

    Word Count: 112

    Comment:
    The second paragraph is general and not giving any information from the book. What about event horizon? You need to talk about it as well.

    Thanks
    Meltem

  17. cemtoreton 08 Nov 2010 at 11:27 am

    When a star three time bigger then sun finishES its fuel and dieS, it can’t refuse gravity and crashES into a single point. This point have (HAS) realy big power. Nothing can escape from this; not even light. Because of this it seemS black and we (!!!!) call it black hole. It’s center IS called singularity.Range of influence of black hole IS called event horizon. Inside event horizon mass has no volume. Black holes can’t find (CAN’T BE FOUND)easily. when black holes pull inside the dust particles, particles emit x-ray so it’s the one way how to find black hole.

    It is nicely written and coherence is maintained. However you need to pay attention to the passive use of the verbs.

    Thanks
    Meltem

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