Black holes lead stars to self-destruct
Scientists have long understood that supermasvive black holes weighing. Millions or billions of suns can tear apart stars that come too close. The black holegravity pulls harder on the neatest part of the star, an imbalance that pulls the star apart over a period of minutes or hours, once it gets close enough.
When the star gets Close enough, the uneven forces flatten it into a pancake shape. Some previous studies had suggested this flattening would increase the density and temperature inside the star enough to trigger intense nuclear reactions that would tear it apart. But other studies had suggested that the picture would he complicated by shock waves generated during the flattening process and that not nuclear explosion should occur.
The devouring of stars by black holes may already have been observed, although at a much later stage. It is thought that several months after the event that rips the star apart, its matter starts swirling into the hole itself. It heats up as it does so, releasing ultraviolet light and X-rays.
Brassart aggress. Perhaps it can be observed in the X-rays and gamma rays, but its something that needs to be more studied,he says. Supernova researcher Chris Fryer of the Los Alamos National Laboratory in Los Almos, New Mexico, US, says the deaths of these stars are difficult to simulate, and he is not sure whether the researchers have proven their case they exploded in the process.
A the black hole could tear apart the star
C the black hole could dwindle its size considerably
2. According to the third paragraph, researchers differed from each other in the problem of
B whether the stars would increase its density and temperature
D whether the uneven forces would flatten the stars
A No nuclear explosion would be triggered inside the star
C. Much of the stars matter thrown by the explosion would be beyond the black holes reach
4. What will happen several months after the explosion of the star?
B the black holes matter will heat up
D the black holes matter will release ultraviolet light and X-rays
第10课 无趣的 - 18
第13课 不重要的 - 10
第13课 不重要的 - 4
第11课 不感兴趣的 - 5
第11课 不感兴趣的 - 6
第13课 不重要的 - 3
第11课 不感兴趣的 - 12
第12课 重要的 - 17
第12课 重要的 - 8
第11课 不感兴趣的 - 8
第13课 不重要的 - 13
第10课 无趣的 - 7
对话20年前的自己 “时光穿越”视频引轰动
第10课 无趣的 - 11
第11课 不感兴趣的 - 3
第13课 不重要的 - 7
第13课 不重要的 - 6
第12课 重要的 - 5
第10课 无趣的 - 10
第12课 重要的 - 2
鑻辫鍙h缁冧範_璇昏糠浣犲皬瀵硅瘽 瀛﹁嫳璇彛璇細绗?2璇?閲嶈鐨?- 14_娌睙鑻辫
第11课 不感兴趣的 - 2
第10课 无趣的 - 3
第12课 重要的 - 13
第12课 重要的 - 9
第12课 重要的 - 7
第10课 无趣的 - 12
第12课 重要的 - 3
第14课 亲切的 - 1
第12课 重要的 - 21
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |