a brief history of time（时间简史）
tabletime
时间简史
《时间简史》是由英国伟大的物理学家、黑洞理论和”大爆炸”理论的创立人史蒂芬？威廉？霍金撰写的一本有关宇宙学的经典著作，是一部将高深的理论物理通俗化的科普范本。
在这部书中，霍金带领读者遨游外层空间奇异领域，对遥远星系、黑洞、夸克、”带味”粒子和”自旋”粒子、反物质、”时间箭头”等进行了深入浅出的介绍，并对宇宙是什么样的、空间和时间以及相对论等古老问题做了阐述，使读者初步了解狭义相对论以及时间、宇宙的起源等宇宙学的奥妙。
《时间简史》自1988年首版以来，已成为全球科学著作的里程碑。它被翻译成40种文字，销售了近10000万册，成为国际出版史上的奇观。该书内容是关于宇宙本性的最前沿知识，但是从那以后无论在微观还是宏观宇宙世界的观测技术方面都有了非凡的进展。这些观测证实了霍金在该书第一版中的许多理论预言，其中包括宇宙背景探险者（COBE）的最新发现，它在时间上回溯探测到离宇宙创生的30万年之内，显露了霍金超人的时空感知能力。
时间简史读后感
宇宙是无限的，因为他是无限的，所以画任何一条线都可以认为是中线，任何一个地方都可以认为是中心。
宇宙是无限的，它没有边缘，那么任何一个地方都可以认为是边缘这不是简单的套用物极必反，这完全是我对无限的推论。
2。然而在广义相对论中，情况则相当不同。这时，空间和时间变成为动力量：当一个物体运动时，或一个力起作用时，它影响了空间和时间的曲率；反过来，时空的结构影响了物体运动和力作用的方式。
空间和时间不仅去影响、而且被发生在宇宙中的每一件事所影响。正如一个人不用空间和时间的概念不能谈宇宙的事件一样，同样，在广义相对中，在宇宙界限之外讲空间和时间是没有意义的。（引用时间简史。）
3。时间和光不是一种东西，这很容易想象。比如在黑夜里虽然没有光，但仍然有时间。光速和时间怎么联系起来我还不清楚。我不用去定义宇宙和时间的概念。宇宙形成之前是一个无穷小的奇点，而且无限紧密，我在这里说成没有，这不是唯心的没有，空间和时间在大爆炸时同时的从无生有。这就会产生两个问题，那个无穷小的产生一切的奇点是什么和它为什么要爆炸。那个奇点什么也不是，不是人类所认识的物质，可以起个随便的名字，比如上帝。它就是一个无穷小无限紧密的点，仅仅是一个点它之所以要爆炸是因为它想那样，因为现在有了一切所以它爆。炸了。这是无法证明的，人类的证明方法必然会引入第三方，为了证明第三方的正确又必须引入第四方，这样的证明会无休止的循环下去。（看到后来，才知道这应该算人择原理。）
4。空间和时间是一个整体，有空间的地方就有时间，有时间的地方就有空间。那么宇宙在膨胀，时间就在延续，宇宙一旦停止膨胀，时间也就停止。那就是世界末日。时间和空间只能是一个整体，它们之间的夹角只能是零。因为它们在大爆炸之前交于奇点，所以它们不可能平行。时间和空间是一个整体意味着它们不可能单独存在。这样，接着我必然得说，空间和时间是连续的，那么它们有速度吗？因为空间膨胀有速度，
So time is bound to have speed, namely the expansion of space velocity equal to the speed of time.
5. in any direction, the universe is the same. Since the expansion of the universe, the speed of expansion? Now that there is speed, it must have a reference, just as light is
supposed to be the ether, what else should we assume? Before everything is formed, it is just a point, the distance between them is zero, and it expands after the explosion. You can imagine that we are far away from us as far away as we can see the farthest away from us. So if we can say that if inflation is faster than light, we're faster than light, and if the speed of expansion is the speed of light, we're the speed of light, and if the speed of expansion is lower than the speed of light, we're less than the speed of light For the first possibility, if we exceed the speed of light, we obviously cannot see the light. For the third possibility, are we from one generation to the speed of light, or later to the speed of light?
6. looking back at the beginning, any line is the center line of the universe, any place is the midpoint of the universe, which is obviously considered infinite equal to infinity. Because infinite and infinite can not be compared, that is to say, we can not compare the size of the line, can not compare the size of the line from the edge of each point. You cannot prove that they are equal, also cannot prove that they are not equal. But I think you can imagine a kind of equality, you say I don't want to oppose it, but you can't say any one of them is big. I am inclined to believe that the infinite is equal to infinity.
7. followed by 4 inferences. If we can travel in time, we go back in time. Because space and time are continuous, the past space and the past time have become the present space and the present time, and we are back to the present. This is meaningful, we return now to now? I can't imagine the time and space that we were at a certain moment in the past, still in some place
in some form, and they have obviously continued into the present.
(I lost a word here, and I was going to put it here when I wrote the last sentence, but I couldn't remember it when I finished writing it. That sentence is I feel contains a word of truth. It may mean the past is now, it is now itself). If they exist in some form, it means that every moment is as static as a photograph, and it is absolutely stationary in one place. This is wrong. I don't want to say that time trav
el is impossible, but I just want to assume that space and time are faster than light. What is the concept of the speed of time, which seems inconceivable as the fire in water?
The sun to go through eight minutes to reach the earth there are two parts in this sentence. One is the speed of light is two, the length of time. The time we know is the time when our earth moves around the sun, and this is a human division, and then we measure the speed of light. We always think of time as a length, as if it's infinitely fast, and as long as the material gets there, the time is there. The speed of the speed of time is the expansion of the universe, it should be faster than the speed of light. This is, will launch a space is finite conclusion.
Why do we always remember the past and not the future, why always move forward?
Here must be concerned about the direction of time, only when the direction of time, there may be time travel. This must appear before and after and inside and outside, it must have a starting point and now the site, then the universe will have a boundary, the universe is limited. Only when we are below the
speed of time do we move backwards relative to time, so that we can go back to the past. That is, all objects are identical with time at the time of the universe, and everything in the universe moves forward with time. If we go beyond the speed of time, there is no space, no time, no everything, there i
s chaos, where we don't see anything,
We can't be there either.
In my opinion, everything has the same speed as time when the universe comes into being, that is, the speed of cosmic expansion. The future of space and time has not produced, to future travel impossible.
The 8. time history tries to describe the universe as a finite but borderless space, which is completely self-contained, without beginning or end. It is existence. Time is described as follows: "disorder" or "entropy" increases with time is an example of the so-called time arrow. The arrow of time will distinguish between the past and the future, giving a direction to time. There are at least three kinds: first, the arrow of time is the thermodynamic arrow of time, which is to increase the degree of disorder or entropy in the direction of time; then the psychological arrow of time, this is what we feel the passage of time, in this way we can remember the past but not the future; finally, the arrow in the cosmological time. The direction of the expansion of the universe, but not in the contraction."
I think unless we find the singularity of the big bang, or the boundary of the universe, we can't find the direction of time,

版权声明：本站内容均来自互联网，仅供演示用，请勿用于商业和其他非法用途。如果侵犯了您的权益请与我们联系QQ:729038198，我们将在24小时内删除。