Space, Time, and Space-time
John Perry

01 April 2017

Common sense sees a clear division of labor between space and time. I am about 11 years older than Ken. I was born in Lincoln, Nebraska, while he was born in Sandusky, Ohio. Lincoln is roughly 800 miles west of Sandusky, and about 500 feet higher. So the events of my birth and his are distant in time and in space. These facts are not causally independent; some event might have led to our being closer in both space and time. But they seem logically independent. This spatial relation between two events is one thing, their temporal relation is another. For one thing, we can travel in space, but not in time, unless continuing to exist counts as time-travel.

我们生活在一个政治家和科学家告诉我们一些荒谬的事情的时代。特朗普说他比世界上任何人都更尊重女性，他和保罗·瑞安将给我们一个很棒的医疗保健系统，成本更低，医疗更好，税收更低，选择更多，全球变暖是中国人编造的谎言。科学家告诉我们，空间和时间实际上是一个单一事物的各个方面，即时空连续体，时间没有内在的方向，也不存在客观的、独立于观察者的同时性，也许时间旅行终究是可能的。

It’s easy and wise to disbelieve what Trump says. It’s difficult but wise to believe what scientists say. People like me read popular explanations of what physicists and astronomers have to say, and accept that they must be right. But I can never remember exactlywhy他们相信他们所做的。

我记得这和光速有很大关系，爱因斯坦坐在一列移动的火车上走来走去，当火车接近光速时，他坐在排障器上。比我聪明的人理解并相信。我确信，但从未完全理解。当我想象自己坐在排风器上时，我感受到的不是光明，而是恐惧。如果铁轨上有一头牛怎么办?

在本周的节目中，我将有另一个机会来理解;蒂姆·莫德林和肯会尽力的。也许我最终会得到它。

Comments(4)

michaelM's picture

michaelM

Sunday, April 2, 2017 -- 8:46 PM

I am convinced that time, as

I am convinced that time, as an aspect of the spacetime fabric, is no illusion but what about the passage of time? Is that an illusion?

DavidTonn's picture

DavidTonn

Thursday, October 17, 2019 -- 10:48 PM

Passage of time is a form of

Passage of time is a form of momentum, just like the passage of distance. We just haven’t found a practical way to directly modify temporal momentum.

Harold G. Neuman's picture

Harold G. Neuman

Tuesday, October 15, 2019 -- 12:04 PM

Back yonder, on the April,

回到那边，2017年4月，在这个话题的报道中，我评论了这位时间旅行研究者，他是中西部大都市的人(也许?)他在这方面已经有一段时间了，而且坚韧不拔。我不知道他的背景，是高等科学、数学还是两者兼而有之。但他对时间旅行的概念感兴趣是有意义的。我认为。这不是一个平庸或缺乏兴趣的话题。根据我们对事物的理解，它很可能是无法解决的。它可能是，嗯，时空难题。这是对的，看。正如你在其他思考中注意到的那样，有很多难题。 Scientists and their ilk have to have these ages-old questions, just as we philosophers have those relating to the pursuit of truth. Is there any truth to the Space/Time Continuum? Would it matter all that much if there were, as long as we are only equipped to think about and theorize over it? This is pretty deep shit (which is what a friend has said when I share notions about philosophy with him). Other friends just scratch their heads and probably feel sorry for me, what with my affliction and all.

It is all good fun, right now. Can you imagine how the world would react, though, if the conundrum were to be understood and found to be terminal to human existence? Sort of like that doomsday clock which thinkers move the minute hand on, from time to time...when things get really hairy. This is purely speculative, as far as I know. I have not spoken with the local time traveler about it. But, I'm pretty certain he would have something to say.

DavidTonn's picture

DavidTonn

Thursday, October 17, 2019 -- 11:14 PM

Simultaneity is a comment on

Simultaneity is a comment on the observer, not the events.

让我感到困惑的是，没有人提及“时间是一种幻觉”这一评论是基于数学的。相对于空间维度，度规距离将时间作为虚数;尽管相反的是更自然的数学方法:时间是实数，空间是四元数结构的其余部分——“虚复化”。

Anyway, at least from my experience, that’s the actual origin of the time is an illusion comment: a play on “figment of the imagination” and “imaginary numbers”.

Also, I’m a mathematician, so I’m apologizing now if that was an inside joke I wasn’t supposed to share...