Space, Time, and Space-time

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.

We live in an age in which politicians and scientists tell us absurd things. Trump says he has more respect for women than anyone else in the world, and that he and Paul Ryan are going to give us a wonderful health-care system, with lower costs, better medicine, lower taxes and more choice, and that global warming is a lie invented by the Chinese. Scientists tell us that space and time are really aspects of a single thing, the space-time continuum, that time has no intrinsic direction, and that there is really no such thing as objective, observer independent simultaneity, and maybe time travel is possible after all. 

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 exactly why they believe what they do.

I remember that it has a lot to do with the speed of light, and Einstein sitting walking up and down in a moving train, and then sitting on the cowcatcher as it approaches the speed of light. People smarter than I understand and are convinced. I am convinced, but never quite understand. When I imagine sitting on the cowcatcher, I don’t experience illumination but fear. What if there is a cow on the tracks?

In this week's program I’ll get another chance to understand; Tim Maudlin and Ken will do their best. Maybe I’ll finally get it.




Comments (5)

michaelM's picture


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


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,

Back yonder, on the April, 2017 account of this topic, I commented on the time-travel researcher, native (maybe?) to my mid-western metropolis. He has been at this for some time, and is, resilient. I don't know his background, whether that be advanced science, mathematics or both. But that he is interested in the notion of time travel is significant. I think. This is not a subject for pedestrian or flagging interest. It may well be insoluble, given our understanding of things. It may be, well, The Space-Time Conundrum. And, that's all right, see. There are many conundrums, as you have noted in other ruminations. 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


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

Simultaneity is a comment on

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

It confounds me that no one addresses that the comment that “time is an illusion” is based on the math. Relative to the spatial dimensions, the metric distance involves time as an imaginary number; though the reverse is the more natural approach to the math: time is real and space is a the rest of the quaternion structure-the “imaginary complexifications”.

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...

kanecharles's picture


Wednesday, March 20, 2024 -- 7:25 PM

I felt like I was brought

I felt like I was brought into a conversation with the author, who shared his feelings and thoughts about space and time, as well as about politics and science. The comparison between Trump's words and what scientists say is sharp and thought-provoking. People say time is scary because it keeps passing by without waiting for anyone and that's why it is so precious. With the busyness of modern life that is even more true. Fortunately, technology has developed and we have tools to help us utilize our time more effectively, such as time calculator.

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