# Spacetime and Work issue **URL:** \ **Category:** Factual Questions\ **Created:** [June 24, 2021, 8:43pm UTC](https://boards.straightdope.com/t/spacetime-and-work-issue/944967 "2021-06-24T20:43:55Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![Someonewastaken](https://avatars.discourse-cdn.com/v4/letter/s/ba8739/32.png) [@Someonewastaken](https://boards.straightdope.com/u/Someonewastaken)\ **Post date:** [June 24, 2021, 8:43pm UTC](https://boards.straightdope.com/t/spacetime-and-work-issue/944967/1 "2021-06-24T20:43:55Z")
So I recently learned that space and time are the same thing, spacetime. This got me thinking, does this apply to simpler physics concepts, such as work. If work=force_distance, we could think of 1 second as ~3_10^8 meters, meaning if you apply a 1 Newton force for 1 second, you are using ~3\*10^8 joules. This seems like way too much energy to apply a force for just 1 second. Am I just making a logical error, or is this true? If this is true, where does the energy come from? ---
**Author:** ![Jasmine](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jasmine/32/2964_2.png) [@Jasmine](https://boards.straightdope.com/u/Jasmine)\ **Post date:** [June 24, 2021, 8:52pm UTC](https://boards.straightdope.com/t/spacetime-and-work-issue/944967/2 "2021-06-24T20:52:11Z")
> [@Someonewastaken](#): > > If work=force _distance, we could think of 1 second as ~3_ 10^8 meters I don’t understand this leap, and the results you achieved indicate that it cannot be correct. ---
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [June 24, 2021, 9:44pm UTC](https://boards.straightdope.com/t/spacetime-and-work-issue/944967/3 "2021-06-24T21:44:50Z")
> [@Someonewastaken](#): > > So I recently learned that space and time are the same thing, spacetime. This got me thinking, does this apply to simpler physics concepts, such as work. > > If work=force _distance, we could think of 1 second as ~3_ 10^8 meters, meaning if you apply a 1 Newton force for 1 second, you are using ~3\*10^8 joules. This seems like way too much energy to apply a force for just 1 second. > > Am I just making a logical error, or is this true? If this is true, where does the energy come from? Spacial dimensions and the dimension of time are not the same. Also, if you were to equate them in the way you do it’s not enough to just “apply a force for just one second”. You have to apply the force _ **in the direction of time** _. ---
**Author:** ![Great\_Antibob](https://avatars.discourse-cdn.com/v4/letter/g/e47c2d/32.png) [@Great\_Antibob](https://boards.straightdope.com/u/Great_Antibob)\ **Post date:** [June 24, 2021, 10:05pm UTC](https://boards.straightdope.com/t/spacetime-and-work-issue/944967/4 "2021-06-24T22:05:13Z")
> [@Someonewastaken](#): > > So I recently learned that space and time are the same thing, spacetime. This is where things went off the rails. Our dimensions of space and time are fused into a single “thing” we call spacetime but that doesn’t mean those dimensions of space and time are equivalent or ‘the same thing’ or interchangeable. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [June 25, 2021, 12:35am UTC](https://boards.straightdope.com/t/spacetime-and-work-issue/944967/5 "2021-06-25T00:35:53Z")
There is a distinction between the time dimension and the three spatial dimensions, but it’s not a matter of the units: Both can be measured in the same units just fine. And yes, there are other physical quantities that are related in the same way as space and time. Energy, momentum, and stress are also related in the same way, for instance (strictly speaking, energy density, momentum flux, and stress).