Can I really not tell if I am in motion?

[Nanyang]

Sorry! I think I figured the mistake out right after I posted! This thread can be closed.

I imagine a train powered by an engine of this sort:

A region of hotter temperature evaporates some water and turn the wheels, and the evaporated water is at a lower temperature.

So I am in the train and I observe that the engine works in the way described above. Relative to myself, I claim that I am not the one in motion but the station platform is in motion.

But to claim that the station platform is in motion I must also claim that the wheel turns in the other way (edit: sorry, mistake here. give me a moment to sort this out). This implies that the evaporated water must fall back into its liquid form from a colder temperature to a hotter temperature. But by the second law of thermodynamics, this is impossible. So I must conclude that I am the one in motion and not the platform despite measuring in my own frame of reference.

So, can I really not tell if I am in motion?

 

[maverick_starstrider]

You're forgetting that the reason the wheels have to turn in the first place is because friction slows the train down and the engine needs to compensate by providing a constant acceleration.

 

[Entropia]

It is possible that you may not be able to tell if you are in motion based on your own observations and frame of reference. However, there are other factors that can help you determine if you are in motion, such as feeling the movement of the train or seeing objects outside the train window passing by. Additionally, if you are able to compare your observations with someone else who is in a stationary reference frame, you can determine your own motion. In this case, it seems like the mistake was figured out after posting, so it is possible that you were able to determine your own motion in the end.