I got this idea while exploring the 3 rules of thermodynamics, specially the second one, came up with a device, i know it can't work but i can't but my finger on the reason why. So the second rule states that heat cannot pass by itself from a cold object to a hotter one.

OK so here is the machine, a set of piping and 2 chambers thermally isolated from exterior, and a mirror to focus thermal radiation from the big tank of liquid to the small. Any diffused radiation will tend to equalize temperature in the liquid and the whole room but at the focal point there will tend to be higher temp.

Possible logic error aside this temperature difference would create convection current and tend to create movement that can be tapped , turned to electricity and taken out of the system.

I'm not thinking of a perpetual motion machine of the first kind but one of the second and i know that can't be right.

Moved form r/Physics, realized that is not proper place

EDITED for simplicity's sake: Simpler version Spherical shell with hot liquid having at the center a small ball with the same liquid connected through pipes, would the small sphere tend to be hotter due to concentrated thermal radiation if conduction / convection through pipes is minimized ? And if flow was allowed could convection movement be used to produce some energy ?

As i said for this to work i must be missing something with radiation heat transfer or similar.