[naasking]

> Also, why keeping a history of all memory changes will prevent losing heat?

How much power does a persistent storage (hard drive, SSD) require to preserve its stored data? Zero, which is why it emits zero heat.

> Who needs to go back in time in their computations??

At its most basic level, erasing/overwriting data requires energy. This generates a lot of heat. Heat dissipation is a major obstacle to scaling chips down even further. If you can design a computer that doesn't need to erase nearly as much data, you generate orders of magnitude less heat, and this potentially opens up more scaling potential and considerable power savings.