TL;DW:
Does It Make Sense To Put Data Centers In Space?
At some point in the future, yes.
Can They Really Cost Less To Operate?
In theory, yes.
Scott expresses concerns that current startups have not adequately addressed some of the practical challenges, such as cooling.
Now I am wondering can a fan move heat in a vacuum? I assume not because they don’t move the heat but the air around the hot thing, but I also don’t know much about thermodynamics especially in a vacuum.
You nailed it. Fans move air. Hot air away, cool air in, and that’s how a fan cools. In a vacuum, it would just spin until friction slowed it down, so technically it would generate heat.