[hollerith]

Every planet, every rock emits heat (thermal EM radiation) so why can't the civilization willing to forgo most of its potential computing and industrial capacities choose to emit a heat signature indistinguishabe from a rock by observers at other star systems?

[shiroiushi]

If you want to hide your heat signature, and you have the technological means to capture and direct your waste heat, you could simply radiate it towards your system's star. This is assuming you're producing so much heat that it would stand out more from a distance than similar but lifeless planets.

[hollerith]

s/the/a/