> release so ludicrous ammounts of energy that they might be visible over interstellar distances Ludicrous at human scales, but utterly insignificant compared

> release so ludicrous ammounts of energy that they might be visible over interstellar distances Ludicrous at human scales, but utterly insignificant compared to the output of even the smallest stars. Bear in mind that small stars are hard to detect more than a few dozens of light years away. Well you can detect them, but they are hard to range. It’s difficult to pick out nearby stars in the dense stellar background as being nearby. Take a look at the deep field images to get an idea of the clutter. A drive plume would just be utterly lost in all that background noise. People imagine the sky as being inky black with a few bright objects to look for, and that even a drive plume light years away would stand out against the blackness, but that’s not how it is at all. The sky is full of distant clutter that makes picking out particular objects extremely difficult. And if your plume is in a system anywhere near a star, forget it. You’d have to know exactly what you’re looking for and make extremely precise long term observations to have any chance whatsoever.