Ships CAN be bright, we have the tech now to make them dark.
True, burning fuel is a big problem. Especially if they were traveling rather fast towards us and they flipped over to reverse thrust to slow down. But what if you don't burn fuel as a means of propulsion?
I'm going with the assumption if that if someone wished to do something bad, say invading a neighboring solar system, they would take precautions in being detected.
The point was never that the ships themselves can be bright, it was that the radiation is easily visible.
The article was also operating within the realm of theoretically available technology. There are very few propulsion systems that don't emit hot matter out the back (like solar sails) and the article addressed them suitably.
Ships CAN be bright, we have the tech now to make them dark.
True, burning fuel is a big problem. Especially if they were traveling rather fast towards us and they flipped over to reverse thrust to slow down. But what if you don't burn fuel as a means of propulsion?
I'm going with the assumption if that if someone wished to do something bad, say invading a neighboring solar system, they would take precautions in being detected.