If we had to emit light just like a flashlight vs a lighthouse, aka roughly equivalent wavelengths, you'd be right, however we only have to beat the sun in a si

If we had to emit light just like a flashlight vs a lighthouse, aka roughly equivalent wavelengths, you'd be right, however we only have to beat the sun in a single wavelength. An extreme uv laser is probably the easiest option there. We also only need to beat the sun's output in a single pinpoint (in cosmic scale) Also to damage the example a bit, we can easily detect a flashlight shining from behind a lighthouse. Our eyes are just logarithmic and suck at detecting smaller absolute differences like that. Isaac Arthur does a good video on this topic and talks about some of the specifics of such a beacon starting at around 14 minutes https://youtu.be/DHoOjIEcRV8?t=829 https://youtu.be/DHoOjIEcRV8?t=829