What Other Types of Information Can We Gather from Intergalactic Bodies?

[turbo]

We get electromagnetic radiation (entire spectrum) from extragalactic space, as well as particles. Neutrinos and cosmic rays (some quite energetic) can originate from outside the MW, so we are not limited to "light" in that sense. One saving grace of observational astronomy is that it IS observational. All observers have the same data set to work with, apart from differences in the telescopes and detectors that they have access to.

 

[Dr Lots-o'watts]

Are you of the opinion that the word "light" should only refer to visible light?

Usually, I only use the word "light" if it's visible, but I suppose it can depend who I'm talking to and what's the context.

Thinking about it, in my daily work, we don't even use that word. It's just gamma, x-ray, UV, visible, IR (near, mid, far), THz, microwave and radio. All those are (EM) waves or beams.

Light refers to what happens when you flip the wall switch, and nothing on the optical bench.

As long as the message gets across, I guess.