When we look at the Sun, we are seeing it as it was 8 minutes ago. So we can see the Sun only “in the past.” When you look at the back of your own hand, do you see it “now” or “in the past”? We hear...

When we look at the Sun, we are seeing it as it was 8 minutes ago. So we can see the Sun only “in the past.” When you look at the back of your own hand, do you see it “now” or “in the past”? We hear people talk of “ultraviolet light” and “infrared light.” Why are these terms misleading? Why are we less likely to hear people talk of “radio light” and “X-ray light”?