1. We had eyes sensitive to radio waves? How would we be different, and how would our visual perceptions of the world be different? 2. Humans were unable to detect any electromagnetic radiation? How...

1. We had eyes sensitive to radio waves? How would we be different, and how would our visual perceptions of the world be different?

2. Humans were unable to detect any electromagnetic radiation? How would that change our lives, and what alternatives might evolve (some species indeed have) to provide information about distant objects?