how can we convert radio signals to visible light?
if we can, will it be visible to us?

There are RF to fibre convertors available commercially operating up to (I think) 3GHz. Look up PPM Ltd, they make them.

I guess it means by "convert" and what you mean by "it".

By "convert" do you mean turn the radio energy into visible light, or just that an electronic instrument receives the radio signal and displays it in a visible form?

If it's the former, you will struggle to get a signal strong enough to light any lamp I can think of, but it may just be possible to light an LED with the right antenna and a really strong signal.

If it's the latter then most of us have such a device - it's called a television.

As for the second question, unless you clarify what you mean, then the obvious literal answer would have to be "yes" - if you can convert a radio signal to visible light, then it must be visible.

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S P Barker BSc PhD MIET

@ectophile
It could be high power UV laser light outside the normal visible band - in which case you can see it. Once with the right eye, and once with the left. The health and safety people might have something to say about testing it that way.