Can a lack of evidence be considered proof?

[robvalue]

Are there things we can't detect? If I had to guess, I'd say it's extremely likely.

My problem is when people claim to have knowledge about these things.

Say you are in the middle of the ocean and you can't see the edge, but concentric waves rings are converging right next to where you are.  What can you deduce? Anything?

I can deduce that there's probably something unusual going on. Something is probably causing the difference between the forces I'd normally expect to see and what I observe.

If you're suggesting this is evidence of something, then we are detecting that thing, indirectly.

In any case, further study is required. Also, am I even in a boat?