Seeds Floating Question

[AlittleSalt]

I could have put this in the Misc. section, but it is a General question. I know it has been answered before, because I asked, but I don't remember the answers. Living in constant pain does that to you.

When soaking seeds to be planted, there are usually some seeds that sink and some that will float. In seed saving, those that float are not viable. The picture below shows Emerald Okra seeds from Ferry~Morse. I put them in a tub of water so I can plant them this evening. As you can see, some floated and some did not.

My question isn't just about the okra seeds - it's about seeds in-general. Are floating seeds not viable?