Is there anything to the concave Earth theory?

I have looked into this, and I do not think there is anything to it. I see why they say it, but it just does not make sense to me. The problem with a theory like this is that it is always good at answering a couple of questions that had you scratching your head, but it does not answer all the questions, and it creates problems as well. I am familiar with who writes about it, and I have passed by it. That is my opinion; I put the work into it, and I can safely say it is not what I think we should be following.