Theme is not loading responsive page on iPhone

Hello. I just posted the first article on my blog since June. I noticed that when I look at the post on my iPhone it is loading as though it were on a full size screen. The mobile version is not showing up. This is also happens on my iPad and my friends Android phone. Is there anything I need to do to make the page act responsively? Thanks so much. My webiste is http://earthtokeir.com