At Dragoncon this year I went to a panel on research for purposes of writing. Most panelists agreed that a lot of research needs to go into writing about something you are not familiar with, because "experts" will always pick on details that you got wrong if you are not an expert. One of the writers suggested that you should try to experience something as close to the experience you are describing as you can. For example, you may not ever hope to train to be an astronaut but if you want to write about it, do at least some bungee jumping.
When I took a class on LitReactor with Mark Vanderpool, the first story he asked us to write was something based on a detail in someone else's life (someone in the class), so I found it tremendously fun to research something as far from my own field as I could think of, which is why I chose to write about a student in nuclear physics. Was that pointless? No, because I had a personal investment in that topic, and I think as long as you have that, then you are not a fraud. First have a reason to write about something, then do enough research to have as much understanding of the topic as the story needs. What was personal to me about the field of nuclear physics was my experience (at 16) with being relatively close to the Chernobyl disaster and trying to understand what it was and how it affected me.
To go back to the purpose of writing this blog. I disagree that the only thing you should write about is what you know very well. We don't live in a box. We are touched by others who live other experiences, and we have a duty, if we call ourselves writers, to investigate those aspects of life that crisscross our own. So, yes, research is needed (I am still looking into what it's like to live in Greenland), but allow yourself to imagine experiences other than your own. Please, don't only write about what you know.