On Twitter, you follow and are followed, so if you are going to create a list of most impactful science people, there is only one valid metric - the number of "followers" who are going to see what they write.

In a runaway victory using that neutral metric, astrophysicist Dr. Neil Tyson comes out at number one, and then you go down the chain to people the Science 2.0 audience will increasingly have not heard of - it seems to have been created to give a whole bunch of people on a list something to retweet and generate pageviews; yet there are complaints that the list ends up only having 4 women. Out of 50.

First, is it a fair metric at all? The compiling of impact this way is similar to the Kardashian Index, which showed that popularity begets popularity, not that she was a great actress. Yet it's Twitter, that is all that can be measured. 

So what gives? Well, it may mean women in academic science are busy working rather than screwing around on Twitter. There are claims that women in science academia have to do a lot more work than men to get ahead, so perhaps they are doing it. No one is doing real science outreach in 140 characters, it is mostly just commentary plus links and mobilizing zealots in culture wars.

What is really weird, yet will get mentioned by absolutely no one who will use this list to claim women in science are not respected in 2014, is that though 50 percent of science in America is done in the private sector and not a single one shows up on this list. 

So we know who has the chance to screw on social media even less than women in academia.

The top 50 science stars of Twitter by Jia Yiu, Science magazine