If you had to narrow down everything you know, and could only tell people one thing about your field of study, could you do it?

That's what one person has challenged the internet to do this week, and a lot of scientists have leapt at the chance to tell the world what they think is most interesting or important about their work. It's provided a fun insight into what scientists think the world should know, as well as being a great opportunity to find out some fun facts you wouldn't have otherwise heard about.

It all started with this tweet from Dalton Ludwick, a PhD candidate in entomology.

Scientists used the hashtag to talk about what they want the world to know. Some used it to discuss the important issues of the day.

Or to clear up misconceptions they see from the public.

(Some make scientists madder than others...)

But mostly, scientists used the opportunity to tell people something fun about their field.

Some of it was highly important.

Or depressing.

Some people didn't stick to their own field. A palaeontologist used his one tweet to the world to tell everyone about octopus arms.

And a wildlife biologist used hers to tell us how we're all going to die.

Whilst another archaeologist fired warning shots at Indiana Jones.

The hashtag is still trending, and is crammed full of interesting facts from scientists around the world. We highly recommend checking it out.