Thank you for submitting a Did You Know suggestion. However, each suggestion is expected to introduce a qualifying new article of sufficient length. The new article should be linked and identified with bold letters. Unfortunately, your suggestion doesn't introduce such an article. Did You Know doesn't use facts, no matter how interesting, that don't introduce a qualifying, new enough, long enough article. Our rules in more detail are at Wikipedia:Did you know#Selection criteria. See also "Unwritten Rule" number B1. If the article is new enough but not long enough, we encourage you to make it long enough to qualify.
Frequently asked questions:
editQ: Did you write this page just for me?
A: No. Hooks without qualifying articles are a routine problem.
Q: Does that mean I just need to use a bold font for my article link?
A: No. If your article qualified under our rules, then I would have bolded the link myself. Since it isn't bolded, I may be unsure which article (if any) you were introducing, but none of the articles qualify.
Q: Does that mean I just need to use a bold font for my article link, and make the article longer?
A: Yes, if the article is new enough. We encourage you to make it long enough to qualify.
Q: How do I make the font bold?
A: The short answer is: three single quotes before and after, like this: '''
The long answer is: Assume Wikipedia had no article on calculus, until you had just written that article. Here's how a sample hook would look on the edit page: ... that mathematicians use '''[[calculus]]''' to predict the [[trajectory]] of a rocket? Here's how everyone else would see that hook: ... that mathematicians use calculus to predict the trajectory of a rocket?
Q: But my article does qualify. The link just needs bolding.
A: No, you wouldn't be here if that were true. The article must be new or mostly new, and it must be long enough. There are other rules, but those are the rules I currently check for.
Q: How new and how long?
A: The details of the rules are at Wikipedia:Did you know#Selection criteria.
Q: But I added a whole new section to that article, so it's new.
A: That's not what the above rules say. The whole article has to be new, meaning 5 days old or less. If you make the prose section of the article five times longer, then the article is 80% new, which is new enough. But it has to be five times longer, no matter how bad the old article was, even if it was being deleted.
Q: I can't link and bold my article, because I didn't mention it in my hook.
A: You need to mention the article in the hook, or at least pipe it, according to "Unwritten Rule" number B1. Then link it and bold it.
Q: My hook is truly creative and it should go on the Main Page anyway.
A: I don't actually choose hooks for the Main Page, but if you look at hooks that made it to the Main Page, they don't look like yours. Our rules are at Wikipedia:Did you know, and they may be debated at Wikipedia talk:Did you know. For better or worse, the Main Page says "Did you know... From Wikipedia's newest articles:".