It’s my birthday too!  Or so say the Beatles.

Did you know that not all birth dates are created equal?  According to the folks here and here some birthdays are more popular than others.  From 1973 to 199 the most popular birthday is September 16 and the least popular is December 25.  Other less popular birth dates also correspond to holidays which suggests that those who can choose when their child is born chose to avoid major holidays.

There is also another interesting coincidence known as the “Birthday Paradox”.  Simply put, if you get at least 23 people together there is a 50% chance that two of them have the same birth date.  There are 365 possible birth dates but if you get 23 random people together, half the time 2 of them will share a birthday!

Nonsense you say?  I would explain but these folks do it much better than I ever could.

You can even make this a science fair project!  Get the birth dates of 23 of your closest friends and relatives – do any of the match?  What if you could get several groups of 23?  Ask your teacher for help getting the birth dates of everyone in your school – make sure they know you don’t need names, just dates.

More ideas on using the Birthday Paradox for your science fair project can be found at ScienceBuddies.

They say it’s your Birthday…
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