Not really a paradox,but interesting to learn that in a room of 23 people, there is a 50/50 chance that at least two people share a birthday.

In a room of 70 people, the odds are 99%. Almost a guaranty that of 70 people, 2 will share a birthday.

Seems counter-intuitive. The math says otherwise.

Interesting. The math part makes sense.




Link to original video: https://youtu.be/-SQq0vfzrrg

I wonder how it's affected by when people have sex. More people have sex in winter (nothing else better to do) so there are more summer/fall babies.

I have a son and a granddaughter with October 5th birthdays. I believe it is (or was) the most popular date here. Happy New Year!

quote:

Originally posted by Skins2881:
Interesting. The math part makes sense.



I wonder how it's affected by when people have sex. More people have sex in winter (nothing else better to do) so there are more summer/fall babies.

Reminds me of the time I was visiting an Air Force buddy who was stationed up in the UP (K I Sawyer). We crossed the Mackinac Bridge, pulled into a gas station to fuel up. Station wagon pulled up near us, dude got out, like 5 kids of assorted ages get out, wife gets out & she's obviously pregnant.

I looked at my buddy "What the hell, man?"

He shrugs his shoulders "Long winters"

Let's experiment. Somebody start a thread. First 70 members post. Then, let's see if we will come up with 2 people sharing the same BD.

I always questioned the "winter" thing. A lot of us have winter and are trapped inside but a large part of the population can play outside year round.

I was born on my mom’s birthday.

quote:

Originally posted by Phantom229:
I was born on my mom’s birthday.

One of my brothers was born on our mother's birthday.

As for when people have sex, I read something years ago pointing out that the traditional (European) June wedding was a good one for babies conceived immediately because they would be born in March and their first few months of life would be in the summer, a better time for nutrition and warmth. That is of course not of much relevance in developed countries today, but it would have been significant even 100 years ago.

And because the dates when people have sex isn’t totally random, that will lead to nonrandom birthdates that will affect the percentages. If, for example, more people are born in March than in December, that clustering will increase the chance that a group selected at random won’t have purely random birthdates. Plus in modern countries and times, artificially induced births can also have an effect. “Oh, tomorrow is Friday the thirteenth; I want the baby now [or tomorrow, or …].” I believe my brother was delivered by C-section. Did my mother say, “Saturday is my birthday; I’d like the baby delivered then”? I don’t know, but it’s possible, and if so, that would mean his birthdate wasn’t random.

quote:

Originally posted by 12131:
Let's experiment. Somebody start a thread. First 70 members post. Then, let's see if we will come up with 2 people sharing the same BD.

Do it here. I'll start.

May 6

I was born on August 2.

I have a cousin who is two years younger who was also born on August 2.

February the 17.

October 19.

Sept 30

4/20. Yes, same as Hitler, and pot day, but growing up, I'd point out that it is also Don Mattingly's b-day.

quote:

Originally posted by mark60:
Sept 30

Bang, game over. I'm end of third quarter too.

DAMN!

9/23..

quote:

Originally posted by Patrick-SP2022:
October 19.

Yeah, me too.

quote:

More people have sex in winter (nothing else better to do)

I'll just point out that this isn't just only in the winter.

And the responses here are unlikely to be random either. If I saw someone post my birthdate, I would be more likely to say, “Me, too,” than I would be to just wander in, look around, and move on to other things. We are looking at far more than the first 70 people who post, but rather the entire block of people who view the thread.

It’s like any other poll: Allowing self-selected respondents skews things significantly.

quote:

Originally posted by Skins2881:

quote:

Originally posted by mark60:
Sept 30

Bang, game over. I'm end of third quarter too.

September 27.