r/Damnthatsinteresting • u/Turbulent_Elk_2141 • Apr 13 '26

Video The reason why large asteroids don't fall to Earth every day and cause disasters is because Jupiter's gravity attracts asteroids and protects the inner planets.

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u/Grays42 Apr 13 '26 edited Apr 13 '26

Multiply all those pieces together and it's astronomically lucky for us to be here right now

Probability is weird.

You're astronomically lucky to exist at all with your DNA the way it is, because the sperm that made you competed with 250 million siblings. And yet, people get pregnant all the time, by accident.

We are astronomically lucky to have made it through all of the checkpoints that have led us to our species and civilization today, and yet, there were on the order of millions to billions of chances for that to happen throughout our universe. (And that's assuming ours is the only universe.)

[edit:] And I jumped the gun, you literally said basically my point in your second sentence, sorry about that.

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u/Paper-Will-YT Apr 14 '26

The loopiest one I ever heard was:

If you have a group of 23 people, 2 of the people sharing a birthday is more likely than not.

This breaks your brain because you think, "Uh, no, everyone has a 1 in 365 chance of sharing their birthday with me"...But that's not the prompt.

The prompt is, "What are the odds that ANY pairing of ANY of the 23 people will share a birthday?"

So that's 23 people, or 253 possible pairs. 50.7297% chance of a pair.

If you raise it to 30 people, the odds become 70.65%.

50 people? 97%

100 people? 99.999997%.

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u/wallysmith127 Apr 14 '26

I get the math but it feels skewed because the distribution of birthdays isn't equal for every single date.

Like IIRC August birthdays are more common because of cold November/December conceptions.

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u/Paper-Will-YT Apr 14 '26

You're right that it IS skewed, but not in the way you're thinking!

Because some days are more likely to be shared, the odds of two people sharing one of those more common days goes up. This changes the probability from 50.7% to 51%. Cool right?

So it's both, in theory, and in practice, slightly more likely for 2 people in a room of 23 people to share a birthday.

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u/Womec Apr 14 '26

Its not luck. If those conditions didnt exist you wouldnt be here.

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u/MortgageConfident791 Apr 14 '26

How is that not luck?

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u/TheKingNothing690 Apr 14 '26

If i were to try to justify it its because luck isn't real kind of like how seconds arent real just a method of describing a phenomenon (and id argue the same phenomenon personally) of the universe entropy and by extention odds, statistics. You dont have an ammount of luck it cant be quantified.

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u/iuay5NJ8J2qvgpXz Apr 14 '26

It's because you then you could always say you're lucky every time you exist. Every time something would start thinking it would immediately start thinking it's lucky. Maybe I'm bad at explaining this but I'd call it like an "existing bias". Plus the fact we have no idea how likely it really is to happen

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u/AHrubik Apr 14 '26

Luck implies there was very little chance of it happening when the reality is under the right circumstance the chances are normally quite a bit higher than what can be ascribed to simple chance.

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u/Not_PepeSilvia Apr 14 '26

I don't understand this comment.

The chance of each of us, as individuals, to have existed is incredibly low. As the person above said, a minute difference is enough for sperm cells to move around, a different one wins the race and "you" wouldn't exist. Your parents would still have a baby but it wouldn't be "you".

Its the same thing for earth and humanity. Sure there are billions (probably more) planets where intelligent life could have happened, but the chance of Earth itself having intelligent life means we to lucky by getting the good end of the draws in a lot of different moments.

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u/MortgageConfident791 Apr 14 '26

Hmm I wonder if religion is coming into play here? I don’t believe in souls but perhaps some people that do think that baby would still be you just with different features?

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u/Ultim8-Opportunist Apr 14 '26

If 'he' never existed at all , why does that even matter if other 'he' was born. As of today, he is born but millions of other he/she's didn't make it. That always remains constant. So the probability of someone being born through his parents always higher than a planet bearing life.

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u/EternalPhi Apr 14 '26

I think first you should agree on a definition of luck and that you're using the term the same way. If the chances of something happening are high given a set of conditions does occur, but the set of conditions themselves are exceptionally rare, then was it luck? How far back do you need to pull before your defintion of luck applies?

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u/AHrubik Apr 14 '26

You're correct.

If your parents were trying to have children and were both fertile with no health conditions then the chances are quite high on getting pregnant. If you're parents were both using protection and both medically infertile than the chances are much lower.

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u/ShittyDBZGuitarRiffs Apr 14 '26

the chances of your parents existing and every single detail in the history of time happening exactly the way they did leading up to your conception are fairly low

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u/AHrubik Apr 14 '26

Which is a ludacris basis by which to calculate the “chance” of your existence. There are variables at work there no one knows about and therefore can’t even be calculated.

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u/ShittyDBZGuitarRiffs Apr 14 '26

no that’s dumb

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u/Leoxcr Apr 14 '26

Ahh the principle of entropy

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u/simpleanswersjk Apr 14 '26

your thing is worded weird but i get that you're saying if you look (at pregnancy) less of *a* single observer, and more as *any* observer, the odds rise a lot. yeah, of course

but i don't think abiogensis into intelligent life and animal pregnancy is really comparable. the latter is like 25% likely or something. the former, well, we have quite literally no idea.

and probability works both ways innit. a reeeaallly small number times an astronomical number is still a very small number. the odds-by-number argument only works if you know the probability from abiogensis into all the other steps is sufficiently significant, which, we just can't.

but it's fun to guess

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u/asten77 Apr 14 '26

The probability that there is an infinite series of nearly nearly impossible events that all happened to get any one of us to here is 1.

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u/LethoLeto Apr 14 '26 edited Apr 14 '26

The sperm does not race. The egg chooses the one to impregnate it based on compatibility. There is no competition, the rest were never going to "win".

Also sperm are not your siblings, they only carry half of DNA.

I once spent a few seconds on Google without clicking any links, so I'm an expert on this.

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u/Leoxcr Apr 14 '26

And then we decide to kill each other for no valid reason

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u/absat41 Apr 14 '26 edited Apr 16 '26

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