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magneticnorth 3 hours ago

This is neat, but I don't think it's actually drawing the year from the correct probability distribution - "a random birth is far more likely to fall near the present" is correct, but in 5 "random" choices, only one was from anywhere near modern day.

zhoBEENG 2 hours ago | parent | next [-]

I did a statistical analysis and you are correct. The issue seems to be that crude birth rates from around 500CE and earlier are overestimated significantly. The bad source seems to be Kaneda & Haub, "How Many People Have Ever Lived on Earth?", where they assume a flat crude birth rate of 80 for all BCE dates. The probability distribution is just a function of pop and CBR, so it results in significantly decreasing modern birth probabilities.

fxd an hour ago | parent | next [-]

In other words, the Flat Birth Theory.

We can call them flat birthers

karim79 44 minutes ago | parent [-]

Come on now. We all know the birth is not flat. It can be clearly seen from space.

mmmnnn 43 minutes ago | parent | prev [-]

https://www.youtube.com/watch?v=KKpILoUMMb8

WA an hour ago | parent | prev | next [-]

There are more statistical issues. I drew a person from 1984, living in Germany and recalculated their life several times. In almost all cases, their mother died while they were in their thirties, often both parents. This is simply far from reality.

stickfigure 25 minutes ago | parent [-]

[dead]

yummypaint 2 hours ago | parent | prev | next [-]

The x-axis being log scale by default visually exadurates the effect if you are thinking about it in terms of area under the curve. This confused me also.

throwawayk7h an hour ago | parent | next [-]

They should have scaled the probability curve by the derivative of log(time).

magneticnorth 2 hours ago | parent | prev [-]

This is a good point, it's not as far off as it seems from a quick glance.

Supermancho 2 hours ago | parent | prev | next [-]

> "a random birth is far more likely to fall near the present" is correct,

If the selection is from the population at random (as the UI indicates), but it specifically says it's based on a random year (during which humans were present) first as a filter. It's much more likely to select far from the population explosion.

satvikpendem 23 minutes ago | parent | prev | next [-]

That's sort of boring though, we generally know what it's like to live near the modern day already.

mannykannot 3 hours ago | parent | prev | next [-]

I guess you are right, but it makes it more interesting if the picks are not almost all from the recent past. On the other hand, I would also guess that spreading the picks evenly across the time range might result in many being from times with little data to differentiate them.

benatkin an hour ago | parent [-]

It makes the premise of the entire site flawed, though. And it defeats the purpose of the convenient button provided to redraw a year. That is what should allow you to find a pick that might be more interesting, rather than messing up the randomness promised by the site and the HN title.

Tenoke an hour ago | parent | prev | next [-]

Yes, this is exactly what I expected (showing the anthropic principle in action), so I am disappointed they are not sampling correctly.

wat10000 2 hours ago | parent | prev [-]

How near is near? With ~100 billion people having ever lived, the odds of a randomly selected life falling within the past couple of centuries are not all that high.

riazrizvi 2 hours ago | parent [-]

Okay step away from the waving hands and read the source material.

wat10000 2 hours ago | parent [-]

Could you be a little more specific? https://www.prb.org/news/how-many-people-have-ever-lived-on-... puts the halfway point at over 2,000 years ago, so you'd expect less than 50% probability of getting a random year that's not BCE. "A random birth is far more likely to fall near the present" is true in relative terms; the timeline on the web site goes back 300,000 years and you're very likely to get something in the past few thousand years, which is pretty near to the present when compared to a third of a million years. The random years it gives me fit into that pretty well, so I guessed that the person I replied to might be using a narrower definition of "anywhere near modern day" than that. Hence why I asked. If I missed something, could you kindly point out what I missed, instead of whatever this is?

an hour ago | parent [-]
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