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Comment by AnimalMuppet | Hacker News Reader

> Dinosaurs only died out around 100 mya.

Isn't 66 mya the generally accepted value?

Yes, the Cretaceous–Paleogene extinction is agreed to be 66 mya with some surprisingly tight error bars of about 50k years.

But for the purpose of discussion 100 mya is close enough in terms of orders of magnitude so there's not a need to be pedantic.

I disagree. When one is only concernde about the order of magnitude, it should be given as 1*10^2 mya or as 0.1 bya. What the OP said is analogous to saying that one's grandfather died at the age of 100, when in reality he only lived to be 66.

I don't know if it will make you feel better or worse, but when writing the comment I looked up wikipedia, saw "66", thought "eh" and wrote 100.

If my grandfather had made it to 66 million I would have done the same thing.

At the time scales we're considering that's not even a rounding _error_.

40% is a rounding error? I hope not ;) (edit, fine 34%... but I'll say THAT might be a rounding error grin)

It's not 40%, though; the relevant 100% is not 100 million years, it's "several billion years".

I said specifically it's not a rounding error. You would, at minimum, round to the nearest hundred million years, which was done.

No. First, if the best known number is 66 mya, why throw away almost all the precision and call it 100 mya?

Second, the number it was being compared to in roenxi's comment was 9 million years, not 4 billion years.

So, yes, it is in fact a rounding error.

;-)

As numbers get bigger the amount of rounding gets more acceptable. 100 to 101 is as 1e100 to 1e101, despite te latter technically being off by 90%.

I think 100mya is perfectly fine. It doesn't undermine the point and this isn't trivia I plan to remember more accurately than that.

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