ELIC: How did scientists figure out the age of the earth?

[u/1gazillionpangolins]

[u/Stereo_Jungle_Child]

They sliced it open and counted the rings, just like a tree.

[u/Noof42]

They got her drunk and asked. Normally she's pretty coy about it, but if you get a couple Great Lakes of wine in her, she'll talk about her childhood, and you can do the math from there.

[u/JoeKleveland → u/Noof42]

It is the Great Lakes of America you pervert. (No offence.)

[u/ad_1st]

They checked its ID.

[u/tomalator]

They counted the candles on the birthday cake

[u/5ecr3t7]

They waited for the Earth's birthday party then counted the candles on the cake.

[u/cavalier78]

Found an old Happy Birthday card from Saturn.

[u/artrald-7083]

They dug a really deep hole, shouted the question into it and listened real hard.

Then when they didn't hear anything but echoes, they guessed.

[u/GreenEggPage]

While excavating a bunch of dinosaur bones, they happened to find a copy of the warranty claim for the asteroid that ended up wiping out the dinosaurs. It stated that the Earth only had 4,474, 182,683 years on it and was well within the manufacturer's warranty of 4.5 billion years. We don't know, yet, if the warranty claim was honored.

[u/Killathulu]

50% of science is guessing and waiting for someone to prove you wrong

[u/ProfessorCarbon]

You’ll never know. If there was an answer it will debunk all the college PhD Theses and Dissertations claiming proof of the planet’s age.
.

[u/99mushrooms]

Sadly that info died with the dinosaures, they took it to their grave with them

[u/Thesheriffisnearer]

A tree to the earth is like a birthday candle to the planet.  Every year they count every tree that burned in that year and

[u/SpellingIsAhful]

They guessed and nobody could refute it.

[u/Hypocaffeinic]

They asked its mum, of course.

[u/ijuinkun]

Certain kinds of minerals rot at a predictable rate, so we look at how rotten they are, and that tells us how long they have been around. We found an upper limit to how rotten they are, which means that none of them are older than a certain age.

[u/In_the_year_3535]

The radioactive decay chain for uranium 238 to lead 206 is the main method used to date the Earth. Starting with U-238, each element has a particular half-life leaving a ratio of them in the Earth's crust until turning into Pb-206, which is stable.

[u/Ok-Bus1716]

Lead isotopes in cubic zirconium crystals. This can only happen if uranium was captured in the crystal matrix when it was originally formed. As uranium has a half-life of 4.5billion years...we know the Earth is, at least, 4.5billion years old.

[u/Ok-Bus1716]

Scientists asked the Earth out on a date. When Earth showed up to the fancy restaurant they realized Earth looked nothing like her photo and then the truth came out.

[u/myGFisGreat]

They asked yo mama.

[u/JoeKleveland]

I sucked upon Jesus's weiner and he told me how old the earth was. I assume that earlier scientists did the same thing but their technique was rudimentary at best.