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Kummakivi is a 500.000 kg rock in Finland that has been balancing on another rock for 11.000 years (files.catbox.moe)

submitted 4 months ago* (last edited 4 months ago) by Blaze@lemmy.blahaj.zone to c/pics@lemmy.world

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Source: https://en.wikipedia.org/wiki/Kummakivi

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[-] HonoraryMancunian@lemmy.world 4 points 4 months ago

I'm not convinced that weighs 500 tons, that's the same as at least 65 of the largest African elephants or 2.5 of the largest blue whales

[-] SkyeStarfall@lemmy.blahaj.zone 20 points 4 months ago* (last edited 4 months ago)

After some googling, some of the heavier rock types are 3g/cm^3, which is 3000kg/m^3

If we use the person as a rough ruler of 1.6m, the rock is about 5 person wide, and 3 person high (eye measure), give or take. And if we say it's 3 person deep, then it has a rough mass of 5*3*3*1.6*3000 = 216 000 kg, which is in the same order of magnitude.

Close enough to check out, I'd say.

Edit: I realized since the actual ruler we use is 1.6m (assumed), it should be multiplied by 1.6 three times (one for each dimension/length), not just once. If we do that, we end up with 921 600 kg instead, putting 500 000 kg well within the range of possibilities from a quick calculation.

Edit 2: as pointed out below, the actual correct estimation would be 553 tons

[-] HonoraryMancunian@lemmy.world 6 points 4 months ago* (last edited 4 months ago)

Your edit is correct except I get 553 tons! I'm still shocked it'd easily tip the scales vs 2 large blue whales

Edit: ahh you accidentally did 5x5x3 instead of 5x3x3

[-] EddoWagt@feddit.nl 2 points 4 months ago

I'm still shocked it'd easily tip the scales vs 2 large blue whales

Rocks are dense and blubber not so much, I suppose

[-] SkyeStarfall@lemmy.blahaj.zone 2 points 4 months ago

Oh, whoops, I did make a mistake! Thanks for the correction

[-] Hule@lemmy.world 0 points 4 months ago* (last edited 4 months ago)

You got me confused.

5*3*3*1.6*3000

is the same as

[(5*1.6) + (3*1.6) + (3*1.6)]*3000

[-] SkyeStarfall@lemmy.blahaj.zone 1 points 4 months ago* (last edited 4 months ago)

5*3*3*1.6 is not the same as (5*1.6)*(3*1.6)*(3*1.6), however

The reason we multiply with 1.6 on every dimension is because the ruler we use is 1.6m long. We effectively create a new unit, and have to convert. If a length is 5 person wide, then in reality it's 5*1.6 = 8 meters long, where 1.6 is the conversion ratio from the unit of 'person' to the unit of 'meter'. And this applies for every individual measurement.

Also, 5*3*3*1.6 is not the same as (5*1.6)+(3*1.6)+(3*1.6) in the first place