Mastodawn

Chef Rat Apr 29, 2024

If we took material like rock from space and got it back to Earth enough times, would Earth grow as a planet?

https://sh.itjust.works/post/18544812

If we took material like rock from space and got it back to Earth enough times, would Earth grow as a planet? - sh.itjust.works

As the title says. I’m actually thinking about this hard with my friends because everything that’s produced on Earth stays on Earth so it doesn’t change size, but what if it’s not from Earth but it stays on Earth? [https://sh.itjust.works/pictrs/image/4b10eeca-d3fc-4aca-beff-8d9cb61b303a.png]

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tobogganablaze Apr 29, 2024

I mean yeah. If you add stuff to a ball of stuff it get’s bigger.

Currently Earth is actually losing mass around 55.000 tones of mass per year. (100.000 tons loss due to air escaping to space but we gaing around 45.000 tons in dust and meteorties falling on earth).

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ccunning Apr 29, 2024

If “energy equals mass”, shouldn’t we be gaining mass from the sun too 🤔

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groet Apr 29, 2024

energy equals mass

That doesn’t mean energy has a weight.

It means it is physically possible to transition energy to mass and vice versa. Sunlight hitting the earth does not add any weight.

Also, earth radiates heat out to space. At a rate of (aaaaaaaaalmost, because of the greenhouse effect) 100% of the energy we get from the sun. If it didn’t, earth would be a few million degrees hot by now…

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sushibowl

That doesn’t mean energy has a weight.

No, it literally does mean that. If you put light in a box of mirrors the total weight of the box will literally increase by an amount equal to the energy of the photons. If you put some radioactive material in a theoretically perfectly sealed box from which no heat or light could escape, and weigh it while it decays into radiation, the weight will not change.

This applies to all forms of energy. A spring is heavier when compressed. An object gets heavier when you spin it, or heat it up. Sunlight hitting the earth most definitely makes it heavier. In fact, the sun hits the earth with about 4.4*10^16 watts of power, corresponding to about 0.5 kilogram per second.