What if Earth was the size of Jupiter (not a physics question)

[Holo]

How would history have been different if the Earth was the size of Jupiter, but kept the same properties (eg. gravity, atmospheric pressure)?

To start, we'd have a lot more land and natural resources to work with:

[brooklyn666]

Size in mass, radius, volume? Be specific. If you simply mean Earth would have the radius of Jupiter, other factors have to change as well.

[Seret]

Bit of an odd question. I suppose it might have taken us a lot longer to realise it was spherical.

[11of10]

We'd still overpopulate it, it'd just take longer

[Ralathon]

When we're talking gravity, do you mean surface gravity (As in, 1G on the surface) or total gravity (As in, the mass of the new body is the same)? Because there is a significant difference between the 2. In the former case we would never be able to achieve chemical spaceflight. You'd need so much dV you'd need an orion drive just to get to orbit. In the latter case surface gravity is only 0.01G. We'd be able to fly by strapping pizza boxes to our arms.

[magnemoe]

First you would have to make the core of light materials, even normal rock would be far to heavy, but say you did and still had an magnet field and plate tectonic.

One other major change would be the gravity gradient, Saturn has lower gravity than earth however escape speed is far higher.

This would make Earth hold hydrogen as gas giants do, solution might be to reduce gravity.

[Albert VDS]

What I think he means is what if the Earth had the same surface area as Jupiter and kept the same conditions we live in now.

[Ralathon]

What I think he means is what if the Earth had the same surface area as Jupiter and kept the same conditions we live in now.

Okay, so the same surface gravity, same atmosphere and the same day night cycle. We handwave away the physics that says this planet shouldn't exist.

First of all, we'd obviously have a lot more resources to play with. Jupiter's radius is about 10 times as large as Earth, so we'd have about 100 times the surface area. If we assume that our current civilization was somehow transported to this new planet we could relax. We'd have plenty of resources to give everyone a very comfortable lifestyle while still keeping vast wildlife reserves around. Furthermore, the ecosystem of such a planet is much more stable. We'd have to pump out 100 times the CO2 to have the same effect on the global temperature as we do on our earth.

Volcanism would be on the rise however. Earth doesn't really like big tectonic plates, they trap too much heat under the center which causes them to break up. So we'd likely see the big continental plates fracture after a few million years. This isn't as dramatic as it sounds, it just means some volcanoes pop up in areas you wouldn't expect (African mainland, east coast of north america etc) and over the next few 100 million years they'd drift apart.

What is a reason for concern is the weather. Even on earth rainclouds often have trouble reaching the middle of a continent. If it has to travel 10 times the distance most continents will become very dry. So we'd likely see large scale desertification around the world. Meanwhile the coast has bigger issues. Hurricanes tend to build up energy while over warm water and lose energy while over land. On earth this means that can't get all that strong since they'll eventually reach land and run out of juice. On the new super earth they can stay over the hot ocean for months, building up immense power. If one of those hits the coast you're going to have a bad time.

Heat gradients across the globe are also 1/10th of what they used to be. So a lot of things we take for granted simply stop working. Europe will get very cold without the gulf stream providing warm water for example. And a lot of the prevailing winds will also likely shift. So weather would change on a global scale.

If we manage to adjust to our new climates we still have some other issues to contend with. The larger distances make trade a lot less economical than it is today. So expect the economists to start crying. The larger distance also means slower data transmissions. If you're playing a game in europe on an american server you'll see a significant increase in latency. Flights to other parts of the world will also take longer and require more refueling stops. A trip across the atlantic takes about 9 hours today. So using the same plane it would take nearly 4 days on the new planet. This means transatlantic passenger flights are a no go and they have to divert over the arctic with a few refueling stops along the way.

We'd probably survive, but the world economy would become a lot less prevalent with more focus on local production.

[magnemoe]

What I think he means is what if the Earth had the same surface area as Jupiter and kept the same conditions we live in now.

Obvious, however this would have other impacts like gravity gradient.

Not sure how the weather patterns would be like, anyway if we assume earth like conditions on surface it would have little impact until you started to get decent boats, now you get an age of exploration who would last far longer, you would miss out continents until you had radios and planes.

More place for both animals and cultures to evolve.

[Winter Man]

Higher variance in plant and animal life, resistance to mass extinction events, that sort of thing.

[Drunken Hobo]

What if all plants & animals were proportionally bigger. Would we even notice?

[Ralathon]

What if all plants & animals were proportionally bigger. Would we even notice?

Yes we would, thanks to the cube square law everything would crush itself to mush.

When you make something twice as big in every dimension you increase its surface by 4. This means your structure can support 4 times the stress. But the volume goes up by a factor 8. Since weight is a function of volume your structure weighs 8 times as much. 8 times the weight on just 4 times the structural integrity means your structure is now weaker relatively speaking.

This is why ants lifting 100 times their own body weight isn't that impressive. If we shrunk down a human to ant size (s)he could do the same. Making everything 10 times bigger has the opposite effect. A 20 meter tall human wouldn't be able to stand since his legs would snap under the weight. He would pass out if he even tried since his heart can't muster the pressure needed to pump blood to the brain. Lifting an arm would be nearly impossible and likely disjoint the shoulder. All in all, we'd have a pretty bad day.