What if our planet had ten times it's current diameter, and was always darkened by low hanging clouds and perpetually gritty skies?

I’d move!

We’d probably be slime molds on the face of the planet, if we lived at all. That’s going to be a pretty high force of gravity there.

we’ll be called Moles.

All I can say is…

C.H.U.D. – Cannibalistic Humanoid Underground Dwellers

Finally we would be the center of the omniverse.

Vin Diesel for president in the pitch black.

@CyanoticWasp Low density planet with same gravity as found on Earth.

We can’t know, because without exposure to sunlight, we would not know what we were missing.

Perhaps we would be comforted by the constant winds blowing the grit everywhere.

Would this grit be good to brush with.

I would have to have nice teeth on that world.

Depends. Is the density the same?

Hey, it’s nice to see you again, @AstroChuck.

@AstroChuck—Man of Density!

Well, humans wouldn’t be.
I mean, such simple changes as greater cloud cover would completely alter the path of evolution. On our present Earth, the ocean played a huge role in the creation of life, because it protected “us” from harmful UV rays, and gave “us” a relatively cool temperature.
On this hypothetical earth, bonus cloud cover grants those. You may see life’s beginnings really be on land. If not, they’d certainly manage to get out to land sooner.
So on and so forth.
With greater cloud cover also comes more darkness. Depending on how heavy you’re talking about (If we can’t see the starry night, that’s gotta be pretty damn heavy cloud cover), you’d see eyes be a lot less important, and take a back seat to the other 4 senses more. Who knows, maybe the creatures would have other senses too!

If the sky is obscured enough for us to not be able to see the starry nights..
and if the Earth is 1/10th as dense as it is now (Considering you say it’s 10x the size, but the same gravity)
I’d think we as a species would be digging down, instead of building up. Imagine taking the elevator down 30 floors to get to your office.

You may see major deities be fire, as that’s what’s at the core of our earth, the heat.
In our present Earth, we desire to build up to the clouds. So it’s no surprise that kids are taught that Zeus, God, whatever, lives up there. The sky is our desire.
We place our dead in the ground. The ground is what we fear. That’s where our Devil lives.

In this hypothetical earth, you may see these reversed. We try to reach the bottom. Our hopes, our dreams will be there. So our good gods will be there.
Our demons, devils, whatever. They will be the ones in this mysterious cloud cover. That which is always in our way, and blocking our knowledge of the outside.

I REALLY like this question, @wundayatta.

We’d have to rethink airplane flap degrees and mid-air refueling, since pressure and distance wouldn’t be the same. On the positive, real estate would plummet, making it even more affordable than it is currently. Over time, our eyes would no longer be needed as much, so they would become vestiges, about like appendixes, and our skin would pale out. Of course, that would mean no more skin cancer, either.

and, since there’s no light, there are few trees to exchange gases so we could breathe.

Blood gases and enzyme counts would change enormously, meaning serious, if not unsurvivable, medical issues. If we assumed pressure would be the same, that still doesn’t account for the redistribution of atmospheric gases and layers. That would pretty much be gone, and we along with it, if we can’t breathe. We’d have to walk around with nonrebreathers and 02 tanks. Nasal cannulas wouldn’t be enough. Then there’s the problem of over-oxyenation causing blindness. I guess that doens’t matter, since we’d be in the dark.

What I don’t know is how this would affect the ocean currents and gravitational pull of the moon. Interesting thought! I’d like to hear it, if anyone knows the answer.

We’d all look like stingrays using our flappers to type our Fluther answers.

I was thinking there would be a close, bright, hot star. Enough so that there was a significant amount of light beneath the clouds. Although, I then think the planet might have to be artificial because I don’t think large, light planets can form close to a star.

I’m not sure about the science behind your point, @phillis in terms of air pressure and blood gasses. I mean, I’m not sure because I don’t know anything about it. Why wouldn’t air pressure be the same as on Earth? Why couldn’t the gas mixes be the same? I don’t think flight would be developed by an intelligent species. Not unless engines that could tolerate grit or screen out grit could be invented, and a way to strengthen the exterior of the flying machine would also be able to handle all the crap the planet threw at it. I was thinking the clouds would generally be at 1000 feet or lower.

@Sarcasm That idea of digging down makes sense to me. And the notion of demons could be right because most of the grit would come from an extremely active set of volcanos. I’m not sure what would keep the air clear below those clouds, perhaps some kind of permanent inversion that maybe happened only in a few places, with great distances between them.

There would be dust travelers who went from inversion spot to inversion spot, trading and sharing information. They would be a mysterious tribe, dangerous to mess with, but very competent at survival. Oops. This is getting a bit Dunish. Well, no worms, anyway.

The atmospheric pressure and gas mix and layers could be the same. I wasn’t sure how you were imagining the scenario, so I suggested what changes might occur. To picture it best, liken it to mountain climbing. A pro climber knows that the air thins, the higher he goes. It isn’t just that there isn’t enough oxygen; it changes your blood gases, too. The rate of exchange between carbon dioxide and the usual 16% atmospheric oxygen we are designed for gets thrown out of whack because the lungs can’t adjust to the changes at the cellular level (some of that is due to the molecular structure of atmosheric gases when they combine with the other gases we’re accustomed to breathing. In short, they’re the wrong size). Hence, our breathing slowly poisons us to death no matter how hard we gasp for air.

As a comparison, consider the hyperbaric chamber and “the bends” that divers get. The gas exchange rate goes screwy, the body cannot keep up with it, so carbon dioxide (gas) bubbles form in the blood (called embolisms) because the exchange rate could not take place at the cellular level. This is what kills divers. If it isn’t too severe, a diver can be hauled into a nearby hospital to be placed in hyperbaric chamber (diving resorts, such as on the chain of Hawaiian islands, have the luxury of having nearly all of thier hospitals equipped with these chambers, specifically for this reason), which forces oxygen into the blood through pressure so that carbon dioxide can be safely exchanged at a steady rate until the patient stabilizes. The chamber does a lot of other things besides that, but I just used it to help create a picture for this instance.

Without proper light most plant life would fail, well…you know where it would go from there. lol