What if you never aged? What if dinosaurs were alive today? Explore the hypothetical with these and more 'what if' scenarios.
We wouldn't stop requiring power. So how would a turn to alternative energy sources work out for transportation, international trade and our daily diets?
Remove that pesky drowning risk, and the world formerly under the sea opens with possibility — despite our inefficient limbs and tendency toward hypothermia.
If minerals make up so much of the Earth, why would we ever face shortages? The availability of the resources we use to create products often depends more on our priorities than the planet's supply.
Assuming we got to keep the sun, how bad would be for travelers to not have these little guiding lights? And what else might have changed in history without stars?
People would look underground for water and maybe just stay there to escape the fiery hell on Earth's surface. But could humanity really last without the seas?
Our early ancestors, enjoying the effects of rotten fruit, had stumbled onto something big. How did alcohol serve as a nutrition source and, some believe, help motivate hunters to take up farming?
There'd be some sacrifices. But bird-people society would have its advantages: interchangeable parents, sophisticated gardening skills and a close relationship with trees.
Income inequality contributes to societal ills. Would mandating equal paychecks for all improve the situation or lead to work-shirking and massive government?
When it comes to eating certain questionable foods — like unrefrigerated potato salad — most of us know to stay far away. But what about moldy bread? If you cut the offending areas off, is it a risk worth taking or a ticking time bomb?
Picture this: You're floating through space, minding your own business, when some super-scary alien attacks you. Clearly you need to defend yourself, but all you have is a handgun. Will it do you any good, or are you mincemeat?
Outside of the Arnold Schwarzenegger movie "Junior," men simply can't get pregnant — meaning there's no reason for them to take birth control pills, right? Perhaps, but say a guy mistakes "the Pill" for a breath mint. Is he going to be okay?
Tons of planets have more than one moon. Heck, Jupiter and Saturn have more than 50 each, and they seem to be doing just fine. So why is it that the idea of a second moon for Earth has scientists throwing up red flags?
Double the suns means double the suntan, double the solar energy and double the awesome sunsets, right? Well, not exactly. Having two suns might sound fun, but it would probably make for a pretty different environment here on Earth.
Coral reefs are pretty cool. More than just snorkeling destinations, they shelter tons of marine life — creatures many of us depend on for food and medicine. So what would happen if the coral reefs disappeared? Here's a hint: It isn't good.
We all know what Viagra does and why men use it — not to mention how much money this particular prescription drug has made over the years. But what would happen if a woman took Viagra? Is it a danger, or could it somehow be beneficial?
Cockroaches are among the most reviled creatures on the planet. They bring bacteria and allergens wherever they go — along with severe cases of the creepy crawlies. But would we really want to live in a world devoid of these little pests?
Snakes get a bad rep. They've become so associated with dishonesty, deception and temptation that many might prefer the world just rid itself of them altogether. But creepy as they may be, it turns out that snakes are pretty handy to have around.
The Earth is a pretty stalwart planet, having survived billions of years of punishment at the hands of asteroids and other cosmic bodies. But could it withstand more than 7 billion people jumping up and down in unison? Do we even want to find out?
Solar flares disrupt Earth's magnetic field when they hit the planet, causing issues with power and GPS. But if a major solar flare hit Earth, the consequences could be catastrophic.
Imagine going outside in the summer and not being eaten alive by mosquitoes. Yeah, no mosquitoes! Well, don't celebrate just yet, because a world with no mosquitoes might have a radically different food chain.
Neanderthals are long gone, but they live on in the DNA of some modern humans. If they were still alive today, the differences (and similarities) between us and our ancestors would be astounding.
If you don't recycle, you should. If you do recycle, you should do more. And what if everybody in the world started to recycle? At the very least, it would help us attack that enormous plastic patch in the middle of the ocean.
It's a strange thing to think about, but have you ever wondered what would happen if the ozone layer suddenly wasn't there? Here's a hint: Getting a bad sunburn would be the least of your problems.
Remember learning about photosynthesis when you were a kid? Let's pretend for a moment that this vital process could somehow permanently stop. How tough would it be to continue to live on this Earth?
It's going to take billions of years, but one day the sun will die. Read on to find out how the end of the sun will affect life on Earth.