If it were possible to alter the space-time continuum without consequence, what SINGLE invention would you prevent from ever existing?

I am well aware of that, which is why this whole situation is completely hypothetical.

As intensive as religious fanatics can be, I think religion on some level is a positive as it provides a moral structure for a lot of people to live by. A lot of people would be absolutely lost and reckless without it.

Of course, religion has been the catalyst for some of the greatest conflicts ever waged. It's a pretty pro and con subject.

Is this just modern money, or paper money, or coins, or what? Or do you want to include all forms of currency, even shells and shiny things that they used way back when? Would we just go back to trading? :D

A meat cleaver? Kinda hard to uninvent a sharp edge, lol.

I would hate that, btw. I can't get by without steak...or burgers.

Did you know that the process of killing cows for meat pollutes the air more than planes, cars, factories, and all that junk combined?
Burgers are okay, but I just don't like the process used to make them.

That's incredibly vague and ridiculously hard to believe. Methane gas produced by cows' flatulence actually pollutes a lot to the environment by itself.

"What's the number one cause of global warming? Cars? Nope. Factories? Nope. Planes? Nope. According to the United Nations, raising animals for food generates more greenhouse-gas emissions than all the cars, planes, ships, trucks, and trains in the world combined."

-PETA2