I can into science, so let me ponder a few of these. (Also will include citations.)
To answer the anti-gravity question: We'd have fundamentally changed our understanding of physics if we found a new element that could nullify the effects of gravity within contained spaces. It would lead to a new scientific golden age atop a plethora of criticisms about "science's prior assumptions" by religious fundamentalists.
To explain: Gravity is a force in the universe that warps space and time.
3D Example,
2D Example. To be able to nullify gravity in a particular spot costs a
fuckton of energy. In physical principles, it would require at least an equal amount of energy to produce an anti-gravity field per square meter you wanted to affect.
You would have to combat the entire gravitational pull of the Earth. Theoretically speaking, you'd have to be able to produce a gravitational "bubble" that "keeps out" Earth's gravity, whilst simultaneously producing no gravity whatsoever inside the bubble. The only way you are going to accomplish this is to be able to change mass, because mass is what produces gravitational fields. (The heavier something is, the more gravity it has, generally.) If you have a device that can effectively nullify mass, you have a God device, because that's the ability to casually manipulate matter and energy on a whim. Nothing else--not magnets, especially--is going to help you with this.
On top of this, as an added piece of entertaining food for thought: If you had a gravitational force equal to that of Earth outside of the bubble, everything inside of the Bubble would very rapidly lose momentum and then fall off of the Earth. The Earth is flying through space at around 67,000 MP/H. (It gets great gas mileage.) The main thing that keeps you moving at the same velocity as the Earth is the fact that Earth's gravity keeps you on it. Counter Earth's gravitational effect, and you'll start to lose momentum due to the friction that's in the air. You'll slowly float off of it and out into space.
Same would happen if you "turned off" gravity in the universe--we'd all float away from each other, planets would careen off into oblivion, galaxies would immediately fall apart, so on.
The closest you could get to real anti-gravity would be to have a sufficient amount of physical force constantly projected so as to allow you to
just overpower gravity--IE: Thrusters. That being said, all thrust is a matter of energy input to output, but nothing is 100% efficient, as I'm about to go over...
I hope I don’t come up with anything too obvious for this, but forgive me if you do!
The first thing I think of, after transportation, that is, would be to use your brand of anti-gravity to create a few perpetual-motion machines. Say, switching the anti-gravity on, then off again, then back on would be able to accelerate an object without investing any energy into increasing the speed, if that makes sense? Someone with a better grasp of physics could come up with a better explanation, but if you’re trying to go for super science, I feel like an infinite source of clean energy would be a fantastic place to start. I would recommend that such an engine be either very large or illegal, in order to ensure they aren’t created by anyone who wants to use infinite energy to blow something up, but I’m sure you’ve got a plan. Good luck with your writing!
... Here!
No, you could
never make a perpetual motion machine, even if you had anti-gravity. The reason for this is because 100% energy conversion is impossible--you will always spend more energy than you get back. This is why cars require fuel, and why humans need to eat.
Law of Conservation of Energy. The amount of energy you would spend to turn on any machine will, by necessity, need to be partially utilized by the machine in the process of transforming that energy into another type of energy. In this case, we can assume that
electrical energy is being converted into
kinetic energy, and as part of that process, some of the electrical energy is being spent by the machine itself.
Again, if you can somehow create energy from nothing to do this, you have a god device, and its uses would go far beyond anti-gravity.
Hm. I imagine the amount of energy expended would be less than the energy gained? Part of the problem with power generation is that you always lose some of it as heat.
Oh good, you got it!
I may be underestimating how much energy you’re picturing the anti-gravity divide itself will produce. But my main concept is just letting it fall in order to speed it up, then using that same speed to bring it to the apex again by eliminating gravity’s effects. That way, it’s constantly speeding up, and you can just pull energy from the system before it reaches terminal velocity. Or even better, make the whole thing exist in an artificial vacuum. When you’re trying to make a perpetual motion engine, I feel like you could spring for that.
What is creating the artificial vacuum in your hypothetical scenario? I bet it costs energy...
It vastly depends on three things: how portable it is, how easy it is to use and how affordable it is. Also, let's suppose that power is a non-issue.
Assuming the answer to all of these is "as much as possible", levitation would become like second nature. The world would be changed fundamentally; a time where humans couldn't fly would become unthinkable.
Buildings would no longer require stairs of elevators, roads would cease to be concept and even floors would become an obsolete concept. What you're essentially creating is a world where humanity is no longer bound to a two-dimensional plane like the Earth's surface, but free to move three-dimensionally in every direction. not only that, but without gravity there doesn't even need to be a "down", per se; entering a room through one side would by no means imply which side is the floor and which is the roof. Hell, they all could be floors; space becomes infinitely easier to manage when you can just stick stuff to the ceiling and be done with it.
There wouldn't be floating cities as we'd imagine them; it wouldn't be a bunch of buildings stuck to a flying platform. Instead, every building would be floating; a like debris field suspended in mid-air. Restricting forces would still exist, of course; you can't build a settlement so high up that breathing starts to be a problem, nor do wear and tear or inertia or friction stop. However, you could still have a city built vertically enough that one should pack a coat to float up to the upper sections, or a merchant city where every building acts as a ship in a fleet.
Speaking of buildings, they would no longer be limited by internal structure nor gravity, so the architecture would probably start to go crazy. Settlements would start looking like galleries of giant abstract sculptures, and geometry that would make no sense to us would be incorporated regularly.
the main problem, as you brought up, is that without gravity, nothing is keeping anything on Earth, and people would very quickly start drifting off into space. One way to counteract this is that, instead of making it anti-gravity, you could make it controllable gravity; you don't really need to defy it, you just have to make it weak enough to allow you to float. It would also make moving a lot easier, since you'd just fall in a given direction instead of having to pack a jetpack or whatever else.
All that said, this kind of society supposes the three point I made at the beginning; it could very quickly change given any of those do. if it isn't affordable, the rich would literally be above everyone else, living in the aforementioned floating cities only they can afford. Aside from that, anti-gravity would become a large-scale utility, used for government projects and similar things but unlikely to be accessible to the common schmuck.
If it isn't portable, I'd imagine it would be used more for vehicles than anything else; it could be incorporated in stationary objects like statues and the like, and it would still be used for construction work, but the "floating cities" would likely be the stereotypical ones with buildings on floating platforms. That said, I wouldn't really see the point of such a metropolis; it has no resources and is on no trade routes, so it would have no reason to exist.
If it isn't easy to use, it'd become a specialist technology. It would probably find more military application as soldiers are specialized anyway, but on a day-to-day basis it would be seen less of an essential and more as a commodity.
Also, this is my first post outside of introduction thread. Hi, I'm Sour Rocks.
Oh, boy. There's a lot to unpack here. Let's get started.
#1: Even if levitation became unthinkable, there would be plenty of situations wherein one would want to simply... Walk. The reason being is to maintain physical health, and that a levitation device--even if it were cheap--would still impose a greater cost ratio to simply walking. Then there are locations (such as caves, tunnels, interiors of small structures) wherein levitation wouldn't really be practical most of the time.
#2: We would still, absolutely, have stairs. For the same reason why we have stairs now in spite of having elevators:
This device would require power to maintain it, to turn it on, off, to maintain the power of the field itself, so on. If you ever, for whatever reason lost power, you'd drop to the ground like a rock and die. Then, there would be the people would simply want to use the stairs to, again, maintain their physical health--if you levitated everywhere, you would stop using your muscles and become morbidly obese or frighteningly skinny. Especially given that it produces an anti-gravity field, in which gravity (and the friction it presents) is an every day, every minute phenomenon that our bodies evolved around being in. Take that away and you start doing some pretty fucky things to people.
#3: No, we would not have floating buildings. Again, power constraints. Even in the universes of Star Trek and Mass Effect--which
both feature technologies that can effectively create or infinitely manipulate matter and energy, neither features floating structures for... A lot of reasons.
#4: I could totally see some arts buildings being made for their own sake, just because humans are vain like that, but the majority of infrastructure would still be purpose-designed and logical. Nobody wants to live in a house made out of structural defects that will murder them and their entire family if it ever falls from the sky.
#5: A lack of gravity would actually make it more difficult to move around. Astronauts on the International Space Station have to propel themselves off of the interior of the spacecraft to get around. tl;dr:
Newton's Third Law. It's a thing. We were not made to get around in space, so, actually, yeah, we'd totally still have mini-thrusters. Probably similar to the
ones on space suits, actually.
#6: Its biggest use as a technology would be for large scale construction projects. Instead of having to move around horrendously and notoriously touchy and heavy construction equipment, you'd just attach it to a steel beam weighing 50 tons and lift that shit straight to wherever you need it. Construction workers could float to wherever they need to be with the safe knowledge of knowing that they cannot fall and build in three dimensional angles.
The biggest use of this technology would be construction and common schmuck jobs, as well as "rich kid toys" and arts projects. Its primary revolution would be in allowing us to expand at a rate that would be unfathomable by today's technological standards.
#7: I agree. If it wasn't portable, we'd use it primarily in transportation, though again, I think it'd mostly be seen in use in construction. Because a floating crane that can't tip over is the best crane.
#8: The military would shit its pants over this, agreed.
Whee, science~