Tesla and Edison had the War of the Currents. There was the struggle over gaslights vs. electric bulbs. Then there was VHS vs. Betamax (for those of you old enough to remember videotaping). Mac and Microsoft still aren't talking. Wherever there's a way to build an invention there's likely to be several. But then at Low Stellar and Late Solar levels of technology you get the Gravity Wars!
Gravity control in most settings makes space so much easier (meaning you can get to it and get killed quicker and cheaper.) Instead of using a honking huge rocket to reach orbit you can use a consumer friendly launch with a reasonable payload to fuel ratio. You just throw a switch and some of the Earth's (or other planet's) gravity is negated. Doing a space time sidestep you find yourself in orbit.
This is going to piss off many powerful and wealthy people.
Think about it. You're running a surface to orbit transport company and have invested in a laser launch system or space tower or even just a reusable rocket and launch pad. That's $$$$! Then along comes Pop Jenkins who builds an anti-grav car in his garage for GHU's sake! the cost of getting to orbit becomes the price of some current (pennies unless you're buying it in New York City). What would your reaction be? What would the headlines read?
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Maybe I'm being a little cynical. Maybe Pop Jenkins announces his discovery from orbit in his Solar Winnebago. The secret is out. What the hell do you do with your infrastructure? All those rockets and launch platforms are junk and all your revenue will dry up.
Even worse, anti-gravity negates many reasons for going into space. A popular form form of MacGuffinite is microgravity manufacture. Now you can have microgravity or true zero gravity anywhere. So why even go to space?
Wait! Your company has some long term contracts? Smart. Even if transport to orbit costs go from $10,000 a kilo to $0.25 you have contracts! Tough shit! Build an anti-grav transport with a loan or your savings. Use the increased profit from using it to retire your rocket fleet and build more anti-grav transports. Meanwhile delay the anti-grav revolution as much as you can!
Legislation- You need to carefully monitor and license this new tech. Why you could drive a shuttle up to light speed and have it smack into a planet!
Economics- If you need Element X to produce anti-grav then Element X becomes very expensive. Or in a rift on legislature processing and acquiring Element X requires special licenses.
Health Concerns- the long term effects of artificial gravity on the human body are unknown! This needs further study!
National Security- This new technology can threaten the nation and must be restricted to the military. This might even be a fair cop. Those planet smashing gigs are pretty scary.
Slander! Anti-gravity is weakening the Earth's gravitational field/causing global warming/immorality and pulling meteors at your ship. Besides a little coriolis force never hurt anyone and keeps the coaster manufacturers in business. Those people have kids!
More than likely the new tech will have drawbacks and limits. If it's very short ranged it might only be used to provide gravity on space stations and low gravity worlds to keep settlers from becoming anorexic beanpoles. Those beautiful rotating space stations and passenger sections are all suddenly out of fashion though.
Perhaps anti-gravity is a repulsive force instead of a shield or nullification. In that case it works when you have a planet or other massive body. The chemical rocket guys are out of business. The ion rocket cartel is still going strong for deep space missions. Just to further ruin Doc Jenkins' day, getting to orbit and being in an orbit are two different things. If anti-gravity lifts you a couple hundred klicks you are just hovering. Shut off the anti-grav and you fall. Worse, there are things moving in orbit that can hit you like little bits of dynamite. So an anti-grav might reduce the fuel and thrust needed to get to orbit but not negate it but Big Rocket stays in business.
It does feel a little immoral though. Like you build a fusion reactor that uses hydrocarbons as fuel so Big Oil (boo!) stays in business or a super rocket fueled by tobacco.