What should a powerful inventor invent first?

A digital copy of their mind that is smarter than the original.
Which then creates a version smarter than itself.
Repeat ad nauseam.

Nobody sets out to invent ‘something’.

Almost always, an invention is an extension of an existing product, or a new take on an older idea, or the product of research and experimentation. It’s not like someone says “I’m going sit down and invent a new fizzlygig today”.

So your premise is sort of faulty.

Secondly, just because he or she invents a new variant of something that came before – doesn’t mean it will be lucrative, or even sell at all. Or even be something useful.

Finally, what is a ‘powerful’ inventor? How does that differ from any other sort?

@ragingloli , this is my thought, too.

If you know your mind has a finite timespan, you would try to avoid death, but, probably that is such a difficult task you would want to first build a second copy of yourself (or more) to help with everything.

Apprentice minds are the most important inventions.

@Ltryptophan What should a powerful inventor choose to make first, if anything they could conceive is possible?

They should invent the inconceivable.

A cure for stupid is desperately needed.

^^^^ Drink came out my nose ! ^^^^

A time machine.

A antibiotic that never loses it’s effectiveness.

Find Tesla’s power generator and claim it as his own.

A jump-to-conclusions mat. It’s a mat with different conclusions that you can jump to.

In all seriousness, a benevolent, general AI would be a game-changer. It’s kind of like wishing for more wishes.

A media-like filter sieve that extracts energy from the Brownian motion of air molecules and sends it to batteries.or converts it to hydrogen. It would be a free clean energy source as long as the planet stays above absolute zero.
With infinite, free, clean energy we can provide clean water, grow crops, light and heat homes and help the World’s entire population.

A powerful computer that reinvents itself to solve complex problems and can predict outcomes of anything .

A machine that can completely neutralize all military weapons and devices…lol….when I was a kid….(waaay back in antiquated times), I always fantasized of being a world savior…where I invented a machine that could instantly send waves (some kind of invisible wave that travels through the air) and jam all enemy weapons, guns, tanks, vehicles, electronic equipment, nuclear warheads…everything! Immobilizing the enemy completely! After I did that and saved my country, I unleashed the weapon on the rest of the world too….and completely blunted every weapon of destruction in the world. After I did that, my righteous self turned around and told the premier of my own country that true peace can only be attained if every weapon is destroyed….so, I unleashed my amazing invention on my own country’s armoury! Thereby making the world weapon free…..That was my fantasy and I was completely sure that I’d follow up on that when I grew up….and then I got older…...

A futuroscope would be interesting. It allows you to see 100 years into the future.

cold fusion.

A stupid product that will bring in the money to make their good inventions.

(Like how Tesla started out with a frivolous luxury car, with the hope of making world-changing products after that.)

(In this example, Musk is not the inventor—more like Eberhard or one of those people.)