What are propellers used for?

The propeller

Not only small aircraft are operated with a propeller. Fans too. Propellers move air from one side to the other. In addition, the surfaces of the propeller are slightly bent. Who might have invented that?

Link to Wikipedia: Propeller

Modifications made by Radu

What kind of invention is it and what is it made of?

Propeller is a technical creation that consists of a propeller and three or more blades evenly spaced.

Is there an example of using this invention?

In most cases a propeller, fans or aircraft is used.

What are the advantages of this invention?

Enable aircraft to fly so people can get to their destination faster (than with any other mode of transport).

What are the advantages of this invention for an entire country?

Since the flight is relatively expensive, a lot of VAT is paid for the state.

What are the disadvantages of this invention?

People / animals / birds can be injured by driving the propeller.

Who can operate or use this invention?

It depends on each invention.

Are there alternatives if these inventions didn't exist?

Unfortunately, I am not aware of it.

Are there any dangers that could arise for individuals and society in using this invention?

Unfortunately I am not aware of it.

What is this invention made of?

she consists from a driver and three or more sheets evenly spaced, it can be made of metal or plastic.

Which technologies must be known so that the invention can be manufactured?

A propeller can only be made if it is known what it is being used for. Propeller "delivers" air, how much air should it deliver so that the product has enough air.

Which partial inventions had to be made so that the invention could be operated?

The leaves and the impeller.

Did the invention arise suddenly, or was it improved and perfected over a long period of time?

Due to new technology, I believe that the invention would be improved and perfected.

Is there any improved version of this invention, or perhaps will there be? What could it look like?

It depends on the technology.