Technology is often a consequence of science and engineering â although technology as a human activity precedes the two fields. For example, science might study the flow of electrons in electrical conductors, by using already-existing tools and knowledge.
Depends: Depends on your body mass, the type of anesthesia used, the length of the procedure, and how your body metabolizes the anesthetic agent. Usually mostly worn off in 30 minutes to 2-3 hours, but may have some residual effects for 24hrs or longer.
Some induce sleep, some (like the anesthesia gases) maintain sleep, some relax muscles, some relieve pain, etc. Each is metabolized at a different rate. In general, you can expect them to vanish within 6-8 hours, but it will take longer if the kidneys or liver don't work well. Don't drive within 24 hours of having anesthesia.