Proof-of-work mining (the type of mining used for Bitcoin and other cryptocurrencies) has some negative environmental impacts… as do the systems behind most other mediums of exchange.
Technology is a broad category that deals with the usage and knowledge of tools. Applied Sciences are the study and application of those tools.
Bitcoin and other cryptocurrencies look like they are in a bubble here in 2017, in terms of historic bubbles, but no one can predict the future.
Mixed Reality is a mix of Augmented Reality and Virtual Reality where physical and digital objects co-exist and interact in real time.
Andrew Carnegie, John D. Rockefeller, and other Barons of Industry freely gave away most of their fortunes to charitable and philanthropic causes.
Carl Sagan and NASA gained popularity when the longtime space program scientist created the Pioneer plaque and the Voyager Golden Record to be sent to space.
When the plutonium bomb to be dropped on Nagasaki was tested, the Manhattan Project scientists made a bet on whether or not it would destroy the world.