One of the more interesting inventions to me is the GPS, because it is such an amazing <em>combination</em> of technologies. The satellites are amazing to begin with. The idea that something that fits in my pocket can calculate where the satellites are, time their arrival of their signals precisely enough to measure the distance to three satellites within a few meters, do the spherical trigonometry to calculate the position on the earth's surface from that, hold a complete map of all of the streets in North America on a chip the size of a thumbnail, <em>and cost only a few hundred dollars</em> is... well, it's impossible, that's what it is.

Science-fiction novels predicted a lot but I can't remember any of them predicting GPS.

In 1971, I visited the US research vessel USNS Kane, which was doing a kind of propaganda tour to show off our technology. I remember being stunned by a rack of computer equipment connected to the LORAN system, because it actually displayed latitude and longitude as direct digital readouts, using Nixie tubes (neon tubes with a set of ten wire cathodes in the shape of the digits 0 through 9).

I have two inventions that I think had a huge influence on almost everyone's life:

1 The invention of and the popular availability and use of personal computers starting in the 1980s.

2 And also in the 1980s, the widespread use of fax machines.

However, the greatest invention of all times has to be the invention of chocolate cake... :)

Hello Peter,

Only now did I see that you updated your answer by adding a link to a photo. It's very interesting.

Thank you very much.

Personally I like automated antiaircraft system by a father of cybernetics Norbert Wiener. This have led us to an era of deep machine learning. But it is 75 year old.

Yet I can come up with thousands of inventions, I think the most two practical inventions are transistor and Lithium ion battery.

If the transistor had not been invented, we would never think of electronic devices, and if the Lithium ion battery had not been developed, we would never mobilize electronic devices (imagine the good old 1990s~2000s huge dumb-looking phones, computers, etc.).