[ryanlol]

Assuming "trillions" means 3 trillion. Divided by the average work hours during a persons career that'd come up to about 33 million people.

That's quite a few engineers.

[scarmig]

It's like the Civilization technology tree. To get the laptop, you first have to invent Electronics, and before that Physics, and before that...

Easily adds up to trillions of hours.