/diy/ - Do It Yourself

This is the technology board, so why not a thread about this?

Here is the scenario:
>2000 people are sent through a time machine to the dino days to study things
>they can't bring anything but themselves, not even the clothes on their back
>they need to build everything from scratch when they arrive
(this creates an alternate timeline, does not interfere with ours)

How long would it take for them to create:
>steel
>guns
>electricity
>lightbulbs
>cameras
>cars
>computers
and eventually, a time machine back home

https://www.youtube.com/watch?v=ZEl-Y1NvBVI