Explanation:
(x2) 741 OpAmps (Radioshack Catalog #: 276-007)
(x1) 9V Relay (Radioshack Catalog #: 275-005)
(xvar) jumper wires (Radioshack Catalog #: 276-102)
(x2) Heavy duty 9V battery clips (Radioshack Catalog #: 270-324)
(x2) 9V batteries (Radioshack Catalog #: 23-866)
(x1) Prototyping PCB (Radioshack Catalog #: 276-170)
(x1) Piezo Buzzer (Radioshack Catalog #: 273-080)
(x1) 5K Ohm Potentiometer (Radioshack Catalog #: 271-1714)
(x1) Potentiometer cap (Radioshack Catalog #: 274-415)
(x1) 470 Ohm Resistor (Radioshack Catalog #: 271-1317)
(x1) 3" diameter acrylic tube
(x1) Magnet (Radioshack Catalog #: 64-1888)
(xvar) lamp-pull ball-chain
Tools:
Solder
Soldering Iron
Wire Snips
Hot Glue Gun
I used a laser cutter to make my own personal enclosure, but one could easily modify a pre-made project enclosure to suit the needs of this project.
Answer:
To increase our survival chance.
Explanation:
In order to survive in the harsh environment, Humans generally need to do 2 things : fulfill our basic needs and defend ourselves from external threats.
Both of them would be much easier if Humans are working together in a group.
For example, during hunter/gatherer eras, catching animals that can run faster than humans will be much easier if we have teammates to surround the prey rather than working alone.
On top that, being in a group also provide better protection from the attacks of wild animals or other humans. This is why human creatures get transformed into a social being.
District of Columbia v. Helle