A ruler
A calculator
Pen/Pencil/Paper
Microscope
Telescope
Binoculars
Camera
Microphone
Eyes
Ears
Mouth
Fingers
Compass
GPS
Map
MRI
CAT
Beakers
Solutes
Solvents
Acids
Bases
The internet
Human Brain
The list is ANYTHING that can be used to test and record results, then publish them for peer review.
