Diameter (3.5-inch form)9.5 hundredths m
1 thousandthsAmerican football fields
1.5 billionHelium atoms
Photo from Wikimedia Commons
Hard Drive Platter
The spinning magnetic disk inside a traditional hard drive/Technology
Hard drive platters are polished aluminum or glass discs coated with a thin magnetic layer. Data is read and written by a head floating just nanometers above the spinning surface. A typical 3.5-inch desktop drive contains 1 to 5 platters stacked on a central spindle spinning at 7,200 RPM.
Measurements
Thickness2 thousandths m
1.4 thousandthsDanny DeVitos
3.3 thousandthsDachshunds
250Red blood cells
Mass (single platter)4 hundredths kg
8 thousandthsHuman heads
28.6 millionthsHonda Civics
4 millionPollen grains
Head flying height5 billionths m
5.9 billionthsCricket bats
273 trillionthsBowling lanes
333 billionthsBlueberry diameters
5 nanometers
Magnetic coating thickness20 billionths m
824 billionthsQuarters
1 billionthsCricket pitches
Center hole diameter2.5 hundredths m
2.2 tenthsPopsicle lengths
25 millionNanometers