The oldest stone tools found are dated from 2.7 - 2.9 million years ago. The species that made these tools is unknown.
13
An unprotected human can survive up to 1.5 minutes in space with no permanent bodily damage.
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The oldest glowing lightbulb was first switched on in 1901 and lives in fire stations in Livermore, CA. It is known as the Centennial Light.
118
The focusing muscles of the eyes move around 100,000 times a day. To give your leg muscles the same workout, you would need to walk 80km (50 miles) every day.
21
If you have 1 billion dollars and spend $1,000 every day, it would take you 2,740 years to go broke.
31