There are 64 records in the database
(20 in this table).
You may up- or downvote records to gauge their relevance.
You may up- or downvote records to gauge their relevance.
| Type ▲ ▼ | Description ▲ ▼ | Value | Importance ▲ ▼ |
|---|---|---|---|
| World population | 8 billion people | ||
| Wavelength of X-rays | ~ 1 nanometer | ||
| Wavelength of visible light (blue-red) | 400 - 700 nanometers | ||
| Walking speed | 3.6 kilometers per hour | ||
| Typical size of a plant/animal cell | 10 - 100 micrometers | ||
| Typical size of a bacterium | 1 - 5 micrometers | ||
| Time it takes light to travel from Sun to Earth | 8 minutes | ||
| Temperature of maximum density for water | 4 degree Celsius | ||
| Temperature of a candle flame | 1 400 degree Celsius | ||
| Surface temperature of the Sun | ~ 5 500 degree celsius | ||
| Sun - Earth distance | 150 million kilometers | ||
| Speed of sound in air | ~ 340 meters per second | ||
| Speed of raindrops | ~ 8 metres per second | ||
| Speed of light | 300 000 kilometers per second | ||
| Size of an atom | 10-10 meters | ||
| Rise of modern humans in africa | 100 - 200 thousand years ago | ||
| Radius of the earth | ~ 6 400 kilometers | ||
| Pulse rate at rest | 60 - 100 beats per minute | ||
| Pitch standard | 440 herz | ||
| Pi | 3.141 59... |
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Not just any numbers: It provides a topically broad list thereof – worth to be memorized, not just as part of general knowledge, but as a benchmark to gauge the world we live in.
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For more background information click here.
Not just any numbers: It provides a topically broad list thereof – worth to be memorized, not just as part of general knowledge, but as a benchmark to gauge the world we live in.
These numbers can either be explored one after another in a quiz-like fashion, or accessed in an aggregated, tabular form. In addition, there is a simple voting mechanism that allows visitors to up- and downvote records to rate their importance.
The purpose of numbers2know.org is not to provide a comprehensive list to look up numbers, but to encourage and support people memorizing selected numerical values of general interest.
For more background information click here.
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