How many? How big? How far? How old?

How many people? There are 6.4 billion people1 in the world, of which 1.3 billion are in China, 1.1 billion in India, 457 million in the European Union, 296 million in the United States and 45 in the Pitcairn Islands2.

If 6.4 billion people were packed together, shoulder to shoulder, they would extend for 4 million kilometers (2.5 million miles), or about 100 times around the earth's circumference3.

How big is the earth? The earth is approximately 40,075 kilometers (24,901 miles) in circumference3.

Traveling at 100 km/hour (62 mi/hour), never stopping or slowing down, it would take only 17 days to travel around the earth.

How big is the sun? The sun is approximately 4,366,813 kilometers (2,713,406 miles) in circumference3. The sun's diameter is more than 100 times larger than the earth's diameter.

Consider a 1.8 meter (6 feet) tall person. A person that is 100 times taller would stand at more than 180 meters (600 feet). This is taller than the great pyramid of Egypt which stands at 149 meters (482 feet).

How far is the sun? The distance between the sun and the earth is approximately 150,000,000 kilometers (93,000,000 miles).

Traveling at a constant speed of 1000 km/hour (620 mi/hour) it would take over 17 years to reach the sun.

How old is the universe/earth/man? The universe is approximately 15 billion years old. The earth is approximately 4.5 billion years old. Dinosaurs roamed the earth approximately 230 million years ago (and lived for roughly 65 million years). Homo sapiens, our species, first appeared on earth approximately 100,000 years ago. The great pyramid of Egypt was built approximately 4,500 years ago.

If we compare the age of the universe to a 100 year old person, the age of homo sapiens would be the equivalent of less than 6 hours of that life, and the age of the pyramids would be less than 16 minutes.

1approximate populations as of October 2005 2the Pitcairn Islands are in the South Pacific Ocean, about midway between Peru and New Zealand 3the circumference of a sphere is the distance around the sphere as measured at its middle (e.g., along the equator of the earth). The circumference is PI times the diameter.

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