Day 34.

The more I witnessed the complexity of the universe, the laws of physics, chemistry and living organisms, the more I was convinced they had a designer. The next time you go for a walk in nature, why not consider how fragile our environment is. Did you know that you are standing on a small speck in the universe, travelling at over 100, 000 kilometres an hour? Every year we cover over 900 million kilometres. If the speed at which we travel were just 1/3rd slower then we would move further from the sun and the planet would become too cold. If the earth were to become faster, we would move too close to the sun and the planet would become too hot. Even if we were 10% further away from the sun, our polar regions would expand by 1500 kilometres.

If our sun, which is a small star on the galactic scale, were just a little bigger our oceans would boil away. If it were a little smaller our atmosphere would lie frozen on the ground. Yet our sun, which is a million times bigger than our earth, was made for the earth, it is our clock, our calendar, our laboratory, our gravitational anchor, our celestial portrait painter, our light giver and life giver. The sun’s orbit has a “habitable halo” and if we move out of it there can be no life.

Do you find it strange that the earth has a near-perfect round orbit, when nearly everything else moves in elliptical orbits? If our planet were to move in an elliptical orbit, like other heavenly bodies, then the seasonal variations as we move closer to and further away from the sun would become intolerable.

Even the earth’s size is critical. Earth is a rocky ball of six sextillion tonnes which has a slim film of water over 71% of it’s surface. It is surrounded by a thin halo of gases. The earth’s diameter is 12,800 kilometres; it’s circumference is 40,000 kilometres. Is this a good size? If it were to increase to 15,000 kilometers across it’s diameter, then a person who weighed 80 kilos would weigh 120, and their health would quickly break down. If it’s diameter were reduced to 8,000 kilometers that same person would weigh 40 kilos. The good news is that that person could jump higher, they could do more work and they would be less tired. The bad news is the gravitational pull of the earth would no longer be strong enough to keep the atmosphere on the ground and the earth would become uninhabitable. Scientists calculate that the difference between too large and too small for the planet is almost exactly what it is.