You are familiar with sukhasana. In yoga, sukhasana is a body posture where there is a minimum stress on the body, a minimum use of the body. An example of the minimum use of the body is what you see in statues of Buddha or of Mahavira: sitting cross-legged, keeping the spine straight, with both hands in the lap with the palms crossed over each other – absolutely unmoving. In this posture there is a minimum use of the body and its energies.
And there is a very scientific reason for this minimum use: when your spine is absolutely straight the effect of the Earth’s gravitation on your body is the least. When your spine is even slightly curved, the Earth’s gravitational field will pull on a larger area. But if the spine is absolutely upright, the effect of the Earth’s gravitation is only on the bottom point of your spine. If your spine is bent in any way, then the pull of gravitation is on your whole spine, and to the same extent there will be stress on your body. This is a scientific fact, this stress can be measured.
Gravitation takes a maximum toll on your body. This is why the scientists say that if man started living on the moon, his life span would increase by six times because the gravitation on the moon is six times less than the Earth’s. So a man living on the moon would have a life span that is six times longer, because there would be less exertion and stress on his body.
Scientists even say…. This was an amazing concept of Einstein’s, and it seems unbelievable – but if Einstein says it, it must be right! Einstein says that if we were to send a man into space in a spaceship traveling at the speed of light – the speed of light is 186,000 miles per second – that man would not age. No matter how many years passed, when he returned to the Earth, his age would be almost the same as when he left here. His children will have grown old, but he will still be young. The first time Einstein said this it was almost unbelievable, but when his reasons were clear it wasn’t unbelievable at all. A spaceship traveling at such a tremendous speed will have no gravitational pull, so gravity will have no effect on the man at all. He will be traveling in the vacuum of space.
Your body does not age because of the body itself, it ages because of its relationship and interaction with the gravitational pull of the Earth. The Earth is pulling you down all the time; your weight is because of the Earth’s gravitation. If you put a thing on a scale, what we call the weight of a thing is not of the thing itself, it is the force of gravitation that the Earth is exerting on it. The pan of a scale tips downwards to the same degree as the force of the Earth pulls it downwards. Without gravitation, no matter how big a thing you put on a scale, it will not tip it down at all. The weight is there only because of gravity.
The greatest exertion on the body is happening even without putting it through any work. No matter what you do about it, in seventy or eighty years your body will become old. Even if you just go on sitting idly or lying down the whole time, your body will still grow old because the Earth is keeping it under stress the whole time. Even when you are sleeping your body is growing old because the Earth is pulling it down – and there are many reasons for this.