No matter how deep you bury the seed, the little seeding will always grow with its shoot up and roots headed down. Not only that, if you took a bunch of little seedlings and buried them with their shoots in the ground and the roots in the air, they would sense that they were upside down.The seedlings would then take a double U turn to make sure that they were again positioned with the shoot up and root down.

Thomas Andrew Knight of the British Royal Society, was certain that plants could sense gravity and would always send out their roots towards the gravitational pull. This was the hypothesis to be tested nearly 200 years ago by Thomas in a crazy experiment involving spinning plates. He planted some seedlings on a disk and then has a water wheel move the disk at a speed of 150 revolutions per minute for a period of several days.

In such a situation, if you know you basic physics principles, the centrifugal force pushes the gravity outwards. So Thomas felt that the plants would also point their roots to the outside of the spinning disc if they were influenced by gravity. This is precisely what did happen. So now you know thanks to this old science experiment that the reason why plants don’t get confused about up and down is due to gravity.