An Illustration of Illusion of Knowledge: Gravity

Gravity lulls us into thinking we “know” all about it. Nothing could be farther from truth. Truly and squarely, we do not know:

1. Why Gravity exists
2. What is the Source of Gravity?

It is listed as one of the Greatest Mysteries at livescience.com here – Greatest Mysteries: What Causes Gravity?.

Newscientist.com adds 7 more questions in their SEVEN MYSTERIES OF GRAVITY:

1. What is gravity?
2. Why does gravity only pull?
3. Why is gravity so weak?
4. Why is gravity fine-tuned?
5. Does life need gravity?
6. Can we counter gravity?
7. Will we ever have a quantum theory of gravity?

So, here we are – one of the most fundamental dimensions of our existence – and we almost know nothing about it.