I gave it a few posts back, with a link, unlike you. So that covers the physical and chemical properties of patio construction materials, and the biological and geological factors of evolution, both of which you decline to discuss; not to mention the basic concept of scientific consensus, to which you appeal but refuse to argue.
I gave the dictionary definition.
And patio construction materials are soooooo boring. How could you expect anyone to want to discuss THAT. And evolution is not a hard science.
And I believe you must have know what I meant when I said the hard sciences. This usually refers to physical sciences, such as chemistry or quantum mechanics.