re:Lower case earth is dirt, Upper case Earth is a planet.
Frank’s viewpoint is closest to my viewpoint , the oldest record of the word “earth†that I have found is in the Bible.
GENESIS 1:1. In the beginning God created the heaven and earth.
1:2. And the earth was without form and void; and darkness was upon the face of the deep.
According to this description the lowercase “earth†is far more fundamental than dirt.
Genesis deals with the “beginning†of the universe. (at least in my opinion)
If the word earth was meant to convey the idea of a planet or even dirt, then that creation could not be described as being without form and void.
If on the other hand the word earth was meant to convey some type of a “protomass†in other words, something that the mass itself is composed of, then such a creation could be described as being formless and void.
1:10. And God called the dry land Earth;
King James Version
According to my understanding, the word “earth†represents something very fundamental to the structure of mass, and the word Earth represents a planet. (And not necessarily this planet that we live on.)
So; one would still plant things in the “earth†and deal with earthworms even when living on Mars.