At 19, I read a sentence that re-terraformed my head: “The level of matter in the universe has been constant since the Big Bang.”
In all the aeons we have lost nothing, we have gained nothing - not a speck, not a grain, not a breath. The universe is simply a sealed, twisting kaleidoscope that has reordered itself a trillion trillion trillion times over.
Each baby, then, is a unique collision - a cocktail, a remix - of all that has come before: made from molecules of Napoleon and stardust and comets and whale tooth; colloidal mercury and Cleopatra’s breath: and with the same darkness that is between the stars between, and inside, our own atoms.
When you know this, you suddenly see the crowded top deck of the bus, in the rain, as a miracle: this collection of people is by way of a starburst constellation. Families are bright, irregular-shaped nebulae. Finding a person you love is like galaxies colliding. We are all peculiar, unrepeatable, perambulating micro-universes - we have never been before and we will never be again. Oh God, the sheer exuberant, unlikely face of our existences. The honour of being alive. They will never be able to make you again. Don’t you dare waste a second of it thinking something better will happen when it ends. Don’t you dare.
Wow. Good question.
Ummm…*vanishes into the deep web for several hours*
OK, online dictionary defines sharp as (among other things) Having a thin edge or a fine point suitable for or capable of cutting or piercing.
Now the two bolded words are highly subjective, but the second phrase - suitable for or capable of cutting or piercing - is a good start.
So what you say is correct, sharpness level is dictated by the scale we are talking about. My pen-knife is “sharp” enough to cut or pierce my skin, whereas the pencil I’m using is not. However, my pen knife would not be sharp enough to cut a long-chain molecule in half. That would require a much sharper implement with a much finer blade.
AFM tip, pretty freaking sharp.
Hair is not stiff enough to pierce anything bu the sheerest tissues, so it does not fulfill that requirement. But what about along its edge? Could a good strong hair be used to slice a soft cheese perhaps? The Washington Monument would probably burst a giant balloon bouncing around DC. But a giant’s foot might crush it before it pierced the skin because the material it is made of is not resilient enough.
As for the last part to your (excellent) question. Very tiny nano-particles such as silver nanowires and carbon nanotubes can be so tiny that they can slip through your skin barrier without breaking it, enter your cells and, because they have a very high aspect ratio (they are much longer than they are wide) they pierce the cell walls and kill the cell. That’s a whole new level of sharp.
We seem to crave privilege, merited not by our work, but by our birth, by the mere fact that, say, we are humans and born on Earth. We might call it the anthropocentric—the “human-centered”—conceit. This conceit is brought close to culmination in the notion that we are created in God’s image: The Creator and Ruler of the entire Universe looks just like me. My, what a coincidence. How convenient and satisfying! The sixth-century-B.C. Greek philosopher Xenophanes understood the arrogance if this perspective:
The Ethiopians make their gods black and snub-nosed; the Thracians say theirs have blue eyes and red hair… Yes, and if oxen and horses or lions had hands, and could paint with their hands, and produce works of art as men do, horses would paint the forms of the gods like horses, and oxen like oxen…