So, we can see the stars and the planets, but we can't see what holds
them apart or what draws them together. With matter, as with people, we see
only the skin of things. We can't see into the engine room. We can't see what
makes people tick, at least not without difficulty. And the closer we look at
anything, the more it disappears. In fact, if you look really closely at stuff,
if you look at the basic substructure of matter, there isn't anything there.
Electrons disappear in a kind of fuzz, and there is only energy. And you can't
see energy….
Another thing we can't see is the human genome. And this is increasingly
peculiar, because about 20 years ago, when they started delving into the
genome, they thought it would probably contain around 100,000 genes.
Geneticists will know this, but every year since, it's been revised downwards.
We now think there are likely to be only just over 20,000 genes in the human
genome. This is extraordinary. Because rice -- get this -- rice is known to
have 38 thousand genes. Potatoes, potatoes have 48 chromosomes. Do you know
that? Two more than people, and the same as a gorilla….
Time, nobody can see time. I don't know if you know this. Modern
physics, there is a big movement in modern physics to decide that time doesn't
really exist, because it's too inconvenient for the figures….
Another thing you can't see is
the grid on which we hang. This is fascinating. You probably know, some of you,
that cells are continually renewed. You can see it in skin and this kind of
stuff. Skin flakes off, hairs grow, nails, that kind of stuff. But every cell
in your body is replaced at some point. Taste buds, every 10 days or so. Livers
and internal organs sort of take a bit longer. A spine takes several years. But at the end of seven years, not one cell
in your body remains from what was there seven years ago. The question is,
who, then, are we? What are we? What is this thing that we hang on, that is
actually us?...
Anyway, so the biggest thing that's invisible to us is what we don't
know. It is incredible how little we know. Thomas Edison once said, "We
don't know one percent of one millionth about anything."…
But the point, what I've got it
down to, is there are only two questions really worth asking. "Why are we
here?" and "What should we do about it while we are?”
[Source: John Lloyd’s TEDtalk “Inventories the Invisible”
Animated TedED version
