Consider this...

"You can't look at a sleeping cat and be tense." - Jane Pauley

Limited perception is good for you

In order to understand a possible reason why Natural Selection has left us with such limited perceptions of what is around us, let’s suppose we could see individual atoms.

When we saw a pizza, all we would see were points somewhat spread out in space. Similarly, if our smell detectors (whatever they are) were different, we could not detect the wonderful odour of tomato and garlic and pepperoni and cheese and… but I’m getting carried away. And if we could not touch pizza-size objects, we could not eat them. Quel horreur!

And if our ancestors had seen particles in space instead of, say, an attacking lion, well, they would not have had any descendants — us! So we really are talking about adaptation for survival.

So perceiving what little we can is useful for us. I assume it is clear to the most casual observer that love of pizza is of great benefit for survival.


So what is?

We have survived partly because we can perceive so little of everything. For this reason, we should not be particularly surprised that the universe is not really what we have come to think it is. For instance, we can perceive (and eat) pizzas but we would not notice a neutrino if it passed right through us — which, in fact, neutrinos are constantly doing. Ouch!

Well, to start with, space is. That is, space is not immutable emptiness in which real stuff is located. Space is something. We should really talk about space-time, i.e., spatial and temporal distances, together. Space time can shrink or expand, according to how fast you are going (for more info, google “special relativity”), and it changes shape depending on the presence of matter (google “general relativity”). This change of shape makes for what we call gravity and is what holds us and galaxies all together.

The universe is considered to have started about 13.5 thousand million years ago. At that time, it was an infinitesimally small (tiny) point. The point exploded in what is called the Big Bang (with two capital “B”s) and has been expanding ever since, though not always at the same rate. Achtung/attention: Objects are not expanding, space is. Bizarre, n’est-ce pas?

In this expanding, curved space-time, matter is to be found. As already noted, matter exerts an attractive (pulling, not pretty) force called gravity, which makes space-time curve. Also, there is something in General Relativity called the Cosmological Constant, which exerts a repulsive (meaning pushing apart, not ugly) pressure which makes the universe expand even faster. This is the source of the so-called dark energy, “dark” because we cannot see it.

According to quantum mechanics, gazillions of particles and waves, or particle-waves, are zooming around in this vastness. Physicists know how these work and they can calculate lots of things they need to know. But no physicist understands what quantum mechanics means, dixit one of the greatest of 20th-century physicists, Nobel prize winner Richard Feynman. And he should know.

Indeed, what physicists calculate using quantum mechanics is something which can be used to predict the probability that a physical system is in a particular state. That’s not all. In addition, it can be shown that one cannot measure everything about the system: the better you measure a particle’s speed, e.g., the less well you will be able to measure its position. This is the famous Heisenberg Uncertainty Principle. In fact, there are errors in the measurement of all these quantities — speed, position, energy. And, for very, very brief periods of time, a system can have other values for these quantities, values which would be forbidden on the average. The result is an inherent variation in physical quantities which leads to an inability to predict the precise future of a system.Exit pre-destination.

So what we have is this: Gazillions of waves are floating around in curved, expanding space-time. The waves represent probabilities that particles or waves are in a given state. The particle-wave may behave like a particle or like a wave and we cannot measure all that we would like to.

Is it any wonder we did not evolve to perceive all this, but to perceive, rather, cats and dogs, pizza and beer?

For more, see our next exciting installment.