Category Archives: HOW?
230.HOW DO WE SEE IN THREE DIMENSIONS?
When we look out across a field, how do we know one distant object is bigger than another, or that one is behind another? Why do we see everything in three dimensions, in proper relation to each other, instead of seeing everything “flat?”
The fact is that when we “see” things, we see them not only with our eyes, but with our minds as well. We see things in the light of experience. Our mind, based on certain experiences, helps us interpret what we see. And unless the mind can use the cues it has learned to interpret what we see, we can become very confused indeed.
229.HOW DO WE FALL ASLEEP?
We know pretty well what happens during sleep. Our body is inactive, we lose consciousness, and we fail to respond to things that are happening around us.
We also know a great deal of what takes place in our body during sleep. We know how the muscles relax, how certain vital functions continue, what happens to our circulation, our temperature, and so on.
228.HOW DO OUR LUNGS WORK?
Man breathes by drawing air into his lungs (inhaling) and letting it out again (exhaling). In breathing, a fresh supply of air is brought into contact in the lung with tissue very rich in blood. In the lung, gases are exchanged between blood and the air.
The lungs are large, soft organs, which fill both sides of the chest cavity. The lung tissue is like a fine sponge in some ways. The spaces, or air sacs, are the pockets where the air is received, the proper gases used, and the unwanted gases forced out.
