Is it a Theory or is it a Theory?

It’s really too bad the word theory has two very different meanings. To a scientist it means one thing to a non-scientist something vastly different.

The non-science meaning, according to old Merriam Webster, is “abstract thought, Speculation”. To the scientist it means something formed from testing a number of hypotheses (what would happen if I did this?) investigating a happening in nature.

For instance, the Theory of Gravity. Scientists over the years have tested a number of what ifs (hypotheses) relating to gravity, like what if I drop these two cannon balls of different weights off a building? Or does this mathematical formula predict the motion of the planets? Or does a lead ball and a feather fall at the same velocity in a vacuum? After enough what ifs are proven to be true a theory begins to take shape to describe the thing being investigated, whether it is the Theory of Gravity, The Germ Theory of Disease, Einstein’s Theory of Relativity or The Theory of Evolution.

Scientists do not assign the title ‘Theory’ casually. To achieve this high level of trust it must be rigorously and ruthlessly tested, again and again. This does not mean that scientific theories are never rejected. Some have been in the past as we have come to better understand how things are. For instance, the Phlogiston Theory of Combustion which tried to explain burning as the release of a substance called Phlogiston and its absorption by air. The argument was that burning stopped in a closed container because the air inside the container could only absorb so much Phlogiston and when it had absorbed all it could, burning ceased. Other hypotheses tested the role of oxygen in burning eventually proving the Phlogiston Theory false.

Scientific theories are also modified as new hypotheses are tested and new information is discovered.

However, the Theory of Gravity, Theory of Relativity, Germ Theory and Theory of Evolution have survived many, many years of brutal scientific challenge and while they may be modified they will not be disproven.

Why do we have a moon?

If you asked one of my second grade buddies that question they might say, ‘because’.

That answer usually works pretty well, but I thought if I poked around some I could do a little better.

I found four ‘becauses’.

An early theory explained the moon by saying it formed from the same gas cloud from which the Earth and other planets formed. This explanation doesn’t fly because the moon contains very little iron. The Earth has a lot, mostly at its molten core. If the moon formed out of the same stuff as the Earth, the moon ought to have more iron.

A second theory explained away the Moon’s small amount of iron by suggesting the Moon formed somewhere else, where there wasn’t much of that pesky iron, and captured by the Earth’s gravitation as it swung by. This one didn’t work out either. When samples of the moon were brought back by Apollo astronauts and analyzed, it was found that they had a chemical composition almost identical to Earth’s making it unlikely that it came from somewhere else.

A third idea tried to explain away the Moon’s ‘iron deficiency anemia’ by suggesting the early Earth spun so fast that some of its surface was flung off and went into orbit. The hole it left was the Pacific Ocean basin. Since most of the Earth’s iron is at its center, the flung off material would not have a lot of iron in it. Nice try, but when they crunched the numbers relating to the Moon’s orbit, they found the math didn’t work out.

The latest theory is that a chunk of debris, leftover from the formation of the Solar System, slammed into the Earth and knocked a large amount of the iron poor crust loose. Scientists estimate that the piece that hit us was a third to half the size of the Earth. The material blasted loose formed a ring around the Earth which clumped together to form the moon. This is the currently accepted theory.

It’s interesting that even after decades of head-scratching, scientists are still not really sure how the moon came to be.

Maybe ‘because’ isn’t such a bad answer after all.

Are we really descended from Apes?

The quick answer is NO! Apes are more like cousins than ancestors. At some point in deep time we went one way, they went another. We share the same common ancestor, but they are not our ancestors.

As a matter of fact, all life on Earth shares a common ancestor whether you’re human, an ape, carrot, broccoli (echhh), fish, bird, oak tree—you get the idea. The common ancestor of all life on Earth was a single celled organism that lived billions of years ago.

How can we be related to a broccoli? That’s a plant not an animal.

All life on Earth shares the same cellular chemistry, cell structure, DNA and is either a single cell or made up of cells working together. What makes sense is that the problem of deriving energy from food, a means of passing on heredity, reproducing and all the necessary structures of a cell were solved by single-celled organisms, probably around two and a half billion years ago.

Some of their descendants branched off to become plants or animals, branching and branching through billions of years of evolution to populate the Earth with all the millions and millions of species living or extinct. The odds that millions of different living things evolved the same chemistry, hereditary material, and cellular structure independently are so beyond astronomical as to be non-existent. That means we are related to every living thing, even broccoli, because all living things descended from those single celled ancestors.

What about our supposed Ape ancestor? Well, we branched off from the nearest ancestor common to both of us around five to seven million years ago.

You know, if you think about it---we do kinda look alike.