The scientific method & evolution.


Sometimes, you hear a phrase and it sticks to your mind. You know something is wrong, but you are not able to put your finger on it. Years may pass until you find out what's nagging you, the original circumstances forgotten.

That's what happened to me with the phrase 'science has been proven wrong lots of times'. I saw that phrase again, lately, and I finally realized what's wrong with it. Some scientific theories are proven wrong by using the scientific method, and are replaced with improved scientific theories. It's not the whole of science that has been proven wrong by using science, but 'just a theory'.

That's another phrase that sticks to the mind. 'Just a theory'. A scientific theory is an explanation of a number of facts. It's not a bar-room insight that explains some detail. It's the 'Truth as we know it'. Currently, this theory is the best we have. It might be improved in the future.

Science starts with somebody making observations, let's call them 'Facts'. After thinking about these observations, he or she proposes a theory. This theory should explain all the facts. If that is so, this theory should then be considered 'the truth as we know it'. This theory will remain 'true' until one of four things happen.

  1. Somebody questions the facts; the observations were wrong. This is the worst thing that can happen, because it means that the observations were not correct and therefore the theory is based on nothing. This happens all the time in science. Sometimes it's an honest mistake, sometimes it's fraud. Either way, it gives science a bad name.
  2. Somebody proposes an alternative theory. Whichever theory is easier, more elegant, and still explains all the facts, must be accepted as the theory of choice. For instance, the Heliocentric theory is easier to model than the Geocentric theory.
  3. More facts are found and cannot be explained by the theory. This means the theory has to be improved to fit reality or it should be discarded. For instance, Keppler found that the planets move in ellipses around the sun, instead of circles.
  4. Better observations become available and cannot be explained by the theory. This happens when there's a technological advancement. For instance, the invention of the telescope showed that some planets have moons which was another nail in the coffin of the geocentric theory.

That's all there is to it. Either the observations are wrong (1, 3 and 4) or an easier explanation is found (2). Sometimes two theories are considered at the same time, and only time will tell (as more data becomes available) which theory will be adopted by the scientific community.

A scientific law, is a description of how facts are related. A scientific law is not 'superior' to a scientific theory. It's a different animal. A theory is an explanation.

One important thing to note about scientific theories is that they can predict the future. Mendeleev's periodic table was adopted when new atoms were found that fit with Mendeleev's predictions. Neptune was found where a scientist (Le Verrier) predicted it would be. Darwin predicted the existence of an insect that pollinates the orchid that was named after him. 21 Years after Darwin's death, a moth was found to do just that.
Some people distrust or hate science. Some think that science has a hidden agenda, but in reality, scientists are people that have no common objective. Quite the contrary, they struggle for funding just like anybody else. If any scientist would find a way to debunk the theory of evolution, for instance, she'd be famous instantly.

One of the things scientists do to try and debunk a theory is to create tests. These tests are aimed at disproving the theory. Tests are conducted in various places (laboratories) under controlled conditions. If the results are consistent, the theory becomes stronger.

Some people dislike science because they believe it clashes with their religion. Instead of changing their religion, they try to change science. For instance, Creationists try to debunk the 'Theory of Evolution', ignoring the fact that this is a scientific theory (it's the truth as we know it).

Looking at the bullet points above, we can see that Darwin's theory has overcome all of them. When Darwin published the theory, he presented numerous facts that could be explained by it. No scientist has questioned Darwin's facts (1). The 'natural selection and survival of the fittest' is such an elegant concept, that no alternative, simpler, theory has ever been proposed (2). All additional facts discovered after the publication of the theory can be explained by it (3). Even DNA research, which was discovered 100 years later, can be explained by it (4).

Best of all, scientists have used Darwin's theory to make predictions for the last 150 years, ever since the publication of the 'On the origin of the species' in 1859.

Whenever scientists have proposed theories, peoples believes have been affected. Gods that were responsible for the weather, earthquakes, crops, day and night, have disappeared. Because gods are unpredictable, but science makes predictions that come true.

The exact sciences create a framework that's mutually supporting (more about that in my next post).  Evolution calls for a long period of time to reach the current biodiversity. Geology, palaeontology, physics, astrophysics... all estimate that the earth is very old. More than 4 billion years. Long enough for evolution.

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