The scientific framework

As I hinted in my previous post, there is a framework of mutually supporting fields of exact sciences; the scientific framework.

Chemistry, physics, biology, math, all study reality from different angles. Some of these fields are explicitly linked together. For instance; biochemistry, geophysics or astrophysics.

Scientific knowledge grows daily. More and more facts are added to already existing facts. Old facts are rarely discarded. Maybe if they are proven to be fabrications (frauds) or otherwise inaccurate.

This means that new facts can be tested against old facts. This process works both ways. If new facts enhance old facts, that's great. If new facts contradict old facts, there is a conflict. Either the new facts are wrong or the old facts are wrong. Only by carefully examining the old facts (and the experimental settings) and the new facts (and the experimental settings) can the 'truth' be established.

Verification and repetition are central in scientific research.

To explain the framework a little, let's look at astrophysics for starters. Humans have watched and documented the night sky for centuries. Around 1608 CE, the optical telescope was invented. There's a one on one translation between a telescope and the human eye. A single bright spot at a certain place visible to the bare eye, becomes a cluster of stars through the telescope. There is more detail available.

With the invention of the radio telescope in 1931, the observations are different. Instead of visible light, radio waves are observed. But the telescope finds information in the exact same spot as earlier stars were found. It's coherent. Scientists, at first, may not know what the radio telescope signals mean, but the observations are accumulating and eventually a theory that explains them arises. It's a slow process but it works. Maybe the first theory is not adequate... see my earlier post.

Around 1800 CE, scientists were looking at the sun through a spectrometer and found curious dark (absorption) lines. A spectrometer is an optical instrument consisting of some lenses and prisms. It shows a rainbow of colors when looking at white light. Later, they found that these lines corresponded to chemical elements. When chemists burn these elements they see emission lines at the same frequency of the absorption lines. This way, astrophysicists can infer the composition of stars. The framework remains coherent.

The Doppler effect can be observed by anybody here on earth. When watching cars racing on television, the car coming towards the camera has a higher pitch, and when it passes the camera, the sound changes to a lower pitch.

The Doppler effect can be observed in the spectrometry absorption lines of stars other than the sun. In a static universe, these lines should be at the same place as the sun's lines. However, most stars and galaxies show red-shift. The lines are displaced towards the longer wave-lengths, that would correspond to a lower pitch in racing cars. This means most stars and galaxies are moving away from us; the universe is expanding. Galaxies that are further away show a greater red-shift meaning they are moving away from us faster.

Observations on earth and observations of the universe should be coherent.

Nuclear physics looks at elements (atoms) and how they change into other elements under certain conditions. Experiments on earth have created both nuclear fusion and nuclear fission. There are detailed diagrams showing how fusion forms higher-mass elements from lower-mass elements. And also how fission degrades higher-mass elements into lower-mass elements. These processes are well understood.

Astrophysicists, take these diagrams from nuclear physics and use them, and other data, to calculate how stars are formed, and how old stars are.

A couple of years ago, a new, more exact, telescope started giving more detailed data on the rate of expansion of the universe. The result of these observations was that the estimated age of the universe should be lowered by a couple of billion years. At which point alarm clocks started ringing. Some stars were calculated to be older than the universe. An impossibility! This meant that either the newly calculated age of the universe was wrong, or the theory of star formation was wrong. In the end, the scientists agreed that the universe is younger and that the calculations of star-age were wrong, and had to be adjusted.

Lastly, the age of the earth is calculated by using radiometric dating. Based on the composition of rocks, and the half-times of radioactive elements. Radiometric dating of meteors (that were formed when our solar system was formed) shows very consistent results. The earth is 4.54 × 10^9 years ± 1% (4,54 billion) old. The error is 1%, so the earth may be 50 million years older or younger than that.

Science doesn't deal in absolutes. Facts are gathered within a certain range of precision. When we look at a measure, our eye can see 1 cm with ± 1 mm error. A more precise tool can give us 1mm with ± 0,1mm error, and so on.

With all the accumulated data, it's hard to imagine a radical new world view. The big bang, evolution, the age of the earth...