Is the ‘Scientific Method’ Different in Astronomy?
The scientific method is common to all the sciences; however, in astronomy the ‘objects of study’ are often millions of light years distant!
The scientific method, per se, can be illustrated by considering how Galileo used his telescope in 1610. When he aimed it at Jupiter he saw four points of light, rather like stars, strung out in a line from the planet’s disc. Subsequent views showed the star-points in many different positions. Galileo then made a hypothesis to explain the data; he wrote that the objects were orbiting Jupiter and were in fact, moons. He calculated their orbits and predicted their motions.
Although astronomers cannot usually experiment on tangible substances in the laboratory (unlike chemists and biologists) they can, nevertheless, use instruments such as telescopes to make many thousands of observations and make hypotheses to explain the observations. The hypotheses can then be tested by predicting an event, for example, and confirming it. A large part of the method involves rejection or refinement of hypotheses once they have been found in error.
Astronomers nowadays use other types of telescope such as radio, infra red, X-ray – these advances have established that the universe is expanding and that what we can see visually with a telescope is only a fraction of the electromagnetic spectrum.
Spacecraft have landed on bodies such as our Moon. Instruments on board have been able to do experiments similar to those done by a chemist in a lab. Astronauts have also brought back rock samples from our Moon. Our knowledge of the origins of the solar system has thus increased by these more lab-based analyses. Probes have landed on Mars and other planets and sent back interesting data. For example, a small moon of Jupiter called, Enceladus, was found to have geysers containing sodium. Titan, a large moon of Saturn, has lakes and rivers of methane and ethane. These solar bodies are far from inactive and may even harbour primitive life.
Another huge area that has contributed to astronomical knowledge has been mathematics and its use in theoretical cosmology. Stretching from the Ancient Greek’s measurements of the Earth to Einstein’s Theory of Relativity and beyond – we can see how logic, calculation and measurement are embedded in the scientific method. Hipparcus (170-120 BCE ) even measured the length of the year with great accuracy – 365.2467 days, whereas the modern figure is 365.2422 days. A foundation for modern astronomy was laid with feats of calculation such as this.
We only have to think of the Four Forces in the Universe to sense how much science and theoretical cosmology have developed in the last hundred years. The Four Forces in nature are:
- Strong Nuclear Force – (holds the atomic nucleus together)
- Weak Nuclear Force – (radioactive decay)
In this respect – the use of mathematics and making theoretical models– astronomy is no different to the other sciences. And, of course, chemistry, physics, and even biology, play their parts in astronomy. Perhaps that suggests astronomy is the ‘mother’ of all the sciences.