.two steps forward

on science

.two steps forward

Our thesis seem sound. All things fall to the ground. That is, until a school replicates it and child lets an helium balloon lose. It doesn’t fall to the ground. It shoots up into the air.

"School children prove eggheads wrong"

You’d imagine the scientific community to be enraged. How dare children mock them ? More likely, you’d imagine that if you are an army general. The scientific community however is ablaze with excitement. Multiple labs replicate the balloon experiment, it checks out. New data, multiple new hypothesis flourish. They have work again!

You might find this tale ridiculous, but it’s just allegoric to the real history of research into gravity. It really did start with vague empirical knowledge of things falling. In ancient times most things feel like rocks (most where actual rocks) while others seemed to float like feathers (specially the ones that were feathers). This led to a non unified theory of things that float, things that sink, things that fall fast and things that fall slow and philosophers musing about the nature of the elements and what causes things to not float.

And this was the state of understanding of things until around the time Aristotle was formalizing the basis of the scientific method and Archimedes was observing bodies displacing water and finding their buoyancy being related by the mass of water they displace. Prior to the development of science and research into how things float, whether boats would stay afloat or not was up to the gods.

While Aristotle did formalize the basis of the scientific method that didn’t stop him from concluding heavier objects fall faster than lighter ones. His thesis was supported by his observations and no one imagined a counter experiment. Heavier things fall faster was established knowledge until Galileo nearly 19 centuries later through imagination and new experimental evidence showed all objects accelerate at the same rate towards the ground.

"Crazy new science says heavier things don't fall faster"

This was one of the greatest triumphs of science, through relentless experimentation and rigour 2000 years of common sense was blown away, making way for most of the modern world. This left the question, why do lighter things appear to fall slowly ? Galileo’s hypothesis was correct, it was due to aerodynamics and air resistance, not the weight itself. However, as is common in science, he lacked the technology to construct an experiment to test his hypothesis.

Less than one hundred years later Newton developed a comprehensive theory of gravity. Finally it was demonstrated beyond any doubt things not only fall into the ground but every thing falls into every other thing. Newton also formalized the model of the force between two objects being proportional to their masses and inversely proportional to the square of their distance. This was revolutionary, not only accurately and completely modelled the earth not being the centre of the universe but also that everything revolves around everything else.

Multiple mysticists before Newton failed to find the laws of movement under the false Ptolemnaic geocentric model. They were guided by faith rather than science. Newton however, labouring on the work and observations of Copernicus and Kepler arrived at the undeniable laws describing the universe. How can we say they are undeniable under the methodic scientific doubt ? Not only Newton laws describe all the available observations at the time but they also predicted the existence of the still undiscovered Neptune. That was the true test of Newton’s theory of gravity and any theory, describing not only the discovered but also providing testable new predictions.

"Boffins say we're wrong about gravity"

Being right doesn’t mean being totally right though and a bit over two centuries later Einstein showed Newton’s laws were an approximation to a much more complex theory of gravitation. Seldom a theory with the soundness of Newton’s is proved wrong by new evidence but rather is proven incomplete. Newton’s formula is a complete and precise enough description of the universe to go to the moon, even if 300 years later. To develop GPS, however, we needed Einstein’s Relativity.

The story of gravity is the story of most scientific theories over time, incorrect and incomplete theories are replaced by ever more correct and complete theories. But always forward, never back to mystical beliefs failing the experimental test.

(c) Carlos Morgado 2019,2020