Physics – exciting and for the bold

By THOMAS HUKAHUFOR the past few weeks, I have been sharing stuff on astronomy and structures in space, as well as a bit on the passing of a great cosmologist, who is also known as a theoretical physicist.
In this week’s article, I want point out some interesting stuff in the development of physics as well as the related science of astronomy by looking at the lives of three physicists in history.
Two of the most famous physicists of all time are Isaac Newton (who was also an astronomer and mathematician) and Albert Einstein, whose brain people are still studying.
But I will not write about their lives in this article. I will instead discuss the lives of Archimedes, Galileo Galilei and Marie Sklodowska Curie.

Astrology is not astronomy
Before I discuss the lives of the three scientists, let me sort out a misconception. “Astrology”, as in horoscopes or star guides, is not a natural science like “astronomy”. Astrology is a faith system and it does not follow the laws of physics, as we know them.
Almost every other year, I correct people who mistakenly use the term “astrology” instead of “astronomy”.
Astronomy is the natural science I have been talking about in past articles as well as in this one and was studied by scientists like Galilei and Newton. Astrology is practised by people who think the lining up of stars or constellations can influence their destinies.
Astronomers and physicists call astrology a pseudo-science – a false science. Adherents of astrology give the impression of it being a natural science, but it is not.
Also, people make this common mistake. A physician is not a physicist. A physician is a medical doctor while a physicist is someone who studied physics.

Archimedes: The excited scientist
If there is any Greek you will ever learn in a physics class, it would be the word “Eureka!” – which means, “I found it!”
But – we will come to that later.
Archimedes (287-212 BC) of Syracuse (Sicily) is described by Wikipedia as a Greek mathematician, physicist, engineer, inventor and astronomer.
Like a few of the scientists in history, Archimedes did not allow the boundaries of a discipline from restricting his research into just physics or maths problems. He studied and learned as much as he could to provide solutions to his problems.
One of his main pursuits was to design military weapons for his people hence he had to learn and apply mathematical and physics principles in his inventions.
Among his war machines included the use of heat rays from parabolic reflectors placed onshore and directing rays from the Sun towards an enemy ship at sea to set it on fire. He has also been credited for improving the power and accuracy of the catapult which was used in war then.
Physics students in high school who learnt about the Archimedes’ Principle may have been told the story of how the scientist came up with the solution to a problem.
It has been told that Archimedes was once asked by the King of Syracuse to investigate whether his crown, which was supposed to have been made by pure gold, had silver substituted by a dishonest goldsmith.
Archimedes thought about the problem and could not find a solution at his worktable. However, when he went to take his bath in the public bathhouse, he realised that when he got into the tub, a volume of water was displaced. (That often happens with many creative people. Their most creative ideas come to them in strange places.)
Archimedes figured out that the volume of water displaced by his body should be the same as the volume of his body.
If he applied the same principle to the crown, he could find the volume of the material used in making the crown.
And – if he could measure the mass of the crown and with the known volume, Archimedes could work out the density of the material used (by dividing the mass by the volume).
Since density is characteristic of any material, you can calculate the densities of any given pure substance and compare them to known (or published) values. Gold has a density of 19.3 grams per cubic centimetre while silver has 10.49 grams per cubic centimetre.
If the calculated density of the crown was not 19.3 grams per cubic centimetre, then he would know that another metal was substituted for pure gold.
It is said that when Archimedes figured out the method to verify the metal used in the king’s crown, he was so excited that he ran out of the bathhouse without any clothes and shouting “eureka”.
So, physics can be so exciting that people studying it can get carried away by their new discoveries or inventions.

Galilei: The bold physicist
Even though Newton and Einstein have been hailed as the most famous scientists in this discipline, Galilei (1564-1642) is acknowledged as the “father of modern physics” and “father of the scientific method” and was sadly incarcerated for going against beliefs which were held by the Church and authorities in his day.
That is right; he was imprisoned for standing for the physical truths as he knew them.
In Galilei’s time people and the Church believed, like Aristotle (a philosopher and scientist) did, that the sun orbited the earth. That was the earth-centred (or geocentric) model.
Galilei opposed that theory because he believed the theory that the earth actually orbited the more massive body, the sun. This was the sun-centred (heliocentric) model.
His position may have come from him making observations of the moons of Jupiter after being the first astronomer to use the newly-invented telescope to observe celestial bodies.
He saw that the moons of the giant planet were orbiting it – it was more massive than its moons, so the logic was the earth must be orbiting the sun.
The sun-centred model was not new at that time. In fact, Aristarchus of Samos first proposed it around 3 BC, almost 1600 years ago, but it seemed – as is often the case – a knowledgeable group of people (including popular Aristotle) promoted the earth-centred model that everyone held onto that for centuries until scientists like Galilei tried investigating it by using scientific methods, as in observing another planet and monitoring the changing positions of its moons and providing a mathematical model to describe that.
Galilei’s trait of going against authorities is also observed in another story about him where he argued with the learned over the problem of dropping two objects made from the same material (like a metal) but of different masses.
The question was: Which object will hit the ground first – the heavier or lighter?
Everyone said the heavier of the two will reach the ground first.
Galilei said otherwise, because he knew from his experimentation that, if air resistance is negligible, both objects will reach the Earth at the same time because the same gravitational force (earth’s gravity) was pulling on the two.
He may have taken the group out and demonstrated in a simple experiment that what he said was true – just by dropping two objects of different masses, something that nobody thought about doing.
In that sense, he championed the scientific method: If you cannot test a principle or concept by experimentation, then that cannot be accepted.
The scientific method separated myths and false beliefs from physical truths.
Much of Newton’s work on gravity and some concepts of Einstein’s work were based on Galilei’s work. It is said that in the year that Galilei died, Newton was born.
Lives of physicists like Galilei should teach us that we can be right and yet not be in the majority – and also, the truth will always be the truth.

Curie: The determined physicist
History shows us that the best physicists were also hardworking researchers. They did not just wait around for ideas to get to them, they worked hard to investigate mysteries and provide an answer for what they observed.’
Marie Sklodowska (1867-1934) was someone like that. She was hardworking and very determined in accomplishing tasks.
She was Polish and was fortunate to have a father who was a physics and mathematics teacher and she may have already known at an early age that she would pursue studies in those fields.
Sklodowska was born at a time when Poland was ruled by Russia.
Not wanting to get a Russian education, an older brother and sister of Sklodowska’s left for Paris, in France, to study in university there.
At the age of 24, Sklodowska also left his family in Poland and went to study in Paris. Life was tough there and often she did not have enough to eat or proper clothes to keep warm in winter.
However, at the end of each semester of study, Sklodowska was usually the top student in her physics or mathematics courses.
It was while studying at university that she met French physicist Pierre Curie and the two developed a relationship and later married.
After graduating with two master’s degrees, Sklodowska continued research and worked with pitchblende, the uranium ore.
By then in 1896, another physicist Henri Becquerel had already discovered uranium to be emitting some form of radiation (or rays), like X-rays, which were discovered years before that.
The now Mrs Curie investigated pitchblende and discovered two other radioactive elements – polonium and radium. In her work with her husband, she coined the word “radioactivity” as the phenomenon observed.
The work to separate radium in pitchblende was very tough in that they had to painstakingly go through a lot of material to get a tiny bit of a radium compound – like going through a tonne of material to get a tenth of a gram of radium chloride.
It was for that work – their research on the radiation phenomenon – that the Curies and Becquerel were jointly awarded the Nobel Prize in Physics in 1903.
In 1911, she was again awarded the Nobel Prize in Chemistry “for the advancement of chemistry in the discovery of polonium and radium”.
She was the first woman to win a Nobel Prize and the first person to win two of those prizes.
Her daughter, Irène Joliot-Curie – with her husband – also won a Nobel Prize in Chemistry in 1935. She was Curie’s protégé, raised to be a science researcher.
Curie and Joliot-Curie both died from diseases linked to their exposure to radiation emitted by the elements they handled in their research.
Curie would remain as the most famous woman physicist of all time. In a discipline dominated by males, Curie’s life shows that physics can be appealing to both genders.

•  Next week: Elon Musk, a physicist who thinks big. Thomas Hukahu is a freelance journalist.