Gravity makes getting up in the morning difficult, it’s also responsible that unpleasant kiss of the curb when you've had too much to drink. Well, gravity and alcohol is. With gravity affecting so much of our life, you would think that it was easy to figure out, but it really wasn't, and still isn't. It’s story started over 2000 years ago, and involved a surprising amount of misery and death.
A Greek Conquest
We'll start with the ancient Greek man named Aristotle. During Aristotle's’ era of the 4th century BC, death was a common occurrence, it was a time of conquest and harsh punishment. His mentors’ mentor, Socrates, was executed simply for questioning nature. Aristotle's student, Alexander the Great, had led numerous opium fuelled conquests before he suspiciously died. Suspicions that caused Aristotle to flee from Athens, fearing the same fate as Socrates. During this seemingly chaotic life of Aristotle, a fair amount of work on what we now know to be gravity was done. Aristotle realised that motion depends upon the nature of the object, in a sense that fire would go up, earth would go down. Although it seems rather mundane and basic (and wrong), Aristotle's work was a step towards gravity.
A Post-Dark Age Pandemic
After Aristotle, there was a dark age where not much happened. But the dark age did come to an end, and from the 14th to the 17th century AD, the black death bled across Europe, shattering the population. Amidst the plagued cities and dropping bodies, Galileo Galilei was on top of the leaning tower of Pisa dropping objects. Galileo, perhaps the only scientist that we know by their first name, discovered that an object's acceleration towards the Earth does not depend on it’s mass. If it wasn't for air resistance from the atmosphere, we would see a feather fall to the ground as fast as a hammer does. Unfortunately, Galileo's’ work angered the church. A “suspect of heresy”. He was sentenced to spend the rest of his life imprisoned in his own home, where he died in 1642 - the very year our hero of gravity, Isaac Newton, was born.A Red Cross London
As the 1665 great plague of London splattered doors with red crosses, Newton's door remained clean. Buboes were violently growing on terminally ill Londoners, but he was safe living in the country. It’s at this time that Newton is believed to have been inspired to work on gravity by an apple falling on his head. Although the tall tale of the apple is more unbelievable than Azealia Banks lyrics, a branch from the supposed apple tree now grows at the University of York. Through his work, Newton realised that the force of gravity between two objects depends on how far away they are, and how much they weigh. So, this is why the Earth has an atmosphere but the Moon doesn't, as the Moon is too light to have a gravity strong enough to hold onto the one. More familiarly, it’s why staying stood up can be hard, as we have to counter the Earth pulling us back down.That bit at the end...
The theory of gravity has had slight changes since Newton, but his work is still used and taught now. It is only extreme conditions, such as near a neutron star or when travelling 1,000,000 mph, that Newton's work becomes invalid and the slight changes are used. However, when we look deeper and deeper, smaller and smaller, it becomes apparent that gravity still needs tweaking for particle physics. Fortunately, those small and extreme conditions are small and extreme, so Newton’s gravity is like your everyday pair of converse. |
| Newton's shoes? |
A website with a lot of information on Galileos life:
http://galileo.rice.edu/chron/europe.html