How Galileo Unlocked The Doors To The Universe | Galileo Galilei

It's 5pm on Thursday the 7th of January 1610. Galileo Galilei is in his garden in Padua, northern Italy, where he is just about to make a revolutionary decision. To point his newly constructed telescope, for the first time in humanity's history, towards Jupiter. Little does he realise that this simple action will utterly change the world forever. With a simple turn and point, the final chapter in a long and bitter debate about our place in the universe will begin. But how did Galileo get to this point? How did he get to this moment, alone, under these darkened skies, diligent and determined? Welcome to Savantium. Part of the answer lies two years earlier. It's the 17th century. The fifth Mughal emperor, Shah Jahan, has just commissioned the construction of the Taj Mahal in Agra, India. The Romanovs have just gained control of Russia, a dynasty which would reign for over 300 years, until its definitive end in 1917. Meanwhile in Europe, the first cracks of the Spanish Empire's Siglo de Oro are beginning to emerge. And this is where the seeds of our answers lie. Where a new nation has just gained its freedom and is fast gaining momentum and influence. It's late 1608, and this new nation, the Dutch Republic, is on the up. Capitalism and innovation are rife. The Dutch own world trade and will soon reign supreme over the seas. With a competitive edge on innovation and science, optimism, openness, experimentation and daring are the currency of the day. And beginning in the 1590s, glassmaking and lens grinding techniques have also been vastly improving. It's only a matter of time until someone holds two lenses together and discovers just exactly what they can do. And it is one such man from the coastal town of Middelburg, a lens grinder and spectacle maker named Hans Lippehe, who is the first to act, and on the 2nd of October 1608, he lodges a patent to the state in The Hague, noting a Dutch perspective glass which serves to see things far away as if they were nearby. An extended eyeglass, in other words, which is soon to be known as the telescope. The first stages of the scientific revolution have begun. And in only a matter of months, word of this revolutionary device would spread far and wide throughout the kingdoms of Europe, eventually falling into the hands of some of the greatest minds of the age. Court mathematicians, professors and astronomers like Simon Marius, Thomas Harriot, Johannes Kepler and, of course, a 45-year-old Italian polymath named Galileo Galilei. It's June 1609. Galileo is in Venice when he first learns of this Dutch perspective glass, which increases human vision by a factor of three, as news of Lippehe's invention continues to quickly spread. Galileo has no time to waste. And on that very night, on his return from Venice to Padua, he gets straight to work and commits to building his very own version. Within days, he's designed one. And in less than two months, on the 25th of August 1609, he demonstrates his telescope to the Venetian lawmakers and offers it as a gift to the Senate. With eight times magnification, the Senate quickly sees its military potential. After winning the favour of the Venetians with his gift, Galileo decides to turn his telescope towards the skies, to more peaceful and infinitely more curious endeavours. Our Universe, a device for war and devastation, is now destined for exploration. Galileo's final telescope is exceptional for the day, ranging 20 metres in length, 37 millimetres in diameter, with the ability to see 20 times more than the human eye. It is formidable. This simple idea, to improve a nascent technology, is the very first steps to the heavens. And together with his mathematical abilities of recording, precision and rigour, it's a recipe for scientific revolution. He first points it towards the Moon, where he observes craters, grooves and mountains in what was always presumed to be a smooth surface Moon. He next observes ribbons of diffused light that arc over the sky, our Milky Way galaxy, which he now realises is composed of many stars. And then, a little over three months later, Galileo's investigations take a dramatic turn. Under the clear night skies of Padua, he points his telescope, for the very first time, towards the gas giant Jupiter. This simple decision changes everything. And so, on this unassuming Thursday evening on the 7th of January, at approximately 5pm, armed with only his notebook and his telescope, Galileo observes three fixed stars, which he scribbles are extremely close to Jupiter, two on the east and one to the west. He continues to observe these objects on subsequent nights and realises that these three stars are in fact wandering like satellites around Jupiter. And these objects often obscure one another, falling in and out of range, so much so that Galileo misses the full amount of objects in Jupiter's orbit. And by January 13th, and much to his own confusion, he now glimpses four objects moving about Jupiter. By January 15th, he fully confirms that a fourth satellite is in existence. The moons of Jupiter are finally unveiled. Io, Europa, Ganymede and Callisto. The realisation is now clear. Jupiter too, like Earth, has moons. And these moons too rotate around Jupiter just as our Moon orbits the Earth. The ramifications of this moment are immense, because now he realises with irrefutable proof that the Earth is not at the centre of our Universe. And so Galileo hurries to make his discoveries known. And in a little over two months of pointing his telescope towards mighty Jupiter, Galileo publishes 500 copies of his findings in a 24-page pamphlet called Siderius Nuncius, better known as the Starry Messenger, in March of 1610. The book sells out almost immediately, creating a veritable sensation across Europe. At long last, heliocentrism is here, a view that since Aristarchus was silenced by fear. As for Galileo, the battle has just begun. He will spend the rest of his days observing the skies and battling the Church with irrefutable proof that we too orbit the Sun. Never has such a simple gesture as pointing a stick to the sky, as Galileo did with temerity and curiosity in 1610, had such immense ramifications for the future of humanity. A scientific revolution held together in 20 metres of wooden glass is unleashed on the world, and the floodgates of scientific learning now pour open. NASA Jet Propulsion Laboratory, California Institute of Technology