For a long time, much of the universe was a mystery because it seemed so far out of reach, but the emergence of spectroscopy in the 19th century has allowed us to study the distant skies using the only information we have: light. Amazingly, it’s shown us that everything in the known universe is made up of the same elements we find here on Earth. Basically, spectroscopy uses the light of a star, planet or galaxy to decipher its properties. The light is separated out according to wavelength much like a prism separates out colours, and a spectrum is then generated: a unique pattern of lines that can show us all of the elements present in the star, almost like a cosmic barcode. Because an atom of a certain element will both emit and absorb the same frequency of electromagnetic radiation, we can detect what elements make up a star in two different ways, depending on our vantage point. Firstly, using the emission spectrum, which is produced by elements that emit radiation of a specific wavelength when heated, and secondly using the absorption spectrum, which is produced by elements absorbing certain wavelengths of light travelling outwards through the star, then re-radiating it in another direction, giving us dark lines in our spectrum. However, if we were looking at the star from the direction of the re-radiation, we would then view the spectrum as emission and not absorption. It all depends on perspective.
It’s Tumblr Tuesday! Here are some Tumblr blogs I hope you like!
If You Leave A collection of the work of over 250 photographers from all over the world, If You Leave features snapshots of a journey made by wanderers who study the mysterious yet uncannily peaceful feeling of desolation and loneliness. Above: Photo byCarla Andrade.
Museum of Broken Relationships Ever had a broken heart? Own an object that won’t let you forget? This is your opportunity to give it a perfect new home. This museum safeguards the mementos of our once grand loves.
Maldito Juanito Street artist based in Geneva who works with walls, paper and glue.
Stop for a moment, and let me tell you the story of you. You were born in the heart of a star, in a brilliant white furnace that churned and trembled and dazzled the darkness. Every atom in your body was cooked in a stellar crucible as dense as fifty elephants crammed inside a thimble, and then, as its world raged and shook, the star tore open its own heart for you, exploding suicidal atoms far across the oceans of the universe—atoms that came to reside in you. The remnants of such a dead star—a vast cloud of stellar gas and dust—acted as a nursery for our solar system too, forming the sun and the planets swirling around it over billions of years. You’re just clinging to the crust of this rocky world, encased in the blue skin of its atmosphere. You’re fresh on the crest of of tens of thousands of generations, and you’re moving faster than you could ever imagine. The earth beneath your feet is spinning at 1,600 km/h, the planet is hurtling around the sun at 107,500 km/h, the sun is moving towards Vega at 70,000 km/h, the Orion arm of our spiral galaxy is rotating at 900,000 km/h, and the Milky Way is heading for the Andromeda galaxy at 3,600,000 km/h…. And still here you are—a lovely collection of atoms, a perfect composition of organic molecules, a child of the stars themselves. You are the universe, every speck of you, and in a hundred billion galaxies, there is not another like you.