A Brief History of the Selfie

A Brief History of the Selfie Selfie is the slang term for self portrait, a photograph you take of yourself, usually taken using a mirror or with a camera held at arms length. The act of taking and sharing selfies has become widely popular due to digital cameras, the internet, the ubiquity of social media platforms like Facebook and, of course, because of peoples endless fascination with their own image. The word selfie was even chosen as the Word of the Year in 2013 by the Oxford English Dictionary, which has the following entry for the word: a photograph that one has taken of oneself, typically with a smartphone or webcam and uploaded to a social media website. History of the Self Portrait So who took the first selfie? In discussing the invention of the first selfie, we have to first pay homage to the film camera and the early history of photography as photography self portraits were taking place long before the invention of Facebook and smartphones. One example is American photographer Robert Cornelius, who took a self portrait daguerreotype (first practical process of photography) of himself in 1839. The image is also considered one of the earliest photographs of a person. In 1914, 13-year-old Russian Grand Duchess Anastasia Nikolaevna took a self portrait using a Kodak Brownie box camera (invented in in 1900) and sent the photograph to a friend with the following note, I took this picture of myself looking at the mirror. It was very hard as my hands were trembling. Nikolaevna appears to have been the first teenager to take a selfie. So Who Invented the Selfie?   Australia has laid claim to inventing the modern day selfie. In September 2001, a group of Australians created a website and uploaded the first digital self portraits onto the internet. On 13 September 2002, the first recorded published use of the term selfie to describe a self portrait photograph occurred on the Australian internet forum (ABC Online). The anonymous poster wrote the following along with posting a selfie of himself: Um, drunk at a mates 21st, I tripped over and landed lip first (with front teeth coming a very close second) on a set of steps. I had a hole about 1cm long right through my bottom lip. And sorry about the focus, it was a selfie. A Hollywood cameraman named Lester Wisbrod claims he is first person to take celebrity selfies, (a self-taken photo of himself and a celebrity) and has been doing so since 1981. Medical authorities have begun to associate the taking of too many selfies as a potentially unhealthy sign of mental health issues. Take the case of 19-year-old Danny Bowman, who attempted suicide after failing to take what he considered the perfect selfie. Bowman was spending most of his waking hours taking hundreds of selfies everyday, losing weight and dropping out of school in the process. Becoming obsessed with taking selfies is often a sign of body dysmorphic disorder, an anxiety disorder about personal appearance. Danny Bowman was diagnosed with this condition.

Red Supergiants are the Largest Stars in the Universe

Red Supergiants are the Largest Stars in the Universe Red supergiants are among the largest stars in the sky. They dont start out that way, but as different kinds of stars age, they undergo changes that make them big...and red. Its all part of star life and star death.   Defining Red Supergiants   When astronomers look at the largest stars  (by volume) in the universe, they see a great many red supergiants. However, these behemoths are not necessarily- and almost never are- the largest stars by mass. It turns out theyre a late stage of a stars existence and they dont always fade away quietly.   Creating a Red Supergiant How do red supergiants form? To understand what they are, its important to know how stars change over time. Stars go through specific steps throughout their lives. The changes they experience are called stellar evolution. It starts with star formation and youthful star-hood. After they are born in a cloud of gas and dust, and then ignite hydrogen fusion in their cores, stars usually live on something astronomers call the main sequence.  During this period, they are in hydrostatic equilibrium. That means the nuclear fusion  in their cores (where they fuse hydrogen to create helium) provides enough energy and pressure to keep the weight of their outer layers from collapsing inwards. When Massive Stars Become Red Supergiants A high-mass star (many times more massive than the Sun) goes through a similar, but a slightly different process. It changes more drastically than its sun-like siblings and becomes a red supergiant.  Because of its higher mass, when the core collapses after the hydrogen burning phase the rapidly increased temperature leads to the fusion of helium very quickly. The rate of helium fusion goes into overdrive, and that destabilizes the star. A huge amount of energy pushes the outer layers of the star outwards and it turns into a red supergiant. At this stage, the gravitational force of the star is once again balanced by the immense outward radiation pressure caused by the intense helium fusion taking place in the core. The star that transforms into a red supergiant does so at a cost. It loses a large percentage of its mass out to space. As a result, while red supergiants are counted as the largest stars in the universe, they are not the most massive because they lose mass as they age, even as they expand outward. Properties of Red Supergiants Red supergiants look red because of their low surface temperatures. They range from about 3,500 - 4,500 Kelvin. According to Wiens law, the color at which a star radiates most strongly is directly related to its surface temperature. So,  while their cores are extremely hot, the energy spreads out over the interior and surface of the star and the more surface area there is, the faster it can cool. A good example of a red supergiant is the star Betelgeuse, in the constellation Orion. Most stars of this type are between 200 and 800 times the radius of our Sun. The very largest stars in our galaxy, all red supergiants, are about 1,500 times the size of our home star.  Because of their immense size and mass, these stars require an incredible amount of energy to sustain them and prevent gravitational collapse. As a result, they burn through their nuclear fuel very quickly and most live only a few tens of millions of years (their age depends on their actual mass). Other Types of Supergiants While red supergiants are the largest types of stars, there are other types of supergiant stars. In fact, it is common for high mass stars, once their fusion process passes beyond hydrogen, that they oscillate back and forth between different forms of supergiants. Specifically becoming yellow supergiants on their way to becoming blue supergiants and back again. Hypergiants The most massive of supergiant stars are known as hypergiants. However, these stars have a very loose definition, they are usually just red (or sometimes blue) supergiant stars that are the highest order: the most massive and the largest. The Death of a Red Supergiant Star A very high-mass star will oscillate between different supergiant stages as it fuses heavier and heavier elements in its core. Eventually, it will exhaust all its nuclear fuel that runs the star. When that happens, gravity wins.  At that point, the core is primarily iron (which takes more energy to fuse than the star has) and the core can no longer sustain outward radiation pressure, and it begins to collapse. The subsequent cascade of events leads, eventually to a Type II supernova event. Left behind will be the core of the star, having been compressed due to the immense gravitational pressure into a neutron star; or in the cases of the most massive of stars, a black hole  is created. How Solar-type Stars Evolve People always want to know if the Sun will become a red supergiant. For stars about the size of the Sun (or smaller), the answer is no. They do go through a red giant phase, though, and it looks pretty familiar. When they begin to run out of  hydrogen fuel their cores begin to collapse. That raises the core temperature quite a bit, which means theres more energy generated to escape the core. That process pushes the outer part of the star outward, forming a  red giant. At that point, a star is said to have moved off the main sequence.   The star chugs along with the core getting hotter and hotter, and eventually, it begins to fuse helium into carbon and oxygen. During all this time, the star loses mass. It puffs off layers of its outer atmosphere into clouds that surround the star. Eventually, whats left of the star shrinks to become a slowly cooling white dwarf. The cloud of material around it is a called a planetary nebula, and it gradually dissipates. This is a far more gentle death than massive stars discussed above experience when they explode as supernovae.   Edited by Carolyn Collins Petersen.