The end of the world is an oft-discussed topic about international tensions and global politics, the most common methods of demise narrowing down to nuclear war and unmediated global warming. However, there are others, such as pandemics (both natural and man-made) and supervolcanic eruptions, to name only two. Also, all these can occur with or without the added apocalyptic beliefs of some of the world’s religions, many of which feature the end of the world as we know it and the establishment of some type of divine kingdom or transcendent state of being.
However, science sees the end of the world as a given. Everything, every system, moves toward entropy. And there are several ways the universe can mete out an ending long before the last star burns down.
Daniel Brown, an astronomer at Nottingham Trent University in the United Kingdom, compiled a list of such end-of-the-world deliverers for the Conversation. Some might not completely wipe out the human race, but their occurrence would certainly alter humankind’s existence on the planet.
Probably the least devastating might be a high-energy solar flare, where the Sun fires off an electromagnetic stream of energy that overwhelms the Earth’s natural defenses against it — its electromagnetic fields. The entire world is highly dependent on electronic equipment to run everything from cars to hospital equipment. A massive solar flare could potentially knock out much of the world’s electrical systems, much like it did on a far smaller scale in 1859 in an episode known as the Carrington Event (per Gizmodo). Brown noted that although such an occurrence might not be an extinction event for humans, it would produce quite a challenge as social systems broke down regionally or even worldwide.
Another method the world could end from space is via an asteroid impact, a popular Hollywood catastrophe construct. Also, since the Earth does not have an asteroid detection system in place, death by asteroid could occur at any given moment (using the Chelyabinsk meteor episode as an example, considering it appeared undetected in the skies over Russia and detonated). However, for it to be an extinction event, the asteroid would have to be miles across in diameter, much as the asteroid that impacted off the Yucatan coast some 65 million years ago and contributed to the extinction of the dinosaurs and other species. Still, a regular-sized asteroid could cause serious damage, and social upheaval should it directly impact the Earth.
One of the less fearsome — but an inevitable — consideration will be the ultimate expansion of the Sun. Scientists estimate that in roughly 7.59 billion years, the Earth will have gotten so close to the Sun (from its expansion and its gravitational pull on the planet) that it will disintegrate.
However, that, of course, is billions of years in the future. Things could end more quickly for the Earth long before then and not just potentially, as with the high-energy solar flare and the possible asteroid strike. The end of the world could come in a split-second should a local gamma ray burst ever sweep over the planet, caused by a firing of a concentrated beam of energy from a binary star system or a supernova. Not that the initial blast itself would end everything. According to a 2009 Washburn University study, gamma ray bursts could cause damage to the ozone layer, cause a rise in ultra-violet radiation, a breakdown in plant photosynthesis, and produce high amounts of nitric acid rain.
Supernovas have a second potential life-extinguishing capability. Besides the ability to produce gamma ray bursts, the explosion itself, if relatively nearby, can conceivably cause the end of the world. In fact, astronomers estimate that a star would need to be within about 50 light-years of the Earth to produce enough radiation to cause damage.
Brown’s last example of the end coming from space involves the disruption of the Solar System by a passing wandering star. Such a rogue star could pass close enough to cause comets in the Oort Cloud to rain down upon the Earth. Of course, what Brown does not say is that a wandering star just might one day collide with the Earth, thus ending everything in one final collision. A 2012 study from the Kavli Institute for Particle Astrophysics and Cosmology suggested that there might be as many as 100,000 times the number of rogue planets than the number of stars in the Milky Way. Some of those rogue worlds, all difficult to detect, could actually be brown dwarfs –substellar objects that are, at the same time, not quite stars and not quite planets — wandering the galaxy.
However, Brown suggests that, instead of worrying about what might kill us next, we embrace the universe and wonder. We should become inspired by it. The end of the world is a given and will come sooner or later, but it does not have to define humanity itself or even a single human being.
[Featured Image by Twin Design/Shutterstock]