Something we have no control over could wipe us all out in a matter of seconds with absolutely no warning. It could happen while you’re sleeping, or even while you’re reading this very article. Sounds a bit sensationalistic, but it’s absolutely true. Let us take a look at the ways the universe can cause the end of the world as we know it.
10. Asteroid Impact
This one is pretty self-explanatory. A giant rock smashes into earth causing varying effects based on size. A small one wouldn’t end life on earth, but could certainly put an end to modern life in the unlucky country it landed in. If it struck water, the tsunamis would be devastating to all coasts. A medium sized strike would cause a nuclear winter. This would eventually destroy a huge percentage of life and only the most hearty creatures would live due to starvation. A very large asteroid impact would turn the crust of the earth into magma. All life dies. This is a complete global killer.
9. Solar Flare
This one isn’t as deadly, as the effects are more long term but a large enough solar flare could destroy our ozone layer. A world without an ozone layer wouldn’t be a place where life could thrive.
It would be unshielded against cosmic rays, suns dangerous UV rays etc. Most life that exists now would eventually die off due to exposure if the Earth didn’t have such a shield.
8. Black Hole
This might be the most interesting way for the world to end despite being very unlikely. It is estimated that there are over a million black holes in our galaxy alone. Black holes are very tough to see for obvious reasons. Scientists use a few indirect methods of looking for them — the effect of gravity on nearby objects and gravitational lensing of stars as they pass in front of them. It’s likely that we would only have a couple of months warning if one was passing through our solar system.
Though, rather than being gobbled up by the black hole, a more likely scenario is that its gravity would disrupt the orbit of the planets, asteroids and even Earth. Thus causing objects to collide with the Earth at a rate similar to when the Earth was formed.
If you are someone who likes to gamble, the safest bet for being Earth’s killer would probably be the supernova. A supernova is the explosion of a dying star. It happens once every 100 years or so in our galaxy. Most of the time, they’re generally far away and a not a threat to us. However, there have been some close calls. While no potential supernovas are close enough to blow our planet up Hollywood-style, a few are close enough to destroy our ozone layer and send deadly radiation pouring down onto our planet. One such star is Betelgeuse which is only 600 light years away. It’s a red giant at the end of its life, and it has been unusually active lately.
6. Gamma-Ray Burst
Gamma-ray bursts are the most intense blasts of radiation that we are aware of. They are created when the largest of stars explodes, likely during the formation of a black hole. We see these all the time, and they can even be spotted in different galaxies due to the extreme energy that is produced. It is hypothesized that a GRB caused the mass planetary extinction on Earth about 444 million years ago. If one were to hit us head on, the planet would be set on fire. Even if one just grazes Earth, most life on Earth would perish thanks to the ozone layer being obliterated.
5. Alien Attack
Stephen Hawking recently said, “If aliens visit us, the outcome would be much as when Columbus landed in America. And that obviously didn’t turn out well for the Native Americans,” he said. “We only have to look at ourselves to see how intelligent life might develop into something we wouldn’t want to meet.”
According to Dr. Hawking, he believes aliens would likely be hostile, looking to either colonize earth or mine its resources. That wouldn’t be the only problem, however. Just like in the movie ‘The War of the Worlds’, where our viruses won the day, their viruses could also harm us. Unlike the movie, these aliens would have done their homework.
If an alien invasion did occur, they won’t come down guns-a-blazing like in the movie Independence Day. Instead, they would probably release some kind of probe or craft with virulent agents aboard. Then they would just sit back, and wait for us to die off.
4. Death of the Sun
This one will certainly happen, but we have a couple billion years to go. Death by sun is pretty straight forward. As the sun ages, it will get bigger. Once it gets to a certain point, Earth’s oceans will boil away and our planet will be burn to a crisp. Better put on your sunblock SPF 2 million.
3. Galactic Collision
This one will also happen for certain. Andromeda, a neighboring galaxy, is on a collision course with the Milky Way and expected to merge with it in 3-5 billion years’ time. There are a few outcomes of this collision regarding Earth. The first is that if we’re on one side when it happens, we will likely get caught in the torrent — stuck in a merger of the two dense centers. This puts Earth right in the middle of two merging super-massive black holes.
If we’re on the opposite side when it happens, it will be relatively peaceful and we’ll have one helluva view in our night sky. There is also the possibility that the gravity could fling us completely out of our galaxy hurtling deep into intergalactic space.
2. The Big Rip
There is a mysterious force operating in the universe called “dark energy.” If that sounds scary, it’s because astrophysicists like to come up with scary names for things that are actually code for “We have no idea what this is”. This energy is causing the expansion of the universe. It’s also causing the expansion to speed up.
If it continues to speed up, it will eventually cause galaxies to fly apart due to gravity being weaker than the dark energy. It would be like placing marbles on a merry-go-round then spinning it. Shortly after, solar systems would fly apart, then planets, then molecules and then finally, even atoms and subatomic particles would be annihilated. Luckily this probably won’t happen, and wouldn’t for billions upon billions of years.
1. The Big Freeze
Also known as the Heat Death. This is what happens when the universe runs out of energy. The entropy of the universe continuously increases until it reaches a maximum value. The moment that happens, heat in the system will be evenly distributed, allowing no room for usable energy (or heat) to exist.
Basically, every star runs out of fuel and even black holes eventually evaporate away. Luckily this won’t happen for trillions upon trillions of years. The number is so staggeringly high, it’s tough for our minds to comprehend it.
0. Vacuum Metastability Event
This might be the scariest one of all, and even more frightening, it is still currently unknown whether this can or will happen. It all depends on the precise measurements of a few key particle properties (notably the Higgs Boson and the top quark).
Our Universe may exist in what’s known as a “false vacuum”. This is bad news because it means that at some point, our universe can and will drop to a lower energy state in what’s known as a “vacuum metastability event“. If this happens, a true, real vacuum bubble could form at some place within our Universe and it would expand forever at the speed of light. Anything and everything in its path would be vaporized and cease to exist before it knew what hit them. One moment you’re there, the next you don’t exist. Nothing in the universe could survive a vacuum metastability event and because it moves at the speed of light, there’s no way to know it’s coming.
In a way, it’s like a real life version of “The Nothing” from The NeverEnding Story… only scarier.