Buzz
Almost everyone has gazed up at the night sky, awestruck by the infinite expanse of space and the mysteries it holds. However, movies, TV shows, and books often distort our understanding of the cosmos, giving rise to several inaccurate beliefs. Let’s set the record straight with science and explore ten of the most common myths and misconceptions about the universe.
10. A Large Number of the Stars We See Are Already Dead and No Longer Shine
The light from faraway or dying stars takes an extended period to reach Earth. As a result, many people think that the thousands of stars visible to us at night must be long gone, their light extinguished. But is that the case?
Not exactly. The 6,000 stars visible to us are most likely still alive and burning brightly. These stars are all within 1,000 light-years of Earth, which is relatively close in cosmic terms. So, it's extremely unlikely that any of them have perished in the time it takes for their light—traveling at 186,000 miles per second (300,000 km per second)—to reach us.
9. The Universe Is Endless
The universe is undeniably vast, but it is not infinite. In fact, it has boundaries. It does come to an end.
Our own galaxy, the Milky Way, contains over 200 billion stars, and there are an estimated two trillion galaxies in the cosmos. Despite this immense number, the universe is still finite. The farthest reaches of the universe are 47 billion light-years away from us in all directions, which marks its radius. The total distance across the universe (its diameter) is 94 billion light-years.
A more mind-boggling question is: what exists beyond the outer limits of planets and stars at the edge of the universe?
8. Black Holes Are Not Giant Vacuum Cleaners—They Don’t Just Suck Everything In
Contrary to what we often see in movies, black holes are not terrifying cosmic whirlpools that indiscriminately consume everything in their path. Nor do they hunt for planets to devour in order to grow or survive.
Black holes form when massive stars exhaust their fuel and collapse under their own weight. As this collapse occurs, the star becomes increasingly dense, resulting in stronger gravitational pull, which can attract nearby objects, including light! Yes, this gravity can pull in planets, moons, and other stars, drawing them into the event horizon, the boundary surrounding the black hole. But the gravity from a black hole is simply an intensified version of regular gravity. For instance, if a star 10 times the size of our sun were to die, collapse, and turn into a black hole, its gravitational force would be equivalent to the mass of a star 10 times the size of the sun.
7. Dark Matter Is Malicious and Destructive
Dark matter has been featured as a plot device in numerous films and TV shows—The Expanse, Star Trek, Futurama, X-Files, and even Scooby Doo, just to name a few. But is it truly evil, destructive, and dangerous?
Absolutely not.
Dark matter remains completely invisible and undetectable, yet it makes up about 27% of the universe's total matter. Essentially, it's the substance filling the empty spaces between stars and galaxies. Most scientists theorize that dark matter consists of WIMPs—weakly interacting massive particles—which are much denser than protons. These particles interact so weakly with regular matter that they’re incredibly hard to detect, hence the term “dark.”
6. Earth-Like Planets Are Uncommon
Proxima Centauri b is the closest known Earth-like planet—and possibly the most likely to support life—just a mere four light-years away. However, even with today's technology, it would take us over 60,000 years to travel there.
But let’s not confuse the distance to a potentially habitable planet with the rarity of Earth-like planets. Astronomers estimate that the Milky Way galaxy alone contains between 300 million and 6 billion planets similar to Earth. And with an estimated 10 trillion galaxies in the universe, there could be an astonishing 76 quintillion stars with planets in habitable zones.
5. Once We Master Faster-than-Light Travel, We’ll Be Able to Zoom Through the Galaxies
In science fiction, warp speed, hyperdrives, and other advanced technologies allow for quick travel between planets and galaxies. However, in reality, traveling at light speed or even near-light speed is impossible.
Einstein's Theory of Relativity tells us that as objects accelerate, they also gain mass—becoming heavier. Therefore, any object approaching the speed of light would require infinite mass or energy. While photons, which have no mass, have been accelerated to 99% of light speed in labs, the energy needed to propel just one gram of any object to that speed would require an infinite amount of energy.
In short, no object with mass can ever achieve the speed of light.
4. The Big Bang Was an Explosion
While it may sound clear from the name itself—the BIG BANG Theory—that the universe and everything within it began with a massive explosion, cosmologists continually work to clarify this idea.
Scientists generally agree that the universe originated 13.8 billion years ago, starting as an incredibly small, dense ball of matter that eventually expanded. But did it really 'explode'?
The prevailing view is that the universe began with a rapid expansion, not an explosion akin to a bomb going off. This expansion, which occurred faster than the speed of light, affected space itself rather than the objects within it. While the positions of the objects in the universe remain unchanged since then, the space between them is constantly growing. This helps explain why we don’t see a central void in the universe, something we'd expect if everything had been ejected from a single point in an explosion.
3. Our Sun Is a Massive Fireball
In reality, it’s more like an ongoing chain of hydrogen bomb explosions.
In the sun’s core, hydrogen atoms collide and fuse into helium, creating nuclear reactions that release vast amounts of energy, similar to the process in a nuclear power plant. These reactions have been powering the sun for approximately four billion years. Fortunately for Earth, the sun’s immense density and gravity hold everything together, preventing it from exploding.
2. In Space, No One Can Hear You Scream
As the popular saying goes, 'In space, no one can hear you scream.' Since space is a vacuum with no medium for sound waves to travel through, this statement holds true—your scream wouldn’t even make it past your lips.
However, NASA researchers now argue that the situation varies depending on where you are in space. By studying a gas-filled black hole near the Perseus galaxy cluster, 250 million light-years away, scientists detected a range of strange sounds. So, if you find yourself in a region of space rich with gases, plasma, and particles, feel free to scream—you’ll be heard.
1. Aliens Could Visit Earth
This idea may seem plausible, especially considering the numerous UFO sightings reported in North America each year. If even a small fraction of these encounters are authentic, it’s not unreasonable to believe that extraterrestrial visitors to Earth could be a reality.
But let's take another look at those staggering numbers.
With an estimated 76,000,000,000,000,000,000,000 stars in the universe, each with its own orbiting habitable planets, it’s clear that life exists elsewhere—some of it still evolving, some potentially intelligent, and maybe even some that are technologically advanced. The real question is: could these advanced civilizations ever make it to Earth?
Our own galaxy, the Milky Way, spans 100,000 light-years, and even aliens would face the same challenges of space travel—food, fuel, radiation, and so on. Currently, the fastest man-made object in space is the Voyager spacecraft, which travels at an impressive 11 miles per second. But even at that speed, Voyager wouldn’t reach the nearest star for 73,000 years. Considering the dangers along the way, how could any lifeform possibly survive a journey that could stretch across millions of years?
As Neil DeGrasse Tyson put it, 'Scientifically, we have a rule: you want to be alive at the end of your experiment, not dead.'
So, while there’s undoubtedly life elsewhere, it seems unlikely it’s coming to visit us anytime soon.
