It's time to put an end to these myths, misconceptions, and inaccuracies about the universe.
Whenever someone strikes up a conversation with me about the universe, I get animated.
No surprise there: I've made a living writing about astronomy, physics, geology, spaceflight, and related areas of science for nearly a decade, and have read obsessively on these topics for much longer than that.
However, people have shared a lot of peculiar "facts" with me over the years that ended up being totally false.
Below are some of the silliest and most common claims I've heard.
No one is perfect — I believed many of these statements at some point in my life — but it's time to put these myths, misconceptions, and inaccuracies to rest.
MYTH: The sun is yellow.
If you wince and look at the afternoon sun, it might look yellow — but the light it gives off is actually white in color.
The Earth's atmosphere between your eyes and the sun is what makes the star appear yellow.
The gases bend the light in an effect called Rayleigh scattering, which is what also makes the sky appear blue and causes sunsets to blaze into brilliant oranges and reds.
Not helping matters is that astronomers classify the sun as a yellow main-sequence G-type star, or "yellow dwarf."
MYTH: The Sahara is the biggest desert on Earth.
Not all deserts are hot and full of sand. They need only be dry and inhospitable.
Antarctica fits the bill, since it receives only two inches of precipitation a year and has few land animals.
At 5.4 million square miles compared to the Sahara's 3.6 million square miles, the Bottom of the World is a vastly larger desert.
MYTH: Astrology can predict your personality or the future.
Wouldn't it be nice to get a glimpse of tomorrow based on something as simple as where the sun, planets, and moon were located when you were born?
That's what astrology claims to do, what 50% the world at least partly believes, and what as much as 2% of the planet strongly buys into.
Yet thorough scientific investigations of astrology have failed, again and again, to back up any predictions from an astrological sign or horoscope.
A 1985 study in Nature is especially notable. In that experiment, scientists used a non-biased, double-blind protocol and worked in conjunction with some of the top astrologers in the US to test the predictive power of astrological signs.
The results? The astrological predictions were no better than chance.
Sources: The Humanist, Comprehensive Psychology, Nature, Proceedings of the Biennial Meeting of the Philosophy of Science Association, Pseudoscience and Deception: The Smoke and Mirrors of Paranormal Claims,
MYTH: When you call someone, the signal bounces off a satellite.
This is true of satellite phones, which the military uses every day, but your mobile phone works in a much different way.
Mobile phones broadcast a wireless radio signal and constantly look for, ping, and relay data to and from land-based cellular towers.
When you make a call, the nearest tower connects you to another phone via a vast network of tower-to-tower connections and buried cables.
At best, a satellite might be involved in a call around the globe — but 99% of international communications data travels through undersea cables.
MYTH: The Great Wall of China is the only man-made structure visible from space.
The Great Wall of China isn't the only man-made structure visible from space.
It all depends on where you believe space begins above Earth.
From the International Space Station, 250 miles up, you can see the wall and many other man-made structures. From the moon, you can't see any structures at all — only a dim glow of city lights.
MYTH: The moon's gravity pulling on water causes the tides.
This is only partly true.
The moon does pull on ocean water, but that tug at any one point is about 10 million times weaker than Earth's gravity. It's really the interplay of gravity between the moon, Earth, and sun that creates a tidal force, and it's more of a "push" than a "pull."
Each molecule of water is pulled by the moon's gravity, but alone that acceleration is so weak it isn't noticeable. Because ocean water covers about 71% of Earth's surface and is connected as one liquid body, however, all of those tiny tugs add up to form a significant pressure — the tidal force.
Molecules of water near the poles are pulled mostly straight down, those on the face of Earth closest to the moon experience the strongest pull toward the moon, and those on the opposite side of Earth feel the weakest acceleration.
Together, these interactions form a pressure on seawater that generally directs it away from the poles and toward the equator, where it's strong enough to fight gravity to form two bulges: the high tides.
Tides follow the moon as it orbits Earth every 28 days, but it's not as simple as that. Water sloshes around, just as it does within in aquarium, and the shape of the seafloor, the position of the coasts, and the Coriolis effect (caused by Earth's rotation) affect where and to what extent tides occur — resulting in a complex pattern of "tidal nodes."
"Earth rotates so quickly that the tide water wave can't move around the Earth quickly enough," Ted Swift, an environmental scientist who works for the state of California, told Business Insider in an email. "What we see as tides on the coast are resonances — rotating standing waves — set up by the fundamental tidal potential 'signal.'"
Smaller bodies of water, like lakes and pools, don't have noticeable tides because they lack enough liquid to create a pressure that can visibly overcome the pull of Earth's gravity.
The sun's gravity also affects the tides, accounting for roughly one-third of the phenomenon. When the sun's gravity counteracts the moon's, it leads to lower-than-average "neap tides." When the sun lines up with the moon, it triggers larger "spring tides."
Correction: An earlier version of this article mischaracterized the nature of tides.
MYTH: Lightning never strikes the same place twice.
Lightning does strike twice.
Some places, like the Empire State Building, get struck up to 100 times a year.
MYTH: The Earth is a perfect sphere.
The Earth rotates at about 1,040 mph. That's about 60% the speed of your typical bullet after it shoots out of the muzzle.
This inertia slightly flattens the planet's poles and causes a bulge of rock around the equator.
Due to global warming and the melting of glaciers (and less weight pushing down on the crust), scientists think that bulge is now growing.
MYTH: Mount Everest is the tallest thing on Earth.
The world's tallest mountain, if you want to get technical, is not Mount Everest.
Mount Everest is the tallest mountain above sea level, but if we're talking mountain base-to-summit height, then the tallest is the island of Hawaii that peaks as Mauna Kea.
Everest stands 29,035 feet above sea level. Mauna Kea only stands 13,796 feet above sea level, but the mountain extends about 19,700 feet below the Pacific Ocean. Over half of it is submerged. That puts the total height of Mauna Kea at about 33,500 feet — nearly a mile taller than Everest.
Mount Chimborazo in Ecuador is another candidate. The mountain is within 100 miles of the equator, where the planet's crust bulges out, and is 3,967.1 miles from the center of Earth — a full 1.3 miles taller than Everest, by that measurement.
MYTH: Water conducts electricity.
Pure or distilled water doesn't conduct electricity well at all.
The reason we get shocked when standing in electrified water is because water we come across will be contaminated by minerals, dirt, and other things that will conduct electricity.
MYTH: The "dark side" of the moon.
It's easy to think this, since we never see it, but the far side of the moon isn't always dark. It goes through the same lunar phases as the near side, which faces the Earth, but in reverse.
When there's a new (and very dark) moon on the near side, for example, that means there's a full moon on the far side. We just can't see it from our earthbound vantage point.
So yes, there is a "dark side" to the moon — but it's always moving and sometimes faces Earth directly.
MYTH: Tectonic plates move because volcanism pushes them apart.
Older edges of a tectonic plate are cooler and denser, causing them to sink into the mantle where they're recycled. Where two plates are being yanked apart by this sinking, ocean ridges appear.
That's where the tectonic plate is being built — by hot, buoyant rock that convects upward and emerges from the stretched-out weak point. The resulting volcanism isn't what pulls two plates apart.
MYTH: Going past the edge of space makes you weightless.
Most scientists agree space begins 62 miles up, where the Earth's atmosphere is more or less a vacuum.
Yet going past this line does not magically make you weightless. If you're in an accelerating rocket, you will feel many times Earth's gravity. It's only when you start falling that you feel weightless.
This is what it means to orbit something: to seemingly fall forever around that object. The moon around the Earth, the Earth around the sun, the solar system around the Milky Way Galaxy ... They're all falling into one another in a crazy cosmic dance.
If you're 250 miles above the Earth, you have to travel 17,500 mph around the planet to experience continuous freefall — precisely the speed of the International Space Station and its astronauts.
MYTH: Diamonds come from coal.
Most diamonds aren't formed from compressed coal.
Instead, they're carbon that is compressed and heated 90 miles below the surface of the Earth. Coal is found about 2 miles down.
MYTH: People in the Middle Ages thought the Earth was flat.
During the early Middle Ages, almost every scholar thought the Earth was round, not flat.
This myth picked up steam in the 1800s, right around the same time the idea of evolution was rising in prominence — and religious and scientific interests clashed.
MYTH: Summer is warm because the Earth is closer to the sun.
The Earth is not closer to the sun when it is summer in the Northern Hemisphere — quite the opposite: The planet is actually at it's farthest point from the sun during the summer.
It is always warmer during the summer because Earth is tilted. During its orbit, our home planet's tilt allows the sun's energy to hit us more directly.
MYTH: Lightning causes thunder.
A scientific and philosophical nitpick here, but lightning is just a stream of electrons zapping from cloud to cloud or ground to cloud. This in turn heats air into a tube of plasma that's three times hotter than the surface of our sun.
That tube violently expands and contracts nearby air, creating an unmistakable crack and rumble — not the flow of electrons itself.
Source: Scientific American
MYTH: The Asteroid Belt is dangerous.
Movie scenes of spaceships flying through a dense field of tumbling, colliding rocks are imaginary.
The Asteroid Belt — a zone between 200 and 300 million miles from the sun — is an incredibly lonely and desolate void.
In fact, if you pulled all the asteroids in that belt together they'd only weigh about 4% the mass of Earth's moon.
This is why NASA gets really excited when it catches even one asteroid colliding with another.
MYTH: The moon is very close to the Earth.
The moon sometimes looks so close you could reach up and up and grab it.
In reality, the moon orbits at a distance of about 239,000 miles from Earth. If you could somehow hop in a Boeing 747 and cruise to the moon at full speed, the journey would take about 17 days.
The moon is far, far away.
MYTH: You can only balance an egg during the Spring Equinox.
It's possible to stand an egg on its head on any day of the year — not just on the Spring Equinox.
The trick just requires a well-textured egg shell and a skilled hand.
Source: Business Insider
MYTH: A nuclear weapon could destroy an asteroid.
Nuking an asteroid would not vaporize every single bit of rock.
Most asteroids are heaps of rubble to begin with, so a powerful blast would probably just break everything apart further. That's may be a bad idea if you're trying to save the planet — it's like turning a single bullet into a shotgun blast.
However, some researchers think a well-directed, smartly designed nuclear attack could irradiate an asteroid's surface, vaporize some of the rock, and shoot off gases that'd push an asteroid on off-course. Whew.
Source: National Geographic
MYTH: Nothing can go faster than light.
Wrong on a few levels.
While light can move unimpeded at 299,792,458 meters per second in a vacuum, it slows down when it travels through different substances. For example, light moves 25% slower through water and 59% slower through diamond.
Charged particles like electrons can sometimes outpace photons of light in such materials — though they have to bleed off energy as a radiation when they do. It's like an optical version of a sonic boom, and nuclear reactors create a lot of it by knocking electrons loose from water molecules with gamma rays.
What about light in a vacuum? Even then, the expanding fabric of space once exceeded light-speed during the Big Bang.
Physicists also think two quantum-entangled particles might be able to "move" or teleport their states instantly, no matter how much distance separates them.
MYTH: The vacuum of space is cold.
If you're in total darkness at the coldest spot in the known universe, the vacuum of space can get down to minus-454 degrees Fahrenheit. Brr!
But in sunlight near Earth, temperatures can swing to a boiling 250 F. That's why astronauts wear reflective white spacesuits.
MYTH: Enrico Fermi developed the "Fermi paradox" about aliens.
Physicist Enrico Fermi once famously asked "where is everybody?" after seeing a New Yorker cartoon featuring a flying saucer.
But Fermi was questioning the feasibility of travel between stars — not the actual existence of aliens.
The "Fermi" paradox, which explores the contradiction that intelligent aliens are inevitable but we haven't seen them, does question alien existence. And Fermi didn't do that work.
Astronomer Michael Hart and physicist Frank Tipler were the ones who actually fleshed out the idea in the 1970s and 1980s.
"The Fermi paradox might be more accurately called the 'Hart-Tipler argument against the existence of technological extraterrestrials,' which does not sound quite as authoritative as the old name, but seems fairer to everybody," astronomer Robert H. Gray wrote for Scientific American.
MYTH: There are only 3 phases of matter: Solid, liquid, and gas.
You forgot a big one: Plasma.
It's easy to assume solids are the most abundant form of matter in the cosmos, since we all live on a giant rock. But plasma is vastly more abundant; stars, including the sun, are gigantic orbs of glowing plasma.
There are other sub-phases of matter, but solid, liquid, gas, and plasma are the main ones.
Have any favorites we missed? Send them to firstname.lastname@example.org.
Jennifer Welsh and Kelly Dickerson contributed to this post.
Correction: A previous version of this article misstated that neutrons, which have no charge, can cause Cherenkov radiation. This is incorrect. Only charged particles moving at faster-than-light speeds through a medium — or neutral particles able to produce such charged particles (e.g. neutrinos) — lead to Cherenkov radiation.