25 Myths You Shouldn’t Believe About Earth, Space, And Physics

6. September 2016

1. 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.


2. 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


3. 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. 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.


4. 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. At best, a satellite might be involved in a call around the globe — but 99% of international communications data travels through undersea cables.


5. 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.


6. MYTH: The moon’s gravity pulling on water causes the tides

This is only half true. On the side of Earth that’s facing the moon, the moon’s gravity does indeed pull water toward it to cause high tide. It does this by slightly pulling the Earth’s center of gravity toward the moon. But on the other side of Earth it’s different. What causes the high tide there is actually a combination of centrifugal force (from the offset center of gravity), plus the inertia of water from the Earth’s rotation: Spinning at about 1,040 mph, the planet literally flings its liquid toward the side opposite the moon, where it slightly bulges.


7. 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.


8. MYTH: The Earth is a perfect sphere

The Earth rotates at about 1,040 mph. 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.


9. 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.


10. 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.


11. 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.


12. 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.


13. 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.


14. 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.


15. 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.


16. 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.


17. 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.


18. 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.


19. 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.


20. 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.


21. 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.


22. 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. Particles like electrons, neutrons, or neutrinos can outpace photons of light in such materials — though they have to bleed off energy as radiation when they do. What about light in a vacuum? Even then, the expanding fabric of space once exceeded light-speed during the Big Bang, and physicists think wormholes and quantum entanglement might be able to “move” faster as well.


23. 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.


24. 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.


25. 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.


source: IFLScience.com

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