The universe is a vast and mysterious place that encompasses everything we have known, observed or with which we might have the possibility of coming into contact in the future. For millennia, human beings who looked to the sky, our window to the cosmos beyond our world, were amazed and fascinated by the unknown.
Fortunately, and thanks to all the scientific advances made by civilizations around the world over time, we now know -among other things- that the points of light in the sky are stars, which are grouped in galaxies and that are They group at larger scales, in a universe that began with our Big Bang 13,700 million years ago. However, knowing this does not mean that we know everything about our cosmos. In fact, many people have shared and share some misconceptions, many of them totally false.
It is possible that some of us have believed these claims at some point in our lives (no one is perfect), but it is time to put an end to these myths, these inaccuracies and misconceptions or inaccuracies.
And it is that, although we can think that in the age of internet, the moment of history in which more information can be obtained, that we could not read even in several decades, these ideas or myths would have dissolved, the obstinate myths from the past they seem to continue patents with new and unusual theories.
Who still thinks that the Great Wall of China is visible from space? (The origin of the myth, its oldest reference, dates back to 1754, but there are still people who believe in this possibility, since it is also normal to find this type of affirmation in the textbooks of many schools around the world).
There is much to explore, so we will review some of the most important myths about the universe. Among them, we will talk about if the Sun is really yellow, if the Sahara is the largest desert on Earth or if astrology can really predict your personality or the future (eg, ahem).
1Myth: The Sun is yellow
Certainly the afternoon sun looks yellow, right? but the light it emits is technically white. The Earth’s atmosphere makes our star look yellow. The gases bend the light in an effect called Rayleigh scattering, which is exactly the same phenomenon that makes the sky look blue and the sunsets glow in bright orange, red and violet. The fact that astronomers classify the Sun as a G-type star of yellow main sequence, or “yellow dwarf”, has nothing to do with color.
2Myth: The vacuum of space is always cold
If you are in total darkness at the coldest point of the known universe, the void of space can drop to -234 ° C. However, near the Earth and thanks to sunlight, temperatures can oscillate to a boiling point of 121 ºC. That’s why astronauts wear reflective white space suits.
3Myth: The Sahara is the largest desert on Earth
Not all deserts are full of sand and have high temperatures. They just need to be dry and inhospitable. So things, Antarctica fits these terms, since it receives just 100 mm. with a water equivalent of only 30 mm- of annual rainfall and has few terrestrial animals.
So things and although it seems difficult to conceive that the largest desert in the world is Antarctica, compared to the Sahara that has 9,065,253 km², Antarctica is a much larger desert with its 13,829,430 km².
4Myth: The asteroid belt is dangerous
In this sense, the “fault”, in a certain sense, has the cinema. Despite being fiction, the scenes of movies / series of spacecraft flying through a dense field of rocks that fall and collide… are not realistic. The asteroid belt is only an incredibly lonely and desolate emptiness.
In fact, if we add all the asteroids of the belt, they would represent about 4% of the mass of the Earth’s moon. That’s why NASA – and we – get so excited when you get to capture an asteroid colliding with another.
5Myth: Astrology can predict your personality or the future
Would not it be great to have a look at tomorrow based on something as simple as where the Sun, the planets and the Moon were when you were born? It is what astrology claims and what half the world believes -at least in part- (and at the same time it is an incredible business). However, the exhaustive scientific investigations of astrology have failed, again and again, always. It is impossible to support any prediction of an astrological sign or horoscope. A 1985 study published in the journal Nature was especially notable. In that experiment, the scientists used a non-biased, double-blind protocol and worked together with some of the best astrologers in the United States to assess the predictive power of astrological signs. The results? Astrological predictions were no better than chance. So no, astrology does not predict your future or your personality.
6Myth: Black holes are cosmic vacuums
The black holes are bound contractually to appear in all literary and audiovisual times in the field of science fiction because of its mysterious, powerful and still quite unknown character. From the black hole that destroys the planet Vulcano in Star Trek by JJ Abrams to those of Stargate SG-1 and Doctor Who, the black hole is usually portrayed as an inescapable vortex of destruction, which absorbs our universe through a cosmic straw. The reality is that while black holes are certainly frightening, they are not as powerful as most people think. We forget that, however great they may be, they still have mass. This means that no matter how big and strong they may seem, they also have a finite force. In other words, a black hole is like any other object in the universe, since its gravitational attraction can only be as powerful as its mass allows. If it is the mass of the sun, its attraction is the same as that of the sun. No more no less.
7Myth: A nuclear weapon could destroy an asteroid
We regret it (again here science fiction is the big responsible), but throwing a nuclear weapon at an asteroid would not vaporize the rock. Most asteroids are piles of debris, so a powerful explosion would simply make it break even more. It would be like turning a single bullet into a shotgun blast. It does not seem like such a good idea if we want to save the planet, right? However, some researchers think that a well-directed and intelligently designed nuclear attack could radiate the surface of an asteroid, vaporize part of the rock and shoot gases that would push an asteroid out of its orbit coincident with the planet.
8Myth: When calling someone, the signal bounces on a satellite
This approach is true for satellite phones (which the army uses every day), but our smartphones work in a very different way. The mobile phones emit a wireless radio signal and constantly seek, ping broadcast and retransmit data to and from terrestrial towers. When we make a call, the nearest tower connects it to another telephone through a wide network of tower to tower connections and buried cables . In the best case, a satellite could be involved in a call around the world, but you must know that 99% of international communications data travels through submarine cables.
9Myth: The Great Wall of China is visible from space
We have discussed it at the beginning. It is one of the most widespread myths around the globe. It’s false. Astronauts like Neil Armstrong who after his trip to the Moon said he could not distinguish any structure made by man from there or Jeffrey Hoffman have provided their testimony. But it did not seem to be enough. The myth was widespread. An image from the International Space Station should have clarified the doubts, because the Great Wall of China is priceless from there. What is visible from the ISS are the Egyptian pyramids of the Sahara desert.
10Myth: Jupiter orbits the Sun like the other planets
Jupiter is so large that it does not actually orbit around the Sun. It has a mass that is 318 times that of Earth, or 2.5 times the mass that all the other planets add together. Its enormous size causes that the center of gravity between the Sun and he himself is not located in the Sun, but beyond the surface of our star (just above the surface of the Sun). This circumstance causes that Jupiter does not orbit around the Sun (not exactly, as we see), but the Sun and Jupiter orbit the two their common center of mass or barycenter, the center of gravity of these bodies. Thus, both the Sun and Jupiter orbit around that point in space.
11Myth: Nobody really knows how gravity works
The forces that affect our universe: gravity, governed by Einstein’s General Relativity and electromagnetic forces, weak and strong, described by the quantum field theory, are easy to observe and measure. The underlying theories are separated, with General Relativity describing the relationship between matter and energy with the curvature of space and time, and the theory of the quantum field that describes the interactions between particles that occur in that space-time. We may worry that gravity must be intrinsically a quantum force in nature, and that there must be gravitons that mediate that interaction, but the purpose of science is to explain the observations and General Relativity does it with all of them to the limits of what we are able to observe. Each theory has a limit in its range of validity; so general relativity will break down at some point. Although we hope that one day it will be replaced by a quantum description of gravity, our image of curved space-time affected by matter and energy, where curved space-time determines the paths of objects, is fundamentally valid in the most important sense: it perfectly describes every observation we can conceive.
12Myth: The Earth is a perfect sphere
It is probably one of the oldest myths. The Earth rotates at approximately a. 1,700 kilometers per hour and orbits the Sun at a speed of 107.00 kilometers per hour. This inertia slightly flattens the poles of the planet and causes a bulge around the equator. Due to global warming and the melting of glaciers (and, therefore, less weight pushing down on the crust), scientists think that this bulge is growing, although it should be decreasing as the rotation of the Earth decreases in a fraction of a second each year.
13Myth: Mount Everest is the highest mountain on Earth
Technically the highest mountain in the world is not Mount Everest. Everest is the highest mountain above sea level, but if we talk about the height of a mountain to the summit, then the highest is the island of Hawaii that reaches its peak as Mauna Kea, the inactive volcano. Everest rises 8,848 meters above sea level but since most of the volcano is underwater (in total it would be approximately 10,000 meters) it can be considered the highest mountain in the world.
14Myth: There is a “dark side” of the moon
It is easy to think that the other side of the moon is dark, since we never see it, but it goes through the same lunar phases as the closest side, which is oriented towards the Earth, but the other way around. When there is a new moon (and very dark) on the side closest to the Earth, for example, it means that there is a full moon on the other side. We just can not see it from our point of view. So the answer would be that there is a “dark side” of the moon, but it moves. In the stage of formation of the Moon there was a temperature difference between the two faces that remained for quite some time, hence the creation of both faces is so disparate.
15Myth: In summer it is warmer because the Earth is closer to the Sun
When it is summer in the northern hemisphere, the Earth is no closer to the sun. In fact, it is just the opposite: the planet is at its furthest point from the sun during the summer. It is warmer during the summer because the Earth is tilted. During its orbit, the inclination of our home planet allows the sun’s energy to hit us more directly.
16Myth: Nothing can go faster than light
Without obstacles, light can move at 299,792,458 meters per second in a vacuum. But it slows down when traveling through different substances. For example, light moves 25% slower through water and 59% slower through the diamond.
Particles such as electrons, neutrons or neutrinos can outperform photons of light in these materials, although they have to purge energy as radiation when they do so.
So yes, we can break the light barrier, but not in the way we see in the movies. In fact, there are several ways to travel faster than light. For example, the Big Bang itself expanded much faster than the speed of light. Quantum entanglement also moves faster than light. If I have two electrons very close together, they can vibrate in unison, according to quantum theory. If I then separate them, an invisible umbilical cord emerges that connects the two electrons, although they may be separated by many light years. If I shake an electron, the other electron “detects” this vibration instantly, faster than the speed of light. Einstein thought that this, therefore, refuted quantum theory, since ‘nothing can go faster than light’. This is because the information that breaks the light barrier is random and therefore, useless.
17Myth: The Earth is flat
Despite the current terraplanists, our erudite ancestors during the High Middle Ages, for example, thought that the Earth was round, not flat. Where the incredible myth that the Earth is flat comes? This myth gained strength in the 1800s, just as the idea of evolution was on the rise and religious and scientific interests clashed. The idea spread during the first half of the twentieth century and the fact that even with infinite scientific evidence there are people defending this tremendous stolidity, serves to show how civilization has been and is so guilty of abusing its intellectual authority and taking advantage of laziness and ignorance of others. With simple arguments based on common sense we can dismantle any of the Terraplanist theories.
18Myth: Lightning causes thunder
Thunder and lightning are two different manifestations but associated with the same meteorological phenomenon: storms. The beam is just a stream of electrons, the electric discharge that occurs in a short period of time. Thunder, on the other hand, is the noise that is formed by the rapid expansion and contraction of nearby air, creating a crack and an unmistakable roar.
19Myth: There are only three states of matter
Solid, liquid and gaseous? We can not forget the plasma. It is easy to assume that solids are the most abundant form of matter in the cosmos, since we all live in a giant rock. But plasma is much more abundant: the stars, including our Sun, are giant spheres of bright plasma. There are also many more phases of matter, such as supercritical fluids, that occur on the surface of Venus. In summary, solid (fixed matter), liquid (fluid), gaseous (gases), plasma (hot and ionized gases) and Bose-Einstein condensate (gaseous superfluids cooled to temperatures close to absolute zero), would be the main ones.
20Myth: If you go out without a suit into space, you explode
We will all remember the scene in the sci-fi movie Total Challenge in which Arnold Schwarzenegger’s eyes get out of their sockets for being in space without a suit. Well, that has nothing to do with what would really happen to our body in space.
Most assume that if the pressure outside an object is greater than the pressure inside, the object will explode like a balloon in the upper atmosphere. So, if you take a human out of the pressure of our atmosphere, after a few seconds, it will explode. Well, no. The reality was best drawn by Stanley Kubrick in 2001: Odyssey in spacewhen astronaut Bowman completely survives a spacewalk without a helmet. He could not breathe, of course, but his head was not going to explode like a balloon.
Fortunately, our skin and circulatory system do an incredible job of protecting our body from the effect of explosive decompression.
So the main dangers of not having the proper space suit -objecting temperatures- are fundamentally related to oxygen: breathing, naturally, and also containing the air in the lungs. Nor would we last long watching the show, since a person / astronaut would be unconscious in 15 seconds.