1) The Big Bang was a huge explosion.
When people are told about a Big Bang they are imagining something like this:
However the Big Bang was not an explosion in space like in this pic, it was a rapid expansion of space itself. Thus it does not have any center and we cant actually imagine it.
2) Universe is a sphere with ~13 bln light year radius.
Its linked to previous point. We know that universe is ~13 bln years old. Thus many people think that its expanded from the bing bang to a sphere with 13 bln light years diameter. But as I noted it was not an explosion. U cant show a point in universe where the Big Bang happened. Simply the space between the galaxies is expanding. Thus the more far is a galaxy the faster it is moving away from us and there is no speed limit. Very distant galaxies are moving from us faster than light! No one knows the actual size of the universe and its shape. We only know its much much larger than sphere with13 bln light years radius, maybe its infinite.
3) Nebulas are dense clouds in space.
In sci fi nebulas usualy look like this, you can hide ur spacecraft inside:
View attachment 287289
In fact the density of nebulas is extremely low: most dense one have only about 10,000 atoms per cm3. For comparison space at LEO orbit where most satellites are flying has MILLIONS atoms per cm3. From close range u wont see a nebula at all.
4) Flying through asteroid belt is very dangerous.
This misconception is similar to above. Flying through asteroid belt looks like this in sci fi:
Although there are billions of asteroids in asteroid belt, the space is so huge that the average distance between two asteroid is hundreds of thousands km.
5) The asteroid belt might be an exploded planet.
The total weight of asteroid belt is less than 1/2000 of earth's. If u merge all asteroids together they will form a tiny moon, much smaller than our own.
6) Black holes are like giant vacuum cleaners which suck everything around them.
In order to notice the gravitational difference between the black hole and star of same mass u need to come very very close (to star radius). Thus is sun magically collapses into a black hole we wont notice any difference except the lack of light and heat. The orbit will remain the same.
7) Our galaxy rotates because of a giant black hole in its center.
In the center of our galaxy there is indeed a supermassive black hole with mass of 4 million sun. But the milky way galaxy has mass of over trillion suns. If u remove a black hole from our galaxy it will keep rotating as before. Supermassive black hole does not affect the galaxy rotation at all.
8) The moon color is yellow/whitish.
The albedo (reflection rate) of the moon in visual light is only 7%. That's very dark grey close to black. The moon seems bright only compare to black space. If moon was yellow it would be many times brighter.
9) The Sun is yellow.
The sun emits all spectrum of colors, but the peak lies in green! But our eye sees it as clear white in space. And on earth because of atmosphere it seems yellowish to our eyes.
10) Our Sun is very small star.
Although there are stars much much bigger than our sun, the average size of stars in universe is much smaller than our sun.
11) Winter is colder because the orbit is oval and we are further from the sun then.
Winters are colder because of inclination of the earth. In fact in Northern hemisphere we are actually closer to the sun in winters.
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You can add other misconceptions u know.
