Frequent misconceptions about space.


We continue a series of publications about common misconceptions about space, the universe, astronomy and cosmonautics. In this post, we’ll cover some new common misconceptions.

The big bang model, in a very simplified form, is the idea that our universe has been expanding and cooling over the course of its history from its original extremely hot and compressed state.

At the same time, the analogy between an ordinary explosion, in which matter scatters from one point, is erroneous. So looking from the Earth, we see that the vast majority of galaxies have a redshift, i.e. this means that they fly away from us. However, if we were in one of these galaxies, we would see exactly the same picture. The answer to the question of where the big bang point is is: «everywhere.»

Another common misconception is that the «big bang theory» is just a theory without proof. In fact, the «Big Bang Theory» is an American comic television series, and the modern cosmological model, which uses the concept of the Big Bang, is called the ΛCDM model.

The arguments in favor of this model are so wide, numerous and varied that this model / hypothesis is as close to what it actually is as it is generally possible at the current level of development of science.

Confirmation and evidence include, among other things: the detection of relic radiation, the chemical composition of the universe, the expansion and accelerated expansion of the universe, features of the large-scale structure of the universe, the discovery of fluctuations in the relic radiation, and much more.

At the same time, further research, testing and development of new cosmological models are constantly being carried out, but so far no one has succeeded in creating a model that would fit into the entire huge array of observational and experimental data better than the ΛCDM model.

Some time ago, a gif began circulating on the Internet illustrating the supposedly real shape of the Earth, if you remove all the oceans from it. Say the shape of the Earth is not a ball or an ellipsoid, but a geoid resembling a potato and looking something like this:

In fact, the gif above does not at all illustrate the real shape of the Earth. It really shows a geoid — a mathematical model that serves to illustrate and describe the inhomogeneities of the Earth’s gravity. So on the gif in the areas colored in blue, the force of gravity is lower, in the areas colored in red — higher.

The average radius of the Earth is 6371 kilometers, the highest point on the Earth rises 8 kilometers above sea level, and the deepest one falls 11 kilometers below sea level. These deviations are approximately 0.1% of the radius.

The Earth, of course, is not a perfect ball and is slightly flattened at the poles, but again, this deviation is insignificant. The difference between the equatorial and polar radii of the Earth is 21.3 kilometers, i.e. about 0.33% of the average radius.

These deviations are so small that it is almost impossible to distinguish them with the naked eye. For comparison, the average height of bumps on a basketball is 1.5 millimeters, which is about 1.25% of the radius of a basketball. If there was a mountain of the same height on Earth, then it would be more than 11 times higher than Everest.

To be continued.