Universe is full of unexplained mysteries (Image source: NASA)

According to scientific legends, the British physicist Lord Kelvin said in 1900 that there was nothing more to be discovered by physics at that time and that thereafter science could only be perfected with increasingly accurate measurements. However, it took a few decades for Kelvin's statement to be refuted.

During the first half of the twentieth century, the foundations of Quantum Physics began to be built by such powerful names as Einstein, Planck, Bohr, and Heinsenberg. After that, nobody ventured to repeat that we already know everything about the universe. And, increasingly, scientific advances open new areas that need to be understood.

Want a test? For then we go to some mysteries that are not yet fully understood by science.

1. Dark energy and our universe

Even though gravity pushes everything to the center of our universe, it continues to expand. To explain this, astrophysicists have suggested the presence of an invisible energy that opposes the force of gravity.

Known as dark energy, this cosmological constant is taken as an inherent property of space itself. As space expands, more space is created and hence more dark energy.

And that's not all. Based on observations of the universe's rate of expansion, scientists estimate that more than 70 percent of the universe is composed of dark energy. However, no one knows how to actually ascertain the presence of this energy.

2. Dark matter makes up 84% of the universe

One more curiosity about our universe: 84% of the matter present in our universe does not emit or even absorb light. Dark matter, as it is called, cannot be seen directly and could not yet be detected indirectly. However, scientists believe in the existence of this matter thanks to the gravitational effects that act on the radiation and structure of the universe, besides visible matter.

Dark blue matter circling the Milky Way (Image source: ESO / L. Sidewalk)

This type of matter is believed to be composed of particles known as WIMPs, which stands for “Weakly Interacting Massive Particles, ” in free translation. However, so far none of these particles have been detected.

3. Are there parallel universes?

Expansion and creation of new universes: the red X indicates the end of inflation (Image Source: Starts With a Bang)

And as if we no longer had enough problems here on Earth, scientists have come up with the concept of multiverse, that is, several parallel universes coexisting without contact with each other. If you want to know more about one of the theories that support this idea, read the article "Parallel Universes: What the hell is this?"

4. Why is there more matter than antimatter?

This is one of the questions whose answer is far from being answered. We know that when a particle of matter meets its counterpart, the two disappear. However, many believe that during the Big Bang, the same amount of matter and antimatter was formed.

But if that really happened, protons would have been annihilated with antiprotons, neutrons with antineutons, and so on. The universe would not have been created and you would not be here reading this article. So there is speculation that there is much more matter than antimatter in the universe. But if this is true, no one can explain how or why it all happened that way.

5. The fate of the universe

The universe is expanding. But will this process have an end? Well, there are some answers to this possibility, and basically it depends on a variable whose value is unknown: the measurement of the density of matter and energy in space. From this it would be possible to clearly stipulate the shape of the universe.

Dark energy can define the future of the universe (Image source: NASA)

The universe can be closed, like the shape of a sphere, and if there is no such dark energy, it will eventually begin to shrink again, in reverse of the Big Bang process known as the Big Crunch. If dark energy does exist, this spherical universe will expand eternally.

Alternatively, the universe may be curved and open, like the surface of a saddle for riding horses. If this is the case, the universe may be heading for two processes known as Big Freeze and Big Rip, that is, first, the acceleration of the universe will eventually destroy galaxies and stars, leaving cold and abandoned matter. Then the acceleration would grow so high that it could even surpass the force that holds the elements of an atom in place, completely destroying it.

Timeline of our universe since its inception (Image source: NASA)

Finally, the universe can have a planar structure, similar to a table that expands in all directions. If dark energy does not exist in this model, the universe would slowly reduce the acceleration of its expansion until it completely stops. But if dark energy exists, everything would be destroyed with the Big Rip.

6. Measurements Destroy Quantum Waves

The subatomic world is strange. The laws of physics are different and everything behaves quite oddly by our standards. To begin with, particles do not behave as small spheres, but as waves that occupy a certain area. Thus, properties such as location and velocity of a particle are measured in probabilities, a value range that the particle can occupy.

However, the unexpected happens when someone tries to accurately measure one of its properties: the particle is no longer a wave function but only one location or velocity, for example. But how and why this wave breaks, no one knows.

Source: Life's Little Mysteries

* Originally posted on 05/07/2012.