Nothing in our Universe stands still: the Earth orbits the Sun, the Sun surrounds the galaxy, and even the galaxies are in constant motion. So why is everything in space moving?
It all comes down to how the Universe and the objects in it were created, Edward Gomez, astrophysicist and director of education at the Las Cumbres Observatory in California, USA, told Live Science.
Scientists believe that the Universe began with the Big Bang, an ultra-rapid expansion from a single infinitely dense point that eventually led to the formation of everything we see today.
“From the very beginning of the Universe, it began to expand outward as the force from the Big Bang pushed everything apart,” Gomez said.
“It’s kind of a fingerprint of the beginning,” said Carol Christian, an astrophysicist and project scientist for the Hubble Space Telescope at the Space Telescope Science Institute in Baltimore. “The beginning was motion, and thus motion was incorporated into the Universe from the beginning.”
Nothing in the Universe stands still
So one of the reasons why everything in space is moving is because the Universe is expanding. But this expansion has effects only on very large scales.
“We only see it really happening for things that are very far away, because it’s not necessarily that these objects are moving through space,” Gomez said. “It’s about the space between objects getting bigger.”
At smaller scales, however, rotation is the motion that governs objects in space, he writes LiveScience.
When two objects in space come close, their mutual gravity pulls them towards each other, and unless they collide or fly in different directions, they tend to orbit each other. This phenomenon affects everything from the smallest mineral grains to the largest galaxies.
The universe is expanding
This is why the planets in the Solar System orbit the sun: The Solar System began as a spinning mass of gas and dust that eventually turned into a star and planets. Along the way, the angular momentum caused the system to never stop rotating.
But the rotation effect of a galaxy occurs differently than you would expect just from the things we can see.
Dark matter doesn’t interact with light, so we can’t see it with telescopes. However, it has mass and interacts with other objects that have mass through gravitational effects. Dark matter also exhibits kinetic momentum. This is another reason why all things in space move.
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Source: www.descopera.ro
