What comes to mind when you think about space? Imagine a friend bragging about a large building, stadium, or museum they recently visited. Do you think the building is vast and expansive? Is it just very large, or does it seem empty?
The word ‘vast’ does not necessarily mean empty. It simply means that there is enough space for objects to move around in it. Likewise, space is not completely empty. It is vast and extends forever, but there is a lot of stuff in it.
As a child, I wondered about questions like how far away the clouds are, what lies beyond the Earth, and how vast the universe is. This curiosity led me to earn my master’s and doctorate degrees in astronomy. I have been teaching these concepts for 20 years. Physics professor At the University of Texas at Arlington.
Where does the universe begin?
The Earth is surrounded by several layers of different gases. At sea level, The Earth’s atmosphere contains: About 100 billion molecules per cubic centimeter. As we ascend, the atmosphere becomes thinner.
At altitudes of about 50 to 62 miles (80 to 100 km), there is not enough air. For the plane to fly. This boundary separating the Earth’s atmosphere and outer space It’s called the Karman line.Named after the Hungarian-American engineer and physicist Theodor von KarmanEverything above the Karman line is called space.
The density of the universe can vary, but on average it is about one atom per cubic centimeter. Imagine this: a cube the size of a dice in the Earth’s atmosphere contains billions of air particles. But in space, a cube the size of a dice contains only one or two particles.
Interstellar matter and radiation
Space or outer space is almost a perfect vacuum, there is almost nothing there. Of the substance. This vacuum has very few particles compared to Earth’s atmosphere, but it is not completely empty.
The universe is filled with scattered matter It’s called interstellar mediumContains hydrogen and helium atoms. These are the most common elements in the universe, and exist in both charged and neutral forms. Interstellar matter is also Contains cosmic dust – Tiny particles of various elements, including carbon and silicon, are scattered throughout the universe.
high energy particles called a spaceship Mainly protons and Nucleus – Traveling through space at nearly the speed of light, the spacecraft passes through various stars, including our sun. Supernovaingredient Fall into a black hole, Colliding galaxies And many more.
The universe is filled with many different forms of radiation, including: cosmic microwave background radiation. This is the remaining heat from the origin of the universe, a high-energy cosmic event such as a supernova. Black hole also emit x-rays and Gamma rays.
Magnetic field The fields produced by stars, planets, and many other celestial bodies also permeate the universe. These fields act like magnets, attracting or repelling charged particles and influencing their movements.
Dark matter and dark energy
Scientists predict that: Forms of matter not yet visible Does not emit light or energy, It’s called dark matterIt makes up a significant portion of the universe’s mass. Researchers speculate that it exists because we can see its gravitational attraction to other visible matter.
Scientists predict similar things. Mysterious form of energy It’s called dark energy It is driving the accelerated expansion of the universe. dark matter, dark energy It has nothing to do with matter or gravity, but is a property of space itself.
Imagine the universe as a balloon. Dark matter is like the material of the balloon, affecting its shape, and dark energy is like the air pumped into the balloon. It doesn’t change the material of the balloon, but it affects how fast the balloon expands.
Can space be warped? Can gravity warp space?
Space can also be curved. Imagine space as a large, stretchy trampoline. If you put a heavy ball, such as a bowling ball, in the center of the trampoline, it will create a large depression. This depression is similar to the way space curves around large objects, such as planets or stars. The larger the ball, the stronger the gravity and the deeper the depression.
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If you place a bowling ball in the center and roll a small marble over the trampoline, the marble will start to circle the depression created by the bowling ball’s gravity. The marble will follow the curve of the depression, just as the planets follow the curve of space around the sun.
Imagine shining a flashlight on a trampoline. As the light approaches the dent made by the bowling ball, it may bend slightly as it travels. This is similar to how light bends when passing by very large objects in space, such as galaxies.
Think about it Black holeIt has tremendous gravity, and it becomes a much larger and deeper depression on the trampoline. If you roll a marble too close to this very deep depression, it will fall and disappear. It’s like objects are being pulled in. Black hole Trapped in space, unable to escape.
So space can warp or bend around a large object with strong gravity, much like a trampoline bends when a heavy ball is released.
Space is more than just a void. It is a mixture of particles, radiation, magnetic fields, and mysterious forms of matter and energy. Imagine space as a three-dimensional playground, where objects such as stars, planets, nebulae, and galaxies exist, all of which together form our fascinating and complex universe.
Neelakshi ViravathinaProfessor of Physics Education, University of Texas at Arlington
This article was republished from conversation Under Creative Commons License. Read more Original article.
