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How Many Galaxies Are There in the Universe?

Estimates among experts vary. One estimate done by Mario Livio, an astrophysicist at the Space Telescope Science Institute in Baltimore, Maryland, puts the number between 100 billion and 200 billion galaxies. However, more recent data seems to suggest there could be as many as two trillion galaxies in the universe.


What Are the Largest Known Structures in the Universe?

Galaxy filaments, also called supercluster complexes, are the largest known structures in the universe. They consist of walls of gravitationally connected galaxy superclusters. These super large, thread-like formations can be 160 to 260 million light-years long. Interestingly they rotate and this kind of rotation on such a massive scale has been observed only recently.

Why is it Called the Solar System?

Our planetary system is named the “solar system” because our Sun was named after the Latin word for sun, “Sol”. Therefore, anything related to the Sun is called “solar”. 

What is an Atom?

Atoms are the tiny building blocks from which everything around us is made. They are the smallest unit of a chemical element. By small, think incredibly tiny; a single atom is hundreds of thousands of times thinner than a human hair. You have no chance of ever seeing one unless you have an incredibly powerful electron microscope. In ancient times, people thought an atom was the smallest possible thing in the world. In fact, the term atom comes from a Greek word meaning “something that cannot be split up any further”.

Atoms consist of smaller particles: protons and neutrons in the nucleus, and electrons circling around them. Elements, substances that generally cannot be simplified or broken down any further, are composed of one type of atom depending on the number of protons it contains. For example, an atom with 8 protons is the element Oxygen.

What is Dark Energy?

Dark energy is the name given to the mysterious quantity that’s causing the rate of expansion in our universe to accelerate over time, rather than to slow down. Dark energy makes up 74% of everything in the universe, yet scientists are unsure of what it is and how how it functions.

The properties of this unknown quantity are still unknown. One possibility is that dark energy is what the universe is filled with: a changing energy field, known as “quintessence.” Even today, Dark energy is one of the great unsolved mysteries of cosmology.

What is Dark Matter?

Dark matter does not interact with the electromagnetic force unlike normal matter. This means it does not absorb, reflect or emit light, making it extremely difficult to detect. In fact, researchers have been able to infer the existence of dark matter only from the gravitational effect it seems to have on visible matter. Dark matter seems to outweigh visible matter roughly six to one, making up about 22% of the universe.

What is Light?

The visible spectrum is the portion of the electromagnetic spectrum that is visible to the human eye. Electromagnetic radiation in this range of wavelengths is called visible light or simply light. The planet Earth is just a tiny speck in the Universe and is surrounded by lots of space. Light travels across this empty space which Astronomers use to gather information about the Universe.

What is a Black Hole?

A Black Hole is a cosmic area of extreme gravitational intensity that the fastest moving particles can not escape, hence the name ‘black’ hole. Black holes are some of the strangest and most fascinating objects in outer space. As of 2021, the nearest known area to contain a black hole is around 1,500 light-years away. Though only a couple dozen black holes have been discovered so far in the Milky Way, there are thought to be hundreds of millions of them in our galaxy.

What Does E=mc^2 Mean?

“E=mc2 means that, from the standpoint of physics, energy and mass are interchangeable. In the equation:

E is energy
m is mass
c is the speed of light

“In other words, energy equals mass times the speed of light squared.

“It sounds simple. And its simplicity might obscure the genius, and the innovation of thought, required of Einstein to express it all so elegantly. Mass and energy are interchangeable. Plus, a small amount of mass can equal a large amount of energy. After all, the speed of light is a huge number (186,000 miles per second or 300,000 km/s). And, in Einstein’s famous equation, that huge number is squared. So it doesn’t take much mathematical skill to see that a tiny mass can equal big energy.

“E=mc2 explains why the sun and other stars shine. In their interiors, atoms (mass) fuse together, creating the tremendous energy of the sun as described by Einstein’s famous equation.”

Source: — https://earthsky.org/

How Big is the Universe?

“[Today], the volume containing our observable Universe has expanded to be 46 billion light years in radius, with the light that’s first arriving at our eyes today corresponding to the limit of what we can measure.”

Source —Forbes Magazine

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