Understanding the Cosmos

What is Cosmos ?

The Universe seen as a well-ordered whole.

 This blog is all about the theory and understanding of the entire existence.

Starting off the blog by appreciating the contribution to the study of physics by all the wonderful human beings.

What I personally believe is that the ultimate goal for we humans should always be to try to make sense of what we see and wonder about what makes the universe exist in the first place. Be curious.

We are just an advanced breed of monkeys on a minor planet of a very average star. But we can understand the universe. That makes us something very special. Stephen Hawking

My goal is simple. It is a complete understanding of the universe, why it is as it is and why it exists it all. Stephen Hawking

It makes us special because of the curiosity which is inbuilt in us, from the birth till the last moment of our lives. The questions of WHY and HOW are what we seek for.

The HOW questions are answered by the following branches of physics

• Classical mechanics
• Thermodynamics and statistical mechanics
• Electromagnetism and electronics
• Relativity
• Quantum mechanics
• Optics, and atomic, molecular, and optical physics
• Condensed matter physics
• High energy/particle physics and nuclear physics
• Interdisciplinary fields

The WHY questions are answered by the following

• Relativity
• Quantum mechanics
• Cosmology

As the answers for all the HOW questions are answered by the topics which everybody is familiar with, because of the most common syllabus in all the schools and colleges all around the world, I’m here to talk and discuss about all the WHY questions of physics.

THE COSMOLOGICAL PRINCIPLE​ Any observer in any galaxy sees the same general features of the universe as any other. Based upon:​

• Homogeneity: Matter is uniformly spread throughout space.​

• Isotropy: The universe looks the same no matter in which direction one looks.​

• Universality: The laws of physics that work on Earth work the same in every part of the universe.​

RED-SHIFTED LIGHT​ Red-Shifted light from galaxies means that the galaxies are receding from us.​

• Hubble’s Law shows that the radial velocity of a galaxy is proportional to its distance.​
• This observation is explained by assuming that the entire universe is expanding.​

BIG BANG THEORY​ Big Bang Theory: When the expanding universe picture is run backward, it leads to a point of common origin for all matter in the universe. This point of common origin is the Big Bang, where everything in the known universe was created in a single instant. Because time and space also originated in the Big Bang, it is not possible to state that any specific location of space is where the Big Bang occurred. Every point in the universe was there when the Big Bang happened. Thus, every point in the universe is where the Big Bang happened.​ EXPERIMENTAL VERIFICATION​ The cosmic microwave background radiation is the echo of the Big Bang. When the Big Bang occurred, it sent an enormous electromagnetic wave out into the universe. As the universe expanded, the wave itself was stretched-out, much like a phone cord is stretched as you walk away from the base. The stretched-out wave would be very long and have very low energy. Two scientists, A. Penzias and R. Wilson, discovered this radiation, and we therefore have experimental verification of the Big Bang.​

Black Holes​

A black hole is a region of spacetime exhibiting such strong gravitational effects that nothing—not even particles and electromagnetic radiation such as light—can escape from inside it. The theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole. ​ Time does not exist in a Black Hole. And that’s exactly what happened during the start of the universe. The role played by the time at the beginning of the universe is the final key to remove the need for a grand designer and revealing how the universe created itself.​ THEORIES THAT DEAL WITH THE FUTURE OF THE UNIVERSE​

• Critical Density: If the universe has the density 4×10(-30) g/cm(3), then the universe will continue expanding forever.​
• Expanding Universe: If the universe has a density less than the critical density, which it does according to current scientific theory, then the universe will keep expanding forever.​
• Big Crunch: If the universe has a density greater than the critical density, then the collective gravity of all the matter in the universe will cause it to stop expanding and begin to contract. One variation of the Big Crunch theory is that after the universe collapses, it bounces back in another Big Bang. This idea, known as the oscillating universe theory, is not generally accepted because the oscillations would lose a great deal of energy to entropy.​

Heat Death​

The heat death of the universe is a plausible ultimate fate of the universe in which the universe has evolved to a state of no thermodynamic free energy and therefore can no longer sustain processes that increase entropy.​ In roughly one billion years the sun will be so hot that life on earth becomes impossible. The death of the sun in 4 billion years later marks the end of life in the solar system.​ In the next 100 billion years, most of the biggest stars around the world will die. Only red and white dwarfs will be left and eventually they will also die.

The fact that we humans, who are ourselves mere collections of fundamental particles of nature, have been able to come this close to an understanding of the laws governing us and our universe, is a great triumph. Stephen Hawking

WE HAVE THIS ONE LIFE TO APPRECIATE THE GRAND DESIGN OF OUR WONDERFUL UNIVERSE AND FOR THAT, I’M GRATEFUL.​ Thank You ❤ ​