Tuesday, June 16, 2020

How can I create my own theory of gravitation? Currently, I'm using differential equation

For starters, identify the problem that you wish to solve. Is it, e.g., galaxy rotation curves? The failure to detect dark matter/dark energy? The cosmological constant problem? Something else?

Second, identify your playground. Are you looking for a classical theory of gravitation, presumably an extension of Einstein’s theory of relativity? If so, would your theory respect, e.g., conservation laws or the weak equivalence principle? Or is your playground quantum physics and you’re looking for a quantum (field) theory of gravitation?

Third, identify the constraints. Existing theory works very well in most scenarios, and has been tested exquisitely well in some. Whatever modified theory of gravitation you come up with, it has to reproduce those successes in addition to its own claims.

Now notice that I have not said anything yet about the mathematical machinery. That would be putting the cart before a horse. Would you ever call a plumber to please, “do something with a wrench”? Or a car mechanic to please, do some screwdrivering? Of course not. You tell them what the job is. The job defines the tools, not the other way around.

Having said that, a pretty universal tool in the theorist’s toolchest is variational calculus and the principle of least action. Learn how to use these tools in the case of four dimensions, and in the case of a field theory. Understand what an expression like S=(16πG)1d4x(R+2Λ)g means, why the terms are there, what they do, and how varying this equation with respect to gμν leads to Einstein’s vacuum field equations. Understand what current modified theories do: e.g., scalar-tensor theories, f(R) theories, theories involving unit or arbitrary vector fields, etc. Understand why people tried these approaches and why they were not altogether successful.

Though it’s more than half a century old, recommended reading would be Feynman’s Lectures on Gravitation. That book provides an approach that is different from the usual perspective: instead of presenting gravitation as a theory of 4-dimensional geometry, Feynman approaches it from a particle physicist’s perspective. From it you learn why it is not viable to use anything less than a tensor (or spin-2) theory to describe gravitational phenomena. With that and a bit of grounding in quantum field theory, including non-Abelian gauge theories, you may be ready to take the plunge and study quantum field theory on a curved background, and think about why gravitation is special. Also, why it resists attempts to be “tamed” by way of renormalization.

At this point, mind you, you’d no longer be asking random strangers on Quora how you could create a theory of gravitation. You’d probably have informed ideas of your own.

Answered by Viktor. T.Toth



Tuesday, June 9, 2020

DON'T HATE PHYSICS

The reason you hate physics is because you learned it from the wrong teachers. What if you learned from the founders. Let Newton himself teach you how this game works. Click the link below:

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Monday, June 8, 2020

Quantum Gravity in a Nutshell2: Beyond Hawking-The Cosmic Quest for a Quantum Theory of Gravity

Beyond Hawking is a book in a series of quantum gravity in a nutshell that employees new ideas towards the development of a quantum theory of gravity in a bid to solve the major unsolved problems in physics. If you read it carefully and stop to think about the message as it unfolds then you will get a worthwhile if imperfect picture of what the theory is saying and how it was invented,It's buried treasure and you will have to do some digging.This wonderful and exciting book is optimal for physics graduate students and researchers. Not since Stephen W Hawking's celebrated best-seller Brief History of Time has physics been so vividly, intelligently and entertainingly revealed.

When you buy the book I get a commission which helps me write and search for other physics books just for you. Please click the link below to buy and support me.

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Astrophysics for People in a Hurry


Over a year on the New York Times bestseller list and more than a million copies sold.

The essential universe, from our most celebrated and beloved astrophysicist.

What is the nature of space and time? How do we fit within the universe? How does the universe fit within us? There’s no better guide through these mind-expanding questions than acclaimed astrophysicist and best-selling author Neil deGrasse Tyson.


But today, few of us have time to contemplate the cosmos. So Tyson brings the universe down to Earth succinctly and clearly, with sparkling wit, in tasty chapters consumable anytime and anywhere in your busy day.


While you wait for your morning coffee to brew, for the bus, the train, or a plane to arrive, Astrophysics for People in a Hurry will reveal just what you need to be fluent and ready for the next cosmic headlines: from the Big Bang to black holes, from quarks to quantum mechanics, and from the search for planets to the search for life in the universe.

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From School Library Journal

Celebrity scientist Tyson's profound intellect is matched by his charm and wit. In this slim title, he attempts to explain some of the most complex astrophysics concepts in layman's terms. Readers should be prepared for a challenging yet edifying experience from the get-go: "In the beginning…all the space and all the matter and all the energy of the known universe was contained in a volume less than one-trillionth the size of the period that ends this sentence." Tyson riffs on topics such as gravity, the speed and makeup of light, the shape of space, and dark matter, maintaining as chatty a tone as possible as he tries to make these important principles comprehensible to the uninitiated. VERDICT Likely to resonate the most with those with a scientific bent, but Tyson's pop culture appeal expands the audience somewhat.—Jamie Watson, Baltimore County Public Library

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About the Author

Neil deGrasse Tyson is an astrophysicist with the American Museum of Natural History, host of the hit radio and Emmy-nominated TV show StarTalk, and the New York Times best-selling author of Astrophysics for People in a Hurry and Accessory to War: The Unspoken Alliance Between Astrophysics and the Military. He lives in New York City.

Review

“Neil deGrasse Tyson makes a big bang with Astrophysics for People in a Hurry.”
- Sloane Crosley, Vanity Fair

“Tyson is a master of streamlining and simplification....taking mind-bogglingly complex ideas, stripping them down to their nuts and bolts, padding them with colorful allegories and dorky jokes, and making them accessible to the layperson”
Salon

“This book will keep you fascinated with succinct and dynamic explanations of a wide variety of astronomical topics. A winner that every astronomy enthusiast should have on the bookshelf!”
- David J. Eicher, Astronomy

“This may have been written for people in a hurry, but I urge you to take your time. It will all be over far too soon.”
BBC

“Engaging and illuminating.”
GoodReads

“Tyson manifests science brilliantly....[his] insights are valuable for any leader, teacher, scientist or educator.”
Forbes


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Astrophysics for People in a Hurry will blow your mind....it is awesome.”
Hackernoon

“Infectiously enthusiastic, humorous and, above all, accessible....reading Astrophysics for People in a Hurry is both a humbling and exhilarating experience.”
BookPage

Saturday, June 6, 2020

Mathematical Principles of Natural Philosophy by Sir Isaac Newton

It was Isaac Newton's Principia that founded the law of universal gravitation on 5th July 1687. It is the same principia that inspired Albert Einstein into formulating the Einstein field equations (the general relativity theory). It is still the same principia, I believe, will lead us to the quantum theory of gravity (Quantum gravity)

According to Newton’s Principia, the force of gravity governs the movement of bodies in the solar system. It is this simple mathematical law which determines the motion of bodies. The force of gravity accurately predicts the planetary orbits, it was used to put the first man on the moon, it predicts the return of comets, the rotation of galaxies, the solar eclipses, artificial satellites, satellite communications and television, the GPS and interplanetary probes. I almost forgot, it is why NASA was established in the first place.

Click the link below to by the book

https://www.amazon.com/Newtons-Principia-Mathematical-Principles-Philosophy-ebook/dp/B089QR2ZG3


You don't understand modern physics? Try this book

“There are grounds for cautious optimism that we may now be near the end of the search for the ultimate laws of nature.”
Stephen Hawking

“Nature uses only her longest threads to wave her patterns, so each small piece of her fabric reveals the organization of the entire tapestry.”
Richard Feynman

The major Unsolved problem in Physics

Our two foundational descriptions of nature, quantum mechanics and general relativity, are incompatible with each other.
When this conflict is resolved, a different view of reality may emerge that unifies matter, space, and time.

Cosmological observations are providing additional clues that our understanding of reality is in need of drastic modification.

Only 4% of the Universe energy content is known

23% is in the form of some unknown dark matter

73% is in the form of an unknown dark energy that is accelerating the expansion of the universe

The fundamental questions every physicist must answer:

1)What is the dark matter?
2)What is the nature of the dark energy?
3)How did the universe begin?
4)Did Einstein have the last word on gravity?
5)What are the masses of neutrinos and how have they shaped the evolution of the Universe?
6)Are protons unstable?
7)Are there new states of matter at exceedingly high density and temperature?
8)Are there additional space time dimensions?
9)How were the elements from iron to uranium made?
10)Is a new theory of matter and light needed at the highest energies?

In pursuing our quest to solve the above given fundamental questions in physics this book will:

1)Fulfill the innate Human desire to understand our place in the universe
2)Build the foundations for tomorrow’s breakthrough technologies
3)Unite Quantum mechanics with General relativity into a Quantum theory of gravity.


Monday, June 1, 2020

My Inventions: The Autobiography of Nikola Tesla

Nikola Tesla has been called the most important man of the twentieth century. Certainly, he contributed more to the field of electricity, radio, and television than any other person living or dead. Ultimately he died alone and impoverished having driven all of his friends away through his neurotic and eccentric behavior. Tesla was never able to fit into the world that he found himself in. This autobiography, originally serialized in 'Electrical Experimenter', is an intensely fascinating glimpse into the mind of a genius, his inventions, and the magical world in which he lived. To buy this book click the link below:

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#physics #quantummechanics #quantumgravity #science #education #phd #NASA #CERN #relativity #generalrelativitytheory #alberteinstein #stephenhawking #gravity #cosmology #astrophysics #richardpfeynman #nobelprize #books #forbes #neildegrassetyson #us #uk #trump #research #galaxies

Relativity: The Special and The General Theory A Popular Exposition


From his mind (A.Einstein) writes about his own theory and what it means for scientists and non scientists. You surely want to read the mind of a genius? Then look no further, this will make you think and understand Relativity like Einstein. Want to read? Click the link below

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A Dynamical Theory of the Electromagnetic Field by James Clerk Maxwell


In 1865 James Clerk Maxwell (1831 - 1879) published this work, "A Dynamical Theory of the Electromagnetic Field" demonstrating that electric and magnetic fields travel through space as waves moving at the speed of light. He proposed that light is an undulation in the same medium that is the cause of electric and magnetic phenomena. The unification of light and electrical phenomena led him to predict the existence of radio waves. Maxwell is also regarded as the founding scientist of the modern field of electrical engineering.

His discoveries helped usher in the era of modern physics, laying the foundation for such fields as special relativity and quantum mechanics. Many physicists regard Maxwell as the 19th-century scientist having the greatest influence on 20th-century physics. 

His contributions to physics are considered by many to be of the same magnitude as the ones of Isaac Newton and Albert Einstein.In this original treatise Maxwell introduces the best of his mind in seven parts, to include:

PART I.—INTRODUCTORY.
PART II. – ON ELECTROMAGNETIC INDUCTION.
PART III. – GENERAL EQUATIONS OF THE ELECTROMAGNETIC FIELD.
PART IV.— MECHANICAL ACTIONS IN THE FIELD.
PART V. — THEORY OF CONDENSERS.
PART VI. — ELECTROMAGNETIC THEORY OF LIGHT.
PART VII. — CALCULATION OF THE COEFFICIENTS OF ELECTROMAGNETIC INDUCTION.

To Buy this book ( $0.99), click the link below:

https://www.amazon.com/dp/B089F7VL1J