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What are Virtual Particles? A 10 Minute Introduction

Definition/Summary Virtual particles are a mathematical device used in perturbation expansions of the S-operator (transition matrix) of interaction in quantum field theory. No virtual particle...

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What is the Double Slit? A 5 Minute Introduction

Definition/Summary The double-slit is a simple configuration used to demonstrate interference effects in waves. Equations At distances that are large compared to the spacing between the slits (i.e. the...

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What is the Moment of Inertia? A 10 Minute Introduction

Definition/Summary The moment of Inertia is a property of rigid bodies. It relates rotational force (torque) to rotational acceleration in the same way that mass relates ordinary (linear) force to...

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What is Potential Energy? A 5 Minute Introduction

Definition/Summary Potential energy is simply another name for (minus) the work done by a conservative force. Since the work-energy theorem states that change in energy minus work done is constant,...

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What is Mass Inflation? A 5 Minute Introduction

Definition/Summary Abstract from Poisson and Israel’s 1990 paper, ‘Internal structure of black holes’- ‘The gravitational effects associated with the radiative tail produced by a gravitational collapse...

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What is Impedance? A 5 Minute Introduction

Definition/Summary The impedance of a load (a combination of components) in an AC current is a complex number [itex]Z\ =\ R+jX[/itex] where [itex]R[/itex] is the resistance of the load and...

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What Are the Thermodynamics of Black Holes? A 5 Minute Introduction

Definition/Summary The four laws of black hole thermodynamics are as follows… The Zeroth Law Surface gravity [itex](\kappa)[/itex] is constant over a black holes event horizon. The First Law ‘This law...

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Why We Don’t Discuss Perpetual Motion Machines (PMM)

Authorship Contributions From Anorlunda You may want to believe the article you read, or the video you saw, or you may be very proud of your PMM invention.   It can be very difficult to analyze what is...

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Is there Evidence for the Big Bang?

Key Points Hubble‘s law (redshift of galaxies) and Doppler effect provides direct evidence for the universe expanding away from our reference point, implying the universe is expanding. Low temperatures...

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What Are Tensors and Why Are They Used in Relativity?

If you try learning general relativity, and sometimes special relativity, on your own, you will undoubtedly run into tensors. This article will outline what tensors are and why they are so important in...

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