The mechanical universe - 34 - magnetism .

Lesson 34: Magnets William Gilbert, personal physician by appointment to her Majesty Queen Elizabeth I of England, discovered that the earth behaves like a giant magnet. Magnetism as a natural phenomenon, the behavior of magnetic materials, and the motion of charged particles in a magnetic field.

Instructional Objectives

* Be able to calculate the magnetic force on a current element and on a moving charge in a given magnetic field.
* Know the definition of torque and potential energy for a magnetic dipole.
* Be able to explain the concept of domains in ferromagnetic materials.
* Be able to use the definition of magnetic flux and discuss the significance of the result that the net magnetic flux out of a closed surface is zero.
* Be able to calculate the magnetic moment of a current loop and the torque exerted on a current loop in a magnetic field.
* Be able to discuss the magnetism of the Earth.

This series helps teachers demystify physics by showing students what it looks like. Field trips to hot-air balloon events, symphony concerts, bicycle shops, and other locales make complex concepts more accessible. Inventive computer graphics illustrate abstract concepts such as time, force, and capacitance, while historical reenactments of the studies of Newton, Leibniz, Maxwell, and others trace the evolution of theories.

The Mechanical Universe helps meet different students' needs, from the basic requirements of liberal arts students to the rigorous demands of science and engineering majors. This series is also valuable for teacher professional development. Produced by the California Institute of Technology and Intelecom.


Caltech: The Mechanical Universe - 34 - Magnetism.

Obsessed & Scientific?

Is time travel possible? In this fascinating short documentary, director Jay Cheel explores the real-life theories behind the science of time travel and the strange subculture of enthusiasts who are obessed with it.

Meet Michio Kaku, world-renowned theoretical physicist and author of the book Hyperspace. Meet Rob Niosi, a hobbyist building his own full-scale home replica of H.G. Wells' time machine. Meet Larry Haber, the entertainment lawyer representing the family of John Titor, an alleged time traveller from the year 2036. Do these people know something about the world that the rest of us don't?

Obessed & Scientific is a quirky look at the intersection of science-fact and science-fiction.

Obsessed & Scientific?

Horizon - Nuclear fusion.

In March 2002, the scientific world was rocked by some astonishing news: a distinguished US government scientist, Rusi Taleyarkhan, claimed he had made nuclear fusion out of sound waves in his laboratory.

Taleyarkhan's fusion breakthrough was based on a little-understood process called sonoluminescence. It's a process that magically transforms sound waves into flashes of light, focusing the sound energy into a tiny flickering hot spot inside a bubble. It's been called the star in a jar.

The star in a jar effortlessly reaches temperatures of tens of thousands of degrees, hotter than the surface of the sun. Many scientists had wondered if the core of the bubble was even hotter – maybe even as hot as the core of the sun. If so, fusion would happen there. But until Taleyarkhan, no one had been able to either prove it or disprove it.

Horizon - Nuclear fusion.

Einstein and his equation E=mc2.

The history behind how this equation could be invented..and who all played their role in inventing this wonderful and powerful equation which can destroy the world or also make the whole world glow.

Einstein and his equation E=mc2.

Doppler effect & The Big Bang.

This lecture is part of a serie of 36 video lectures on Electricity and Magnetism, by Professor Walter Lewin, they were recorded on the MIT campus during the Spring of 2002. Prof. Lewin is well-known at MIT and beyond for his dynamic and engaging lecture style.

The Big Bang is a cosmological model of the universe that has become well supported by several independent observations. After Edwin Hubble discovered that galactic distances were generally proportional to their redshifts in 1929, this observation was taken to indicate that the universe is expanding.

Ironically, the term 'Big Bang' was first coined by Fred Hoyle in a derisory statement seeking to belittle the credibility of the theory that he did not believe to be true. However, the discovery of the cosmic microwave background in 1964 was taken as almost undeniable support for the Big Bang.

Analysis of the spectrum of light from distant galaxies reveals a shift towards longer wavelengths (Doppler effect) proportional to each galaxy's distance in a relationship described by Hubble's law, which is taken to indicate that the universe is undergoing a continuous expansion.

Lecture 35: Doppler effect & The Big Bang.

Einstein’s unfinished symphony.

As Albert Einstein lay on his deathbed, he asked only for his glasses, his writing implements and his latest equations. He knew he was dying, yet he continued his work. In those final hours of his life, while fading in and out of consciousness, he was working on what he hoped would be his greatest work of all. It was a project of monumental complexity. It was a project that he hoped would unlock the mind of god.

Einstein’s unfinished symphony.

Mathematical infinity and human destiny.

There are two approaches to mathematical infinity. It can be seen as defining limiting cases that can never be realized or as existing in some philosophical sense. These mathematical approaches parallel approaches to meaning and value that we can call absolutist and evolutionary. The absolutist sees ultimate meaning as something that exists most commonly in the form of an all powerful infinite god.

The evolutionary sees life and all of a creation as an ever expanding journey with no ultimate or final goal. There is only the journey. There is no destination. This video argues for an evolutionary view in our sense of meaning and values and in our mathematical understanding. There is a deep connection between the two with profound implications for the evolution of consciousness and human destiny.

Mathematical infinity and human destiny.

What on earth is wrong with gravity?

Particle physicist and ex D:Ream keyboardist Dr. Brian Cox believes that the answer to the meaning of the universe lies in gravity. On a road trip across the USA, Brian fires lasers at the moon in Texas and goes wild in the desert in Arizona. He encounters the bending of space and time at a maximum security military base and tries to detect ripples in our reality in the swamps of Louisiana.

Horizon - What on earth is wrong with gravity?

Richard Muller - Atoms and heat.

Lecture by Professor Richard Muller of the University California, Berkeley. Taken from Lecture 26 of the spring 2006 webcasts of Physics For Future Presidents. Also known as Descriptive Introduction to Physics. Empahsis is on conceptual understanding, rather than mathematics.

Richard Muller - Atoms and heat