What is M-theory?

In less than 100 seconds, Leron Borsten explains how M-theory has the potential to unify the various forms of string theory with the theory of supergravity.

 

MAGNETS: How Do They Work?

How do magnets work? Why do they attract and repel at long distances? Is it magic? No... it's quantum mechanics, and a bit more, as we explain in this, the longest MinutePhysics video ever.

 

 Magnetism seems like a pretty magical phenomenon. Rocks that attract or repel each other at a distance - that's really cool - and electric current in a wire interacts in the same way. What's even more amazing is how it works. We normally think of special relativity as having little bearing on our lives because everything happens at such low speeds that relativistic effects are negligible. But when you consider the large number of charges in a wire and the strength of the electric interaction, you can see that electromagnets function thanks to the special relativistic effect of length contraction. In a frame of reference moving with the charges, there is an electric field that creates a force on the charges. But in the lab frame, there is no electric field so it must be a magnetic field creating the force. Hence we see that a magnetic field is what an electric field becomes when an electrically charged object starts moving.

 

NASA | Tracking Energy through Space

This short video features commentary by David Sibeck, project scientist for the THEMIS mission, discussing a visualization of reconnection fronts.

 Taking advantage of an unprecedented alignment of eight satellites through the vast magnetic environment that surrounds Earth in space, including NASA's ARTEMIS and THEMIS, scientists now have comprehensive details of the energy's journey through a process that forms the aurora, called a substorm.
Their results showed that small events unfolding over the course of a millisecond can result in energy flows that last up to half an hour and cover an area 10 times larger than Earth.

 Trying to understand how gigantic explosions on the sun can create space weather effects involves tracking energy from the original event all the way to Earth. It's not unlike keeping tabs on a character in a play with many costume changes, because the energy changes form frequently along its journey: magnetic energy causes eruptions that lead to kinetic energy as particles hurtle away, or thermal energy as the particles heat up. Near Earth, the energy can change through all these various forms once again.

 Most of the large and small features of substorms take place largely in the portion of Earth's magnetic environment called the magnetotail. Earth sits inside a large magnetic bubble called the magnetosphere. As Earth orbits around the sun, the solar wind from the sun streams past the bubble, stretching it outward into a teardrop. The magnetotail is the long point of the teardrop trailing out to more than 1 million miles on the night side of Earth. The moon orbits Earth much closer, some 240,000 miles away, crossing in and out of the magnetotail.

 

Hewitt-Drew-it! 65. Atmospheric Pressure

Applications of atmospheric pressure lead to the famed Magdeburg hemispheres.

 

How to Destroy a Magnet (+ interactive periodic table)

Magnets are amazingly strong... but there's a very easy way to destroy them. All you need to know is a little bit about ferromagnetism, paramagnetism, and temperature!

 

E=mc² is wrong? - Sixty Symbols

It's the most famous science equation in history... but E=mc² is not technically correct.

Modern Physics: Special Relativity (Stanford), Lecture 2

Lecture 2 of  Leonard Susskind's Modern Physics course concentrating on Special Relativity. Recorded April 21, 2008 at Stanford University.

 

Cavitation

Phillip Eisenberg, Hydronautics Inc.
National Committee for Fluid Mechanics Films

Film notes

Other videos from this series

Finding the Center of Mass...achusetts

A cutout of Massachusetts is hung in several orientations and a line is drawn straight downwards. The lines intersect at the center of mass.

 

NASA | Chasing Comet ISON

Comet ISON (C/2012 S1) may become a dazzling sight as it traverses the inner solar system in late 2013. During the weeks before its Nov. 28 close approach to the sun, the comet will be observable with small telescopes, and binoculars. Observatories around the world and in space will track the comet during its scorching trek around the sun. If ISON survives its searing solar passage, which seems likely but is not certain, the comet may be visible to the unaided eye in the pre-dawn sky during December.

This animation shows two views of comet ISON's path through the inner solar system. The first is a view following the comet along its orbit. The second is a view perpendicular to ISON's orbit. Like all comets, ISON is a clump of frozen gases mixed with dust. Often described as "dirty snowballs," comets emit gas and dust whenever they venture near enough to the sun that the icy material transforms from a solid to gas, a process called sublimation. Jets powered by sublimating ice also release dust, which reflects sunlight and brightens the comet.

 

Star Classification - Sixty Symbols

The Sun is designated as a "G2V" star. What does that mean?

 

A Capella Science - Bohemian Gravity!

A song about string theory...

 

Hewitt-Drew-it! 64. Pascal's Principle

Piston arrangements and examples of multiplying forces.

 

ScienceCasts: The Strange Attraction of Hot Jupiters

An exotic class of exoplanets called "hot Jupiters" are even weirder than astronomers imagined. While these worlds may have Earth-like blue skies, new data show that they are anything but Earth-like.

 

Prof Jim Smith: Is the future nuclear?

Professor Jim Smith is an environmental physicist from Portsmouth University and he is an expert in the Chernobyl accident's causes and consequences.

He was one of many big names who gave talks at the IOP's Physics in Perspective event at the Royal Institution of Great Britain in 2013.

Feather and Coin in a Vacuum

The free fall of a coin and feather are compared, first in a tube full of air and then in a vacuum. With air resistance, the feathers fall more slowly. In a vacuum, the objects fall at the same rate independent of their respective masses.

 

Asteroids - Sixty Symbols

Find out why astronomers no longer use symbols for asteroids. More astronomy and physics at http://www.sixtysymbols.com/

 

The Aurora Borealis

This video explains how particles originating from deep inside the core of the sun creates northern lights, also called aurora borealis, on our planet.

See an extended multimedia version of this video at forskning.no (only in Norwegian).

All the animated parts of the video was made with Apple Motion 4.

 

Hewitt-Drew-it! 63. Buoyancy Problems

Problem solving with buoyancy is investigated.

 

Flow Inbstabilities

Erik Mollo-Christensen, MIT
National Committee for Fluid Mechanics Films

Film notes

Other videos from this series

Granular Jets (slow motion) - Sixty Symbols

Dropping metal balls into granular glass beads. Featuring Professor Roger Bowley.

 

ScienceCasts: The Harvest Moon

The full Moon closest to the northern autumnal equinox is coming this week.  Don't miss the Harvest Moon.

 

Natthi Sharma: Making Sense of the Weird Quantum Reality at TEDxEMU

The audience will first be exposed to experimental results on electrons/photons that require for their explanation very counter-intuitive concepts, such as being here and there or spinning up and down at the same time, underlying quantum physics. Very special visual analogs will be used --- analogies are always useful to comprehend new in terms of known --- to comfort the intellectual paralysis of our (predisposed) mind in understanding the co-existence of mutually exclusive attributes in the microscopic quantum world.

 Dr. Natthi Sharma is professor of physics at Eastern Michigan University since 1986.

 

How to Make a Neutrino Beam

Neutrinos are elusive particles that are difficult to study, yet they may help explain some of the biggest mysteries of our universe. Using accelerators to make neutrino beams, scientists are unveiling the neutrinos' secrets.

 

Double Cone and Plane

A double cone is placed on the bars of an inclined plane. Instead of rolling down the plane the cone rolls up. Although the plane slants upward, the bars diverge so that the rotational axis of the cone, which passes through the center of mass, actually moves downward.

 

Laser Cooling - Sixty Symbols

Learn how lasers can be used to cool atoms to temperatures approaching absolute zero. More physics at http://www.sixtysymbols.com/

 

The Kinetic Theory

Solid, liquid, gas.

 

MAKE presents: The Integrated Circuit

A brief introduction to the technology that makes it possible for today's electronics to do so much with very little space - the IC (aka microchip)

 

Hewitt-Drew it! 62. More on Buoyancy

How density affects sinking, floating, and remaining in equilibrium doing neither.

 

Lorentz Force in Action

A tin foil speaker experiment. Which means: Playing music through a tin foil. ;-)

 

MIT 8.02 Electricity and Magnetism Lecture 36

X-Ray astronomy.

Farewell Special.

 

ScienceCasts: ISS "Firestation" to Explore the Tops of Thunderstorms

Sometimes, Earth mimics a supernova, producing a Terrestrial Gamma-ray Flash from the tops of thunderstorms. A new lightning sensor on the International Space Station could solve the mystery of these energetic bursts.

 

How to Survive a Lightning Strike

Conductors, Faraday cage...

 

Parallel RC circuits

US Department of Defense 1972-01-01

 Reviews the operation of parallel RC circuit and specifically points out how to solve for branch currents and total impedance by using ohm's law. Reviews vector representations and show how approximate total current and phase angle are found by measuring the vectors. Introduces trigonometric functions used to solve for total impedance, total current, phase angle, and power factor. Concludes with a brief review of apparent and true power and their relationship to the power factor.

 

Spinning Water

The spinning water takes on a curved shape, which sure looks like a parabola. But why does it do that?

 

Waves in fluids

Arthur E. Bryson, Harvard University
National Committee for Fluid Mechanics Films

Film notes

Other videos from this series

The Shrinking Proton - Sixty Symbols

The proton may be smaller than we thought. Our experts explain why this could be a really big deal for physics. More videos at http://www.sixtysymbols.com/

 

Spring Paradox

A mass hangs from two identical springs. First, the springs are attached in series by a short string between them. The springs are also connected in parallel by two peripheral strings that are initially slack. The center string is cut, changing the system from series to parallel. The mass does not move downwards, as one might have thought. Rather, the mass moves upwards because the spring constant of the system is increased.

 

How to Melt Cars and BBQ Pigeons - Sixty Symbols

Geometric Optics - discussing the Walkie Talkie skyscraper and the Nottingham Sky Mirror.

 The Walkie Talkie, or Walkie Scorchie (?), is a new building in London which has been reflecting light in a rather hazardous way! The Sky Mirror is a sculpture at the Nottingham Playhouse. This video features Professor Mike Merrifield from the University of Nottingham.

 Visit our website at http://www.sixtysymbols.com/

 

NASA | Downloads the Future

LLCD will be NASA's first-step in creating a high performance space-based laser communications system.

The LLCD mission consists of space-based and ground-based components.

The Lunar Laser Space Terminal (LLST) is an optical communications test payload to fly aboard the LADEE Spacecraft and it will demonstrate laser communications from lunar orbit.

The ground segment consists of three ground terminals that will perform high-rate communication with the LLST aboard LADEE. The primary ground terminal, the Lunar Laser Ground Terminal (LLGT) is located in White Sands, NM and was developed by MIT/Lincoln Laboratory and NASA.

The ground segment also includes two secondary terminals located at NASA/JPL's Table Mountain Facility in California and the European Space Agency's El Teide Observatory in Tenerife, Spain.

The main goal of LLCD is proving fundamental concepts of laser communications and transferring data at a rate of 622 megabits per second (Mbps), which is about five times the current state-of-the-art from lunar distances. Engineers expect future space missions to benefit greatly from the use of laser communications technology.

Hewitt-Drew-it! 61. Buoyancy on a Submarine

How is the buoyancy of a submarine affected when it is submerged?

 

A trip through space to calculate distance - Heather Tunnell

View full lesson: http://ed.ted.com/lessons/a-trip-through-space-to-calculate-distance-heather-tunnell

 Imagine two aliens racing across outer space to their moon. Who can we deem the fastest alien? With DIRT -- or the equation Distance = Rate x Time -- we can calculate their rates, using the distance they traveled and the time they took. Heather Tunnell explains how to use this helpful equation to determine which of our alien friends is truly faster.

 Lesson by Heather Tunnell, animation by Karrot Animation.

 

The Art of Science Learning

"The Art of Science Learning" is an exciting project funded by the National Science Foundation that seeks to spark innovation and creativity in science education through the integration of art-infused learning methods. The Museum of Science and Industry, Chicago, is one of only three Incubators for Innovation nationwide that will be implementing and testing a new innovation curriculum which uses the arts to energize creative thinking and critical analysis.

 

Series RC Circuits

US Department of Defense 1972 Reviews the use of vector analysis, pythagorean theorem, and trogonometric functions as applied to a series RC ciruit. Graphically illustrates the consruction of the impedance and voltage vector. Shows use of Ohm's law for AC to solve for unknown circuit parameters. Uses an oscilloscope to demonstrate phase relationships and relative amplitudes.

 

MAKE presents: The Inductor

The deceptively simple wire coil that proves incredibly useful in the world of electronics - the inductor's ability to store energy in an electromagnetic field is the key to making transformers, electromagnets, and many more components. It truly is an awesome device!

 

MIT 8.02 Electricity and Magnetism Lecture 35

Doppler Effect. The Big Bang. Cosmology.

 

Four ways to understand the Earth's age - Joshua M. Sneideman

View full lesson: http://ed.ted.com/lessons/the-earth-s-age-in-measurements-you-can-understand-joshua-m-sneideman

The Earth is 4.6 billion years old -- but how can humans relate to a number so colossal, and where do we fit on the geologic timeline? Comparing the Earth's lifetime to one calendar year, events like the extinction of dinosaurs and Columbus setting sail took place relatively recently. Joshua M. Sneideman reminds us of our time and place in the universe.

 Lesson by Joshua M. Sneideman, animation by Powerhouse Animation Studios Inc.

How to find black holes with lasers: Dr Andreas Freise

In 1916, Einstein -- as a consequence of his new theory of gravity -- predicted the existence of gravitational radiation (ripples in the fabric of space--time that propagate at the speed of light).

Today, the hunt for such gravitational waves has sparked a new field of fundamental and instrumental science, using kilometre-sized telescopes that exploit laser technology. These new instruments are now in operation and close to observing Einstein's prediction for the very first time.

The observation of gravitational waves has the potential to change dramatically our understanding of the universe; we will be able to "hear" some of the most violent events in cosmic history, including black holes colliding in the centre of galaxies and the first fraction of a second after the Big Bang.

 

INSIDE a Spherical Mirror

BBC Science Club - The Story of Physics

Short animation, which was part of the Science Club series on BBC2 hosted by Dara O Briain Directed by: Åsa Lucander Art&Design: Åsa Lucander Additional Art: Marc Moynihan Stop Motion & Compositing: Julia Bartl Animation: Kim Alexander, Marc Moynihan, Anna Fyda, Barry Evans, Lucy Izzard, Simon Testro, Phoebe Halstead, Michael Towers Sound: Laura Coates Produced by: 12foot6

 
BBC Science Club - Physics from Asa Lucander on Vimeo.

ScienceCasts: NASA Mission Seeks Lunar Air

A NASA spacecraft slated for launch in September will fly to the Moon to investigate the tenuous lunar atmosphere. Researchers hope "LADEE" will solve a mystery that has been puzzling them since the days of Apollo.

 

Michelson Interferometer

In this setup, an interferometer is used to measure the wavelength of laser light. The incident beam is split into two paths, recombined, and projected on a screen. When one of the path lengths is varied, the interference pattern on the screen changes. By measuring the distance that a path length must be changed in order to achieve the original interference pattern, one can determine the wavelength of the incident light.

 

Voltage Doublers

US Department of Defense - 1970-01-01

Explains the theory of operation of a voltage doubler. Traces charge and discharge paths for the capacitors. Determines peak output voltage and ripple frequency.

 

Vacuum Cannon - Sixty Symbols

We discuss vacuums, pascals and show you a special vacuum cannon, which fires ping pong balls at 400 miles per hour. More physics at http://www.sixtysymbols.com/

 

We let the particle physics people give their version of what a vacuum is like.

Big Questions: Missing Antimatter

Einstein's equation E = mc2 is often said to mean that energy can be converted into matter. More accurately, energy can be converted to matter and antimatter.

During the first moments of the Big Bang, the universe was smaller, hotter and energy was everywhere. As the universe expanded and cooled, the energy converted into matter and antimatter. According to our best understanding, these two substances should have been created in equal quantities. However when we look out into the cosmos we see only matter and no antimatter.

The absence of antimatter is one of the Big Mysteries of modern physics. In this video, Fermilab's Dr. Don Lincoln explains the problem, although doesn't answer it. The answer, as in all Big Mysteries, is still unknown and one of the leading research topics of contemporary science.

Hewitt-Drew-it! 60. Archimedes

Archimedes' principle has a fascinating application, the famous Falkirk Wheel in Scotland.

 

How do we see beneath the surface of tissue with light?

In less than 100 seconds, Bruce Tromberg provides an introduction to the art of seeing beneath skin using light.

 

Bullet Block Experiment

A bullet is fired upward into a wooden block.  Does the block raise higher if the bullet hits its center of mass, or if the bullets hits elsewhere?

Experiment, prediction, results:


Explanation: