How a quartz watch works

The amazing everyday wristwatch: We never think about it, but only because engineers have made it so reliable and durable that we don't need to. At its heart lies a tiny tuning fork made of the mineral quartz. In this video Bill takes apart a cheap watch and shows extreme close-ups of the actually tunings fork. He explains how the piezoelectric effect of quartz lies at the heart of the watch's operation.

Other "Engineer Guy" videos

Using Refraction to Make Things Invisible

Movement of light through different media with the same indices of refraction.

Other videos by St-Mary's High School

Shoot-n-Drop

An apparatus that at once shoots a billiard ball horizontally and drops another one vertically from an equal height. Even though the two have different initial velocities, they both accelerate in the same direction and at the same rate due to Earth's gravity--this is confirmed by seeing and hearing both balls land simultaneously.

While we did our best to make sure the setup is level and the apparatus is precise, the video shows the balls actually land about 0.02 s apart from each other (the slow-motion part was done in 60 fps, and there seems to be a difference of about 1 frame). We consider this difference to be negligibly small. Normally the apparatus is positioned about 2 meters above the floor, and the difference in landing time is just as imperceptible. You will notice the "drop-ball" bounces towards the center of the picture. We think this is mostly because the concrete floor has small pockmarks and other local irregularities, which on average combine to form a level surface but individually can cause funny bounces. The ball may also have a very small horizontal velocity due to the way in which it is dropped.

Other Harvard demonstrations

Cloud Chamber to Observe Radioactivity

A simple cloud chamber can be made to observe radioactivity.

 

ScienceCasts: Getting to Know the Goldilocks Planet

NASA's Kepler spacecraft is discovering a veritable avalanche of alien worlds. As the numbers mount, it seems to be just a matter of time before Kepler finds what astronomers are really looking for: an Earth-like planet orbiting its star in the "Goldilocks zone".

 

Einstein's Proof of E=mc²

Ever wonder how Einstein proved E=mc²? This is how.

Other Minute Physics videos

Rolling gear (physics quiz question)

Two gears share the same axis.  How will the gear rotate:  clockwise or anticlockwise?

MIT 8.02 Electricity and Magnetism Lecture 18

MIT 8.02 Electricity and Magnetism, Spring 2002

Professor Walter Lewin

Displacement Current, Synchronous Motors, Induction Motors, Secret Top: How does it work?

Other lectures from the same course

Large Hadron Collider (and Small Hotrod Collider) - Sixty Symbols

What is the Large Hadron Collider and what is it looking for? This video also features sixtysymbols' very own "Small Hotrod Collider".

Other Sixty Symbols videos

Frequency modulation - Part 1 - Basic Principles

Department of Defense 1964. Fundamentals of AM and FM radio communication, how FM eliminates problem of electrical interference, functioning of FM radio examined in detail.

 

Lenz's Law

Two bar magnets of the same size are dropped through an aluminum tube and a glass tube. The magnet dropped in the glass tube falls at the normal rate of acceleration due to gravity, but the magnet falling through the metal tube is slowed. This slowed acceleration occurs because the falling magnet induces currents inside the metal tube. The induced currents then produce a small magnetic field that opposes the direction of the original magnetic field. This effect is known as Lenz's Law, a result of Faraday's law of induction.

See other MIT physics demos

Taylor Wilson: Yup, I built a nuclear fusion reactor

Taylor Wilson believes nuclear fusion is a solution to our future energy needs, and that kids can change the world. And he knows something about both of those: When he was 14, he built a working fusion reactor in his parents' garage. Now 17, he takes the TED stage to tell (the short version of) his story.

Other TED Talks

ScienceCasts: The Surprising Power of a Solar Storm

A flurry of solar activity in early March dumped enough heat in Earth's upper atmosphere to power every residence in New York City for two years. The heat has since dissipated, but there's more to come as the solar cycle intensifies.

 

Inside the Large Hadron Collider (CMS) - Sixty Symbols

Professor Ed Copeland shows us inside the CMS Experiment at the Large Hadron Collider - will it find the elusive Higgs Boson? We'll be uploading another film from the sister experiment ATLAS very soon! CMS stands for Compact Muon Solenoid and is one of the experiments on the main ring at the Large Hadron Collider.

CMS website

Professor Ed Copeland is particle physicist at the University of Nottingham.

Other Sixty Symbols videos

Superconductor

A bismuth-based superconducting disk sits on a copper base and is immersed in liquid nitrogen. Two small, very strong magnets are placed on top of the superconductor. The magnets levitate due to the expelled magnetic field from the superconductor. Superconductors have the unique property of providing zero resistance for electrical currents when cooled to low enough temperatures. Thus, a current induced in a superconductor will last for an extraordinarily long time. This property also leads to the fact that superconductors will expel all magnetic fields, a phenomenon called the Meissner Effect. As a result of this effect, a magnet approaching a superconductor will "see" an opposite magnet of the same size and field strength as itself, which causes it to levitate.

Other demonstrations from MIT

Resistance of a light bulb

We plot a current versus voltage graph for a light bulb.

 

Wave changer

Are your students forgetting that sound is a longitudinal wave? Maybe this is the answer.

 

Science off the Sphere: Lenses and Vortices

NASA Astronaut Don Pettit takes advantage of the weightless environment aboard the ISS to do diffusion and lens experiments with pure water. Distributed as part of a collaboration between NASA and the American Physical Society.

Other Science off the Sphere videos

Creating the Elements - Sixty Symbols

How do stars and supernovae create the elements.

Other Sixty Symbols videos

Coulomb's Law and Inverse Square Relationship

Princeton professor Eric Rogers.  See the whole movie (30 minutes) here.

Einstein and The Special Theory of Relativity

How Einstein (& others) discovered Special Relativity.

Other Minute Physics videos

Energy Efficient Light Bulb Comparison

A comparison of energy efficient compact fluorescent and LED light bulbs with a standard incandescent bulb. Produced by AlternativeE.org.

 

Three polarizers

Tinkering with a LED array and three sheets of polaroid.

 

Angela Belcher: Using nature to grow batteries

Inspired by an abalone shell, Angela Belcher programs viruses to make elegant nanoscale structures that humans can use. Selecting for high-performing genes through directed evolution, she's produced viruses that can construct powerful new batteries, clean hydrogen fuels and record-breaking solar cells. At TEDxCaltech, she shows us how it's done. Angela Belcher looks to nature for inspiration on how to engineer viruses to create extraordinary new materials.

Other TED Talks

Air Apparent

Over 50,000 deaths each year in the UK are attributed to air pollution. Physicist, entrepreneur and father Mark Richards is concerned about the environment and in particular what we expose our children to.

 Dr Mark Richards, Duvas Technologies and Department of Physics, Imperial College, London.

 

Paramagnetism of Oxygen

Oxygen gas is condensed into liquid form and then poured between the poles of a strong magnet so we can observe its paramagnetic properties. We send O2 gas through a copper coil, which is then immersed in about 2 liters of (very cold--77 degrees Kelvin) liquid nitrogen. As the O2 travels through the coil it loses enough heat to change from a gas to a liquid, and that liquid is collected in a small pre-cooled dewar. Liquid nitrogen is poured between the poles of the permanent magnet, but since its diamagnetic properties lead to only a very weak interaction with the field, it just sloshes through as if it were water. The liquid oxygen, on the other hand, sticks between the poles of the magnet until it boils away. Because the oxygen molecule has an electronic structure that favors the non-cancellation of two of the electron spins, its net magnetic moment is free to point in the direction of an external magnetic field (just as a compass needle does). When enough of these moments are aligned, the material as a whole behaves like a single magnet. At room temperature only a small fraction of the moments are able to line up perfectly with the external field, but when oxygen is cooled and condensed into a liquid the effect is more noticeable. Nitrogen atoms are paramagnetic, but molecules are not.

Other Harvard demonstrations

Resonance using Audacity

How to show resonance with a tuning for and the software Audacity.


 

Albert Einstein: Why Light is Quantum

Pi day (3.14) is Albert Einstein's Birthday! To celebrate, we'll explain 4 of his most groundbreaking papers from 1905, when he was just 26 years old.

Other Minute Physics videos

 

Rube Golderg Contest 2012

On February 17, 2012, Argonne National Laboratory held its annual Rube Goldberg Contest at the Chicago Children's Museum at Navy Pier. The Rube Goldberg Machine Contest is named after cartoonist Reuben Lucius Goldberg, the spirit of whose work inspires the contest's weird machines and crazy mechanisms. This year's objective: Inflate and then pop a balloon.

The physics of firewalking

Paul Hewitt explains the secret of fire walking, which is Physics and not mind over matter:

 

 Firewalking experiment by high school physics teachers:

 

Heat conduction

Heat conduction. Wooden and metal pedestal stand in hot water.  Since metal is a better heat conductor than wood, the ice cube on a metal pedestal melt faster than the ice cube on wooden pedestal.

 

Science Off The Sphere: Thin Film Physics

NASA astronaut Don Pettit examines the behavior of thin films of water aboard the International Space Station. Distributed as part of a collaboration between NASA and the American Physical Society.

Other Science off the Sphere videos

 

MIT 8.02 Electricity and Magnetism Lecture 17

MIT 8.02 Electricity and Magnetism, Spring 2002

Professor Walter Lewin

Motional EMF, Dynamos, Eddy Currents, Magnetic Braking.

Other lectures from the same course

Walking On Eggs - Sick Science!

The phrase "walking on eggshells" is an idiom that is often used to describe a situation in which people must tread lightly around a sensitive topic for fear of offending someone or creating a volatile situation. Literally walking on eggshells would require exceptional caution, incredible skill, and a sense of self-control that would be nothing short of amazing. But what if eggs were really much stronger than most of us imagine? What if nature's design of the incredible edible egg was so perfect that the thin, white outer coating of an egg was strong enough to withstand the weight of your body? Wake the kids! Phone the neighbors! It's time for the Walking on Eggshells challenge.


 

Science Off the Sphere: Drinking tea in microgravity

The crew aboard the International Space Station try out a novel new design in microgravity teacup technology.

Other Science off the Sphere videos

 

Total Internal Reflection

Professor Bowley demonstrates a few tricks involving waves and prisms, with visible light and microwaves.

Other Sixty Symbols videos

Lecture 3 | Modern Physics: Classical Mechanics (Stanford)

Lecture 3 of Leonard Susskind's Modern Physics course concentrating on Classical Mechanics. Recorded October 29, 2007 at Stanford University. Principle of least action, lagrangian, conservations laws and symmetry.

Other lectures from this course

 

Science off the Sphere: Dancing Droplets

NASA Astronaut Don Pettit, aboard the International Space Station, demonstrates some interesting interplay between water droplets and charged knitting needles in microgravity.

Other Science off the Sphere videos

TEDxYYC - Kirk Sorensen - Thorium

At TEDxYYC 2011, Kirk Sorensen talks about the liquid fuel thorium reactor -- a way to produce energy that is safer, cleaner and more efficient than current nuclear power.

Other TED Talks

 

Symphony of Science - the Quantum World!

This one is weird: a music video based on interviews with Stephen Hawking, Michio Kaku, Brian Cox and Richard Feynman!

 

CERN news : ALPHA2 ANTIMATTER

CERN experiment makes spectroscopic measurement of antihydrogen.

 

Kelvin - Sixty Symbols

The Kelvin temperature scale is linked to the concept of absolute zero.

Other Sixty Symbols videos

Baths and Quarks

David Tong spends a lot of time in the bath. For him, this is work. Lying in the bath, he thinks about the problem that he has been working on for five years. It is a problem which has been troubling scientists for 40 years and which has a $1 million prize waiting for whoever is able to solve it.

 Professor David Tong, Department of Applied Mathematics and Theoretical Physics, University of Cambridge

 

Written in the Sky (aurora borealis)

The northern lights, or aurora borealis, have fascinated people for generations. Some believe these ghostly lights in the night sky are the souls of the dead sending messages to the living. For space plasma physicist Jim Wild, the messages sent by northern lights are vital. They are messages from the sun and we need to listen carefully. 

Dr Jim Wild, Department of Physics, University of Lancaster

 

What are years... and the galactic supermassive black hole!

It's leap year time... so what are years, anyway? And what do they have to do with the supermassive black hole in the core of the milky way?

Other Minute Physics videos

MIT 8.02 Electricity and Magnetism Lecture 16

MIT 8.02 Electricity and Magnetism, Spring 2002

Professor Walter Lewin

Electromagnetic Induction, Faraday's Law, Lenz Law, Complete Breakdown of Intuition, Non-Conservative Fields.

Other lectures from the same course

Science at the Theater: Extreme Science

On Feb. 27, 2012 at the Berkeley Repertory Theatre, four Berkeley Lab scientists presented talks related to extreme science - and what it means to you. Topics include: Neutrino hunting in Antarctica. Learn why Spencer Klein goes to the ends of the Earth to search for these ghostly particles. From Chernobyl to Central Asia, Tamas Torok travels the globe to study microbial diversity in extreme environments. Andrew Minor uses the world's most advanced electron microscopes to explore materials at ultrahigh stresses and in harsh environments. And microbes that talk to computers? Caroline Ajo-Franklin is pioneering cellular-electrical connections that could help transform sunlight into fuel.

 

Lenz's Law with Copper Pipe

A magnet is dropped down a conducting copper pipe and feels a resistive force. The falling magnet induces a current in the copper pipe and, by Lenz's Law, the current creates a magnetic field that opposes the changing field of the falling magnet. Thus, the magnet is "repelled" and falls more slowly.

Other demonstrations from MIT

 

Temperature & Ultra-Cold Atoms - Sixty Symbols

We look at what makes things hot and cold - and look at some of the coldest atoms in the Universe!

Other Sixty Symbols videos

Phil Plait: How to defend Earth from asteroids

What's six miles wide and can end civilization in an instant? An asteroid -- and there are lots of them out there. With humor and great visuals, Phil Plait enthralls the TEDxBoulder audience with all the ways asteroids can kill, and what we must do to avoid them.

Other TED Talks