212 results found for physics

In an extended medium, inertia and a restoring force can lead to waves, which reflect at boundaries, either erect or inverted.

Inertia and restoring forces can, with low friction or damping, lead to oscillations and resonance. We analyse the mechanics of vibrations.

The inverse square law explains planetary motion - and apples falling. Newton's law, measuring G, calculating orbits.

Plastics - or, more correctly, polymers have traditionally been used by the electronics industry as passive materials. Now however, new types of polymers have been discovered which behave as semiconductors. For example, they can emit light when subje....

Structures looking broadly the same in the optical microscope are found in starch granules within plants, in polythene bags and in sections of diseased brain tissue. Athene Donald explores structural similarities between different assemblies of polym....

99.9% of the visible material in the universe is made of quarks and yet we know surprisingly little about them. Professor Davies describes how the properties of the quark are now being revealed, and the implications that this will have for our unders....

In this talk Wilson Sibbett introduces some of the underlying concepts that have enabled us to develop practical ultrafast lasers and a selection of applications that range from the fundamentals of chemical bonding to weapons decommissioning!

What might 'new Einsteins' achieve in the 21st century? Science offers more intellectual challenges than ever, but is a less individualistic enterprise. Technology offers imense opportunities, but poses threats and ethical dilemmas. Can scientists re....

In his talk Sandu will explain this quantum non-locality and present some of the uses of non-locality for quantum information and communication - strange effects such as teleportation - and will discuss the implications of non-locality for understand....

Dr Cristina Lazzeroni, a Royal Society University Research Fellow from the University of Birmingham, reveals the secrets of the world's largest accelerator, the Large Hadron Collider and how the LHC experiments hope to answer big questions about the ....

The LHC is the most powerful particle accelerator ever built. It is capable of recreating the very energetic conditions last seen in the universe a billionth of a second after the Big Bang, and allows particle physicists to study the fundamental ingr....

We will look at the role of pictures and images in the development of science. From the first graphs and illustrated books to Molscript, the influence of the first pictures of spiral galaxies on Van Gogh's 'Starry Night', to the artistic resonances o....

Devices are now reaching the realm where individual structures are made up of only a few atoms so that quantum mechanics, the theory of the very small, is playing a crucial role. The inevitable quantum fluctuations produce noise which was initially e....

Emergence, and its contrary, reduction, are buzz-words in both physics and philosophy. Both physicists and philosophers disagree about the extent to which we can understand large-scale or complex phenomena in terms of their microscopic parts.

Torques produce angular acceleration, moment of inertia 'resists' it. Rotational kinetic energy and angular momentum.

Peeling sticky tape emits energy that extends into the X-ray regime, reports a study in Nature. The research provides evidence for a phenomenon that was first observed more than 50 years ago.nnIt is well known that unwinding sticky tape produces spar....

Smoot's Nobel Prize was awarded for his analysis of that whisper from the Big Bang, the cosmic microwave background radiation. Today he hopes CERN's data will again transform our understanding of the universe. Young scientists Bilge Demirkoz and Benj....

Awarded a Nobel Prize for using lasers to control and cool atoms, producing the Bose-Einstein condensation, Bill Phillips is eager to hear about new theories from young scientists like Hannah Venzl. An exciting dialogue develops between them on a boa....

Fine tuning the frequencies of light gave John Hall a Nobel Prize, and helped transform the fields of precision measurement and information transmission. Iris Choi and Andrei Ghicov are young scientists excited by the ways physics can change our worl....

David Gross's Nobel Prize was for work on the 'strong' force which acts between quarks inside the atom. Now he works on string theory, hoping to understand how all the forces of nature could be united. He believes the next steps may involve throwing ....

The boss of CERN wants the next big experiment in particle physics after the Large Hadron Collider (LHC) to be built at the Geneva lab. Speaking in an interview with physicsworld.com, Rolf-Dieter Heuer said that CERN should host the experiment, which....

p=mv. If external forces are zero, momentum is conserved. In collisions, energy may be conserved (elastic) or not (inelastic).

Emily Dougherty presents on the nature and physics of lightning.

Shalini Golla presents on the science behind light.

Kelly Schwirian presents on nuclear power in the United States.

How we are affected by the very widespread manifesations of diffraction.

John talks about diffraction and the limits it puts on our ability to image atoms. Can we make an electron-microscope without lenses?

In finite objects, the total external force equals the total mass times the acceleration of a point called the centre of mass.

Looking at how hard disk drives can be improvedn

The total work done on an object equals the increase in its kinetic energy. For conservative forces, we can define potential energy.

Professor Harrison Prosper of FSU Physics Department looks at the science behind the recently released movie 'Angels and Demons', starring Tom Hanks and based upon a Dan Brown novel. Prof. Prosper discusses topics such as antimatter, dark matter, dar....

A short video showing a simple classroom method of checking the way in which this force is related to mass, speed and radius.

A presentation showing both the ideas about centripetal force and a simple classroom method of checking the way in which this force is related to mass, speed and radius.

A short clip showing the experimental measurement of the speed of electrical pulses in a cable - a large fraction of the speed of light.

A presentation showing how to measure the speed of sound over a short distance on a laboratory table.

A short clip showing the measurement of the speed of sound over short distances.

Carefully distinguish mass and weight. Hooke's law quantifies deformation. Contact forces have normal and frictional components.

Dr. Tonomura is a world renowned pioneer and authority in the field of electron holography, for which he has received many national and international recognitions. He is recognized for his contributions in the development of electron holography, the ....

Light is reflected off a flexible shiny surface fixed to the end of a plastic tube. When one speaks into the tubes sound vibrations pass down the tube and make the surface vibrate. The reflected light is therefore sent off from the surface in a con....

When two different types of conductors are pushed into a potato chemical reactions take place charging them up - we have a simple electrochemical cell. A potato, zinc screw and carbon rod produce about 1V. We experiment joining a few of these cells u....

This is a simple yet effective demonstration of electricity generation. 500 turns of wire are wound onto a 35mm film can and the two ends are attached to an LED light. A strong magnet is placed in the can and the lid fixed back in place. The generato....

When two different metals are placed in a salt solution (an electrolyte) the chemistry produces a voltage. This is called a cell. By wiring up a number of these cells we can make a battery and use it to power electrical circuits.

Converting wind power into electricity seems like an ideal way of helping to solve our energy problems. However, the power generated by a windmill is dependent on the wind speed. If the wind drops to half its speed there is as little as an 1/8th of t....

Parabolic surfaces can be used to concentrate energy for example to focus sunlight to heat things. Using an old World War II spot light mirror we demonstrate how easy it it is to concentrate enough energy to cause combustion. Finally, we show how to ....

A short video explaining how to measure temperature.

John Murrell explains scales and colour changes with temperature, boiling and melting,