Gravitational Lensing

In a long line of intellectual triumphs, Einstein’s theory of general relativity was his greatest and most imaginative. It tells us that what we experience as gravity can be most accurately described as the bending of space itself. This idea leads to consequences, including gravitational lensing, which is caused by light traveling in this curved space. This is works in a way analogous to a lens (and hence the name). In this video, Fermilab’s Dr. Don Lincoln explains a little general relativity, a little gravitational lensing, and tells us how this phenomenon allows us to map out the matter of the entire universe, including the otherwise-invisible dark matter.

 

How to make something invisible | Do Try This At Home | At-Bristol Science Centre

Invisibility cloaks might sound like science fiction, but Ross of the Live Science Team shows you how a trick of light can make things disappear in this great experiment to try at home!

This video was presented by: Ross Exton, Live Science Video Producer
Produced by: Ross Exton & Seamus Foley, Big Screen Produce

 

How Do Rainbows Form?

SciShow explains how three important ingredients -- sunlight, water, and you -- interact to create the illusion of a rainbow. The colorful details are inside!

 

What Color Is A Mirror?

Mirrors, reflection, colors...

 

How Modern Light Bulbs Work

Incadescent lamps, halogen lamps, fluorescent lamps, vapor lamps, LED.

Metamaterials and the Science of Invisibility: Newton Lecture 2013

A lecture given by the 2013 winner of the Isaac Newton medal, Professor Sir John Pendry, Imperial College London, and chaired by Professor Roy Sambles, Exeter University.

 

Wind lidars: using laser beams to detect wind speeds

The accurate measurement of wind speeds is critical for effective siting of wind farms. The ZephIR lidar calculates wind speed and direction by projecting a laser into the air and detecting the Doppler-shifted backscatter from tiny particles and dust in the atmosphere. The process is explained here by their team of scientists.

 

Light Darkness And Colours - A fascinating Journey Through The Universe Of Colours

Using Goethe's Theory of Colours (Zur Farbenlehre) as point of departure, Light Darkness and Colours takes us on a fascinating journey through the universe of colours. In 1704, Sir Isaac Newton published *Light and Refraction*, his study of the interactions between sunlight and prisms. Newton was, as a good scientist, intent on achieving objectivity, which meant studying sunlight in isolation. He thought colours were contained solely in light, and found the spectrum he was looking for. When he reproduced this experiment, Goethe found another, hidden set of colours missed by Newton. Goethe found the hidden colours in the boundaries between light and darkness. He felt, as an artist, that one could not talk about light without including darkness. Calling it 'the light-darkness polarity', Goethe made this new scientific discovery using artistic methods in conjunction with science.

 

Light waves, visible and invisible - Lucianne Walkowicz

Each kind of light has a unique wavelength, but human eyes can only perceive a tiny slice of the full spectrum -- the very narrow range from red to violet. Microwaves, radio waves, x-rays and more are hiding, invisible, just beyond our perception. Lucianne Walkowicz shows us the waves we can't see.

 Lesson by Lucianne Walkowicz, animation by Pew36 Animation Studios.

 

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/

 

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.

 

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.

 

MIT 8.02 Electricity and Magnetism Lecture 34

Gratings. Resolving Power. Single-Slit Diffraction. Angular Resolution. Human Eye. Telescopes.

 

MIT 8.02 Electricity and Magnetism Lecture 33

Double-Slit Interference, interferometers.

 

MIT 8.02 Electricity and Magnetism Lecture 31

Rainbows. A modest rainbow will appear in the lecture hall! Fog Bows. Supernumerary Bows. Polarization of the Bows. Halos around the Sun and the Moon. Mock Suns.

 

What is a frequency comb?

In less than 100 seconds, Paul Williams explains how optical frequency combs fill an important technological gap between the light bulb and the laser.

 

MIT 8.02 Electricity and Magnetism Lecture 30

Polarizers. Malus's Law. Brewster Angle. Polarization by Reflection and Scattering.  Why is the sky blue? Why are sunsets red? The sun will set in the lecture hall!

 

Why is light slower in glass? - Sixty Symbols

Professor Merrifield largely "uncut" discussing refraction.

 

What If The Sun Disappeared?

No more natural light, no more photosynthesis, freezing temperatures...

Other VSauce videos

Total internal reflection breakdown

This experiments show total internal reflection at the boundary between wax and air. When we place a drop of water at the surface the conditions changes and total internal reflection disappears.