Tag Archives: physics

Light Bending Yields Odd Images

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Weird Light-Bending Experiment Turns Scientists Into ‘Coneheads’

by Clara Moskowitz, LiveScience Senior Writer
A new light-bending experiment turns physicists into coneheads.
Top, clockwise from left: Patrice Genevet, Nanfang Yu, Federico Capasso, Zeno Gaburro, and Mikhail A. Kats. Bottom: A simulation of the image that would appear in a large mirror patterned with the team’s new phase mirror technology.
CREDIT: Eliza Grinnell and Nanfang Yu

In a mind-bending, and light-bending, discovery, scientists have produced a fun-house-like warping of light that defies existing laws of physics.

For centuries, simple equations (taught every year to high-school physics students) have described how light moves through different media, for example from air into glass. Now, however, researchers have found that if the boundary between media is sufficiently complex (in this case, coated with nano-sized wires), those laws no longer apply.

The discovery has prompted the physicists to rewrite the traditional equations to account for the characteristics of the boundary surface. In most cases where these tweaked equations are applied, the new laws simplify back to their traditional forms, but sometimes, they show that light can behave in incredibly strange ways

What is Time? Another Theory

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What Is Time? One Physicist Hunts for the Ultimate Theory

SAN DIEGO — One way to get noticed as a scientist is to tackle a really difficult problem. Physicist Sean Carroll has become a bit of a rock star in geek circles by attempting to answer an age-old question no scientist has been able to fully explain: What is time?

carroll_mug2Sean Carroll is a theoretical physicist at Caltech where he focuses on theories of cosmology, field theory and gravitation by studying the evolution of the universe. Carroll’s latest book, From Eternity to Here: The Quest for the Ultimate Theory of Time, is an attempt to bring his theory of time and the universe to physicists and nonphysicists alike.

Here at the annual meeting of the American Association for the Advancement of Science, where he gave a presentation on the arrow of time, scientists stopped him in the hallway to tell him what big fans they were of his work.

Carroll sat down with Wired.com on Feb. 19 at AAAS to explain his theories and why Marty McFly’s adventure could never exist in the real world, where time only goes forward and never back.

Wired.com: Can you explain your theory of time in layman’s terms?

Sean Carroll: I’m trying to understand how time works. And that’s a huge question that has lots of different aspects to it. A lot of them go back to Einstein and spacetime and how we measure time using clocks. But the particular aspect of time that I’m interested in is the arrow of time: the fact that the past is different from the future. We remember the past but we don’t remember the future. There are irreversible processes. There are things that happen, like you turn an egg into an omelet, but you can’t turn an omelet into an egg

to read more, go to:   http://www.wired.com/wiredscience/2010/02/what-is-time/

Can your Physics Teacher Do This?

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Video Lectures

Photo of Prof. Lewin swinging on a pendulum.

Professor Walter Lewin demonstrates that the period of a pendulum is independent of the mass hanging from the pendulum. This demonstration can be viewed on the video of Lecture 10. (Image courtesy of Markos Hankin, Physics Department Lecture Demonstration Group).

to see the lecture, etc. go to:    http://ocw.mit.edu/courses/physics/8-01-physics-i-classical-mechanics-fall-1999/video-lectures/