Friday, November 05, 2010

Two cool videos, + science funding

Here are two extremely interesting videos related to physics topics.  Both combine two things I enjoy in life:  physics and coffee.  Here is a video made by scientists at the Institut Laue-Langevin, a neutron science laboratory in Grenoble funded by the EU.  The scientists decided to use a neutron beam to image through a little espresso maker as it brews.  They did this partly for fun, and partly to demonstrate how neutrons may be used to examine materials - for example, one could use this sort of imaging to look for flaws or cracks in turbine blades.  The cross-section for absorbing neutrons varies quite strongly from element to element, giving good material contrast.  The aluminum housing for the espresso maker shows up as very light gray, while the water (and resulting espresso, which is still mostly water, even when my old friend Sven makes it) shows up as very dark.  This is because the hydrogen in the water has a relatively large cross-section for capturing a neutron and becoming deuterium.

The second video I saw thanks to Charles Day's blog.  To me, a former mechanical engineer, this is rather jaw-dropping.  Hod Lipson and his graduate students at Cornell have managed to leverage a great piece of physics called the jamming transition.  Many physics students are surprised to learn that some "simple" problems of classical statistical physics can exhibit complex phenomenon and remain active subjects of research, even though they seem on the surface like they should have been solved by 19th century French mathematician whose name started with L.  The jamming transition is one of these problems.  Take a bunch of dry grains (in this case, ground coffee).  When there is a bit of air mixed in with the grains, the grains can slide over and past each other relatively easily.  A latex balloon filled with this mixture is squishy.  If the air is removed, however, the grains jam up, and the grain-filled balloon becomes very hard (as if the effective viscosity of the blob of grains diverges).  The Cornell researchers have used this phenomenon to make a universal "gripper" for picking up objects.  Just watch the movie.  It's very impressive.

Finally, a tidbit about science funding.  Well, it didn't take long.  The Heritage Foundation (a US conservative think-tank) is already proposing cutting the research budgets of NSF, DOE, and NIST, as well as eliminating NSF support for K12 education.  This isn't a surprise - they do this all the time - though it's interesting that they propose absolutely zero cuts to the Department of Defense (though they have no problem suggesting cuts for veterans benefits).   

3 comments:

sam said...

thank you for these. they are awesome. especially the first video!

Anonymous said...

con·serv·a·tive
disposed to preserve existing conditions, institutions, etc., or to restore traditional ones, and to limit change.


The National Science Foundation (NSF) is an independent federal agency created by Congress in 1950 "to promote the progress of science; to advance the national health, prosperity, and welfare; to secure the national defense…"

Joeffrey said...

Is the science can explain why are head lice exist?hehehehe...coz im so mad at them pest live in me...