Ultima Thule

In ancient times the northernmost region of the habitable world - hence, any distant, unknown or mysterious land.

Tuesday, July 04, 2006

What Do Racquel Welch And Quantum Physics Have In Common

By Aussiegirl

Nowhere in this very interesting article does it explain what these two have in common, but I think I know what it is. I'll bet that the male authors have noticed that they feel a strange attractive force when in the presence of a beautiful woman, and, being your typical scientists, they naturally attribute this to a heretofore unknown force, the Welch effect, akin to the Casimir effect.

Here's the Wikipedia article on this mysterious Casimir effect -- of course, to the average layman with an intellectually curious mind, all of quantum physics is mysterious.
Since this is such a fascinating topic, I found another article, entitled The Casimir effect: a force from nothing, with this provocatively interesting beginning:What happens if you take two mirrors and arrange them so that they are facing each other in empty space? Your first reaction might be "nothing at all". In fact, both mirrors are mutually attracted to each other by the simple presence of the vacuum.

And here's a very clear explanation that I found of why the void/vacuum can't be actually empty: The Casimir force arises from one of those unlikely sounding real world manifestations of quantum mechanics. It begins with considerations of what exactly is a vacuum. In the classical everyday sense we think of a vacuum as what is left after we have removed all of the stuff, molecules atoms etc. But that still leaves photons, so if we remove those as well – including all the thermal energy then surely we should now have an absolute vacuum which contains precisely nothing. Therein lies the problem. Heisenberg’s uncertainty principle, describes the limitation on the knowledge of pairs of parameters in terms of Planck’s constant; most well known being position and momentum. An equally important pairing is energy and time, and quantum mechanics forbids the precise independent knowledge of these two parameters. The absolute energy of a system is thus unknowable as a single parameter, including the unique value of zero. So we cannot have a vacuum of absolute zero energy because it violates the uncertainty principle. The theoretical physics resolution of this paradox is to assume the existence of virtual particles which pop out of the vacuum and wander around for an undefined time and then pop back – thus giving the vacuum an average zero point energy, but without disturbing the real world too much. One of the most remarkable results of Quantum Field Theory is the existence of vacuum fields, particles and zero-point energy. Vacuum is not a tranquil void but a quantum state made up of matter fields and energy fields.

What Do Racquel Welch And Quantum Physics Have In Common

What Do Racquel Welch And Quantum Physics Have In Common

by Staff Writers

Recent investment by the University of Leicester in the Virtual Microscopy Centre and the Nanoscale Interfaces Centre has put the University in a key position to take a lead in Casimir force measurements in novel geometries.

The Casimir force is a mysterious interaction between objects that arises directly from the quantum properties of the so-called 'void'. Within classical Physics the void is a simple absence of all matter and energy while quantum theory tells us that in fact it is a seething mass of quantum particles that constantly appear into and disappear from our observable universe. This gives the void an unimaginably large energy density. [....]

Chris Binns, Professor of Nanoscience at the University of Leicester explained: "The research will help to overcome a fundamental problem of all nano-machines, that is, machines whose individual components are the size of molecules, which is that at this size everything is 'sticky' and any components that come into contact stick together.

If a method can be found to transmit force across a small gap without contact, then it may be possible to construct nano-machines that work freely without gumming up.

"Such machines are the stuff of science fiction at present and a long way off but possible uses include the ability to rebuild damaged human cells at the molecular level.

"In a sense the actual value of the zero-point energy is not important because everything we know about is on top of it. According to quantum field theory every particle is an excitation (a wave) of an underlying field (for example the electromagnetic field) in the void and it is only the energy of the wave itself that we can detect.

"A useful analogy is to consider our observable universe as a mass of waves on top of an ocean, whose depth is immaterial. Our senses and all our instruments can only directly detect the waves so it seems that trying to probe whatever lies beneath, the void itself, is hopeless.

"Not quite so. There are subtle effects of the zero-point energy that do lead to detectable phenomena in our observable universe.

"An example is a force, predicted in 1948 by the Dutch physicist, Hendrik Casimir, that arises from the zero-point energy. If you place two mirrors facing each other in empty space they produce a disturbance in the quantum fluctuations that results in a pressure pushing the mirrors together.

"Detecting the Casimir force however is not easy as it only becomes significant if the mirrors approach to within less that 1 micrometre (about a fiftieth the width of a human hair). Producing sufficiently parallel surfaces to the precision required has had to wait for the emergence of the tools of nanotechnology to make accurate measurements of the force."

The new instrumentation at the University of Leicester will enable researchers to extend measurements to yet more complex shapes and, for the first time, to search for a way to reverse the Casimir force.

This would be a ground-breaking discovery as the Casimir force is a fundamental property of the void and reversing it is akin to reversing gravity. Technologically this would only have relevance at very small distances but it would revolutionise the design of micro- and nano-machines.


At 2:03 AM, Anonymous Anonymous said...

Speaking of Raquel Welch and physics, I've always thought that cleavage exerts a gravitational pull on the male eyeball.


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