Jennifer Marohasy

a forum for the discussion of issues concerning the natural environment

Physics

The Magnetic Effect of Light

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At the right intensity, when light is traveling through a material that does not conduct electricity, the light field can generate magnetic effects that are 100 million times stronger than previously expected. This is the remarkable conclusion from work in applied physics at the University of Michigan. Quoting from their website:

“A dramatic and surprising magnetic effect of light discovered by University of Michigan researchers could lead to solar power without traditional semiconductor-based solar cells.

William Fisher, a doctoral student in applied physics, performing research on laser-induced magnetism.

The researchers found a way to make an “optical battery,” said Stephen Rand, a professor in the departments of Electrical Engineering and Computer Science, Physics and Applied Physics.

In the process, they overturned a century-old tenet of physics.

“You could stare at the equations of motion all day and you will not see this possibility. We’ve all been taught that this doesn’t happen,” said Rand, an author of a paper on the work published in the Journal of Applied Physics. “It’s a very odd interaction. That’s why it’s been overlooked for more than 100 years.”

Light has electric and magnetic components. Until now, scientists thought the effects of the magnetic field were so weak that they could be ignored.

by Nicole Casal Moore

[Via Alan Siddons]

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More information here:
http://michigantoday.umich.edu/2011/04/story.php?id=7980&tr=y&auid=8154157

Louis Hissink is one reader of this blog who will perhaps not been surprised by this finding.

And it reminds me of that great quote from Albert Einstein, “All our science, measured against reality, is primitive and childlike-and yet it is the most precious thing we have.”

Radiative Transfer According to AGW: A Note from Neutrino

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RADIATIVE transfer is an incredibly important topic when it comes to the earth’s climate system. It is the only way for the earth to either heat up, via absorption, or cool down, via emission.  The temperature of the earth is set by these two counter acting mechanisms. To solve this balance for the earth’s dynamic systems is incredibly difficult. But to understand the basic principles involved is fairly straight forward and central to understanding the theory of anthropogenic global warming (AGW).

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Determining the Total Emissivity of a Mixture of Gases Containing Overlapping Absorption Bands: A Note from Nasif S. Nahle

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Abstract

According to anthropogenic global warming (AGW) theory, carbon dioxide increases the potential of water vapor to absorb and emit IR radiation as a consequence of the overlapping absorption/emission spectral bands. I have determined the total emissivity of a mixture of gases containing 5% of water vapor and 0.039% of carbon dioxide in all spectral bands where their absorptivities/emissivities overlap. The result of my calculations is that carbon dioxide reduces the total absorptivity/emissivity of the water vapor, working like a coolant, not a warmer of the atmosphere and the surface.

Update  April 8, 2011.   There was an error in calculating the overlapping bands, discovered thanks to criticism from ‘Neutrino’.   The errors are now shown with lines through them, the correct figures beside them.   The ‘adjusted’ calculations give a greater cooling effect from carbon dioxide . 

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Calling for Essays in Defence of Back Radiation

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MOST scientists sceptical of the theory of anthropogenic global warming (AGW) accepted that carbon dioxide is a greenhouse gas; they simply don’t believe it is very potent relative to other natural forces.  But there are a group of physicists, most notably several of the authors of the book ‘Slaying the Sky Dragon: Death of the Greenhouse Gas Theory’ who even argue against the greenhouse effect theory. 

For some weeks, every Friday, I have been publishing an essay from one of these scientists a Mexican Nasif S. Nahle – though Nahle is not an author of ‘Slaying the Sky Dragon’.  When I first started publishing Dr Nahle I received emails from various sceptics suggesting that in promoting his work I was doing a disservice to the sceptic’s cause; that I should not be challenging the basic accepted physics of back radiation.

The essence of greenhouse theory is that thermal radiation from the earth’s surface is absorbed by atmospheric greenhouse gases, and is re-radiated including back towards the earth’s surface.  As a result of this back radiation the temperature of the earth is higher than it would be if direct heating by solar radiation were the only warming mechanism.

Dr Nahle argues that there is no warming from back radiation and one reason is because heat cannot flow from a cooler area (the atmosphere) to a warmer area (the earth surface). 

I have enjoyed posting essays from Dr Nahle as he argues from first principles, and with examples, and he engages with his critics in the comment threads.    In short, he provides food for thought.

And given the importance of back radiation to greenhouse gas theory, I have been surprised that there has not been a more definitive rebuttal of his core argument in the comment threads.   Indeed it is irrelevant to argue that he is wrong because his work is not published in the peer-reviewed literature, or that it does not accord with what is written in mainstream textbooks or that it is too specific.  

I am keen to publish more essays on this important topic, particularly from the more mainstream perspective that is in defence of back radiation as a core part of anthropogenic global warming theory.

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Total Emissivity of the Earth and Atmospheric Carbon Dioxide: A Note from Nasif S. Nahle

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Introduction

Central to the theory of Anthropogenic Global Warming (AGW) is the assumption that the Earth and every one of its subsystems behaviors as if they were blackbodies, that is their “emissivity” potential is calculated as 1.0. [1]

But this is an erroneous assumption because the Earth and its subsystems are not blackbodies, but gray-bodies. The Earth and all of its subsystems are gray-bodies because they do not absorb the whole load of radiant energy that they receive from the Sun and they do not emit the whole load of radiant energy that they absorb. [8] [9] [10]

Furthermore the role of carbon dioxide is misunderstood.   According to AGW hypothesis, carbon dioxide is the second most significant driver of the Earth’s temperature, behind the water vapor, which is considered the most important driver of the Earth’s climate. [2] Other authors of AGW discharge absolutely the role of water vapor and focus their arguments on the carbon dioxide. [3]

What is the total emissivity of carbon dioxide?   I will consider this question with reference to the science of radiative heat transfer.

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Temperatures of Void Space and Microstates: A Note from Nasif S. Nahle

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Introduction

The general belief on the conditions of the deep space, beyond the terrestrial exosphere, is about a completely empty place without temperature.

However, highly accurate measurements made by satellites, like the Wilkinson Microwave Anisotropy Probe (WMAP) [2], have corroborated that the deep space has a temperature and, additionally, that it is not an absolutely empty space.

WMAP has revealed a deep space temperature of 2.7251 K and a density of 1 particle/cm^3 (density based on protons in the outer space) [3].

The theoretical temperature was confirmed by WMAP measurements. The theoretical basis related to the temperature of the deep space is given by the correlation between the temperature and the kinetic energy of the particle. On this case, the root mean square (rms) speed vrms of protons in deep space is 260 m/s.

The purpose of this essay is to know the amount of energy emitted by the Earth towards the outer space and the concept of microstates.

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