I recall back to my first days in physics class where I read the quotation “Nature abhors a vacuum”.  The phrase was accompanied by an image of two teams of horses trying to pull two hollow hemispheres apart after the air was pumped out from inside.

These were called Magdeburg hemispheres and the experiment was performed by Otto von Guericke.  I didn’t realize this, but according to Wikipedia it was Aristotle’s theory Horror Vacui that von Guericke was trying to disprove.  This theory suggested that nature hates a vacuum and that the vacuum will suck material in to fill it.  Von Guericke demonstrated that it is not a sucking force, but a pushing force from the outside air.  However, as I recall from the physics text, the presentation was written as if this experiment was a demonstration of this “principle”.  I imagine that this misconception is why you still see the phrase commonly used today.  This is one of the science myths that keeps floating around.

A more accurate viewpoint is that Nature Abhors a Gradient.  It isn’t that there is a vacuum that is holding the hemispheres together.  Nor is it that there is air surrounding the hemispheres that is holding the hemispheres together.  Rather it is that there is an enormous gradient in the air density outside the hemispheres with respect to the inside.  The result of this gradient is a force.

Gradients in potential energy cause forces.

More generally, gradients in any scalar field result in generalized forces.

The gradient of the electric potential is the electric field.  The gradient of the gravitational potential energy is the gravitational force.  Over and over again these ideas reappear.  In physics, we learn them as separate concepts, and then later in the abstract topic of statistical mechanics we are expected to put it all together.  But each of these gradients resides in its own little box in the student’s cortex, and statistical mechanics is in its own little box.  Rarely do these ideas merge to form a unified concept.

Temperature gradients are responsible for our weather. 
Huge temperature gradients are responsible for hurricanes.  The temperature of the extremely warm air at the sea surface in the Gulf of Mexico drops quickly as one rises higher into the atmosphere.  This enormous gradient powers the heat engine known as a hurricane.  Nature abhors gradients, and will do something about them.  The gradients will result in forces that tend to eradicate the gradient.  Watching this NASA video of satellite imagery during the 2005 hurricane season, one can clearly see that hurricanes are designed to cool the sea surface.

Our weather here in Albany is due mainly to cyclonic storms that act to relieve the temperature gradient between the Earth’s equator and the poles.  Forces due to this gradient brings parcels of warm air north from the south and exchanges them with parcels of cold air from the north.  The spinning of the Earth results in the Coriolis force which deflects the northbound warm air eastward and the colder southbound air westward.  This creates a counter-clockwise rotating structure that brings warm air north on the eastern front and cold air south on the western front.  The result is that the extremely warm weather we had a few days ago had to be followed by the extremely cold weather as this cyclonic structure moved over us from the west.

However, the weather is not the only system driven by the Earth’s energy gradients.  Life itself is driven by these forces.  The “purpose” of life is to relieve gradients.  This is why forests are cooler, they are working to dissipate thermal gradients induced by incoming light heating the surface.  During the process of relieving these thermal gradients, the plants grow.  This excess organic matter results in residual chemical potential energy, which again creates a gradient.  The herbivores devour the plant matter to further relieve the chemical potential gradients.  This works up to a point, but again there is a residual chemical potential, of which the carnivores take advantage.  The cycles of life are driven by energy gradients.

But it doesn’t stop here.  There are other scalar fields that have gradients.  Wealth gradients result in generalized forces.  In cites where there are enormous gradients between the wealthy and the poor one sees violence.  Across the southern U.S. border there is another enormous gradient in wealth.  This gradient results in forces that drive Mexican immigrants into this country.  Building a wall won’t help because it doesn’t eliminate the gradient.  The gradient will merely increase until new forces become strong enough to eliminate it. 

How does one solve the problem? 
Eliminate the gradient.
Nature abhors a gradient.

Kevin Knuth
Albany NY

Launch of www.greenerstill.com, which is a site focused on keeping our world healthy.

Kevin Knuth
Albany NY

A friend of mine forwarded me a news video of a man, John Kanzius, from Sanibel Island Florida, who has invented a way to burn salt water with radio frequency generator.

The question here is what exactly is burning.
The most probable explanation is that the radio waves are breaking the water molecules into oxygen and hydrogen.  The hydrogen then burns creating the hot flame.

The problem is that the energy that it takes to separate the water molecule in the first place is what you get back again when you burn it (since the process of burning Hydrogen is the same as recombining the Hydrogen back together with the water).  If that is the case, then he is pumping energy in as radio waves, which he then retrieves by burning the hydrogen.  This will result in no net energy gain, which means that this is not a useful energy source.

 Another possibility is that it is burning the Sodium ions.  However, if you compare the color of the Kanzius’ flame in the video to the color of a sodium flame, you can see that Kanzius’ flame is pink or red, and not yellow which is an indicator of sodium.  The red color could indeed be from the burning hydrogen, which has a strong emission line in the red.  Look at the Hydrogen spectrum here and compare to the sodium spectrum.

However, some of the videocaps from the same news report show a yellow flame.  They probably did not do a careful white balance adjust, and so it is possible that there is not much we can learn from these images.

As much as I would like it to be true, this is another example of obtaining the same or less energy than you put in.  This is not useful.  Instead, we are looking for ways to release stored energy—not store it and then release it.  It may be, however, that Kanzius’ radio wave generator may have other uses… including curing cancer.

In the meantime, I will leave the idea that salt water burns and I will go back to thinking about Frank Burns:

Kevin Knuth
Albany NY

The above graph is taken from OILNERGY and shows the oil and unleaded gasoline prices (among others) over the last year.  Clearly one can see by visual inspection that the two curves are correlated.  The point to notice however, is that there has been a growing gap between the two curves indicating that gasoline prices have been increasing with respect to the oil prices.  This is what those in the media are referring to when they say that the prices are no longer correlated.

I collected the following data from the U.S. Energy Information Administration’s This Week in Petroleum website and made some useful graphs.  First look at the Crude Oil WTI prices

The gasoline prices are clearly correlated, as one would expect

To compare the oil prices to the gas prices, I adjusted the oil prices by subtracting the mean oil price, rescaling the oil price so that it is on the same scale as the gas price, and added the mean gas price:

[tex]Oil_{adj} = (Oil-Oil_{mean})*\frac{\sigma_{gas}}{\sigma_{oil}} + Gas_{mean}[/tex]

where [tex]\sigma_{oil}[/tex] represents the standard deviation (scale) of the oil prices and [tex]\sigma_{gas}[/tex] represents the standard deviation (scale) of the gas prices .

The figure above plots both the gas prices with the rescaled oil prices.  The result is that the gas prices follow the rescaled oil prices pretty well, which indicates that the price of gasoline is approximately linearly proportional to the price of oil. However, since April 2007, the gas prices have begun to deviate from this linear correlation by as much as 62 cents a gallon on May 14. Given that the price of a gallon of gas was $3.07 on that date, this is a 20% unexplained deviation.  This difference plot is shown below, where green indicates that gasoline is lower than average from the rescaled oil price, and red indicates that it is higher than average.

This deviation is of a magnitude unseen in the last two years.  A 20% deviation like this requires an explanation, and the nature of the deviation indicates that a new mechanism is at work.

Kevin Knuth
Albany NY

 The plastic sheet, nearly a millimeter thick, can deliver up to 40 Watts of power to receivers that have a special receiving coil.  The power transfer is 81.4% efficient compared to the 93% efficiency of a wired power system.  The sheet has as its base a layer of transistors that vary the conductivity of the organic molecule pentacene.  The upper layers have microscopic copper coils that sense when a receiver is nearby.  These copper coils can switch on nearby micromechanical-machine (MEM) switches that then deliver power to the device via induction.

 The picture above shows the sheet below a goldfish bowl in which is a live goldfish and an LED, which is being powered by the sheet.

“Any sufficiently advanced technology is indistinguishable from magic” — Isaac Asimov

Sekitani T., et al. Nature Materials, advance online publication; doi:10.1038/nmat1903 (2007).  

Kevin Knuth
Albany NY