Saturday, 13 June 2009
A meniscus is the curved surface of a liquid. A concave meniscus curves downwards, with the middle being lower than the sides; this is what we see with water in a glass tube. A convex meniscus curves upwards, with the middle being higher than the sides; as found with liquid mercury in a glass tube. A good textbook explaination is as follows:
A meniscus is usually concave (upward) because the surface tension of the fluid is less than that of the walls of the tube, and the liquid wets the surface of the tube and tends to "crawl up" the tube. That is what is usually seen in aqueous solutions. In the case of high surface tension liquids, mercury for example, the high surface tension of the liquid metal tends to make the liquid attract it to itself. The result is a meniscus that is convex (upward). The size of the tube and the surface tension of the liquid versus the surface of the tube affects the curvature of the meniscus. A side note: I have seen very pure (99.9999% mercury) in a rigorously flamed quartz container (This drives off all the adhered water and gases.) in which the meniscus is flat, at least so far as the naked eye can detect. Both surfaces then have high surface tensions.
I wonder if there is something else at work here. Something which might be explained by pressure differences in the aether as it interacts between the water, the glass, and the air. I am going to start with suggesting that the aether in the water is under a higher pressure than the aether in the air. I think that this pressure difference in the aether generates a suction force in which the water in a tube is trying to "suck" in the air. What though of the pressure differences of the aether between water - glass - air - interfaces? I wonder what influences glass has on the meniscus in a tube?
The term "glass" in a general sense is applied to the hard brittle, non-crystalline, transparent, opaque or translucent vitreous substance which results from fusing silica with active mineral solvents or fluxes, such as the alkalies, earthly bases, or metallic oxides. Some consider glass to be a supercooled liquid. It is sometimes said that glass is therefore neither a liquid nor a solid. It has a distinctly different structure with properties of both liquids and solids.
For crystalline substances the distinction between the solid and liquid states is very clear, but what about glasses? Indeed, where do polymers, gels, foams, liquid crystals, powders and colloids fit into this picture? Some people say that there is no clear distinction between a solid and a liquid in general. A solid, they claim, should just be defined as a liquid with a very high viscosity. They set an arbitrary limit of 1013 poises above which they say it's a solid and below which it's a liquid.
Solids are elastic when small stresses are applied. They deform but return to their original shape when the stress is removed. When higher stresses are applied some solids break while others exhibit plasticity. Plasticity means that they deform and don't return to their original shape when the stress is removed. Many substances including metals such as copper have plasticity. The resistance to flow under plastic deformation is called its viscoplasticity. This is like viscosity, except that there's a minimum stress known as the elastic limit below which there is no plasticity. Materials with plasticity do not flow, but they may creep, meaning they deform slowly but only when held under constant stress.
I think that the "plasticity" of a substance is important with regards to electricity. I think electricity might be the aether under high pressure, and that this high pressure creates a lot of stress, and that this stress generates higher pressures. Glass, at least normal glass, is brittle and does not exhibit plasticity until it is heated under high temperatures.
When a piece of glass has been expanded under the influence of heat, and is rapidly cooled, the superficial outer portions become intensely strained and contracted upon the interior portions, which retain the heat longer. These stresses or strains are relieved in the process of annealing, under which they are gradually eased by a slow and regular cooling from the heated condition.
If droplets of molten glass are dropped into a bucket of cold water to rapidly cool, they form something known as "Prince Rupert drops". The drops are an example of unannealed glass. The exterior of the drop cools and hardens immediately, while the interior material cools slowly. As the interior material cools, it contracts and sets up powerful compressive stresses on the surface. It is under these conditions that a vacuum bubble forms inside the drop's head.
The pieces of glass are tadpole-shaped. They can withstand the crack of a hammer, but if the tail is broken, or snapped off, the whole piece explodes (or implodes?). It's as if all the energy from the stress is contained due to the surface tension. The potential energy inside the glass is stored in the stressed structure, but having the unfortunate belief that there's no such thing as potential energy, I prefer to write that it is the structure of the glass which manipulates energy in the aether field. You can see some experiments with the drops here on YouTube:
Recently an examination of the shattering of Prince Rupert's Drops by the use of extremely high speed video done by Dr. Srinivasan Chandrasekar at Purdue University has revealed that the "crack front" which is initiated at the tail end, propagates in a disintegrating drop within the tensile zone towards the drop's head at a very high velocity (~ 1450-1900 m/s, or up to ~4,200 miles per hour).
I think there's something special about glass. We've seen its influence in creating X-rays. Early experiments with electricity used glass bottles partially filled with water, known as Leyden jars, as capacitors. They were used to "store" static electricity. It was initially believed that the charge was stored in the water. Benjamin Franklin investigated the Leyden jar, and concluded that the charge was stored in the glass, not in the water, as others had assumed. From my perspective, the glass does not simply store the electricity, but rather it is converting the everpresent aether into electricity.
To increase the capacitance you need a bigger bottle. The larger the surface of the metal or tinfoil, the greater the capacity. The thickness of the metal though is of no value. The thicker the glass, the less the capacity. Can I then say that the thicker glass is less able to convert the aether into electricity? Does a thinner glass therefore induce the aether at a higher pressure? This is by no means an original line of thought, and the following was taken from "Elementary Lessons in Electricity and Magnetism" By Silvanus P. Thompson:
...Electrical phenomena are due to stresses and strains in the so-called "ether", the thin medium pervading all matter and all space... As the particles of bodies are intimately surrounded by ether, the strains of the ether are also communicated to the particles of bodies, and they too suffer a strain... The glass between the coatings of tinfoil in the Leyden jar is actually strained or squeezed, there being a tension along the lines of electric force
The Leyden jar was also once referred to as a "condenser". It was coined by Alessandro Volta in 1782 (derived from the Italian condensatore), with reference to the device's ability to store a higher density of electric charge than a normal isolated conductor. There's something else though. William Leithead, in his book "Electricity" made an interesting observation:
On the inner surface of a Leyden jar a quantity of moisture frequently becomes condensed - although the jar must have been perfectly dry, otherwise it could not have recieved and retained an intense charge. These are subjects of enquiry that are deserving of attention.
This puzzles me a bit, not least because this condensation is barely ever mentioned elsewhere. Perhaps this condensation is another reason why the jar gained the name "condenser". It appears that air, and not simply the electric fluid of the aether, was important in the generation of electricity. The condenser, according to Volta, allowed for the detection of even the smallest discharge of electricity from vaporization and chemical effervesence. The condensation of vapors seemed to hold a lot of importance to Volta. The atmospheric discharge of electricity, such as lightning, was attributed by him to the condensation of vapors.
Condensation is the process of water returning to the air. Condensation occurs when water vapor meets cooler air. One of the most important principles applied in the operation of steam power is the creation of vacuum by condensation. Basically, condensation can pull a vacuum. It works on the premise that steam takes up more space than water. If you cool the steam it condenses to a much smaller amount of water. If the steam were made to rapidly condense in something which was airtight, say an oil can, the water would then only occupy a tiny space, and the rest of the container would be empty - absolutely empty except for the aether - there would be a vacuum.
If we were to experiment we'd find that as the steam condensed, the oil can would crumple up like paper. It's like a paper bag full of air, and then something's come along and sucked the air right out of it. The can has imploded. I'm getting way-laid, I know, but I get a sense that later I'm going to turn to this and understand its importance. For the low-down on this experiment, and steam power in general, I found this site very informative, and really helpful:
So I'm left looking at the concave meniscus in a glass tube with water. If the aether is at its highest pressure in the walls of the glass tube (because it is denser than both water and air) - then is it possible that the glass is trying to suck both at the water and the air? The water could be pulling down the air from above, while the glass is pulling at the water from the sides and below. Could this help explain the concave shape ?
We see a convex meniscus with liquid mercury in a glass tube. I think that the convex shape looks a bit like we are baking a loaf in the oven. Now we have mercury being the most dense medium, and I suspect that it is here that the aether is under the highest pressure. It would appear then that the pressure is on a gradient, being the highest in the mercury, a bit lower in the glass, and then the least in the air.
A convex meniscus occurs when the mercury molecules have a stronger attraction to each other than they do for the container. That's the textbook answer and it pretty much agrees with what we are seeing. The mercury doesn't look like it's trying to suck down the air, or suck to the sides of the glass. The mercury looks pretty much self-contained. I think we have the pressure differences in the aether, but these fail to materialise physically. What, if anything, am I missing?
I can't help but mention that when I look at the convex and concave shapes of the meniscus, and I put the two together, I think of the movement of a diaphragm. So? ......
I quite liked this. A bit different. I wouldn't hope to fully understand it though... whoops, better be careful, or I could end up standing in a greenhouse with a rock in one hand, while pouring myself a nice cup of tea from a black kettle....
And this one too is really good. Washburn et al, were investigating dissolved gases in glass. (I think dissolved gases might be what we call ions). Anyway, the article fits in beautifully with this post.
Electricity By William Leithead