Beginners Electromagnetism Class

[KarenAnn23]

Okay I got it now ...I'm way to tired but when I reread that post it will make a whole lot more since..hummm, wonder if I even can sleep now..LOL

Thanks

[langley]

Could this have something to do with the elusive Eather??

Karen

Similar to why couldn't you walk threw a wall, do you know what I mean , anyone ? If matter is mostly made of empti space why can't we walk threw stuff?? I'm not really looking for an answer to that just a weird thought..

Another infamous Langley analogy (annoyogy?)
In world war one, they wanted to mount machines on the bonnet of the old fighter planes, but being really really bright people (as people are when they fight wars) they realised that the propeller would be shot off if a gun mounted on the bonnet was used. So it was a problem. And they realised that if the propeller had four blades, and the gap between each blade was x inches then every revolution of the prop there would be 4 x x inches of empty space through which bullets could pass without shooting holes in the propeller.

So they synchronised the machine gun with the turning of the propeller and it worked. The mechanism allowed the machine gun to fire through the propeller without hitting the blades.

This is a true story. The faster the propeller turned, the faster the machine gun on the bonnet fired.

Meet the Fokkers
http://en.wikipedia.org/wiki/Interrupter_gear

" An interrupter gear is a device used on military aircraft and warships in order to allow them to target opponents without damaging themselves.

The term covers two related technologies: the first, more accurately referred to as synchronization gear, or a gun synchronizer, is attached to the armament of a tractor-type craft so that it can fire through the arc of a spinning propeller without the bullets striking the blades. Introduced during the First World War, the gun synchronizer was a significant development in the history of aerial warfare and remained in operational use until the Korean War, after which the universal adoption of propeller-less jet aircraft rendered such gears redundant.

The other, true interrupter gear stops the firing of the machine gun when some part of the aircraft is in the way. For much of the early history of the fighter aircraft this was limited to the propeller. This would change with the introduction of gun turret mounts on bomber aircraft.

Though their effects were the same, there was a subtle difference between the concept of the interrupter and the synchronizer. A machine gun fitted with interrupter gear had the trigger normally enabled and the interrupter mechanism would disable the trigger when a propeller blade was in the way. A machine gun fitted with synchronization gear had the trigger normally disabled and the synchronizer mechanism would enable the trigger when the propeller was clear, essentially with the rotating parts of the engine (the crankshaft and other parts connected to it with an inline engine, the crankcase with a rotary engine) firing the gun. In reality, the technical difficulties associated with reliably halting, or co-ordinating, the firing of a Maxim-type machine gun meant that no working interrupter system was ever developed — all successful implementations used the concept of synchronization."
Have a look at the picture Karen. OK. Why cant we walk through walls if atom is many empty space. (Just like the diameter of a propeller or fan blade is)

I guess you dont have a Fokker biplane at home. So OK (DONT DO THIS) (Its an analogy in 2 dimensions) Take the fan guard off a domestic pedastal fan. Keeping the fan turned off, move your finger between two of the blades. No problem right? Now turn the fan on.

Try it again (Dont do this its just an example)

OK around every nucleus are electrons. And they whirl around in a spherical cloud. You cant tell where each is precisely (Heisenberg) Oxygen has 32 of the critters. Now every atom has an electron sphere or layers of spheres (arranged according to Coulomb's law) and so (ignoring things like valence and chemical bonding and stuff like that which spoils another wise perfect analogy) when another atom - like an atom in your finger - approaches say the atoms in the whirling fan blades, they cant pass, and you loose the end of your finger and you end up in hospital with a solicitor preparing to sue for suggesting the experiment. See the electrons are whirling in a spherical cloud at a very high rate of speed. And synchronising the frequency of your finger so as to pass through the fan blades would have been beyond even Fokker. He could do it with bullets through a propeller, but not with fingers through fan blades or bodies through walls. Jesus did apparently.

[langley]

Its really hard trying to example the atomic realm - which is normally invisible - in terms of the normal senses. Which operate on the normal scale. Like, a spinning propeller seems solid, but it isnt. In a twin blade propeller, well most of the diameter of the propeller's circle is empty space right. Its the same with atoms. But the whirling electron spheres are similar to the spinning propeller. Sort of. And of course, electrons repel each other too.

Im in Australia. I dont know how to be subtle or profound. If it works it works, if it dont it dont.

[langley]

OK now in the example of the machine gun on the bonnet of the fighter firing through the propeller, we have an important analogy. The number of times the machine gun fires and the number of times the propeller turns so that the blade is in front of the gun barrel is called the FREQUENCY . Now when the gun fires it only fires when there is no propeller blade in front of the barrel. So the bullets pass through. So the relationship between the timing of the firing of the machine to the position of the propeller blades is called the PHASE. (or Timing)

When two or more electromagnetic waves interact in the same way, the results are the results of the FREQUENCY OF THE WAVES and of the PHASE OF THE WAVES.

A wave is a curvy line with peaks and valleys. Where two waves meet and they peaks and valleys match, they reinforce each other. If they meet out of PHASE it means one waves valleys meet the other waves peaks and vice versa and they CANCEL EACH OTHER OUT.

If they meet and the valleys and peaks dont line up either in phase or in perfect (reverse phase) then there is SLEW RATE between them.

These effects have been used in everything from dolby surround sound (the time delay in the rear channel has a slew rate in relation to the front channels) to Electronic counter measures, to the polyphase AC electrical supply.

Here's a picture of the 3 waveforms of the electricity in 3 phase electrical circuits as used by industry. http://en.wikipedia.org/wiki/Three-phase

If you shifted the black waveform along a bit so it matched the red waveform, you'd have 2 phase. If you took away the red waveform and moved the black waveform so its valleys were were directly underneath the peaks of the blue waveform, would there still be useful electricity? The graph gives the clue. The value of the maximum peak is given as +1. The value of minimum valley is given as -1 . Add +1 to -1 . Answer = zero. Null. A null. The waveforms null out. shift the blue or black waveform back or forward a fbit, (that is , added some slew rate) you'd get some juice back.

Thats one way in which EM interact. As I was tryiing to explain with the example of the fan in front of the oven clock earlier. When two separate things that are vibrating come together or interact, interesting things happen.

Everythng vibrates. Everything has frequency. Everything has a phase relationship.

[langley]

Who invented AC and polyphase AC electricity and motors?

clue: NT.

Where did he go from there?

[langley]

and this leads us to a certain sort of study.

http://en.wikipedia.org/wiki/Interferometry
Interferometry is the technique of diagnosing the properties of two or more waves by studying the pattern of interference created by their superposition. The instrument used to interfere the waves together is called an interferometer. Interferometry is an important investigative technique in the fields of astronomy, fiber optics, engineering metrology, optical metrology, oceanography, seismology, quantum mechanics, nuclear and particle physics, plasma physics, and remote sensing.[1]

Please go to that link KarenAnne and have a look.

And http://en.wikipedia.org/wiki/Optical_interferometry
Optical interferometry combines two or more light waves in an optical instrument in such a way that interference occurs between them.

Early interferometers used white light sources and also monochromatic light from atomic sources (e.g., Young's double slit experiment of 1805) . Such interferometers had a wide range of applications, for example, calibration of slip gauges and measurement of gas flow [1]. In 1960, when the definition of the meter was based on one of the spectral line emitted by krypton-86, interferometry was essential in setting up the standard. The development of lasers has made it much easier to produce optical interference and has led to the development of a wide range of measurement methods in engineering, physics and other fields.

And that all brings us back to HT's example of scalar wave weapons earlier. The concept that two separate waves might come together in suitable phase over a target and destroy it. (in the process creating a scalar wave of great power and as HT and I exchanged, the exact nature of a scalar wave is difficult).

I have a headache and there is still washing up to do. I might turn the fan on and lay down for a while.

but anyway, whenever you adjust the timing of your ignition system on your car, all you are doing is making sure the frequency of the spark is phased so that it occurs at the right time according to the frequency of number 1's firing position.

A bit like Fokker and firing a bullet through a propeller.

And thats why we cant walk through walls in our physical bodies. Interference.

[langley]

Ok now what humans can see is limited by the limited FREQUENCY RESPONSE of our visual system. Its not "hi fi" over very much of the EM spectrum. Not surprisingly, its limited to what we call "the Visible spectrum" - a small part of the total EM spectrum.

We see "through a glass darkly". the rest is a fog, the fogginess of which depends upon the "image in nation" imagination of the person. How much they can picture on the basis of uncommon or scientific sense.

Insects however, are critters that can see in ultraviolet light. We cant. this site has photos of flowers taken in normal light and photos taken with film sensitive to ultraviolet light.
So scroll down the page and there are links to flowers as humans see them and coresponding photos of how insects see them.

http://www.naturfotograf.com/UV_flowers_list.html

There are times when the common senses and common sense can be trusted, and times not.

I think thats all I can say really. Now, given that Ive failed in my attempt to beam the washing up to Scottie, Im having a lay down as my head is killing me.

[KarenAnn23]

As I start to read what you are writting about walking threw walls ...well, I didn't think anyone was really going to try and answer that Thank you..

I am very aware of the problem of shooting and propelers of the plane and how they fixed it..although not to worrie you didn't waste your time.. You added to that knowledge, remember I'm a WW2 buff.

And finally then I'll finish reading your posts..Can you believe I got kicked out of a 8th grade science class only for asking that one q. (about walls)... I was totally serious and thought the teacher would try to answer me...for I had considered this very q. for yrs..way before 8th grade...BTW I got sent to the principal office and ended up having my last grading peroid review and went from an F to a C..and that's where I stayed in that class, no matter if I goofed off or study.

Karen

[langley]

As I start to read what you are writting about walking threw walls ...well, I didn't think anyone was really going to try and answer that Thank you..

I am very aware of the problem of shooting and propelers of the plane and how they fixed it..although not to worrie you didn't waste your time.. You added to that knowledge, remember I'm a WW2 buff.

And finally then I'll finish reading your posts..Can you believe I got kicked out of a 8th grade science class only for asking that one q. (about walls)... I was totally serious and thought the teacher would try to answer me...for I had considered this very q. for yrs..way before 8th grade...BTW I got sent to the principal office and ended up having my last grading peroid review and went from an F to a C..and that's where I stayed in that class, no matter if I goofed off or study.

Karen

well that a weak as pee science teacher you had in 8th grade Karen. Knowledge and understanding starts with imagination and the insight of the unseen starts with wondering about that which seen. Any teacher that does not know this is not a teacher but merely a class controller. And should be paid accordingly. Peanuts. Because if they were teaching instead of controlling, they wouldnt need to control and would be teaching instead. Cant stand ignorant teachers. Shouldnt be there. Takes guts to ask questions.

[KarenAnn23]

Thank you for taking the time to write that down ..It was ..well..like a light turning on...in my head LOL

No really that was great..

Karen