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compare the diagrams of an electric and magnetic dipole field. One of these is not like the other, it's easier to see in diagram then my attempt to describe in words.

No, they are the same: just that the diagram of the electric dipole has the two charges separated by some distance, whereas they are next to each other in the lower diagram. If you move the charges together, the top diagram turns into the bottom diagram (well, and flip the direction of the arrows too - that is of no consequence). If you made a dipole out of two separated magnetic monopoles (or a bar magnet!) rather than a single fundamental dipole, you would get field lines exactly like the top diagram.

You're thinking of a diode, not a capacitor.

No idea what you are talking about here. I didn't mention (or intend to mention) either a diode or a capacitor. I was referring to the well-known phenomena where the electric field inside a conductor is zero. See, for example, http://www.glenbrook.k12.il.us/gbssci/phys/Class/estatics/u8l4d.html : "One characteristic of a conductor at electrostatic equilibrium is that the electric field anywhere beneath the surface of a charged conductor is zero"

Wrong. 20dB is 10x the power.

Measuring from 0dB? Are you sure?

From the link a few of us are too lazy to click:

The threshold of hearing is assigned a sound level of 0 decibels (abbreviated 0 dB); this sound corresponds to an intensity of 1*10-12 W/m2. A sound which is 10 times more intense ( 1*10-11 W/m2) is assigned a sound level of 10 dB. A sound which is 10*10 or 100 times more intense ( 1*10-10 W/m2) is assigned a sound level of 20 db. A sound which is 10*10*10 or 1000 times more intense ( 1*10-9 W/m2) is assigned a sound level of 30 db.

In what units are they working? Contrary to popular belief, decibels are not a unit, but rather a scale.

Let's see. From what I have seen from a large number of people who speak of electromagnetic radiation at ranges usable by human-kind: when they say dB, they often mean dBm. It's a typical usage, unless in an environment where both are used frequently. After all, most people try to say things as quickly and easily as possible.

However(!!), there is this thing call Sound Pressure Level, or Intensity Level, which is what we are talking about here. For a quick ruler on such things: go here. I don't know if we have one of these things for dolphins, but it may be in the works by now.

The word you are searching for is hypothesis.

There are 4 terms that need to be understood in the realm of science - hypothesis, theory, law & fact. They are all separate & distinct, except for the only progression that occurs - hypothesis => theory.

A fact is what has been carefully observed.
A law describes that observation.
A hypothesis is a proposal intended to explain that observation.
A theory seeks to explain that observation & has been confirmed by considerable evidence and has endured all attempts to disprove it.

example:

Fact
Objects fall at the same rate regardless of mass.

Law
http://www.glenbrook.k12.il.us/GBSSCI/PHYS/Class/circles/u6l3c1.gif

Hypothesis => Theory
Mass causes a curvature of spacetime which creates the effect of gravity.

Actually, the energy or frequency of the photons is not important when you're making fiber-optic cables. In fact, fiber-optic cables require no insulation except to protect them from exterior harm (sharp things falling on them, etc). The reason is that when light (or, I think, any other wave) is incident on the boundary between a high-index material and a lower-index material (we're talking index of refraction, here) from the high-index side, if it approaches at a slight enough angle, it will be completely reflected back into the high-index material. This is called "total internal reflection." None will be transmitted into the low-index medium. This is the reason that if you sit in the deep end of a pool, you can see the sky above you, but at the other end of the pool, the surface of the water looks like a mirror.

You can read about it here: http://www.glenbrook.k12.il.us/GBSSCI/PHYS/Class/refrn/u14l3c.html.

The result is that if you're trying to communicate by firing photons down a curving tube of glass, you just have to make sure that it never bends too sharply, and all the photons that go in will come out the other end, and none will be lost in transit (assuming the surface of the glass is very smooth). ...hm, smooth...

It would have to be smooth relative to the wavelength of the photons being transmitted, which is a serious problem for gamma rays. I calculated that the wavelength of these photons should be 3 x 10^-13 m (based on E=mc^2 and E=f*hbar and c=f*wavelength), which is one three hundredth the radius of a silicon atom. So glass would not be smooth, and fiber-optic communication would be impossible with ordinary materials.

Well now I'm all confused about whether I'm a wave, a particle, or a horse, so I'm just going to cheese out and post a reference:

http://www.glenbrook.k12.il.us/gbssci/phys/class/r efrn/u14l1c.html

KFG

Light does act like a traverse wave:
http://www.glenbrook.k12.il.us/gbssci/phys/Class/l ight/u12l1e.html.

You hit the nail on the head when you said "unless you want your waveguide to act like an antenna". The purpose of the coax shield (really a misnomer) is to keep all the em inside the cable and channel it. The same thing occurs with light. You normally can't get light down a 300nm hole, but they have demonstrated that they can channel it down this coax-looking setup. It's an interesting demonstration, but has a long way to go if you noticed how short their tube is.

How is this a factor? It is in orbit, and relatively stable.

Anything in orbit is in a constant state of free-fall. Learn about it...

I thought, ignoring atmosphere, objects accelerate in free-fall at the same rate regardless of mass. So, the apple should fall at the same rate as the feather. A quick google search found this which backs my recollection.

Also, nearsightedness means you can see that deer across a field pretty well. You'd only run into trouble trying to 'read' the cave painting about the hunt.

Stop spreading false information. Here is a link for you so you can learn.

http://www.glenbrook.k12.il.us/gbssci/phys/Class/r efrn/u14l6e.html

Nearsightedness is when you can see things NEAR to you.

I hope you get modded down down down

No, it's not. The first harmonic of 23 kHz is at 46 kHz. Harmonics increase in frequency.

You are both wrong. The first harmonic is the fundemental or 23 KHz. The second harmonic is 46KHZ

Clip "
There are a variety of patterns which could be produced by vibrations within a string, slinky, or rope. Each pattern corresponds to vibrations which occur at a particular frequency and is known as a harmonic. The lowest possible frequency at which a string could vibrate to form a standing wave pattern is known as the fundamental frequency or the first harmonic. The second lowst frequency at which a string could vibrate is known as the second harmonic; the third lowst frequency is known as the third harmonic; and so on. An animation of a string vibrating with the second harmonic is shown below.


from website http://www.glenbrook.k12.il.us/gbssci/phys/mmedia/ waves/harm2.html

The loud noise in many older sets and monitors is not the scan frequency. It may be the switch mode power supply. Many of these run in the 15 - 30 KHZ range. They try to run them high enough so most people can not hear them, but low enough so less expensive capacitors and powdered iron cores can be used, so many are right on the margin of some people's hearing.

These power supplies have the full power the set uses, not just the scan and HV power, so they can be as loud or louder than scan circuits.

Given that logic a vehicle may be able to start moving, but as soon as the momentum from the flywheel was effectively countered the car would stop moving.

No.
You missed the point.
Your engine needs to run at a certain minimum RPM in order to sustain operation. If your flywheel has enough momentum, it can allow your car to stay within that range under a temporary load that is greater than the engine's ability to create torque and stay within that range.

Of course it's possible to set you idle ridiculously high, waste gas, and therefore have significant extra power at idle (a "high" idle) but this just means your engine is being managed poorly. The solution to that is to manage the engine properly. There's no reason to install an expensive hybrid system if you're not coing to control the engine properly in the first place.

Okay, here's one for you guys. If I put my car in neutral, and put the gas half way to the floor, it will spin up to 4000+ rpms.

Which means that *gasp* IT ACCELERATED!

Now if you were to increase the load on the engine, guess what? It's going to decellerate.

Eventually you'll reach an equilibrium state where the forces balance out. This is what I've been saying all along. If your engine is running at a constant RPM, all the forces are in balance, period.

You guys are both trying to apply partial armchair physics.

I'm trying to explain a very simple concept to someone who isn't getting it. It's called "Newton's First Law". (You may have heard of it.)

This is basic Newtonian mechanics. I am not going to take the time--a basic physics primer should suffice. But according to Newton's Second Law, the faster you want to accelerate a mass, the more force is required to achieve the acceleration. As for slowing down, it doesn't matter with cars which do not use regenerative braking. That is, if your car stores energy output from slowing down, then it makes sense to brake slowly. This is due to limitations in technology. To be brief, faster braking means more energy gets turned into heat as more load is placed on the brakes rather than your electric motor (which doubles as a generator when being turned by external forces) or what have you.

I think you'll find it's the moment um.

3.5 Billion km Divided by 7 Years Divided by 365 Days Divided by 24 Hours gives you the aproximate velocity at which Cassini was travelling for the last 7 years in Km/h

Travel Velocity: 2,976,190.48 Km/h
Speed of Light: 1,079,252,849.00 Km/h(link)

Using the equation: KE = 1/2 * Mass * Velocity Squared (link) we get

Mass: 1 ton = 907.18474 kg - 6 tons = 5443.10844 kg (Ton Conversion Number Link)
Velocity: 2,976,190,476 m/h is = 178,571,428,560 m/s

KE = 0.5 * (5443.10844) * (178,571,428,560.0)^2 = 86,784,254,453,177,329,714,641,182.592 Joules
8.68 x 10 25 J (Amount of energy it takes for Cassini to go that fast)? Can someone help me with this? If so, how is this accomplished?
9.53 x 10 19 J (Consumption of energy by the USA in 1995) (link)

This could give you a clue.
14dBA is way below whisper ...

Polarization doesn't really work that way; if you had anything other than very thin straight vertical lines as the polarization pattern, it wouldn't work.

You might get away with different degrees of polarization, like the different frequencies you can pick up on your radio, but that's about it.

This tech isn't very secure, but it's much better than nothing, and it would be kind of obvious that you were snooping if you're standing head on to someone else's monitor wearing big black glasses.

If it can vaporize the target, it's also able to vaporize the weapon that's emitting the beam. Newton's Third Law of Motion hasn't been repealed as far as I know.

Sheesh, for that matter I might be wrong about the definition of a rocket engine versus a jet engine! :)

The reason for that was not so the high g force. The problem was that the high g force started and stopped immediately. Modern (or better well designed) coasters are build so that the forces gradually build up and gracefully go down without aprupt changes.

That's why the loops in modern coasters are more elliptical than circular and don't have straights before and after the looping. Actually a looping in a modern roller coaster consists of two spirals (clothoids) joint together in the highest point.

Read more about the roller coaster maths/physics here (with great picutres ;-), here or here if you are interested.

Just a footnote but it is amazing some of the
pages built by K-12 teachers in math and science. These people have far fewer resources than college faculty who end up using WebCT, SmartCourse, or BlackBoard or something else that lets them drag and drop or having department secretaries convert Word documents to pages.

Here is an example. Here is another one. My webliographies are full of sites like these. The science ones are mine and I coded the html from scratch.

The web is a very powerful tool. Please don't sell those of us in nontechnical professions short.

Roanna

ZOID CITY Community and Community Competition

> On a side note, interestingly, in Popular Science they discussed how Warp drive IS theoretically possible.

No it's not. You need infinite energy to reach 'c' (speed of light.)

You can't physically travel faster then the speed of light. The equations of relativity contain: square root(1 - (v^2/c^2)) which you can see for yourself: http://www.glenbrook.k12.il.us/gbssci/phys/class/r elativity/reltoc.html

At speeds above 'c', you have a square root of a negative number - something which doesnt' exist in the real world (aside from "phase" of a wave.)