Yes, you complete a circuit by plugging in an electronic headset. Complete the circuit and you've got both current and a voltage drop, hence power is consumed.

The old style airline sound systems were actually accoustic. The sound was carried through air channels. In that case, yes the same power is used regardless of the headset being plugged in. The headset merely channeled sound that was already produced to you ear. With no headset in place, the sound just kind of sprays the cabin.

However, a simple circuit that uses an audio circuit as a power source is slightly different than one that uses a transducer to convert vibrational energy into electrical energy.

An audio circuit produces an electrical signal that is often passed to a speaker where the electrical energy is converted into accoustic energy. However, a simple filter circuit can convert the electrical signal a DC (direct current) voltage which is what is used to charge batterys etc.

When you see an advertisement for a "200 Watt audio amplifier" it means that the amp can supply 200 watts of electrical energy to a speaker. A simple circuit can use those 200 watts to light a 200 watt light bulb.

A microphone accepts accoustic energy and produces an electrical signal that carries electrical power. Add in a rectifier circuit and maybe you can light an LED or something. Collect the energy for a while (battery, capacitor, super cap, hydrolysis, ...) and you can power something even bigger.

Another kind of "seat radio" is one with a speaker embedded in the seat. Some cars have 'em because they allow a person to listen without having to work so hard to overpower engine/road noise. Turn them off, there should be no sound. Turn them on and you get sound. Turning them on to "scavenge energy" would be extremely wasteful unless the speakers would be turned to that volume anyway.

You are converting energy thusly: DC electric -> audio electric -> audio accoustic -> audio electric -> DC electric. No conversion is perfect and some lose a huge percentage of energy.

Compare that to a wall wart: AC electric -> DC electric (done).

(Note DC -> DC conversion ignored here)

Go ahead, use your splitter. Energy comes from jack, gets split, some goes here, some goes there. Just don't split too many times. The more times you split, the more power the little seat jack tries to deliver. Too much and it'll heat up and maybe break (or catch fire if you're unlucky).

Also, don't even pretend you're being green or scavenging energy. Your taking advantage of a power source that the aircraft is supplying to your seat. It's clever, but not environmentally nice in any way.

Thanks very much. Is this kinda what you are saying?

In all cases, assume 60 units good stuff @ $70/unit and 80 billion units OK stuff @ 60/unit.

Case 1: refinery capacity = 100 units.

bought 60 good for 4200 + 40 OK for $60 = 100 units for 6600

result $66/unit

Case 2: refinery capacity = 90 units.

bought 60 good for 4200 + 30 OK for $60 = 90 units for 6000

result $66.67/unit

Joan writes: "... and more Republicans show some courage and integrity ..."

Umm, how's about some courage and integrity from the dems too?

mccain decided to try increasing his republican cred by carrying water for bush. Little did he know, but that very act cost him a lot of conservative cred. The republicans currently breaking away from bush is welcome, but too long in coming. It is an expression of a long standing schism, inside the GOP, between fiscal conservatives, social conservatives, and neocons. The three groups are surprisingly distinct and joined only because liberals repulse them all equally.

Sometimes I wonder if that repulsion is the reason the breaks didn't happen earlier. Note: just as liberal does not equate with democrat, nor does conservative equate with republican.

I wonder if those guys have jumped mccain's ship in time to catch another ride. Anyone know whose campaign they're moving to?

It is a fine line. Let's check out some of the possible questions/testimony:

To the woman: "Did he rape you?"

To the man: "Did you rape her?"

These questions ask for opinions regarding a question of fact and the fact is central to the case.

Objection (before the answer)- conclussory, the jury makes decisions of fact and typically only experts are considered competent to give an opinion.

To the man "Did you rape her at your place"

Objections: conclussory and indefinite. Rape is a question of fact, as discussed above. Indefinite because there are two questions hidden in there. "Rape?" and "Your place?"

So, the judge is going to require the jury to determine the legal elements of rape such as sexual contact, consent, ability to consent, actual knowledge of disability, constructive knowledge of disability, ... The rape question is then determined by applying the legal elements.

So, can a rape case be decided this way? Certainly. Does the judges decision bar some of the more emotionally charged testimony/questions? absolutely. Does it weaken the prosecution's case? Maybe. The elements would have to be proven anyway.

Did the judge cross the line? I think so. Everything I've mentioned could be handled by a dilligent defense attny objecting to questions and answers. What is lost is that the prosecution can not make the complete accusation, nor the defense rebut it, during the opening and closing arguments. The charge should be mentionable during those two phases of the trial.