You are assuming that the 9V battery consists of a separation of charge such that (in the absence of a complete circuit to drain the charge) there is +Q on one terminal and -Q on the other terminal. That's not the case. Read the blog post I linked earlier and you will see why.

Yes I read the blog already but the text is far more too complicated for what I know already so I gave up half way. And yes that's exactly what I was thinking. I badly asked my question because even if the circuits would be open in my understandings of things the bird should be (dis)charged.

Occasionally a raven will explode upon contacting a pair of high tension wires. They're just about the only bird up here with a wingspan sufficient to to this.

Ahaha

 

This topic reoccurs so regularly maybe it should be a sticky thread.

activee, you are basically correct if you're looking at the bird on the wire from a physics point of view - yes, there will be some charge transfer, some current flow. The people who disagree are usually looking at this from an engineering point of view in that the charge transfer and current flow will be small enough to have no practical effect.

However, there are plenty of web discussions describing a person standing on an insulated platform and touching the globe of a van de Graaf generator. They always state that the person should be touching the globe before the machine is started. Why is that, unless the person would receive a shock simply from the charging of their body capacitance? (If I had a van de Graaf I'd go try it out!)

The smaller bird would have a lower capacitance than a human, but the wires they sit on can have quite a high voltage at the peak of the cycle. I wonder if birds may actually feel a shock when they first touch the wire?

 

...They always state that the person should be touching the globe before the machine is started. Why is that, unless the person would receive a shock simply from the charging of their body capacitance? (If I had a van de Graaf I'd go try it out!)
...

When we were kids in the school library we used to rub our feet on the polyester carpet and build up a charge. Then we walked up behind an unsuspecting studying victim, and touched them on the ear...

The large crack sound and blue spark (and the victims reaction) showed there was definitely a good current flow, even though perp and victim were both fully insulated.

 

This topic reoccurs so regularly maybe it should be a sticky thread.

activee, you are basically correct if you're looking at the bird on the wire from a physics point of view - yes, there will be some charge transfer, some current flow. The people who disagree are usually looking at this from an engineering point of view in that the charge transfer and current flow will be small enough to have no practical effect.

Yeah well my question wasn't about why the current of the circuit didn't go through the bird it was more about why the bird didn't "discharge" himself when he touches the (non insulated) wire. Discharge himself to the + end of the battery.
For example in static electricity if I have a + charged metallic sphere and a - charged sphere they will attract each others. Now if I have a + charged sphere to me it should be attracted to the - terminal of a battery. I've a feeling people keep telling me it's not the case. Why it's not the case ? I don't know.

If I could rephrase my first question it would be: Why the electrons inside the bird don't go out of the bird to go to the + side of the battery via the wire. And if that happens the bird should be electronegative and should gain electrons and this should happen constantly. If that is how it happens I have No question about the bird anymore.

Except one : Could an object be so electro negative that it attracts neutrally charged object ? I hope the answer to this question is "NO" so things will make sens to me then.

 

As has been said several times, charge and voltage are not the same thing.

You are still insisting on treating a battery as a huge amount of + charge on one terminal and a huge amount of - charge on the other. That isn't what a battery is. I explain that in that blog post that you won't finish reading.

Consider the following: My "battery" (it's actually a capacitor, but it's what you have been thinking of as a battery) is made up of two plates one of which has +1C of charge on it and the other of which has +2C of charge on it. The second plate will be at a higher voltage than the first plate, so the first plate is the negative terminal of my battery and the second plate is the positive terminal. Now I take that sphere you were talking about and charge it to +1C. Which terminal of the battery will it be attracted to? Neither, because both plates are positively charged and so it will be repelled by both. Charge and voltage are not the same thing!