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Electricity (split from Science Project (static charge))


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Posted
4 hours ago, westom said:

To keep others from being confused, better is to replace the term "static electricity" with "static charges".

"To keep from being confused, everyone should stop using the completely standard term and replace it with my preferred term"

As I say, good luck persuading everyone to do that.

4 hours ago, westom said:

Electricity is always different at both ends of a wire for so many reasons. 

What!?

How can "electricity" be different at both each end?

Do you mean "voltage" perhaps?

I think you should stop posting this nonsense now.

4 hours ago, westom said:

OP's science project is always about where two separate charges reside. We simply locate the location of separate positive and negative charges.  Then call one of those locations ground.  That is the only relevant ground.  Either location can be called ground.

It isn't clear, but it seems likely that the charges are split between the person and the belt of the treadmill. Which of those do you wish to call "ground". Because either choice would be fantastical. 

Posted
4 hours ago, westom said:

To keep others from being confused, better is to replace the term "static electricity" with "static charges".

In scientific discussions wouldn't that add confusion? In science it is not uncommon to analyse electromagnetism and electrical phenomenons in different frames of reference. A charge that is stationary in one frame of reference may be moving seen from another frame of reference. A definition of electricity that includes both stationary charges and moving charges does not necessarily have to change when moving between frames of reference. And then, for discussing specific phenomenons, there are "Electrostatics", Electrodynamics" etc each having their own scientific definition.

That said, I agree with:

On 12/21/2019 at 6:25 AM, westom said:

The word electricity has different meanings

But in science I prefer rigorous definitions. In some everyday talk the situation is different. 
(My first language is not english, providing a list of translated example could easily miss the point and be off topic)

Posted
5 hours ago, westom said:

All wire has impedance. So a voltage difference always exists with any current in a wire.

Where is the voltage difference in a transformer secondary which consists of one continuous loop i.e. short circuited output winding?

Posted
On 12/20/2019 at 3:04 AM, westom said:

Electricity is defined by voltage and current. Both must exist.

Using your definitions, what do you use to model and explain superconductivity?
By your definitions, the current running through a superconductor not electricity?

Posted (edited)
8 hours ago, westom said:

It is clearly not zero according to circuit theory.  Electricity is always different at both ends of a wire for so many reasons.  Including this.  All wire has impedance. So a voltage difference always exists with any current in a wire.  How big?  Not provided are many necessary parameters.  So no informed answer is possible.  Other than this.  A voltage difference always exists in two ends of every wire that is conducting a current.

When is voltage between both ends zero?  Only when no current flows.

What can one say to an electrical engineer who denies

Kirchoff's voltage law
Kirchoff's current law
Rosen's Theorem
Millman's Theorem
Node analysis
Loop analysis
Maxwell's mesh curent theorem
Norton's theorem
Thevenin's theorem
 

to name but a few theorems in Circuit Theory that all depend upon defining the impedence of interconnecting wires between circuit elements as zero?

Some of these can be adapted to take into account wiring impedence, but som depend upon replacing the wiring with equivalent circuit configurations embodying a different wiring and even different circuit elements.

 

+1 to strange, Ghideon and Carrock for offering further inconsistencies.

A final comment about current and voltage.

Current can be driven by other mechanisms than voltage e.g. themal drift current, ionic concentration current, solar wind current, nuclear decay current.....

 

Edited by studiot
Posted
2 hours ago, studiot said:

What can one say to an electrical engineer who denies

Kirchoff's voltage law
Kirchoff's current law
Rosen's Theorem
Millman's Theorem
Node analysis
Loop analysis
Maxwell's mesh curent theorem
Norton's theorem
Thevenin's theorem
 

Any fool can make accusations.  Everything accurately posted included reasons why it is known or is relevant.  You constantly contradict Kirchoff's voltage law,  Kirchoff's current law,  Rosen's Theorem, Millman's Theorem, Node analysis, Loop analysis, Maxwell's mesh curent theorem, Norton's theorem, and Thevenin's theorem.  Naysayers and extremists do  that only to argue.

You are clearly and repeatedly wrong.  And anti-social to boot.  Anything you say lacks credibility.  First indication that you are lying are claims made without perspective - numbers.  But once again, your bogus accusations have not one honest reason to justify it.  Your only proof is in demaning others.

An honest person would have said why those concepts were violated. You cannot.  You simply demonstrate that any fool can post fancy terms to look intelligent.  If you knew what those terms meant, then we read why each was relevant. That requires what you do not have - basic knowledge.

The fundamental point remains unchallenged.  Static electric discharges are an electric current between two charges.  Earth ground is irrelevant.  Only relevant are locations of those two charges.  Sorry that is too complicated for an extremist naysayer to understand.  But that is who you are.

A conductor that connects those two charges ALWAYS has impedance.  There is no perfect conductor as  claims by the naysayers emotions.  Electricity is defined by two relevant parameters - voltage and current.  One is the independent variable.  The other is a dependent variable.  That relationship is defined by what always exists on conductors - impedance.   If a conductor was perfects - as a nasty and ignorant naysayer claims, then no voltage can exist. Even students of high school science can understand that.  A naive naysayer will post anything else just to waste bandwidth.

Bugs Bunny best defines him.  What a maroon..

 

4 hours ago, Ghideon said:

Using your definitions, what do you use to model and explain superconductivity?
By your definitions, the current running through a superconductor not electricity?

Apparently a relevant difference between impedance and resistance was overlooked.  That difference is significant even in superconductors.

Furthermore zero resistance does not exist in a superconductor.  A substantially lower resistance exists. 

Posted
19 minutes ago, swansont said:

No, it’s zero.

you can’t have a ring of current and also have a continual voltage drop, which is required if there is a resistance. 

https://en.m.wikipedia.org/wiki/Superconductivity#Zero_electrical_DC_resistance

Thanks fot that +1

Interestingly We are visiting Leiden for Christmas.

More interestingly I learned this on ScienceForums a year or so back when I thought (as you did) that superconductivity was just very low resistance and someone corrected me.
Whn I studied this stuff suprconductivity was known but far from well investigated or mainstream. Now of course it is largely understood and has practical uses.

 

Posted (edited)
57 minutes ago, swansont said:

No, it’s zero.

you can’t have a ring of current and also have a continual voltage drop, which is required if there is a resistance. 

 

If zero, then the current continued forever.  Even the article is clear about his.   It does not continue for ever.  Current just lasts longer - because resistance is so much smaller.  So small as that it cannot be measured (for some superconductors).  But resistance still exists.

Term impedance has again been completely ignored.  Impedance (not just resistance) is relevant.  Do you know what impedance is?  Most here clearly do not.

Meanwhile to point remains.  Earth ground is irrelevant to his discharge of static electricity.  That discharge is between charges are two separate locations.

Edited by westom
Posted
14 minutes ago, westom said:

Meanwhile to point remains.  Earth ground is irrelevant to his discharge of static electricity.  That discharge is between charges are two separate locations.

But this is just not so.

Whilst a static discharge is certainly between two places, it may or may not be between two charges.

Unless you can convince us that the enormous charge in a thudercloud that sends a lightning bolt down to strike an electrically neutral tree is somehow between two charges.

Or perhaps the smaller charge carried by a person and discharged to an electrically neutral door knob is also between charges.

Posted
35 minutes ago, westom said:

If zero, then the current continued forever.  Even the article is clear about his.   It does not continue for ever.  Current just lasts longer - because resistance is so much smaller.  So small as that it cannot be measured (for some superconductors).  But resistance still exists.

There are loss mechanisms other than resistance at play. You have a magnetic field, for example, which can couple to the outside world and dissipate energy. But that’s not resistance.

And you have not addressed the scientific objection that you can make a loop with current flow. How can you have a voltage drop? Pick a point on the loop and it must have different voltages for each time the current completes a cycle. Unless you’re MC Escher, that just can’t happen. The voltage at a point  is not multi-valued. Your definition falls flat.

 

Posted
6 hours ago, studiot said:

But this is just not so.

Whilst a static discharge is certainly between two places, it may or may not be between two charges.

And had you been reading what was already posted, then you know I already said that.  Go back and read what you ignored.  it is all there.

No reason  exists to convince you or anything.  If reasons why were actually read before having an opinion, then you would not now be posting what was stated clearly and previously.  Go back and read what you intentionally ignored.

6 hours ago, swansont said:

There are loss mechanisms other than resistance at play. 

At what point will you finally learn about that "other ... at play".  Impedance (which is clearly not resistance) is a parameter at play. How many times must this be stated before you finally read what was stated repeatedly?  And that is the point.  You want to argue - by completely ignoring what is written.  Apparently you do not even know what impedance is.  And why it is relevant.  So you want to argue anyway.

Why does that ring of current diminish?  Your citation demonstrates it.  But is ignore due to selectively reading only what you want to see. Even resistance exists - no matter how many times you deny it.

 

Posted
7 hours ago, westom said:

Go back and read what you ignored.

You seem to have missed: 

22 hours ago, Ghideon said:

A charge that is stationary in one frame of reference may be moving seen from another frame of reference.

How do you modify your definitions of electricity when the observer is changing frame of reference?

Posted
10 hours ago, westom said:

And had you been reading what was already posted, then you know I already said that.  Go back and read what you ignored.  it is all there.

No reason  exists to convince you or anything.  If reasons why were actually read before having an opinion, then you would not now be posting what was stated clearly and previously.  Go back and read what you intentionally ignored.

 

Whilst I am away, have a happy Christmas reading all the parts of my posts you either didn't or ignored.

 

In particular I mentioned Maxwells's mesh theorem, since you like Maxwell.

Are you aware of th special nature of the current in that theorem?

Posted (edited)
19 hours ago, westom said:

Apparently a relevant difference between impedance and resistance was overlooked. 

"When a circuit is driven with direct current (DC), there is no distinction between impedance and resistance; the latter can be thought of as impedance with zero phase angle."

https://en.m.wikipedia.org/wiki/Electrical_impedance

Static electricity discharge is flow of electrons in just one direction..

Typical use of superconductor is to create powerful external magnetic field around it, impossible for traditional electromagnets (because of too large resistance of existing metals). So you need to use DC. Again.

Edited by Sensei
Posted
3 hours ago, Sensei said:

Static electricity discharge is flow of electrons in just one direction..

Do you switch on a current?  Then it is not DC.  That is taught in first semester course material.  But somehow you know more?  Clearly not.  Because you do not know how to learn.  That wikipedia quote is missing many relevant facts.  And demonstrates how easily one can be scammed.  One who is an expert but forgot to first learn.

You are arguing and accusing when a responsible person instead would be learning and asking. You demonstrate why wacko extremists exist.

Impedance is significant.  Earliest radio transmitters simply turned on and off a DC current.  Which creates currents at many frequencies.  Static electric discharge is also not DC - for same reason.

Lightning is simply a static electric discharge at higher energies.  It causes radio frequency interference because "that flow of electrons in one direction" create radio frequency noise across all frequencies.  Please learn these basic concepts before going off, half cocked, making claims only justified by a soundbite combined with junk science reasoning.

First learn how electricity works.  Quoting something subjective is the first indication that you are so easily scammed.  You have no idea why impedance is significant.   You did not even know that static discharges and its cousin, lightning, create AC currents.  Only impedance (not resistance) is relevant.  But that means becoming educated before lecturing anyone.

Had you taken a first course in electrical theory, then you would have never posted such embarrassing ignorance.  You simple demonstrate why extremism exists.  Experts who did not bother to first learn reality.

Posted
1 hour ago, westom said:

Only impedance (not resistance) is relevant. 

And yet you claimed that superconductors have resistance, rather than impedance. And haven’t addressed the shortcomings of your claim.

 

Posted
1 hour ago, westom said:

Do you switch on a current?  Then it is not DC. 

So you are saying that a battery powered lamp does not use DC current?

Your claims get more bizarre by the moment. 

1 hour ago, westom said:

You are arguing and accusing when a responsible person instead would be learning and asking. You demonstrate why wacko extremists exist.

I think you should read that. And think about your behaviour. 

1 hour ago, westom said:

Earliest radio transmitters simply turned on and off a DC current.

But according to your “logic” if they turned it on and off then it wasn’t DC. 

You can’t even keep your own misunderstandings straight. 

 

1 hour ago, westom said:

Lightning is simply a static electric discharge at higher energies.  It causes radio frequency interference because "that flow of electrons in one direction" create radio frequency noise across all frequencies. 

That "that flow of electrons in one direction" is what is known as DC. The fact that switching that current on and off generates multiple frequencies does not change that.

"Direct current (DC) is the unidirectional flow of an electric charge."

"The electric current flows in a constant direction, distinguishing it from alternating current (AC)."

https://en.wikipedia.org/wiki/Direct_current

Posted
4 hours ago, westom said:

That wikipedia quote is missing many relevant facts.

!

Moderator Note

westom, civility is our most important rule. We attack ideas here, not people. Please focus on the topic and the arguments.

For instance, you make the above assertion but offer no examples or evidence this is so, and instead attack the people involved in the discussion. If there are relevant facts missing that give you insight, why wouldn't you share them and help remove some ignorance? Without this kind of support, you're just waving your hands and talking louder.

You also seem to be cherry-picking which replies you deal with. There have been some excellent questions asked, the answers to which I'm sure would reduce the levels of confusion we're seeing in the thread so far. Please go back and give these a second look, if you will. It's a learning opportunity for everyone.

 
Posted
6 hours ago, westom said:

a responsible person instead would be learning and asking.

I tried that a few times. What's the point with your advice if you choose to ignore the questions?

 

Posted (edited)
7 hours ago, westom said:

 

11 hours ago, Sensei said:

Static electricity discharge is flow of electrons in just one direction..

Do you switch on a current?  Then it is not DC.  That is taught in first semester course material.  But somehow you know more?  Clearly not.  Because you do not know how to learn.  That wikipedia quote is missing many relevant facts.  And demonstrates how easily one can be scammed.  One who is an expert but forgot to first learn.

Actually, I do have Van de Graaff generator in my apartment.. capable to create over 500,000 Volts..

723035584_VanDeGraaff.png.3fa14a4de3f6d413c49d4e5e4c2c1bc1.png

 

In this 5 year old thread I showed how electrodes positioned at different angles influence where discharge will happen:

https://www.scienceforums.net/topic/94255-electric-fields/

 

7 hours ago, westom said:

It causes radio frequency interference because "that flow of electrons in one direction" create radio frequency noise across all frequencies.

Properly would be to say that "accelerated electrons emit photons"..

 

7 hours ago, westom said:

Earliest radio transmitters simply turned on and off a DC current.  Which creates currents at many frequencies.

It is DC which we call pulsating direct current or pulsed DC.

https://en.wikipedia.org/wiki/Pulsed_DC

(anybody who ever created AC to DC rectifier should be familiar with this term)

7 hours ago, westom said:

Static electric discharge is also not DC - for same reason.

If we turn on Van de Graaff generator (or other electrostatic generator), it will continuously create discharge at rate which depends on distance between one electrode and opposite  electrode. It is pulsating direct current. The shorter distance, the smaller delay between discharges. Small distance disallows device to fully charge, and it discharges after reaching enough breakdown voltage to pass electrons through medium. Air requires approximately ~30,000 V for each 1 cm distance between electrodes. It is typical breakdown voltage of air (it varies with pressure and temperature of gas).

https://en.wikipedia.org/wiki/Electrical_breakdown

Presence of radioactive material, or passage of cosmic ray particle, also influences (decreases) breakdown voltage. They ionize air/gas/medium, and electrons gathered at negative electrode easier find path to positive electrode.

This feature has been used in many devices such as Geiger counter, Spark Chamber used by quantum physicists, and widely used smoke detectors using radioactive Americium-241.

https://en.wikipedia.org/wiki/Smoke_detector#Ionization

 

 

Edited by Sensei
Posted
11 hours ago, swansont said:

And yet you claimed that superconductors have resistance, rather than impedance. And haven’t addressed the shortcomings of your claim.

Noted previously that superconductors still have some resistance.  And then noted was, " Impedance (which is clearly not resistance) is a parameter at play."  Superconductors change behavior when frequencies increase.

Which is a transient discussion and really not relevant to static charges (also called static electricity) verses something completely different called a static electric discharges (also called electricity).

Static charges have an E field and no H field.  Static electric discharges are moving charges.  Therefore an H field exists.  Motion is relevant to the location of original static charges.  That current is always between two charges.

Superconductivity really has no place in this discussion.  Discussion is about basic concepts of "static electricity" and "electricity" (two different entities) as defined long before superconductivity was known.

 

 

 

6 hours ago, Ghideon said:

I tried that a few times. What's the point with your advice if you choose to ignore the questions?

After the difference between static charges and moving charges (electricity) were defined, you ask the same question again.  As if never read.  I answered it anyway.  

Now you are asking about some observer.  Neither you nor I are relevant to two separate static charges and any motion between and relevant to those charges.  (Unless you are asking about Schrodinger's cat which is irrelevant here). Discussion is only about static charges and motion of charges between those two locations.  Only those are relevant.  Even earth ground is irrelevant.

I have limited time.  Answers must be limited to misinformation, sentences intentionally taken out of context to simply confuse others, and 'bizarre' accusations that have no place here.

I also ignored his silly belief that electricity is always same at both ends of a wire.  Too many comments that contradict what is all so obvious;

Other misinformation.  Just because Maxwell's equations define electricity does not mean it does not define static charges. In fact, Maxwell's equations define the difference between "static electricity" and a "static electric discharge".  Another misstatement that was best just ignored because it was obvious.

What is relevant?  Two separated charges and a current that can discharge those charges.  Clearly earth ground is irrelevant.  That current (electricity) exists only when two separate charges exist and when connected resulting in moving electrons (charges)..

Just as ridiculous is an inability to grasp many frequencies created when a DC source is switched on or off.  Even high school calculus makes that mistake obvious.

For rigorous definitions, perspective (numbers) must be included.  Unfortunately, denials are constantly using subjective terms. In the world of layman, static electricity and static charges are same.  To quantify that qualitative discussion, then discuss H fields.  Unfortunately naysayers do not even know what an H field nor impedance is.  Making quantitative (rigorous) discussion nearly impossible and really beyond the scope of this discussion.   Discussion must remain at an executive summary level.  Since one does not even know that a switched on or off DC source always results in AC currents at various frequencies.

He even ignores noise created during switching.  Or a well understood example called lightning - that creates frequencies seen on TV screens and heard on radios.  Even the lightning detection network monitors those radio frequencies created when two separated charges are connected (ie a DC current that is turned on and turned off).

Topic is about static charges and electricity when charges are moving.

Posted (edited)
1 hour ago, westom said:

Since one does not even know that a switched on or off DC source always results in AC currents at various frequencies.

Nonsense. It results in pulsating direct current.

https://en.wikipedia.org/wiki/Pulsed_DC

Example of AC to DC transformation creates intermediate half-wave rectification. Full-wave rectification is still pulsing like we can see here (it is later smoothed by capacitor):

1350301343_PulsingDC.png.93ffd25e89217f84c4e2a591eda08d12.png

Edited by Sensei
Posted
13 minutes ago, Sensei said:

Nonsense. It results in pulsating direct current.

Pulse DC was always joke in engineering school.  It does not exist.  Anyone can use math to see why.  For example, use a Fourier Transform on that "pulsed DC".  What is it?  A sum of sine and cosine waves.  A sum of oscillating frequencies.

Either it is a DC voltage (constant  and with no switching).  Or it is a sum of AC voltages.

 

Posted (edited)
1 hour ago, westom said:

Pulse DC was always joke in engineering school.  It does not exist.  Anyone can use math to see why.  For example, use a Fourier Transform on that "pulsed DC".  What is it?  A sum of sine and cosine waves.  A sum of oscillating frequencies.

Play with math is just a play with math (or numerology). One can even get constant result like in equation sin^2+cos^2=1. What is it? A sum of squared sine and sine with shifted phase (aka "cosine") waves.. or other example sin(x)+sin(x+pi)=0. Lack of electricity means that two sine waves cancelled each other due to different phases? Not really..

Variables used in physical equations, have physical meaning.

If you believe that pulse DC has electrons moving in opposite direction, the answer is, no.

 

Edited by Sensei
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