Re: 2nd law of thermodynamics in question

In message <1164038906.592716.280940@xxxxxxxxxxxxxxxxxxxxxxxxxxx>, Paul <softwarelabus@xxxxxxxxx> writes
Richard Herring wrote:
In message <1163784222.354726.83330@xxxxxxxxxxxxxxxxxxxxxxxxxxx>, Paul
<softwarelabus@xxxxxxxxx> writes
>Hi Richard,
>
>
>Richard Herring wrote:
>> In message <1163776334.395266.157840@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>, Paul
>> <softwarelabus@xxxxxxxxx> writes
>>
>> [...]
>> >
>> >Now, has it _ever_ occurred to you that a stabilized AC signal without
>> >a pulse contains no _directional pulses_ and such a signal merely
>> >contains current that changes directions every cycle (oscillates)???
>> >LOL, so if you want to know the direction of current then you don't
>> >even need to swap the probe connector.
>>
>> Strawman.
>>
>> For the hard of thinking, that means "the preceding is an example of the
>> strawman fallacy."
>>
>> I don't want to know the direction of current. I want to know the
>> direction of energy flow.
>> >I can easily tell you which
>> >direction the electrons are flowing.
>>
>> I don't want to know the direction the electrons are flowing. I want to
>> know the direction of energy flow.
>
>You really don't understand, do you. If your AC signal source is
>unchanging from peak to peak then you simply have steady oscillating
>current.

Which, in combination with a steady oscillating potential difference,
may be associated with:

(a) a flow of energy from left to right, or
(b) a flow of energy from right to left, or (for completeness)
(c) some combination of the above, such as a standing wave.

You claimed to be able to distinguish these. Here you are:

=====================================================
>>
>> So if I have a signal generator connected to a 50 ohm resistor via a
>> coaxial cable, with a T-connector in the middle, and I let you use your
>> oscilloscope to measure the voltage across it, do you think you can tell
>> me which way the energy is travelling?
>
>Yes, I can tell you which way the energy is traveling?
=====================================================

Yes, and my claim is correct, LOL, as you just clarified.

No mention there that you can't do it with a "steady oscillating
current".

Richard, again, there are two types of energy flow. 1. Current. 2. A
pulse. What is your problem?

Oh, that's easy. The problem is in seeing your response as anything but a non-sequitur.

>Geez! How many more ways can you twist your ignorance to save
>face, LOL.

If that weren't so sad if would be funny.
>
>>
>> [...]
>>
>> >> You can measure it before it existed, as far as I'm concerned. >> >>You still
>> >> won't be able to determine the direction of energy flow from a >> >>one-point
>> >> voltage measurement.
>> >
>> >We already went over this. We clarified that we are talking about a
>> >common scope probe with _*TWO*_ connectors. You and I both know what a
>> >common voltage scope probe with two connectors is. If you are going to
>> >measure the voltage on or near the T-connector then you'll obviously
>> >need to touch the electrical wire at two locations because the probe
>> >has two connectors.
>>
>> That's right. The centre pin of the T-connector, and its shield. If I
>> swivel the T and everything connected to it through 180 degrees, will
>> there be any difference?
>
>Come on, I really don't have time for this.

You mean you're evading giving a simple "yes" or "no" to the question
above?

Are you blind pal? I clearly stated "yes" from the start.

Mind reading again? That's the first time I've asked that question. You referred to exchanging the conductors. I'm asking about swivelling the T-connector, leaving the scope probe connected to it. You didn't answer that question.

Stop lying.

Be positive. Read for comprehension next time.


>Read my posts ... for the
>umpteenth time, you _*SWAP THE SCOPE PROBE CONNECTORS*_, lol. My
>example is 100% correct and I challenge you to find error.

The hint was in my invitation to draw a diagram, and my mention of the
common-mode return path.

Just as I thought. You can't find error.

So what do you think the following is?

The oscilloscope purports to measure the _potential difference_ between
its terminals. Therefore if you swap the connectors, you reverse the
polarity of that potential difference, and the scope trace should simply
be inverted.

You are not reading. I _*clearly*_ stated that was for measuring a
pulse.

I know you did. That paragraph you've just quoted applies equally to a pulse or a steady signal. Or are you suggesting that the trace isn't inverted when a pulse is on display?

Go back and read. And you _clearly_ replied asking how that
would work, thereby demonstrating you are not thinking deep enough to
see how it works.

I'll freely admit I can't penetrate your reasoning.

If the trace is not simply inverted, then evidently it is not a simple
measurement of potential difference. Therefore you must be superposing
something else (such as a common-mode signal) on that measurement of
potential difference. Therefore what you have is not a single
measurement.

No, think about it for a few months and perhaps you'll see it. I
already described in detail how to detect the pulse direction and how
it works.

What, you think _this_ is "describing in detail"?
=====================================================
We have an effective electrical conducting wire with a pulse traversing down the wire. We know that once the reflected pulses fade out we end up with a steady AC signal. Now lets go back and analyze the pulse during stage 1 where the pulse first hits the scopes ground lead.

So up to this point the scope was displaying what?

And at this point the scope now displays what?
And this display represents a potential difference of what?
And this PD is between which two points?

During this period the positive lead has no idea

"has no idea" ! ;-)

anything has happened because the pulse has not reached the scopes positive connector. After this event and within a certain amount of time any modern oscilloscope will then see the effects of the pulse hitting the positive lead.

And now it displays what?
And this represents a potential difference of what?
And this PD is between which two points?

Again, this is very doable with a modern oscilloscope. We will see a distinct pulse pattern on the oscilloscope, which for the most part is enough to detect the pulse direction, but any minute doubt is cleared up when the scope probe connectors are swapped and we repeat the pulse.

Same set of questions, for the repeated pulse?

=====================================================

Can you rewrite that as a sequential narrative describing exactly what happens to the potential on each of your terminals?

Feel free to draw a graph if it helps.

--
Richard Herring
.

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