Why is EE education mainly glorified math?

Jan 07, 2004 50 Replies

I had concluded your maths was at 'school' level but thank you for confirming it.

I'll keep that in mind when answering your other post.

Chimera

"single exponential continuum" boy, standards in school maths are slipping.

I'll keep this simple for you, please try and follow it. I'm not used to teaching this to those at such a low level of understanding.

Your confusion arises from the model you are using so let us start there.

Two rotating vectors, on clockwise one anti clockwise. OK (Just read it again if I'm going too fast).

One is defined as rotating with a positive angular velocity (how fast it is turning) the other a negative angular velocity. The magnitude (you do understand magnitude I hope) of the angular velocities is the same.

To keep it simple I'll use some numbers. Say w = 2pi radians per second (or

360 degrees per second- sorry I forgot you maths is limited).

So, how long to make on complete turn?

Both 1 second One 1 second the other -1 second Both -1 second

Correct answer is Both 1 second (Not going too fast I hope, Airy).

We call this time the PERIOD

Now, and this is where it gets tricky, the frequency is equal to 1/PERIOD

So, both frequencies are 1/1 which is 1Hz, not -1Hz, 1 Hz.

THAT IS BOTH FREQUENCIES ARE POSITIVE

Now, this is where we jump a bit.

It isn't the 'negative frequency' that makes the generation of SSB you are trying to understand work it it the PHASE relationship.

I recommend you finish you school maths book before worrying about Laplace and Fourior

Chimera.

Ignoring your wont for rather childish forms of expression (which in themselves call into question your suitably to have responsibility for educating young persons), you have presented a rather long winded and somewhat childish exposition to illustrate that the magnitudes of two processes, one positive and the other negative, are equal and positive, even though one quantity is negative - you yourself introduced it as having a negative angular velocity. I do not think that anyone reading this NG will be in any doubt that the absolute magnitude of a negative quantity is itself a positive quantity.

However, that is not the issue that you have raised, you have offered nothing to support your assertion that there is no such thing as, "negative frequency".

Indeed, you yourself seem to be confused on the subject of negative time, where you interchange it with positive time in, "One 1 second the other -1 second > Both -1 second".

What do your two rotating vectors represent?

Sure, they're a graphic representation to assist us in our comprehension, but setting that aside, what do they actually represent?

If you answer for yourself that simple question in all its details, especially how time that existed before the zero time of your plane is represented then perhaps you will understand how negative time is represented, and, as a consequence, negative frequency?

(I am not trying to use insulting or patronising forms of expression as is your wont, but merely trying to help you over a hurdle of negative time that other engineers have taken in their stride. It is very important that you get over that hurdle or else your own students are going to be severely disadvantaged by their exposure to you.)

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