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Only in electricity does the power flow from the negative to the positive.
Pedantic hat on.
Actually wrong, electrics/electronics recognizes positive (vs ground) as the "power source." Directional indicators point arrows from positive, one-way components (diodes and up) show the arrow as working working from or against the positive energy depending what it's supposed to do....
So power is recognized as positive to negative or zero - electronics and electricity deals with charge (positive values indicate positive charge.)
The actual direction that the charge propagates*, that s by way of loosely bonded electrons, is rarely if ever a consideration in electronics/electrical applications. All they know is the + gets eaten.
Oh, while being pedantic power doesn't flow, it propagates* (otherwise electricity would be really slow).
Because the definition of positive/negative charges dates back to the cat-rubbing era of static electricity generation when no one knew how it worked. That the negatively charged particle ended up being the one to move is down to a bad coin flip.
Did you ever see history portrayed as an old man with a wise brow and pulseless heart, weighing all things in the balance of reason?
Is not rather the genius of history like an eternal, imploring maiden, full of fire, with a burning heart and flaming soul, humanly warm and humanly beautiful?
Training a telescope on one’s own belly button will only reveal lint. You like that? You go right on staring at it. I prefer looking at galaxies.
-- Sarah Hoyt
Having said all that, would somebody please kindly tell me why astronomers insist that East is negative, and West is positive?
I guess it's a matter of relative thinking. Are the stars moving above us or is the earth moving below the stars?
I have a feeling the celestial coordinate system might be older than both chronographs and Galileo.
From a navigator's point of view, the stars are anchored to a non-existent point in the sky called the first point of Aries (apart from their proper motion). It is accepted that the earth moves relative to that, for a geocentric position, and then the attitude of the earth is calculated to obtain a topocentric position. All these calculations are related to time - Right Ascension is measured in HH:MM:SS.ss - where East positive rules.
What the astronomers do to get it so wrong, I have no idea.
If I remember correctly (which is doubtful) from my Navigation/Nautical Astronomy lectures of almost 50 years ago. I think it is because the celestial sphere, which comprises all objects in "the sky", moves relative to a static earth.
Astronomy is one of those fields with quite a lot of historical crust. I remember teaching in a foster school reading through the kids' physics books and the one or two that had astronomy in them, made me wonder WTF this stuff isn't expressed in simpler terms/coordinate systems which would totally be possible.
People can't even agree on toilet paper orientation[^].
"Toilet paper orientation is sometimes mentioned as a hurdle for married couples."
And because of that, I've seen it being discussed by Dr. Phil once (his verdict was "who cares!?").
I must admit I've switched from under to over throughout my life and now I think everyone who uses my previous preference is a sick psychopath who should be hanged from the gallows (until I switch back, of course)!
People who own cats always use the "under" roll deployment.
That way the cat can spin the toilet paper without unrolling it.
The cat will quickly bore with the "over" roll deployment after dispensing all of the paper.
If you are lucky enough to have both cats and dogs, this is where the cat tag-teams the dog to rip all of the dispensed paper into shreds.
<Navigators reckon longitude positive to the East, and negative to the West, Why?>
or for compatibility with the Cartesian axis and CAD software which became GIS software and navigation software.
A brilliant case of forward compatibility thinking by those ancient navigators, its what you get from
'sea' programmers ……..
Having said all that, would somebody please kindly tell me why astronomers insist that East is negative, and West is positive? OK, so it means that the Right Ascension increases with time to the West, but that is actually meaningless as the same thing would happen, but just with a minus sign before the number.
Simple. It's based on the direction the sun appears to move across the sky. When the sun is overhead (local noon), how long does it take to get to the western horizon. 6 hours. Likewise, it's been 6 hours since it was on the eastern horizon. From noon, add 6 to the time to get sunset and subtract 6 to get the time of sunrise.
Last Visit: 3-Apr-20 16:25 Last Update: 3-Apr-20 16:25