[sdiy] Speed of electrons? (was mass extinction of thedinosaurs)

[John L Marshall]

You are correct; cellular phones running at 1.9 GHz; cordless phones running
at 2.4 GHz. Hey, these things are full duplex; transmitting and receiving at
the same time. How did they fit cavity duplexers in such a small package?
He-he. A few more GHz, and you are right plumbing time.


----- Original Message -----
From: Magnus Danielson <cfmd at swipnet.se>
To: <ka4hjh at gte.net>
Cc: <synth-diy at dropmix.xs4all.nl>
Sent: Tuesday, July 24, 2001 9:21 AM
Subject: Re: [sdiy] Speed of electrons? (was mass extinction of
thedinosaurs)


> From: KA4HJH <ka4hjh at gte.net>
> Subject: Re: [sdiy] Speed of electrons? (was mass extinction of the
dinosaurs)
> Date: Tue, 24 Jul 2001 04:13:48 -0400
>
> > Magnus:
> > >Now, this seems like a little mess here...
> >
> > I realize that it's not that simple. The reason I asked is because most
> > people just assume that electricity moves at the speed of light "or
> > something". I was just curious about what's happening at the more or
less
> > macroscopic level in the sort of electronic gadgets we're talking about
> > here. Not that I mind hearing the details...
>
> The change in current and potential difference moves at the speed of
> light, but this speed changes with the material and physical
> layouts. It effectively depends on the stray capacitances and stray
> inductance among other things. A "perfect" modelling is a major
> headache, but rougth estimates can make you come into the
> neighborhood.
>
> What the semiconductor people is trying to do is to make better and
> better estimates by automatic means on a fair amount of calculation.
>
> > matti :
> > >Fibreoptics.
> >
> > Well, even then you won't achieve the speed of light because of the
density
> > of the glass, among other things. But it certainly would be faster.
>
> Actually, it moves the speed of light, it's just that the speed of
> light has been lowered! It is however true that it is not at the
> speed of ligth in vacuum, but that is another thing. What did we learn
> by that? Sloppy usage of terms helps to confuse. We think we know the
> meaning, but when we start to analyse we learn we used the wrong wording.
>
> > John L Marshall:
> > >PC computer front side buses are now running at 400 MHz. That is
blazing
> > >saddles, man.
> >
> > It amazes me that this stuff works at all. Thanks for the info
everybody.
> > If your PC board starts glowing blue your electrons are moving too fast,
> > and it ain't from the heat...
>
> Hehehe... at work I see 2.5 GHz signals on the PCBs and I expect yeat
> higher speeds to come. Interestingly enougth, some of the knowledge I
> have gathered by working with audio needed just a thad of update to
> understand the situations here.
>
> I guess soon enougth I'll find myself in the plumbing buissness.
>
> Cheers,
> Magnus
>