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>> Interesting thing: According to Wikipedia [which is never wrong], a
>> nuclear explosion only generates an EMP because of the Earth's magnetic
>> field. Like, if it was in space, it wouldn't do that...
>
> Huh? That doesn't sound right. An old strategic option the USSR apparently
> had was to detonate a -real- big (50 megaton) thermonuke over the US, but
> out in space / low orbit. The idea was to melt all radios and computers,
> the entire US telephone network, etc. As far as I know EMP damage is caused
> by the massive radio waves generated by a nuclear explosion (besides all
> the "hard" gamma radiation, and other nasty stuff besides heat and light).
> These induce current in conductors (i. e. they fry microchips).
>
> Radio definitely travels in a vacuum where there is no magnetism - IMO,
> magnetism CAN effect radio but just to distort or interfere with it. So I'd
> think that a magnetic field will -moderate- or interfere an EMP pulse a
> bit, not be the part-cause of it?
According to Wikipedia, the nuke generates gamma rays, these shred the
Earth's atmosphere and produce current, and the Earth's magnetic field
directs this current towards the ground. (Depending on where in the
world you are. Apparently the USA has a field alignment which makes it a
particularly suitable target to hit.)
All of which makes it sound like if you did this in space, you'd just
get gamma rays...
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Invisible wrote:
> Stefan Viljoen wrote:
>
>> Not sure what it is in BHP (oh you continentals!)
>
> Brake Horse-Power.
Yes, but I've long ago given up trying to convert to that from
joules-per-second, or from it!
--
Stefan Viljoen
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>>> Not sure what it is in BHP (oh you continentals!)
>> Brake Horse-Power.
>
> Yes, but I've long ago given up trying to convert to that from
> joules-per-second, or from it!
Most people refer to that as Watts, not joules per second. But anyway:
http://www.wolframalpha.com/input/?i=brake+horsepower
1 BPH = roughly 0.75 kW.
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Invisible wrote:
> According to Wikipedia, the nuke generates gamma rays, these shred the
> Earth's atmosphere and produce current, and the Earth's magnetic field
> directs this current towards the ground. (Depending on where in the
> world you are. Apparently the USA has a field alignment which makes it a
> particularly suitable target to hit.)
Could be I suppose. Wouldn't that imply that if your PC is fried by a nuke
due to EMP, you wouldn't be far behind (since if gamma rays cause EMP, your
DNA'd be shredded too by them... right along with your electronics based
friend.)
Vs. where if it was the intense burst of -radio- waves that caused EMP, you
might have a chance to biologically survive (at least in the moment) when
your PC is fried by EMP from a nuke.
> All of which makes it sound like if you did this in space, you'd just
> get gamma rays...
Might be. Though I wonder if EMP is caused by interaction between oxygen /
nitrogen being bombarded with high-intensity gamma rays? Because that seems
to be what Wik implies here. Intense radio waves seems to me to make more
sense.
--
Stefan Viljoen
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>> According to Wikipedia, the nuke generates gamma rays, these shred the
>> Earth's atmosphere and produce current, and the Earth's magnetic field
>> directs this current towards the ground. (Depending on where in the
>> world you are. Apparently the USA has a field alignment which makes it a
>> particularly suitable target to hit.)
>
> Could be I suppose. Wouldn't that imply that if your PC is fried by a nuke
> due to EMP, you wouldn't be far behind (since if gamma rays cause EMP, your
> DNA'd be shredded too by them... right along with your electronics based
> friend.)
No - because the gamma rays have all been turned into heat and
electricity and filtered out by the Earth's atmosphere. (There's
actually quite a lot of gamma rays out there, all the time. And cosmic
rays, which are even higher energy. They just never reach the ground.)
The electric current, however, is *not* stopped by the atmosphere...
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Invisible <voi### [at] dev null> wrote:
> >> According to Wikipedia, the nuke generates gamma rays, these shred the
> >> Earth's atmosphere and produce current, and the Earth's magnetic field
> >> directs this current towards the ground. (Depending on where in the
> >> world you are. Apparently the USA has a field alignment which makes it a
> >> particularly suitable target to hit.)
> >
> > Could be I suppose. Wouldn't that imply that if your PC is fried by a nuke
> > due to EMP, you wouldn't be far behind (since if gamma rays cause EMP, your
> > DNA'd be shredded too by them... right along with your electronics based
> > friend.)
>
> No - because the gamma rays have all been turned into heat and
> electricity and filtered out by the Earth's atmosphere. (There's
> actually quite a lot of gamma rays out there, all the time. And cosmic
> rays, which are even higher energy. They just never reach the ground.)
> The electric current, however, is *not* stopped by the atmosphere...
What I found most interesting in that wikipedia article (which is an uncommonly
good one) was that this widespread EMP effect is almost zero for very low
altitude airbursts or ground detonations, and is most effective at
nearly-orbital altitudes. Which means that a pivotal scene in the movie "Broken
Arrow" is particularly impossible. :)
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>>>> According to Wikipedia, the nuke generates gamma rays, these shred the
>>>> Earth's atmosphere and produce current, and the Earth's magnetic field
>>>> directs this current towards the ground. (Depending on where in the
>>>> world you are. Apparently the USA has a field alignment which makes it a
>>>> particularly suitable target to hit.)
>>> Could be I suppose. Wouldn't that imply that if your PC is fried by a nuke
>>> due to EMP, you wouldn't be far behind (since if gamma rays cause EMP, your
>>> DNA'd be shredded too by them... right along with your electronics based
>>> friend.)
>> No - because the gamma rays have all been turned into heat and
>> electricity and filtered out by the Earth's atmosphere. (There's
>> actually quite a lot of gamma rays out there, all the time. And cosmic
>> rays, which are even higher energy. They just never reach the ground.)
>> The electric current, however, is *not* stopped by the atmosphere...
>
> What I found most interesting in that wikipedia article (which is an uncommonly
> good one) was that this widespread EMP effect is almost zero for very low
> altitude airbursts or ground detonations, and is most effective at
> nearly-orbital altitudes. Which means that a pivotal scene in the movie "Broken
> Arrow" is particularly impossible. :)
Also, as I mentioned, millions of films seem to assume that an EMP only
affects devices which are turned on. (E.g., War of the Worlds, only one
working car because it wasn't turned on. WTF? Then again... War of the
Worlds. WTF?)
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Invisible wrote:
>> What I found most interesting in that wikipedia article (which is an
>> uncommonly good one) was that this widespread EMP effect is almost zero
>> for very low altitude airbursts or ground detonations, and is most
>> effective at nearly-orbital altitudes. Which means that a pivotal scene
>> in the movie "Broken Arrow" is particularly impossible. :)
>
> Also, as I mentioned, millions of films seem to assume that an EMP only
> affects devices which are turned on. (E.g., War of the Worlds, only one
> working car because it wasn't turned on. WTF? Then again... War of the
> Worlds. WTF?)
Its movieland! Good science almost never makes for good drama.
Its like Captain Picard saying "Full stop!" on the Enterprise, and in ten
seconds they are at relative dead stop from going several hundred times
lightspeed. I wonder exactly how much energy you'd need to decelerate ten
grammes of mass, from, say, 100 * c to 0 in ten seconds - if
Einsteinian "thou shalt NOT exceed, or even closely approach, C" did not
apply. Nevermind a gigatonne starship.
I guess you'd need the full output of all a the Milky Way galaxy's stars for
a few minutes or something. Even 1701-D's anti-matter power generation
systems would be sucked dry in moments.
But it isn't good drama to have the crew become a biological soup one
molecule thick against the viewscreen each time Geordi or Wesley steps on
the footbrake, thus exposing them all to 100000000000000000000000000G of
deceleration.
--
Stefan Viljoen
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Stefan Viljoen wrote:
> Its movieland! Good science almost never makes for good drama.
>
> Its like Captain Picard saying "Full stop!" on the Enterprise, and in ten
> seconds they are at relative dead stop from going several hundred times
> lightspeed.
Never mind the "minor detail" of the fact that "stationary" doesn't
exist in outer space.
Or that you don't actually need engines in order to move, only to
accelerate or deccelerate.
Or the fact that things don't make that "swoshing" noise in space. In
fact, they don't make *any* noise!
Or the Weighted Companion Cube will never threaten to stab you and, in
fact, cannot speak.
> I wonder exactly how much energy you'd need to decelerate ten
> grammes of mass, from, say, 100 * c to 0 in ten seconds - if
> Einsteinian "thou shalt NOT exceed, or even closely approach, C" did not
> apply. Nevermind a gigatonne starship.
Well, the fastest starships reputedly reach Warp 10 (i.e., 10c). Never
mind the "minor detail" that this would cause the ship to travel
backwards in time, and have an imaginary mass. (Irony?)
> But it isn't good drama to have the crew become a biological soup one
> molecule thick against the viewscreen each time Geordi or Wesley steps on
> the footbrake, thus exposing them all to 100000000000000000000000000G of
> deceleration.
Perhaps you're forgetting the Inertial Dampers?
Even the teleporters have Hiesenburg Compensators on them...
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Invisible wrote:
> Stefan Viljoen wrote:
>
>> Its movieland! Good science almost never makes for good drama.
>>
>> Its like Captain Picard saying "Full stop!" on the Enterprise, and in ten
>> seconds they are at relative dead stop from going several hundred times
>> lightspeed.
>
> Never mind the "minor detail" of the fact that "stationary" doesn't
> exist in outer space.
Correct - "relative dead stop". Apparently according to The Bible (the
Enterprise Tech Manual I bought in '92) StarFleet uses the galactic center
as navref.
> Or that you don't actually need engines in order to move, only to
> accelerate or deccelerate.
>
> Or the fact that things don't make that "swoshing" noise in space. In
> fact, they don't make *any* noise!
How boring would that be?! Its part of what I love about old TNG episodes,
the "thrummmm" sound of the Enterprise is orbits
yet-another-planet-with-human-looking-aliens-and-hot-alien-chicks-only-distinction-is-a-new-head-piece.
>> I wonder exactly how much energy you'd need to decelerate ten
>> grammes of mass, from, say, 100 * c to 0 in ten seconds - if
>> Einsteinian "thou shalt NOT exceed, or even closely approach, C" did not
>> apply. Nevermind a gigatonne starship.
> Well, the fastest starships reputedly reach Warp 10 (i.e., 10c). Never
> mind the "minor detail" that this would cause the ship to travel
> backwards in time, and have an imaginary mass. (Irony?)
... and need infinite energy to move an infinite mass that occupies all
points in the universe simultaneously. Sounds painful.
>> But it isn't good drama to have the crew become a biological soup one
>> molecule thick against the viewscreen each time Geordi or Wesley steps on
>> the footbrake, thus exposing them all to 100000000000000000000000000G of
>> deceleration.
>
> Perhaps you're forgetting the Inertial Dampers?
No, I intentionally -ignored- them! :)
As I ignored the SIF (structural integrity field) and the artificial gravity
generators, the navigational deflector, subspace radio, etc. etc. and all
the other fanciful things you apparently "need" for supralight space travel
and five year space missions. (And discovering hot alien chicks on remote
planets.)
> Even the teleporters have Hiesenburg Compensators on them...
:-) the thought of uncertainty with a matter dematerialisation and
transportation device gives me the willies! Or could it possibly make you
LOOSE your willy? Along with other bits?
--
Stefan Viljoen
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