Iain Chalmers wrote: >> Watch out for lightning strike!
>> -- >> Cheers
>> Andrew
>> (Make a lightning rod by gluing a blunt ferrous rod to the top of the >> motorcycle helmet, attaching a 4 metre length of copper strap to the rod >> with copper wire, and attaching a suitable boat anchor to the free end >> of the strap to make sure it stays earthed - any Windows 98 computer >> would do.)
> A _blunt_ rod? Have you been taking physics lessons from Hamish again?
> big
" Calculations of the relative strengths of the electric fields above similarly exposed sharp and blunt rods show that although the fields, prior to any emissions, are much stronger at the tip of a sharp rod, they decrease more rapidly with distance. As a result, at a few centimeters above the tip of a 20-mm-diameter blunt rod, the strength of the field is greater than that over an otherwise similar, sharper rod at the same height. Since the field strength at the tip of a sharpened rod tends to be limited by the easy formation of ions in the surrounding air, the field strengths over blunt rods can be much stronger than those at distances greater than 1 cm over sharper ones. The results of this study suggest that moderately blunt metal rods (with tip height–to–tip radius of curvature ratios of about 680:1) are better lightning strike receptors than are sharper rods or very blunt ones. "
C. B. Moore, William Rison, James Mathis, and Graydon Aulich, "Lightning Rod Improvement Studies". Journal of Applied Meteorology: Vol. 39, No. 5, pp. 593–609. Langmuir Laboratory for Atmospheric Research, New Mexico Institute of Mining and Technology, Socorro, New Mexico. April 10, 1999.
> >> (Make a lightning rod by gluing a blunt ferrous rod to the top of the > >> motorcycle helmet, attaching a 4 metre length of copper strap to the rod > >> with copper wire, and attaching a suitable boat anchor to the free end > >> of the strap to make sure it stays earthed - any Windows 98 computer > >> would do.)
> > A _blunt_ rod? Have you been taking physics lessons from Hamish again?
> > big
<snip>
> The results of this study suggest that moderately blunt metal rods > (with tip heighttotip radius of curvature ratios of about 680:1) are > better lightning strike receptors than are sharper rods or very blunt > ones.
OK, I'm wrong (again)...
(at least I'm not alone, it does say "It is commonly believed, erroneously, that a rod ending in a sharp point at the peak is the best"... )
big
-- "Everything you love, everything meaningful with depth and history, all passionate authentic experiences will be appropriated, mishandled, watered down, cheapened, repackaged, marketed and sold to the people you hate." Mr Jalopy quoting Hooptyrides (on jalopyjunktown.com)
> bikerbetty wrote: >> On Feb 19, 10:21 am, "Minx" <sass_my_fr...@hotmail.com> wrote: >>>> So - I finish at 4 in Civic. Let's plot something for Wednesday!!! >>>> bikerbe...@gmail.com >>> 4:30 at corner of Eucumbene Dr and Cotter Rd?
>> I'll be there!!!!
>> betty
> Watch out for lightning strike!
> -- > Cheers
> Andrew
> (Make a lightning rod by gluing a blunt ferrous rod to the top of the > motorcycle helmet, attaching a 4 metre length of copper strap to the rod > with copper wire, and attaching a suitable boat anchor to the free end of > the strap to make sure it stays earthed - any Windows 98 computer would > do.)
Oh poop, there aren't going to be MORE bloody storms, are there? It's just not right in Canberra! Steamy afternoons, celestial pyrotechnics, RAIN?!?!! I've never seen anything like it!
Minx, let's confirm closer to the time, and hope the weather holds!!!
<bigi...@mightymedia.com.au> wrote: >In article <i_9Ch.871$8U4....@news-server.bigpond.net.au>, > Andrew McKenna <NOcmorSPAM3...@NObigpond.SPAMnet.au> wrote:
>> Iain Chalmers wrote:
>> >> Watch out for lightning strike!
>> >> -- >> >> Cheers
>> >> Andrew
>> >> (Make a lightning rod by gluing a blunt ferrous rod to the top of the >> >> motorcycle helmet, attaching a 4 metre length of copper strap to the rod >> >> with copper wire, and attaching a suitable boat anchor to the free end >> >> of the strap to make sure it stays earthed - any Windows 98 computer >> >> would do.)
>> > A _blunt_ rod? Have you been taking physics lessons from Hamish again?
>> > big
><snip>
>> The results of this study suggest that moderately blunt metal rods >> (with tip heighttotip radius of curvature ratios of about 680:1) are >> better lightning strike receptors than are sharper rods or very blunt >> ones.
>OK, I'm wrong (again)...
>(at least I'm not alone, it does say "It is commonly believed, >erroneously, that a rod ending in a sharp point at the peak is the >best"... )
>big
Bigi... is it allowed to admit one is wrong in this group?
In article <aujit29kkbdhhujug0sbk0oavdkt2qb...@4ax.com>,
joebloogs <varc...@msn.com> wrote: > Bigi... is it allowed to admit one is wrong in this group?
I'm not so sure... If it's against the rules, nobody sent me _that_ memo either...
big
-- "Everything you love, everything meaningful with depth and history, all passionate authentic experiences will be appropriated, mishandled, watered down, cheapened, repackaged, marketed and sold to the people you hate." Mr Jalopy quoting Hooptyrides (on jalopyjunktown.com)
<NOcmorSPAM3...@NObigpond.SPAMnet.au> wrote: >bikerbetty wrote: >> On Feb 19, 10:21 am, "Minx" <sass_my_fr...@hotmail.com> wrote: >>>> So - I finish at 4 in Civic. Let's plot something for Wednesday!!! >>>> bikerbe...@gmail.com >>> 4:30 at corner of Eucumbene Dr and Cotter Rd?
>> I'll be there!!!!
>> betty
>Watch out for lightning strike!
Why a ferrous rod? wouldn't a Cu one be a lot better?
> Why a ferrous rod? wouldn't a Cu one be a lot better?
> Johno <just asking>
It would but you can pick up steel bar offcuts at any building site for nix. Dunno where you'd find a copper rod for nix. Might be able to find aluminium rod instead of steel, though. Don't ask me why I'm worrying about the practicalities of this imaginary piece of kit, but for some reason I am.
>> Why a ferrous rod? wouldn't a Cu one be a lot better?
>> Johno <just asking>
> It would but you can pick up steel bar offcuts at any building site for > nix. Dunno where you'd find a copper rod for nix. Might be able to find > aluminium rod instead of steel, though. Don't ask me why I'm worrying > about the practicalities of this imaginary piece of kit, but for some > reason I am.
I think it is the Windows 98 anchor that keeps you hoping...
Andrew McKenna wrote: > " Calculations of the relative strengths of the electric fields > above similarly exposed sharp and blunt rods show that although the > fields, prior to any emissions, are much stronger at the tip of a sharp > rod, they decrease more rapidly with distance. As a result, at a few > centimeters above the tip of a 20-mm-diameter blunt rod, the strength of > the field is greater than that over an otherwise similar, sharper rod at > the same height. Since the field strength at the tip of a sharpened rod > tends to be limited by the easy formation of ions in the surrounding > air, the field strengths over blunt rods can be much stronger than those > at distances greater than 1 cm over sharper ones. > The results of this study suggest that moderately blunt metal rods > (with tip height–to–tip radius of curvature ratios of about 680:1) are > better lightning strike receptors than are sharper rods or very blunt > ones. "
> C. B. Moore, William Rison, James Mathis, and Graydon Aulich, "Lightning > Rod Improvement Studies". Journal of Applied Meteorology: Vol. 39, No. > 5, pp. 593–609. Langmuir Laboratory for Atmospheric Research, New Mexico > Institute of Mining and Technology, Socorro, New Mexico. April 10, 1999.
Check http://www.erico.com/products/s3000_1.asp to see the 3000 series active lighting protection designed and manufactured in Tassy. Note the shape, and read the comments! They actually detect pre-strike and then generate ozone to attract the strike and ground it safely.
Cheers Goaty -- _--_|\ John Lamp - in beautiful downtown Highton / \ IRC:Go...@aus.moto DoD#:1906 Ulysses#:10185 Vulcan Nomad \_.--._/ http://www.gorider.cjb.net/ Phone: 0409 512 254 v mailto:John.L...@gmail.com Fax: 03 5227 2151
> > bikerbetty wrote: > >> On Feb 19, 10:21 am, "Minx" <sass_my_fr...@hotmail.com> wrote: > >>>> So - I finish at 4 in Civic. Let's plot something for Wednesday!!! > >>>> bikerbe...@gmail.com > >>> 4:30 at corner of Eucumbene Dr and Cotter Rd?
> >> I'll be there!!!!
> >> betty
> > Watch out for lightning strike!
> > -- > > Cheers
> > Andrew
> > (Make a lightning rod by gluing a blunt ferrous rod to the top of the > > motorcycle helmet, attaching a 4 metre length of copper strap to the rod > > with copper wire, and attaching a suitable boat anchor to the free end of > > the strap to make sure it stays earthed - any Windows 98 computer would > > do.)
> Oh poop, there aren't going to be MORE bloody storms, are there? It's just > not right in Canberra! Steamy afternoons, celestial pyrotechnics, RAIN?!?!! > I've never seen anything like it!
> Minx, let's confirm closer to the time, and hope the weather holds!!!
> betty
Well..... bloody weather....
Minx and I forgot to pack our lightning rods, and had to abandon our ride this arv. Bugger. This silly tropical weather has GOT to stop!!! More of it expected this week, so we're rescheduling for next week and hoping for some seasonally- and geographically-appropriate sunshine.
On 20 Feb 2007 23:17:36 -0800, "bikerbetty" <bikerbe...@gmail.com> wrote:
>Well..... bloody weather....
>Minx and I forgot to pack our lightning rods, and had to abandon our >ride this arv. Bugger. This silly tropical weather has GOT to stop!!! >More of it expected this week, so we're rescheduling for next week and >hoping for some seasonally- and geographically-appropriate sunshine.
If you wait for the weather, you'll no do much riding. --- Cheers
> On 20 Feb 2007 23:17:36 -0800, "bikerbetty" <bikerbe...@gmail.com> > wrote:
>>Well..... bloody weather....
>>Minx and I forgot to pack our lightning rods, and had to abandon our >>ride this arv. Bugger. This silly tropical weather has GOT to stop!!! >>More of it expected this week, so we're rescheduling for next week and >>hoping for some seasonally- and geographically-appropriate sunshine.
> If you wait for the weather, you'll no do much riding. > --- > Cheers
> PeterC [aka MildThing]
A bit of rain doesn't really bother me - got caught in a lovely storm on the weekend - and besides, it's not usually an issue in Canberra (although I have a few fair-weather rider friends who won't go anywhere if there's so much as a puff of cloud on the horizon....) But this was serious storm stuff. Dunno what's happened to the Canb weather of late - I've had to start putting wet weather gear in the tank bag every day, just in case!!!
"bikerbetty" <bikerbe...@gmail.com> wrote: > Minx and I forgot to pack our lightning rods, and had to abandon our > ride this arv. Bugger. This silly tropical weather has GOT to stop!!! > More of it expected this week, so we're rescheduling for next week and > hoping for some seasonally- and geographically-appropriate sunshine.
God doesn't like it when you start fooling around with nature and pretending you can alter time! -- Clem
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