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Script notes: Electricity

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eggshaped
160239.  Tue Mar 27, 2007 3:23 am Reply with quote

Sugar batteries

Quote:

Sugar is used as fuel by all living things. Now Minteer and her colleagues have adapted enzymes from nature that can strip charges from sugar to generate electricity in fuel cells.

 
Frederick The Monk
160387.  Tue Mar 27, 2007 8:15 am Reply with quote

Urine batteries

Quote:
Cheap, disposable, and renewable, urine-powered batteries may be the perfect power source for disposable healthcare test kits called biochips, the researchers say.

 
Gray
160402.  Tue Mar 27, 2007 8:48 am Reply with quote

Some cyanobacteria (remember, those pesky things that originally 'poisoned our atmphere' with oxygen) if deprived of sulphur, start to give off hydrogen instead of oxygen, and this could easily be used as a power source if you could 'farm' enough of them.
Quote:
Hydrogen gas is seen, as a future energy carrier by virtue of the fact that it does not evolve the "greenhouse gas" CO2 in combustion, liberates large amounts of energy per unit weight in combustion, easily converted to electricity, and is an inexhaustible resource.

The only by-product of burning hydrogen is water, of course, which is nice.

http://www.microbialcellfactories.com/content/4/1/36

 
dr.bob
160408.  Tue Mar 27, 2007 8:57 am Reply with quote

Except water vapour is an even more efficient greenhouse gas than CO2. Are you trying to kill us all?!!

 
Gray
160411.  Tue Mar 27, 2007 9:06 am Reply with quote

I expect to have a condenser with a little straw that leads from my iPod straight to my whisky.

 
Frederick The Monk
160435.  Tue Mar 27, 2007 10:24 am Reply with quote

iDrunk

 
eggshaped
160816.  Wed Mar 28, 2007 11:25 am Reply with quote

I've just recieved the following from one of the Met Office's lightning specialists:

Quote:
I am intrigued by your last paragraph as this is not the case.

I recall a story when a whole football team were electrocuted in South America by a strike on the edge of a waterlogged pitch. In July last year, 21 soldiers in Pennsylvania were injured after the metal framed roof of an open pavilion was struck from the storm that they were trying to shelter from!

If a person were out walking across very flat, open ground, say the Fens, or on hills above the tree line - that person might provide the best route to earth! Your comment doesn't really fit with known measurements in the stepped leader or return stroke minima for a ground stroke, which from reliable sources has not been measured to less than 3 metres per step! (ref: Handbook of Atmospheric Electrodynamics, Vollend volume 1).

Since we do not act as a perfect earth, holding something like an umbrella or golf club merely acts as an attractant for the charge pass through the body, causing a combination of flashover burns and irregular heartbeat. Statistics show that death occurs in around 30% of lightning strikes.

So, if caught out in the open in your scenario, you would feel, possibly hear and smell the build-up of charge around you. You would feel the hairs on your body charging, the crackle or fizz of charge becoming audible, and the smell of the ions being transferred from the ground. If you recognised these features quickly enough, you only have a few seconds (if that) you should throw your brolly away and keeping your feet together, crouch down into a ball, with your head down to your knees and hands clasped behind your head. Pray and do not move until the storm has moved away.

It might be well to look at Prof Derek Elsom's site at:- http://www.torro.org.uk/TORRO/research/lightning.php

For a 100 year bibliography of related papers dealing with death and injury (slightly dated 2000) by Ron Holle of NOAA http://www.nssl.noaa.gov/users/holle/public_html/VictimAlpha.html

These two are renowned for the collected statistics for UK and USA respectively.

Paul Taylor


Frustratingly I can't remember what I wrote in the last paragraph which turns out not to be the case.

Not sure if this completely shoots my fox, but I'll check out those links and see if I can salvage anything from this question.

 
Flash
160823.  Wed Mar 28, 2007 11:39 am Reply with quote

The para which begins "So, if caught out in the open in your scenario" could be imported straight into the notes, I would think - I certainly didn't know that you would be able to feel the lightning strike cranking itself up in the way described. And it answers the question "what should you do?" very well.

From the context, I wonder if the last para that you can't remember from your e-mail might have suggested that being the tallest thing in the area wouldn't make any appreciable difference to your chances of receiving a strike? That seems to be what he's repudiating, for the most part.

 
Gray
160973.  Thu Mar 29, 2007 3:17 am Reply with quote

I seem to remember we had a go at repudiating that in the meeting, as we know that charge builds up on objects (including people) just before a strike, so you really do want to be the furthest object from the charged clouds - i.e. the lowest or least 'spiky'.

 
Gray
160974.  Thu Mar 29, 2007 3:19 am Reply with quote



Simon Singh taking his trust in science to the limit, standing inside a Faraday Cage and being struck with lightning. I hope he took the change out of his pockets...

http://www.simonsingh.com/2005_Show.html

 
dr.bob
161045.  Thu Mar 29, 2007 5:29 am Reply with quote

Gray wrote:
I seem to remember we had a go at repudiating that in the meeting, as we know that charge builds up on objects (including people) just before a strike, so you really do want to be the furthest object from the charged clouds - i.e. the lowest or least 'spiky'.


I think the point is it depends where the lightning's "stepped leader" comes down. The Met Office guy refers to lightning striking the edge of a football pitch upon which a team were playing. A clear example of lightning not necessarily hitting the highest point around.

If you're the tallest thing around, you're certainly improving your chances of being hit, which is why you should crouch down if you feel yourself beginning to charge up. But the stepped leader will follow a pretty rambling path down through the atmosphere, so it's not guaranteed you'll be hit, even if you're standing in the middle of a field waving a golf club at the clouds and calling Thor's mother a whore.

Gray wrote:
I hope he took the change out of his pockets...


Of course, there being no electrical field inside a faraday cage, it wouldn't matter if he had change or not. His mobile phone wouldn't work, though.

 
Gray
161049.  Thu Mar 29, 2007 5:34 am Reply with quote

You can never fully trust these cowboy Faraday cage makers, though...

Yes, I saw the pitch strike on video once, and always thought it was strange that the lightning hit that football pitch, and not the stands. I guess it was a better conductor than them, or it was, as you suggest, just a random striking path.

 
dr.bob
161052.  Thu Mar 29, 2007 5:41 am Reply with quote

Don't forget that the stepped leader has to make its way down through an awful lot of air before it gets anywhere near any buildings or people. The relative conductivity of one bit of air compared to the bits around it will play a much greater role in deciding where lightning strikes than anything else.

 
MatC
161514.  Fri Mar 30, 2007 6:46 am Reply with quote

Link to Elephants:

British colonizers establishing plantations in Ceylon classified elephants as vermin, and paid 5 and 10 shilling bounties for killing them. Major Thomas Rogers was considered the supreme elephant pest control man; in the middle of the 19th century he killed 1,400 elephants before being killed by lightning.

S: Scigliano.

 
eggshaped
166265.  Sun Apr 15, 2007 6:19 am Reply with quote

Potato batteries

 

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