Page 1 of 2 1 2 >
Topic Options
#85773 - 08/09/2004 07:27 Can you hear lightning?
Webster Offline
Weather Freak

Registered: 14/12/2003
Posts: 120
Loc: Ocean View (Dayboro Qld)
Ok, evryone knows what thunder is, but can you hear the actual lightning bolt?

I remember many years ago, in a particularly lightning active thunderstorm with many flangs going off, in the milliseconds before the thunder clap there was a strange (for want of a better description) combination of a whistle and a crack.

I wonder if this was the sound of the lightning itself. It could be sounds generated by the discharge, though it sounds to me as if it is more to do with some kind of air displacement.

Anyone else heard this or know what it is?

Cheers!

Top
#85774 - 08/09/2004 07:48 Re: Can you hear lightning?
dan Offline
Weather Freak

Registered: 08/11/2001
Posts: 727
Loc: ipswich
ya can hear lightning via lower end of the AM band smile

Top
#85775 - 08/09/2004 12:07 Re: Can you hear lightning?
Jacob Offline
Meteorological Motor Mouth

Registered: 17/09/2001
Posts: 6288
Loc: Sydney, NSW
I know exactly what you are talking about.. Like a high pitched whistle/squeal... In the very very very close flangs that Ive endured Ive noted the same thing..

Instead of just the 'crack'.. its like ur outside of the first shockwave.. and all you get is a high pitched almost TV like noise and the sound racing away from u sounds odd..

Im not sure what that whistle is.. evaporation of water in a hurry?...

Top
#85776 - 08/09/2004 13:02 Re: Can you hear lightning?
Kev in Bello Offline
Occasional Visitor

Registered: 23/09/2001
Posts: 5021
Loc: Bellingen NSW 2454
I have heard something similar and also something like a crackle or buzz just before a close lightning strike. In that split second you could feel the air and everything around full of energy and I knew I shouldn't be there!

Top
#85777 - 08/09/2004 16:05 Re: Can you hear lightning?
ErnM Offline
Member

Registered: 15/09/2002
Posts: 590
Loc: Kangaroo Ground, Melbourne
It's my assumption that it's the 'leaders' that make the crackle / buzzing sound a moment before a strike happens. I heard it once just before a very close strike. A sizzling arcing sound. Photos have sometimes shown many leaders reaching up from the ground but only one usually connects up with the CG bolt.

Top
#85778 - 08/09/2004 16:22 Re: Can you hear lightning?
volkl Offline
Volunteer Moderator

Registered: 09/02/2003
Posts: 2239
Loc: Wangaratta.....and proud of it...
Lightning rapidly heats up the air immedietly surrounding the lightning bolt to extremely hot temperatures. That air expands and retracts rapidly with the sudden temp change, and its this expanding and retracting that creates the noise. An actual lightning bolt, although seemingly wide is usually only an inch or 2 wide!!

Top
#85779 - 08/09/2004 17:08 Re: Can you hear lightning?
Jacob Offline
Meteorological Motor Mouth

Registered: 17/09/2001
Posts: 6288
Loc: Sydney, NSW
Moreso referring to that odd eerie whistle sound.. which I guess could come from the electrical 'spray' around the main bolt..

Top
#85780 - 09/09/2004 00:20 Re: Can you hear lightning?
Dale Small Offline
Weatherzone Addict

Registered: 18/11/2001
Posts: 4824
Loc: Greymouth - West Coast, NZ..
I know that whistling sound, the day i got blown off my feet by a <20m away flang..

The stillness, the high pitched whistle similar to what you hear when you are getting your hearing tested when young, then goodnight.

Top
#85781 - 09/09/2004 11:42 Re: Can you hear lightning?
Thunderstruck Offline
Lightning man

Registered: 10/05/2001
Posts: 14835
Loc: Seaford Meadows, SA
LOL Dave awesome! Have had a 5m flang when I was a kid but was inside and 'sleeping' at the time so didnt hear any precursor sounds. Im sure there would be tho some sort of buzzing or hissing.

Robbie, yer the TRUE noise lightning makes is the thunder, as u said the extremely hot temps cause a very rapid expansion of air around the channel of the bolt and because it is heated so suddenly it expands with great force creating a shockwave and of course the lovely music of thunder smile But the precursor sounds would be pretty cool to investigate laugh

TS cool

Top
#85782 - 09/09/2004 20:22 Re: Can you hear lightning?
Laurier Williams Offline
Weatherzone Addict

Registered: 01/02/2001
Posts: 2192
Loc: Millthorpe, 970m, Central W NS...
I've only had two close encounters with lightning, and I'd agree with the crackling/ fizzing/ whistling descriptions. These preceded the crack.

The first was at a caravan rally with my parents at The Entrance, NSW, when I was a kid. The vans were drawn up in a circle (to keep out marauding indians) and we'd retreated into the vans once the downpour started. We'd been playing football in the circle, and the football itself had been left in the middle and now looked like a nipple in a rapidly accumulating field of mud. The lightning hit the football. I was watching it. I clearly remember three things: first, feeling every hair on my body stand up; second, hearing what I can only describe as a short continuous sound something between a fizz and a buzzer; third, a phenomenal ripping, cracking noise that just about knocked my eardrums in but was gone in an instant. Oh, and the football was vaporised.

The second was while camped out on the Barkly Tablelands in eastern NT in December, again as a kid with my parents in a caravan. For most of the evening, we watched a continuous light show in all directions, the storms cells alternately coming closer and retreating. We prudently moved the jerrycans of petrol we carried (fuel stops were a long way apart in the 1960s) off the car roof racks into the bush. There's nowhere to hide on the Barkly in a storm, so we got into the car when things got lively. Over 5 or 6 hours we probably had a dozen or more strikes within 100m, and there were few times that lightning wasn't hitting within a couple of km. Occasionally, the car aerial and other light metallic objects on the car and van would sizzle, and we got quite blase about the way the hair was standing up on our arms and the back of our necks. The close strikes pretty much resembled the experience I had at The Entrance, so much so that I've just always assumed that that's the norm.

My father, who was brought up in the bush, was a good bushman and dabbled in every new electrical and electronic invention during his lifetime, explained it thus, and I haven't read anything to contradict it. Events just prior to the bolt grounding set up a phenomenal static electicity field, and the sounds and experiences are generated by that. If I pull off a fluffy jumper in dry weather, I can hear dozens of little crackles. The sounds I've heard are a bit like that, multiplied many thousands of times. The ripping crack is, I believe, just thunder when heard the instant after its creation. You are so close to it that there is no echo, and I suspect your hearing is temporarily knocked out so that you don't hear the sound of the expansion waves farther up the lightning stroke.
_________________________
Caution: Any items linked to in this post may change and become irrelevant or expire over time. Use good meteorological practice and ALWAYS check date and time on charts before using them.

Top
#85783 - 09/09/2004 20:39 Re: Can you hear lightning?
Lindsay Knowles Offline
Moderator

Registered: 18/01/2003
Posts: 3934
Loc: Pakenham Victoria's Storm Capi...
The day I was struck is something I will never forget. The sound was a hissing/sausage sizzling (maybe that was my brain frying)sound and then the crack. You know it close when its a crack and not a boom. I love the sound of the crack. Defening.
:cheers:
Loo

Top
#85784 - 09/09/2004 21:23 Re: Can you hear lightning?
Scud Offline
Weatherzone Addict

Registered: 27/08/2001
Posts: 1207
Loc: Mcleans Ridges
I have also heard that very high pitched "whisp" or "fizz" sound before a strike a couple of times however it wasnt until around 11pm on the night of January 21 this year in between Forbes and Parkes that I managed to capture it on film. I will try and upload the piece sometime soon so you can hear it however just a millisecond before the CG struck a tree around 100 metres in front of me there was a fizzing noise which my video camera managed to faintly pick up. Below is a capture of the strike which caused it.

Certainly a very amazing and eery experience !


Top
#85785 - 09/09/2004 21:42 Re: Can you hear lightning?
Cloudmaster_dup1 Offline
Weather Nerd

Registered: 15/10/2001
Posts: 5100
Loc: Eastern Suburbs of Sydney, NSW...
Quote:
Originally posted by volkl:
Lightning rapidly heats up the air immedietly surrounding the lightning bolt to extremely hot temperatures. That air expands and retracts rapidly with the sudden temp change
Isn't this just thunder?

EDIT: Oops, didn't see TS comment. Sorry shocked

Top
#85786 - 09/09/2004 22:39 Re: Can you hear lightning?
Fine Elsewhere Offline
Weatherzone Addict

Registered: 02/09/2002
Posts: 1873
Loc: Albany.W.A.
Hi All, yes i agree i've experienced 4 close ones & 2 really stand out in my mind that were near trees that got hit. Yes a fizz is how i'd describe it, the other thing that i find facinating is the absolute silence between the fizz and the splitting CRACK - then what i love is hearing the sound roll away in all 360` directions from you...
i wonder how many other people find that its really strange how you feel a bit frightened when you know its close, but something inside me is wanting to experience that really close fizz, the silence then that spliting crack that IMO nothing else really sounds like in the world. BTW theres a wonderful CD by Garth Brooks entitled No Fences with a song "The Thunder Rolls" thats no a bad sound - if you get the CD theres a rather interesting song called "Friends in low places" that i find rather enjoyable too....but theres no thunder wink wink
:cheers: FE

Top
#85787 - 13/09/2004 08:50 Re: Can you hear lightning?
Marsh Offline
Member

Registered: 27/06/2003
Posts: 465
Loc: Kentucky, USA; was Blackheath,...
Quote:
Originally posted by Laurier Williams:
Events just prior to the bolt grounding set up a phenomenal static electicity field, and the sounds and experiences are generated by that.
Laurier, this is similar to what I learnt in HSC physics. Thus the warning, if you're exposed in a storm and your hair stands on end, it's the possible prelude to being struck by lightning, so take the necessary precautions. IIRC, the charge in the clouds is causing charge separation in your body, so all the similarly charged hairs on your head repell one another, hence the fuzz-ball appearance.

Does anyone else remember the van der Graff generator experiments with all hair standing on end? They were fun.

Top
#85788 - 13/09/2004 09:30 Re: Can you hear lightning?
Tornadosky Offline
Member

Registered: 31/05/2004
Posts: 1739
Loc: Adelaide
Laurier says "Events just prior to the bolt grounding set up a phenomenal static electicity field, and the sounds and experiences are generated by that." Does anyone know if there are any devices on the market that you can set up in your home or in the field, that give readings of the electric field in its vicinity? It would enable one to keep any eye on the potential difference betrween the clouds above and the ground, see how it varies in different weather situations, and aid in forecasting when thunderstorms are likely to develop.

Marsh says "if you're exposed in a storm and your hair stands on end, it's the possible prelude to being struck by lightning, so take the necessary precautions." If you are really exposed and there is no cover around, is there any general agreement on what precautions you can take (other than praying)? Lie down, stand up, run? confused frown

Top
#85789 - 13/09/2004 09:46 Re: Can you hear lightning?
Jacob Offline
Meteorological Motor Mouth

Registered: 17/09/2001
Posts: 6288
Loc: Sydney, NSW
Yes.. there is a setup you can use to detect the electric field, it involves using a slightly radioactive substance and a razor blade.. I cant remember the exact procedure.. Ill look it up..

And I know you need the radioactive stuff from the old Gas lantern mantels.. which probably dont contain the gear anymore.. :\

Top
#85790 - 13/09/2004 09:48 Re: Can you hear lightning?
Jacob Offline
Meteorological Motor Mouth

Registered: 17/09/2001
Posts: 6288
Loc: Sydney, NSW

Top
#85791 - 13/09/2004 11:28 Re: Can you hear lightning?
Tornadosky Offline
Member

Registered: 31/05/2004
Posts: 1739
Loc: Adelaide
By the gods Jacob :rolleyes: - razors, burning radioactive mantles and gluing the ash to the razors, or using the radioactive part of smoke detectors - itd be safer to go outside and earth your feet and hold a long metal pipe in the air and wait for shocks to tell you a storm is overhead! frown But it sounds like it might work without the radioactive bit so I may give the contraption a go.

Now to keep this post within the topic of the thread (otherwise I may have a friendly visit from the moderators) you could probably build a similar device where tiny sparks start to fly across a narrow gap when the potential between cloud and ground gets interesting - tiny lightning in effect, which would produce an audible sound like the ones described in this thread, and you could amplify that sound either directly with a sound amplifier or by using a wireless to pick up the static. smile

I wouldn't be surprised if somewhere on the planet scientists have analysed the sounds made by artificial lightning made in the lab in great detail. Such an analysis might help us understand why we hear the intriguing variety of sounds our intrepid cool storm-watchers have reported in this thread.

Top
#85792 - 13/09/2004 11:45 Re: Can you hear lightning?
Jacob Offline
Meteorological Motor Mouth

Registered: 17/09/2001
Posts: 6288
Loc: Sydney, NSW
Good point! you probably would be safer in the long term holding a lightning rod!! laugh

Ive heard of the 'fencepost' battery chargers et al, very interesting stuff, basically if you have a property with hundreds of metres of fence wire, you can insulate it from ground, and at the end, create a spark gap, and setup a rectifier diode to charge a battery. I dont know if it works, and its supposed to work on drier days out of a static electricity principle..

Subject to verification no doubt.. I know during our nasty storms here, we often have our fluro lights flicker (with the power off) when close lighting is about.. A very eerie thing indeed, but sexy none the less.


J.

Top
Page 1 of 2 1 2 >


Who's Online
5 registered (Funkyseefunkydo, EddyG, Cheers, Foehn Correspondent, 1 invisible), 269 Guests and 4 Spiders online.
Key: Admin, Global Mod, Mod
Today's Birthdays
letecia, mal dinham, Philby, SBT
Forum Stats
29315 Members
32 Forums
23640 Topics
1456250 Posts

Max Online: 2925 @ 02/02/2011 22:23
Satellite Image