snopes.com  

Go Back   snopes.com > Urban Legends > Science

Reply
 
Thread Tools Display Modes
  #1  
Old 26 May 2007, 07:01 PM
snopes's Avatar
snopes snopes is offline
 
Join Date: 18 February 2000
Location: California
Posts: 75,151
TV Use your TV as a tornado detector

Comment: I received this a few years ago by email and have always wondered
if this is true. I do not live in an area that has many tornados, so have
never tried it.

TORNADO WARNING SYSTEM
Warm up the TV set and tune to channel 13. Darken the screen to almost
black.

Turn to channel 2 and leave the volume control down unless you have a
broadcaster on that channel. The TV becomes a tornado detector as
explained.

"As a storm approaches, lightning will produce momentary white bands of
varying widths across the screen. Color sets produce a colored band. A
tornado within 15 and 20 miles will produce a totally white screen and
remain white, or color on color sets.
Should this occur, turn off your TV set, take your portable radio and go
to a place of shelter immediately.

This system was discovered by Newton Weller of West Des Moines, Iowa after
twelve years of study. It works because every TV set has channel 2 set at
55 megacycles. Lightning and tornadoes generate a signal near this
frequency which overrides the brightness control Channel 13 is at the
"high" end of the frequency band and is not affected. This is why the
darkness must be set on that channel.

Keep a protable radio handy for emergency instructions and in case of
power failure. LIghtning will cause intermittent static on a radio tuned
on 550 kilocycles. A tornado will cause steady, continuous static.

The above was featured as the Safety Topic in a newsletter of Argonne
National Laboratory."
Reply With Quote
  #2  
Old 26 May 2007, 07:28 PM
hambubba's Avatar
hambubba hambubba is online now
 
Join Date: 30 June 2000
Location: Gonzales, LA
Posts: 10,052
Default

Actually the electrical frequency of lighting is zero. The higher in frequency you "tune" above zero, the less effect you have. The lower VHF TV frequencies can be detectors, as can any AM receiver. There is also no way to differentiate between a small strike nearby, and a large strike farther away, just based on the electrical noise.

I didn't know tornados generated a frequency on their own; I suppose it's possible it's static electricity, but I wouldn't depend on a TV for reliable detection. Of anything.
__________________
"Write injuries in dust, benefits in marble" - fortune cookie
Reply With Quote
  #3  
Old 26 May 2007, 07:33 PM
hambubba's Avatar
hambubba hambubba is online now
 
Join Date: 30 June 2000
Location: Gonzales, LA
Posts: 10,052
Default

The Weller Method.

Quote:
The bottom line is that the method provide completely unreliable in actual field tests. Did it work sometimes? Yes, but most of the time it did not -- it either indicated a tornadic storm when none occurred, or it did not indicate the presence of such a storm when in fact one was nearby. In meteorological terms, its success score was too low and its false alarm rate too high to be of use.
__________________
"Write injuries in dust, benefits in marble" - fortune cookie
Reply With Quote
  #4  
Old 26 May 2007, 07:38 PM
Doug4.7
 
Posts: n/a
Teacher

Quote:
Originally Posted by hambubba View Post
Actually the electrical frequency of lighting is zero.
They generate EM pulses in just about every frequency band. I have studied lightning using frequencies starting at DC (field mill), up to optical (return strokes), and beyond into x-rays. Okay, I never had an x-ray detector, but some of my fellow scientists do.

A tornado does not have some "fundamental" frequency like that. Although you can use your radio, computer, or TV as a tornado detector: tune to a local radio/TV station and watch for tornado warnings. Or get a weather radio and let it detect the tornadoes for you.
Reply With Quote
  #5  
Old 26 May 2007, 07:45 PM
hambubba's Avatar
hambubba hambubba is online now
 
Join Date: 30 June 2000
Location: Gonzales, LA
Posts: 10,052
Default

I should have clarified, didn't know you were going to spring that kung-fu science stuff on me! The frequency is zero. It's a DC current, whichever way it is going... the "bandwidth" - the amount of radio spectrum it takes up away from "zero hertz" - is tremendous. That's also called "splatter". The reason it may seem to be multifrequency is because of frequency absorption in different parts of the EM spectrum.
__________________
"Write injuries in dust, benefits in marble" - fortune cookie
Reply With Quote
  #6  
Old 26 May 2007, 09:52 PM
Troberg's Avatar
Troberg Troberg is offline
 
 
Join Date: 04 November 2005
Location: Borlänge, Sweden
Posts: 9,234
Default

Quote:
They generate EM pulses in just about every frequency band.
Exactly. That's the way early radios worked, by connecting a morse key to a small spark gap. The sparks caused interference that was easy to detect as it more or less went all over the frequency spectrum.
Reply With Quote
  #7  
Old 26 May 2007, 07:33 PM
Gibbie's Avatar
Gibbie Gibbie is offline
 
Join Date: 20 February 2000
Location: Evansville, Indiana
Posts: 6,228
Default

Just how old is that advice? Warm up your television? References to black and white tv? Even assume it's at all plausible could it work on tvs with cable? It sounds like something you'd expect from rabbit ears or a house antenna.

I didn't find any reference to it on the Argonne National Lab site but I haven't had much time to look yet.

Gibbie
Reply With Quote
  #8  
Old 05 June 2007, 08:12 PM
Robigus
 
Posts: n/a
Default

Quote:
Originally Posted by Gibbie View Post
Just how old is that advice? Warm up your television? References to black and white tv? Even assume it's at all plausible could it work on tvs with cable? It sounds like something you'd expect from rabbit ears or a house antenna.

I didn't find any reference to it on the Argonne National Lab site but I haven't had much time to look yet.

Gibbie
I first heard this in the early to mid 70s. I tried then setting up per the instructions, but never got anything like what was described. Maybe I was just doing it wrong.
Reply With Quote
  #9  
Old 05 June 2007, 10:07 PM
Avril's Avatar
Avril Avril is offline
 
Join Date: 07 August 2002
Location: Princeton, NJ
Posts: 4,127
Default

A much better idea is to have your television tuned to a local broadcast station that will provide actual information about approaching storms.

If a tornado comes close enough that you really need to take cover, you usually won't have time after the signals, but there are such signals, and for that you don't necessarily need a TV. Ears pop. There's the sound of a train far from any actual trains. The sky takes on the color of the ground (greenish if there's a lot of grass, reddish in the red clay parts of Oklahoma, brown where you have just plain dirt, etc.)

The whole thing sounds really impractical.

Avril
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Forum Jump


All times are GMT. The time now is 03:15 PM.


Powered by vBulletin® Version 3.7.4
Copyright ©2000 - 2009, Jelsoft Enterprises Ltd.