View Full Version : Van de Graaf generators and heart problems
Joel Gilmore
May20-04, 03:46 PM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>Hi all,\n\nI run a group of physics performers that do physics shows at primary and\nhigh schools. One demonstration that we do is the Van de Graaf generator.\nThis is a metal sphere that is charged up to a high voltage, say 200,000V or\nmore, which is used to make sparks (say 5-20cm) and do other electrostatic\ndemonstrations. Currents are typically less than 100 microamps (apparently!)\n\nOne demo is to get an audience member to place their hand on the sphere,\ncharging their body up, so that their hair stands on end (each strand become\nlike charged, and so repels the other strands and the head itself.)\nHowever, just recently, someone mentioned to me that they were no longer\nallowed to do this in schools, because of the risk of a heart attack to\nsomeone with a serious, undiagnosed heart condition.\n\nI can\'t find any real details about this on the web, so I thought I\'d ask\nsome physicists and cardiologists for their help. Is there any basis for\nthis? Is the risk real? Is simply being charged to high voltages\ndangerous, or is it being discharged that causes the problem, i.e., when you\nreceive a spark, can the jolt from that cause problems?\n\nAnyone who could offer some literature supporting or discrediting these\nideas, or give some sound reasoning would be greatly appreciated! For\ninformation see http://www.amasci.com/emotor/vdg.html and\nhttp://www.amasci.com/emotor/safe.html, with the latter mentioning the\ndanger.\n\nCheers,\nJoel\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Hi all,
I run a group of physics performers that do physics shows at primary and
high schools. One demonstration that we do is the Van de Graaf generator.
This is a metal sphere that is charged up to a high voltage, say 200,000V or
more, which is used to make sparks (say 5-20cm) and do other electrostatic
demonstrations. Currents are typically less than 100 microamps (apparently!)
One demo is to get an audience member to place their hand on the sphere,
charging their body up, so that their hair stands on end (each strand become
like charged, and so repels the other strands and the head itself.)
However, just recently, someone mentioned to me that they were no longer
allowed to do this in schools, because of the risk of a heart attack to
someone with a serious, undiagnosed heart condition.
I can't find any real details about this on the web, so I thought I'd ask
some physicists and cardiologists for their help. Is there any basis for
this? Is the risk real? Is simply being charged to high voltages
dangerous, or is it being discharged that causes the problem, i.e., when you
receive a spark, can the jolt from that cause problems?
Anyone who could offer some literature supporting or discrediting these
ideas, or give some sound reasoning would be greatly appreciated! For
information see http://www.amasci.com/emotor/vdg.html and
http://www.amasci.com/emotor/safe.html, with the latter mentioning the
danger.
Cheers,
Joel
Dr. Andrew B. Chung, MD/PhD
May21-04, 03:42 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\n\n\nJoel Gilmore wrote:\n>\n> Hi all,\n>\n> I run a group of physics performers that do physics shows at primary and\n> high schools. One demonstration that we do is the Van de Graaf generator.\n> This is a metal sphere that is charged up to a high voltage, say 200,000V or\n> more, which is used to make sparks (say 5-20cm) and do other electrostatic\n> demonstrations. Currents are typically less than 100 microamps (apparently!)\n>\n> One demo is to get an audience member to place their hand on the sphere,\n> charging their body up, so that their hair stands on end (each strand become\n> like charged, and so repels the other strands and the head itself.)\n> However, just recently, someone mentioned to me that they were no longer\n> allowed to do this in schools, because of the risk of a heart attack to\n> someone with a serious, undiagnosed heart condition.\n>\n> I can\'t find any real details about this on the web, so I thought I\'d ask\n> some physicists and cardiologists for their help. Is there any basis for\n> this?\n\nNot, ime.\n\n> Is the risk real?\n\nIt is probably more imagined than real.\n\n> Is simply being charged to high voltages\n> dangerous, or is it being discharged that causes the problem, i.e., when you\n> receive a spark, can the jolt from that cause problems?\n\nIt is the joules of energy (volts times amps) that when greater than 50\nhas the potential to cause cardiac arrest rather than heart attack.\n\n> Anyone who could offer some literature supporting or discrediting these\n> ideas, or give some sound reasoning would be greatly appreciated!\n\nYou are welcome, Joel.\n\n\nServant to the humblest person in the universe,\n\nAndrew\n\n--\nDr. Andrew B. Chung, MD/PhD\nBoard-Certified Cardiologist\nhttp://www.heartmdphd.com/\n\n**\nWho is the humblest person in the universe?\nhttp://makeashorterlink.com/?L26062048\n\nWhat is all this about?\nhttp://makeashorterlink.com/?R20632B48\n\nIs this spam?\nhttp://makeashorterlink.com/?N69721867\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Joel Gilmore wrote:
>
> Hi all,
>
> I run a group of physics performers that do physics shows at primary and
> high schools. One demonstration that we do is the Van de Graaf generator.
> This is a metal sphere that is charged up to a high voltage, say 200,000V or
> more, which is used to make sparks (say 5-20cm) and do other electrostatic
> demonstrations. Currents are typically less than 100 microamps (apparently!)
>
> One demo is to get an audience member to place their hand on the sphere,
> charging their body up, so that their hair stands on end (each strand become
> like charged, and so repels the other strands and the head itself.)
> However, just recently, someone mentioned to me that they were no longer
> allowed to do this in schools, because of the risk of a heart attack to
> someone with a serious, undiagnosed heart condition.
>
> I can't find any real details about this on the web, so I thought I'd ask
> some physicists and cardiologists for their help. Is there any basis for
> this?
Not, ime.
> Is the risk real?
It is probably more imagined than real.
> Is simply being charged to high voltages
> dangerous, or is it being discharged that causes the problem, i.e., when you
> receive a spark, can the jolt from that cause problems?
It is the joules of energy (volts times amps) that when greater than 50
has the potential to cause cardiac arrest rather than heart attack.
> Anyone who could offer some literature supporting or discrediting these
> ideas, or give some sound reasoning would be greatly appreciated!
You are welcome, Joel.
Servant to the humblest person in the universe,
Andrew
--
Dr. Andrew B. Chung, MD/PhD
Board-Certified Cardiologist
http://www.heartmdphd.com/
**
Who is the humblest person in the universe?
http://makeashorterlink.com/?L26062048
What is all this about?
http://makeashorterlink.com/?R20632B48
Is this spam?
http://makeashorterlink.com/?N69721867
J. J. Lodder
May21-04, 04:12 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\n\nJoel Gilmore <gilmore@PH-S-CS.uq.edu.au> wrote:\n\n> One demo is to get an audience member to place their hand on the sphere,\n> charging their body up, so that their hair stands on end (each strand become\n> like charged, and so repels the other strands and the head itself.)\n> However, just recently, someone mentioned to me that they were no longer\n> allowed to do this in schools, because of the risk of a heart attack to\n> someone with a serious, undiagnosed heart condition.\n>\n> I can\'t find any real details about this on the web, so I thought I\'d ask\n> some physicists and cardiologists for their help. Is there any basis for\n> this? Is the risk real? Is simply being charged to high voltages\n> dangerous, or is it being discharged that causes the problem, i.e., when you\n> receive a spark, can the jolt from that cause problems?\n\nIt is a real risk, now that it has been invented.\nNo responsible school board will want to run even imaginary risks.\n\nFor comparison, you can look at electrified fences.\nThese typically give off several pulses a second, at order 10 kV,\nwith pulse energies between 100 mJ and 10 J/pulse.\nIn most countries use of these near public roads is allowed,\nunder suitable conditions. (certification, marking, etc)\n\nThe site you mention states that small Van de Graaff-s\nwill at worst be able to give off a 500 mJ pulse,\nso they should be allowed in countries\nwhere electrified fencing is allowed.\n\nBut that is by logic,\n\nJan\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Joel Gilmore <gilmore@PH-S-CS.uq.edu.au> wrote:
> One demo is to get an audience member to place their hand on the sphere,
> charging their body up, so that their hair stands on end (each strand become
> like charged, and so repels the other strands and the head itself.)
> However, just recently, someone mentioned to me that they were no longer
> allowed to do this in schools, because of the risk of a heart attack to
> someone with a serious, undiagnosed heart condition.
>
> I can't find any real details about this on the web, so I thought I'd ask
> some physicists and cardiologists for their help. Is there any basis for
> this? Is the risk real? Is simply being charged to high voltages
> dangerous, or is it being discharged that causes the problem, i.e., when you
> receive a spark, can the jolt from that cause problems?
It is a real risk, now that it has been invented.
No responsible school board will want to run even imaginary risks.
For comparison, you can look at electrified fences.
These typically give off several pulses a second, at order 10 kV,
with pulse energies between 100 mJ and 10 J/pulse.
In most countries use of these near public roads is allowed,
under suitable conditions. (certification, marking, etc)
The site you mention states that small Van de Graaff-s
will at worst be able to give off a 500 mJ pulse,
so they should be allowed in countries
where electrified fencing is allowed.
But that is by logic,
Jan
Chris Malcolm
May22-04, 04:49 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>nospam@de-ster.demon.nl (J. J. Lodder) writes:\n\n>Joel Gilmore <gilmore@PH-S-CS.uq.edu.au> wrote:\n\n>> One demo is to get an audience member to place their hand on the sphere,\n>> charging their body up, so that their hair stands on end (each strand become\n>> like charged, and so repels the other strands and the head itself.)\n>> However, just recently, someone mentioned to me that they were no longer\n>> allowed to do this in schools, because of the risk of a heart attack to\n>> someone with a serious, undiagnosed heart condition.\n>>\n>> I can\'t find any real details about this on the web, so I thought I\'d ask\n>> some physicists and cardiologists for their help. Is there any basis for\n>> this? Is the risk real? Is simply being charged to high voltages\n>> dangerous, or is it being discharged that causes the problem, i.e., when you\n>> receive a spark, can the jolt from that cause problems?\n\n>It is a real risk, now that it has been invented.\n>No responsible school board will want to run even imaginary risks.\n\n>For comparison, you can look at electrified fences.\n>These typically give off several pulses a second, at order 10 kV,\n>with pulse energies between 100 mJ and 10 J/pulse.\n>In most countries use of these near public roads is allowed,\n>under suitable conditions. (certification, marking, etc)\n\nIn the UK unmarked electrified fences are allowed beside public roads\nwhen a hedge blocks public access to the wire.\n\nI once watched a busload of drunk rock climbers stop to have a piss on\nsuch a hedge. I suspect this possibility was not considered by the\nlegislators. The resultant scene was both unforgettable and very\ndifficult to describe.\n\n\n\n\n--\nChris Malcolm cam@infirmatics.ed.ac.uk +44 (0)131 651 3445 DoD #205\nIPAB, Informatics, JCMB, King\'s Buildings, Edinburgh, EH9 3JZ, UK\n[http://www.dai.ed.ac.uk/homes/cam/]\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>nospam@de-ster.demon.nl (J. J. Lodder) writes:
>Joel Gilmore <gilmore@PH-S-CS.uq.edu.au> wrote:
>> One demo is to get an audience member to place their hand on the sphere,
>> charging their body up, so that their hair stands on end (each strand become
>> like charged, and so repels the other strands and the head itself.)
>> However, just recently, someone mentioned to me that they were no longer
>> allowed to do this in schools, because of the risk of a heart attack to
>> someone with a serious, undiagnosed heart condition.
>>
>> I can't find any real details about this on the web, so I thought I'd ask
>> some physicists and cardiologists for their help. Is there any basis for
>> this? Is the risk real? Is simply being charged to high voltages
>> dangerous, or is it being discharged that causes the problem, i.e., when you
>> receive a spark, can the jolt from that cause problems?
>It is a real risk, now that it has been invented.
>No responsible school board will want to run even imaginary risks.
>For comparison, you can look at electrified fences.
>These typically give off several pulses a second, at order 10 kV,
>with pulse energies between 100 mJ and 10 J/pulse.
>In most countries use of these near public roads is allowed,
>under suitable conditions. (certification, marking, etc)
In the UK unmarked electrified fences are allowed beside public roads
when a hedge blocks public access to the wire.
I once watched a busload of drunk rock climbers stop to have a piss on
such a hedge. I suspect this possibility was not considered by the
legislators. The resultant scene was both unforgettable and very
difficult to describe.
--
Chris Malcolm cam@infirmatics.ed.ac.uk +44 (0)131 651 3445 DoD #205
IPAB, Informatics, JCMB, King's Buildings, Edinburgh, EH9 3JZ, UK
[http://www.dai.ed.ac.uk/homes/cam/]
Al. Lohse
May22-04, 04:50 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>"Dr. Andrew B. Chung, MD/PhD" wrote:\n>\n> Joel Gilmore wrote:\n\n>>>>>. snipped >>>>>>>>\n>\n> It is the joules of energy (volts times amps) that when greater than 50\n> has the potential to cause cardiac arrest rather than heart attack.\n\n\nInstantaneous Volt times instantaneous Amp is\nan instantaneous Watt, not Joule. A Joule is\na Watt-second. A Joule being a measure of\nenergy while a Watt is a measure of power.\n\nSo, might 50 Joules, or 50 Watts have "the\npotential to cause cardiac arrest rather than\nheart attack."\n\nBTW, I saw this demonstration with a long\nhaired girl (quite memorable) some forty\nyears ago. Surely, if there were a problem,\nit would have emerged by now.\n\nA.L.\n\n> <<<<<<<<<snipped >>>>>>>>>>>>\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>"Dr. Andrew B. Chung, MD/PhD" wrote:
>
> Joel Gilmore wrote:
>>>>>. snipped >>>>>>>>
>
> It is the joules of energy (volts times amps) that when greater than 50
> has the potential to cause cardiac arrest rather than heart attack.
Instantaneous Volt times instantaneous Amp is
an instantaneous Watt, not Joule. A Joule is
a Watt-second. A Joule being a measure of
energy while a Watt is a measure of power.
So, might 50 Joules, or 50 Watts have "the
potential to cause cardiac arrest rather than
heart attack."
BTW, I saw this demonstration with a long
haired girl (quite memorable) some forty
years ago. Surely, if there were a problem,
it would have emerged by now.
A.L.
> <<<<<<<<<snipped >>>>>>>>>>>>
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>Joel Gilmore wrote\n\n> Is the risk real?\n\nYes. It is not the current (100 microamps are indeed harmless).\nIt is the charge. With the high voltage, you get a peak current\nfor a huge lot greater.\nIf I go on a dry flooring, and touch for example a door handle,\nI feel it as very unpleasant.\n\nUlrich\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Joel Gilmore wrote
> Is the risk real?
Yes. It is not the current (100 microamps are indeed harmless).
It is the charge. With the high voltage, you get a peak current
for a huge lot greater.
If I go on a dry flooring, and touch for example a door handle,
I feel it as very unpleasant.
Ulrich
Dirk Bruere at Neopax
May22-04, 04:50 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>J. J. Lodder wrote:\n\n> Joel Gilmore <gilmore@PH-S-CS.uq.edu.au> wrote:\n>\n>\n>>One demo is to get an audience member to place their hand on the sphere,\n>>charging their body up, so that their hair stands on end (each strand become\n>>like charged, and so repels the other strands and the head itself.)\n>>However, just recently, someone mentioned to me that they were no longer\n>>allowed to do this in schools, because of the risk of a heart attack to\n>>someone with a serious, undiagnosed heart condition.\n>>\n>>I can\'t find any real details about this on the web, so I thought I\'d ask\n>>some physicists and cardiologists for their help. Is there any basis for\n>>this? Is the risk real? Is simply being charged to high voltages\n>>dangerous, or is it being discharged that causes the problem, i.e., when you\n>>receive a spark, can the jolt from that cause problems?\n>\n>\n> It is a real risk, now that it has been invented.\n> No responsible school board will want to run even imaginary risks.\n\nNot sure if it\'s too off topic, but one could imagine a risk with just about\nevery science demo imaginable.\n\nAnything with UV - burns, cataracts etc\nPotato/iodine test - iodine is poisonous, allergy to potato mould\nAnything flashing - epilepsy\nMagnets - explain why transcranial magnetic stimulation could be dangerous\n\nCare to add to the list of real, but probably miniscule hazards that would\nfrighten school boards?\n\n--\nDirk\n\nThe Consensus:-\nThe political party for the new millenium\nhttp://www.theconsensus.org\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>J. J. Lodder wrote:
> Joel Gilmore <gilmore@PH-S-CS.uq.edu.au> wrote:
>
>
>>One demo is to get an audience member to place their hand on the sphere,
>>charging their body up, so that their hair stands on end (each strand become
>>like charged, and so repels the other strands and the head itself.)
>>However, just recently, someone mentioned to me that they were no longer
>>allowed to do this in schools, because of the risk of a heart attack to
>>someone with a serious, undiagnosed heart condition.
>>
>>I can't find any real details about this on the web, so I thought I'd ask
>>some physicists and cardiologists for their help. Is there any basis for
>>this? Is the risk real? Is simply being charged to high voltages
>>dangerous, or is it being discharged that causes the problem, i.e., when you
>>receive a spark, can the jolt from that cause problems?
>
>
> It is a real risk, now that it has been invented.
> No responsible school board will want to run even imaginary risks.
Not sure if it's too off topic, but one could imagine a risk with just about
every science demo imaginable.
Anything with UV - burns, cataracts etc
Potato/iodine test - iodine is poisonous, allergy to potato mould
Anything flashing - epilepsy
Magnets - explain why transcranial magnetic stimulation could be dangerous
Care to add to the list of real, but probably miniscule hazards that would
frighten school boards?
--
Dirk
The Consensus:-
The political party for the new millenium
http://www.theconsensus.org
Al. Lohse
May24-04, 04:31 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\n\n\n"Dr. Andrew B. Chung, MD/PhD" wrote:\n>\n> Joel Gilmore wrote:\n> >\n> >>>>>>>>>snipped >>>>>>>>>\n\n> It is the joules of energy (volts times amps) that when greater than 50\n> has the potential to cause cardiac arrest rather than heart attack.\n\n\nInstantaneous Volt times instantaneous Amp is\nan instantaneous Watt, not Joule. A Joule is\na Watt-second. A Joule being a measure of\nenergy while a Watt is a measure of power.\n\nSo, might 50 Joules, or 50 Watts have "the\npotential to cause cardiac arrest rather than\nheart attack."\n\nBTW, I saw this demonstration with a long\nhaired girl (quite memorable) some forty\nyears ago. Surely, if there were a problem,\nit would have emerged by now.\n\nA.L.\n\n\n\n\n>>p>>>>>>> snipped >>>>>>>>>\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>"Dr. Andrew B. Chung, MD/PhD" wrote:
>
> Joel Gilmore wrote:
> >
> >>>>>>>>>snipped >>>>>>>>>
> It is the joules of energy (volts times amps) that when greater than 50
> has the potential to cause cardiac arrest rather than heart attack.
Instantaneous Volt times instantaneous Amp is
an instantaneous Watt, not Joule. A Joule is
a Watt-second. A Joule being a measure of
energy while a Watt is a measure of power.
So, might 50 Joules, or 50 Watts have "the
potential to cause cardiac arrest rather than
heart attack."
BTW, I saw this demonstration with a long
haired girl (quite memorable) some forty
years ago. Surely, if there were a problem,
it would have emerged by now.
A.L.
>>p>>>>>>> snipped >>>>>>>>>
Dr. Andrew B. Chung, MD/PhD
May24-04, 04:31 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\n"Al. Lohse" wrote:\n\n> "Dr. Andrew B. Chung, MD/PhD" wrote:\n> >\n> > Joel Gilmore wrote:\n>\n> >>>>>. snipped >>>>>>>>\n> >\n> > It is the joules of energy (volts times amps) that when greater than 50\n> > has the potential to cause cardiac arrest rather than heart attack.\n>\n> Instantaneous Volt times instantaneous Amp is\n> an instantaneous Watt, not Joule.\n\nCorrect. Joule of energy is proportional to volt times amps times seconds.\nThanks for correcting me.\n\n> A Joule is\n> a Watt-second. A Joule being a measure of\n> energy while a Watt is a measure of power.\n>\n> So, might 50 Joules, or 50 Watts have "the\n> potential to cause cardiac arrest rather than\n> heart attack."\n\n50 Joules when delivered at a time when the heart is vulnerable does have the\npotential for causing ventricular fibrillation (ie cardiac arrest).\n\n>\n> BTW, I saw this demonstration with a long\n> haired girl (quite memorable) some forty\n> years ago. Surely, if there were a problem,\n> it would have emerged by now.\n>\n\nAgree.\n\n\nServant to the humblest person in the universe,\n\nAndrew\n\n--\nDr. Andrew B. Chung, MD/PhD\nBoard-Certified Cardiologist\nhttp://www.heartmdphd.com/\n\n**\nWho is the humblest person in the universe?\nhttp://makeashorterlink.com/?L26062048\n\nWhat is all this about?\nhttp://makeashorterlink.com/?R20632B48\n\nIs this spam?\nhttp://makeashorterlink.com/?N69721867\n\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>"Al. Lohse" wrote:
> "Dr. Andrew B. Chung, MD/PhD" wrote:
> >
> > Joel Gilmore wrote:
>
> >>>>>. snipped >>>>>>>>
> >
> > It is the joules of energy (volts times amps) that when greater than 50
> > has the potential to cause cardiac arrest rather than heart attack.
>
> Instantaneous Volt times instantaneous Amp is
> an instantaneous Watt, not Joule.
Correct. Joule of energy is proportional to volt times amps times seconds.
Thanks for correcting me.
> A Joule is
> a Watt-second. A Joule being a measure of
> energy while a Watt is a measure of power.
>
> So, might 50 Joules, or 50 Watts have "the
> potential to cause cardiac arrest rather than
> heart attack."
50 Joules when delivered at a time when the heart is vulnerable does have the
potential for causing ventricular fibrillation (ie cardiac arrest).
>
> BTW, I saw this demonstration with a long
> haired girl (quite memorable) some forty
> years ago. Surely, if there were a problem,
> it would have emerged by now.
>
Agree.
Servant to the humblest person in the universe,
Andrew
--
Dr. Andrew B. Chung, MD/PhD
Board-Certified Cardiologist
http://www.heartmdphd.com/
**
Who is the humblest person in the universe?
http://makeashorterlink.com/?L26062048
What is all this about?
http://makeashorterlink.com/?R20632B48
Is this spam?
http://makeashorterlink.com/?N69721867
Pieter Kuiper
May24-04, 04:31 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\n"Joel Gilmore" <gilmore@PH-S-CS.uq.edu.au> wrote:\n\n> Anyone who could offer some literature supporting or discrediting these\n> ideas, or give some sound reasoning would be greatly appreciated! For\n> information see http://www.amasci.com/emotor/safe.html,\n> with the latter mentioning the danger.\n\nThat site is OK. The total energy is CV^2/2. It is correct in warning\nagainst Leyden jars - do not increase the capacitance.\n\nBut I do not understand the warning against human chains. I believe that\nthis is safer, because the energy is dissipated by more people.\n\n--\n"Electrons damage the brain," said Farish. (Donna Tartt)\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>"Joel Gilmore" <gilmore@PH-S-CS.uq.edu.au> wrote:
> Anyone who could offer some literature supporting or discrediting these
> ideas, or give some sound reasoning would be greatly appreciated! For
> information see http://www.amasci.com/emotor/safe.html,
> with the latter mentioning the danger.
That site is OK. The total energy is CV^2/2. It is correct in warning
against Leyden jars - do not increase the capacitance.
But I do not understand the warning against human chains. I believe that
this is safer, because the energy is dissipated by more people.
--
"Electrons damage the brain," said Farish. (Donna Tartt)
J. J. Lodder
May25-04, 01:29 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>Chris Malcolm <cam@holyrood.ed.ac.uk> wrote:\n\n> nospam@de-ster.demon.nl (J. J. Lodder) writes:\n\n> >It is a real risk, now that it has been invented.\n> >No responsible school board will want to run even imaginary risks.\n>\n> >For comparison, you can look at electrified fences.\n> >These typically give off several pulses a second, at order 10 kV,\n> >with pulse energies between 100 mJ and 10 J/pulse.\n> >In most countries use of these near public roads is allowed,\n> >under suitable conditions. (certification, marking, etc)\n>\n> In the UK unmarked electrified fences are allowed beside public roads\n> when a hedge blocks public access to the wire.\n>\n> I once watched a busload of drunk rock climbers stop to have a piss on\n> such a hedge. I suspect this possibility was not considered by the\n> legislators. The resultant scene was both unforgettable and very\n> difficult to describe.\n\nNow that we are into applied home physics:\nit is a childrens game to test live electrified fence\nwith a blade of grass and to dare each other\nabout how short you can take it.\n\nBut a Van de Graaff for further education is out of course:\nfar too dangerous to expose the kiddies to,\n\nJan\n\nPS This must be one of the most misspelled names in physics,\nscoring far beyond Einstien and Hawkins.\nThe misspelled name was popularized by the rock band\n\'Van de Graaf Generator\'.\nThe one and only correct spelling is \'Van de Graaff\',\nwithout an r after \'de\' and with a double ff at the end.\n\nBiographical detail, photos and explanations may found at\n<http://chem.ch.huji.ac.il/~eugeniik/history/graaff.html>\nwith further references to other web resources.\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Chris Malcolm <cam@holyrood.ed.ac.uk> wrote:
> nospam@de-ster.demon.nl (J. J. Lodder) writes:
> >It is a real risk, now that it has been invented.
> >No responsible school board will want to run even imaginary risks.
>
> >For comparison, you can look at electrified fences.
> >These typically give off several pulses a second, at order 10 kV,
> >with pulse energies between 100 mJ and 10 J/pulse.
> >In most countries use of these near public roads is allowed,
> >under suitable conditions. (certification, marking, etc)
>
> In the UK unmarked electrified fences are allowed beside public roads
> when a hedge blocks public access to the wire.
>
> I once watched a busload of drunk rock climbers stop to have a piss on
> such a hedge. I suspect this possibility was not considered by the
> legislators. The resultant scene was both unforgettable and very
> difficult to describe.
Now that we are into applied home physics:
it is a childrens game to test live electrified fence
with a blade of grass and to dare each other
about how short you can take it.
But a Van de Graaff for further education is out of course:
far too dangerous to expose the kiddies to,
Jan
PS This must be one of the most misspelled names in physics,
scoring far beyond Einstien and Hawkins.
The misspelled name was popularized by the rock band
'Van de Graaf Generator'.
The one and only correct spelling is 'Van de Graaff',
without an r after 'de' and with a double ff at the end.
Biographical detail, photos and explanations may found at
<http://chem.ch.huji.ac.il/~eugeniik/history/graaff.html>
with further references to other web resources.
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>"Al. Lohse" <lohse@cc.UManitoba.CA> wrote in message\nnews:40AE87B0.2681464F@cc.umanitoba.ca... \n>\n>\n>\n> "Dr. Andrew B. Chung, MD/PhD" wrote:\n> >\n> > Joel Gilmore wrote:\n> > >\n> > >>>>>>>>>snipped >>>>>>>>>\n>\n> > It is the joules of energy (volts times amps) that when greater than 50\n> > has the potential to cause cardiac arrest rather than heart attack.\n>\n>\n> Instantaneous Volt times instantaneous Amp is\n> an instantaneous Watt, not Joule. A Joule is\n> a Watt-second. A Joule being a measure of\n> energy while a Watt is a measure of power.\n>\n> So, might 50 Joules, or 50 Watts have "the\n> potential to cause cardiac arrest rather than\n> heart attack."\n>\n> BTW, I saw this demonstration with a long\n> haired girl (quite memorable) some forty\n> years ago. Surely, if there were a problem,\n> it would have emerged by now.\n>\n> A.L.\n>\n>\n>\n>\n> >>p>>>>>>> snipped >>>>>>>>>\n\nI have also seen them around for quite some time and used to play with them in\nscience labs. I have also seen them in carnival side shows where a girl lights\nbulbs, shocks people with quarters, etc. So I guess they are OK in normal\nsituations. If you have a heart condition, pacemaker, etc. I don\'t know.\n\nI think I would forgo the fun of having my hair stand on end. :)\n\nBill\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>"Al. Lohse" <lohse@cc.UManitoba.CA> wrote in message
news:40AE87B0.2681464F@cc.umanitoba.ca...
>
>
>
> "Dr. Andrew B. Chung, MD/PhD" wrote:
> >
> > Joel Gilmore wrote:
> > >
> > >>>>>>>>>snipped >>>>>>>>>
>
> > It is the joules of energy (volts times amps) that when greater than 50
> > has the potential to cause cardiac arrest rather than heart attack.
>
>
> Instantaneous Volt times instantaneous Amp is
> an instantaneous Watt, not Joule. A Joule is
> a Watt-second. A Joule being a measure of
> energy while a Watt is a measure of power.
>
> So, might 50 Joules, or 50 Watts have "the
> potential to cause cardiac arrest rather than
> heart attack."
>
> BTW, I saw this demonstration with a long
> haired girl (quite memorable) some forty
> years ago. Surely, if there were a problem,
> it would have emerged by now.
>
> A.L.
>
>
>
>
> >>p>>>>>>> snipped >>>>>>>>>
I have also seen them around for quite some time and used to play with them in
science labs. I have also seen them in carnival side shows where a girl lights
bulbs, shocks people with quarters, etc. So I guess they are OK in normal
situations. If you have a heart condition, pacemaker, etc. I don't know.
I think I would forgo the fun of having my hair stand on end. :)
Bill
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