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Talk:Nuclear electromagnetic pulse

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EMP from the SunEdit

Wer shoudl include this as a possibel source fo EMP and evience as to what happnened with previous incidents i.e. THE Carrington Event 1859: and modern prpearation for it ALTHOUGH there is nothing preparing for eth nuclear meltdown if we had 100s of power statsions suddenly going critical if there is nothing to stop them. — Preceding unsigned comment added by (talk) 12:09, 23 October 2012 (UTC)

This article already includes a note to the effect that geomagnetic storms are sometimes referred to as "solar EMP." Although there are many similarities between the E3 component of nuclear EMP and the effects of solar storms, calling the effects of solar storms "solar EMP" has caused an enormous amount of confusion. Some of that confusion is reflected in the article mentioned above. There are many very important differences between nuclear EMP and the results of solar storms. X5dna (talk) 04:19, 30 October 2012 (UTC)

US centric?Edit

What's impressive about this article is that it is written exclusively from the point of view of an American with a presumed audience of Americans. The last "FAQ" is rather amazing in this respect—"America isn't defended!" -- (talk) 16:48, 28 July 2009 (UTC)

Agreed! This article is incredibly americo-centric. Actually it's rather arrogant and prejudiced. Please provide more rounded articles! Maybe this is more a reflection of the political system in America, i.e., if something is not American it's not worth listing too. Americans need to become less self centred! (Note the 'r' before 'e'). —Preceding unsigned comment added by (talk) 00:05, 5 November 2010 (UTC)

Popular Culture referencesEdit

Should we add appearances of EMP in movies, books? Matrix, War of the Worlds and Modern Warfare 2 are the 1st to come my mind. OzhanTR (talk) 19:22, 3 January 2010 (UTC) No! Wikipedia is not for trivia. (Axeo) —Preceding unsigned comment added by (talk) 00:08, 5 November 2010 (UTC) There are popular culture references that are not trivial. What about fiction book built around the concept (One Second After - Non-technical folks will also be coming to this page due to the new NBC series ( and may want discussion of this topic outside of technical scientific literature. — Preceding unsigned comment added by (talk) 14:31, 13 September 2012 (UTC)

This keeps coming up over and over again. There is a separate article called Electromagnetic pulse in fiction and popular culture that is specifically for fiction and popular culture references. Please do not use the main article on Electromagnetic pulse for popular culture references. X5dna (talk) 04:00, 30 October 2012 (UTC)

Correcting the US centric problemEdit

The broader question is: Where are the authoritative non-US publications about electromagnetic pulse that can be referenced in order to expand this Wikipedia article more broadly beyond U.S. and Soviet experiences and official reports?

Many EMP experts have stated in verbal reports that Europe, China and Russia have had extensive civilian activities devoted to EMP hardening. I have found hundreds of authoritative US-generated documents about EMP, and I have read many of them. I am sure that other countries must also have published non-classified material about EMP considering the work that they've done. I've only found a very few such articles, and most of them are not available in English. Please put any possible leads to authoritative non-US information here. X5dna (talk) 03:22, 10 August 2009 (UTC)

Effects of EMP?Edit

How does EMP damage sensitive electrical equipment?

How does it damage power systems?

How does one protect against it? Does shielding help?


Gypsydoctor (talk) 03:33, 15 August 2009 (UTC)

More specifics:

My computer is off but connected to the power grid, will it be damaged?

Is the whole power grid in danger?

Does the article implies a large enough EMP over the US would send it back to the middle ages with no electricity, no computers, no spares, no water, no cars...? How far can this go? —Preceding unsigned comment added by (talk) 19:18, 24 October 2009 (UTC)

It would send the US back to the middle ages. If you computer is off but connected, it will be toast. If you computer is off and unplugged, it will be toast. Yes the entire power grid is in danger. I would suggest reading "One Second After" to get an idea of what may happen. Just an FYI, the guy that wrote the story is highly respected and knowledgeable in the area of EMP. --Brian(view my history)/(How am I doing?) 04:21, 31 March 2010 (UTC)

Effects of EMP. Best Available Information.Edit

This article, and especially the now-archived section of this discussion page, had (for a few years) been a rather chaotic forum-like discussion of questions and answers about EMP effects and EMP protection. That problem went away for a long time after a link to the United States EMP Commission's excellent Critical National Infrastructures Report was put in the very first paragraph of the article. The link was removed on 9 August by Cybercobra on the grounds that it doesn't belong there. (By Wikipedia standards, he's right, and the link is still in the references at the bottom of the page.)

I'm afraid, though, that we're going to get right back into the same lengthy question-and-answer forum session about EMP effects unless the link to that report is featured quite prominently. The report is at:

There are many problems with a Wikipedia article about specific EMP effects. One is that the article would necessarily be extremely long (literally book-length, and a very long book at that). The concise EMP Commission Critical National Infrastructures Report is more than 200 pages long. Another problem is that the likely EMP effects change continuously as electronic technology rapidly changes. Yet another problem is that EMP protection technology is continuously and rapidly evolving. Although the EMP Commission Critical National Infrastructures Report is a look at the situation in 2008, they were able to take a fairly good snapshot of the situation at one particular time. The report can also be extrapolated, to a large extent, to most other industrialized nations besides the United States. The EMP Commission was also able to do EMP simulator testing to substantiate their statements; however scientists and engineers involved in discussions on Wikipedia talk pages had to make educated guesses based on their individual widely-varying experiences with electromagnetic disturbances. X5dna (talk) 13:13, 15 August 2009 (UTC)

Merging or Deleting Electromagnetic Bomb articleEdit

It has been suggested that the Electromagnetic bomb article be merged into the Electromagnetic pulse article. I can see nothing of value in the Electromagnetic bomb article. In fact, the Electromagnetic bomb article contains some important errors. The Electromagnetic bomb article has always been mostly a repository for rumor and opinion, with some occasional information from popular media articles that contain no scientific references. The Electromagnetic bomb article contains little valuable information beyond what is in the Electromagnetic pulse article. I suggest that the Electromagnetic bomb article simply be deleted if others agree with this assessment. X5dna (talk) 00:30, 2 October 2009 (UTC)

I found some material in "electromagnetic bomb" that was not overlapping and had references, so I merged the articles rather than nominating for deletion. I left out dubious material, but I did end up pulling over some unreferenced passages. It's clearly tagged as such, and unless I think unreferenced material is probably wrong, I prefer to leave it around until someone can at least make a good-faith effort to find sources. Please feel free to yank anything unreferenced which you know is wrong, and I expect some amount of smoothing out will be necessary as the new content settles out. (But at least now we have one article in need of improvement, instead of two largely overlapping articles in need of improvement.) -- Beland (talk) 02:51, 3 October 2009 (UTC)
I deleted two sections that were imported from the "electromagnetic bomb" article that contained so many errors that the sections were pretty much beyond repair. It will take some time to fully integrate and reference the remaining material. I think that the topic of "Electromagnetic Pulse in Fiction" would be a good one for a separate article. I have been told that the Mythbusters on the Discovery Channel did a show on how Hollywood gets EMP wrong. I haven't seen that show, but Electromagnetic Pulse is usually portrayed incorrectly in fiction, although a few recent works of fiction have done a pretty good job. X5dna (talk) 03:35, 3 October 2009 (UTC)

Weapon Yield TerminologyEdit

When discussing weapon yields, I don't mind the parenthetical conversion to terajoules or petajoules, but the repeated use of "kilotons of TNT" or "megatons of TNT," rather than just kilotons or megatons, seems to make this article much harder to read. It seems to me that we no longer need to continually refer to a 146-year-old chemical explosive that the average reader of this article probably considers to be completely irrelevant to the understanding the topic of this article. Most readers think of kilotons or megatons as nuclear weapon yields. Wiki-links, as appropriate, to the "TNT equivalent" article seem more reasonable than the repeated references to TNT. X5dna (talk) 05:50, 10 October 2009 (UTC)

Since no one else has commented on this, I went ahead and removed the repeated references to TNT in the nuclear weapons yield statements in this article. In addition to making the article more difficult to read, the often-repeated TNT references added to the possible confusion since many methods of non-nuclear generation of electromagnetic pulse use chemical explosives. Where the references to TNT equivalence were removed, I wiki-linked to the article on "Nuclear Weapon Yield" in case any reader actually had any confusion about the terms kiloton or megaton. X5dna (talk) 11:18, 17 October 2009 (UTC)

Common Misconceptions SectionEdit

I re-wrote the "Common Misconceptions" section to be more encyclopedic, and less like a part of an essay. Although this section mostly repeats material in earlier sections, I don't think that this section should be deleted since the misconceptions that it addresses appear almost daily in new writings in the popular press and on the internet. Further suggestions are welcome. X5dna (talk) 01:56, 6 November 2009 (UTC)

On the topic of this section, I am missing the "misconceptions" part of the section. All I see is a list of explanations, but the actual misconceptions are not explicitly stated. I think it should mention the (cited) misconception, and then debunk it. As it stands, these are just random fragments of information. Remco47 (talk) 15:17, 17 March 2010 (UTC)
This is an inherent problem with Wikipedia as it pertains to subjects which have many very common and widespread misconceptions. Although it is very easy to find these misconceptions about EMP all over the internet, the misconceptions are not specifically listed as such in any authoritative source. Wikipedia has a strict "No Original Research" policy. This means that the misconceptions cannot be listed. The corrections to the misconceptions are easily confirmed in many authoritative sources, so the facts correcting the misconceptions can be listed. This article originally had these very common misconceptions listed along with the actual facts, but there were a lot of complaints about listing the misconceptions, so they were removed. (In fact, I am the one who originally listed the misconceptions because they were so widespread. I am also the one who took the misconceptions out, because I could not figure out a way to include them without violating Wikipedia policies.) There is also a bit of a problem with listing statements that are known to be false in an encyclopedia, even if the false statements are immediately followed by a correction of the false statement. X5dna (talk) 05:38, 19 March 2010 (UTC)
I saw a glaring problem with the fifth 'misconception'. The original statement was "Not every electronic device will be damaged if an EMP occurs. Items like battery-powered handheld radios that have no wire or antenna exceeding 30 inches will survive." However the FEMA source did not imply that devices under 30 inches wouldn't be affected. IMHO the FEMA source is hardly a reputable scientific source. The only thing true about any of this is the implication that some devices may not be affected. Who is to say that all types of batteries won't be affected? I changed it a little to at least reflect what the FEMA source said. However I think scientific sources reflecting real research is necessary here - not re-mashed-bureaucratic-talk-down sources. -- (talk) 02:30, 17 May 2010 (UTC)
I agree with the above posting about FEMA being a poor source of information on this. I changed that sentence to a direct quotation from the FEMA manual. The direct quotation was, at least, more accurate than the earlier statements paraphrasing the old FEMA manual. Since the FEMA manual is a U.S. Federal Government publication, Wikipedia policy permits a direct quotation. The old FEMA statement basically agrees with more authoritative statements made about the affects of 1962 and earlier nuclear weapons technology. The 25-year-old FEMA manual would NOT be accurate for any kind of enhanced-EMP weapon. I wish that people would refrain from citing material from the 1980s and earlier for what EMP effects would be on 21st century electronics. X5dna (talk) 22:03, 18 May 2010 (UTC)
I still find that quote confusing. I understand the grounding part but I do not understand the "30 inches". Is this implying that there is some kind of wave-length factor in the EMP? I've never seen any reference to that before so if the FEMA quotation is based on reality where is a source that clarifies this? -- (talk) 05:10, 26 May 2010 (UTC)
A process known as a Fourier transform can show that any pulse is equivalent to a group of frequency components. This means that for any particular electromagnetic pulse, it does contain a group of wavelengths. To see some actual results of EMP for various nuclear weapon yields, and the corresponding frequency components that it contains, see on pages 28 and 29. That report shows that most nuclear weapons don't yield frequency components much above 100 MHz. and the strength drops off steeply at higher frequencies. On the other hand, the greater the gamma ray output of the nuclear weapon, the higher the frequency components (and the shorter the wavelengths in the pulse).
The 2008 EMP Commission Critical National Infrastructures Report stated that, for portable two-way radios, the results of current testing were essentially the same as tests done in 1973 (which is where the 30-inches rule of thumb originated). This is a bit deceptive, though, because portable two-way radios have sophisticated filtering in the circuits connected to the antenna and much more rugged components that most types of electronics equipment. This ruggedness cannot be extended to other types of electronics equipment. The EMP Commission found that most public safety two-way base stations would be destroyed because they contain microprocessor-based circuits. X5dna (talk) 17:00, 26 May 2010 (UTC)
I replaced the 25-year-old FEMA information with a quotation from the 2008 U.S. EMP Commission Report. I agree with others that very old information from non-scientific sources has no place in this article. Whoever wrote this paragraph originally with the old FEMA information probably wanted to make it clear that an EMP is unlikely to destroy every electronic device. However most electronics equipment in use today is not decades old, and information about extremely old electronics systems is not relevant. X5dna (talk) 22:00, 28 May 2010 (UTC)

External link to Popular Mechanics 2001 articleEdit

Would anyone object to the deletion of the External link to the cover article in the September 2001 issue of Popular Mechanics? The lead-in to that article states, "In the blink of an eye, electromagnetic bombs could throw civilization back 200 years. And terrorists can build them for $400." This statement has caused confusion in discussions all over the internet since it confuses nuclear EMP with non-nuclear EMP, and leaves the impression that terrorists can build a nuclear weapon for 400 dollars. This Popular Mechanics article has been responsible for so much misinformation and confusion that I don't believe that the Popular Mechanics article should be linked from a Wikipedia article. X5dna (talk) 05:49, 23 November 2009 (UTC)

Electromagnetic pulse in fiction/popular cultureEdit

Someone has added a description of a video game which includes an EMP to this article. The video game reference clearly does not belong in this article. Whenever I can find the time, I hope to create a new page called "Electromagnetic pulse in popular culture," although anyone else is welcome to begin such a page if they have time to start the page before I do.  There was once an article called "Electromagnetic pulse in fiction," but it was deleted back in the days when articles were deleted by Wikipedia administrators for trivial reasons. That deletion has proven to be a very serious mistake because whenever there is no article for "Electromagnetic pulse in fiction," then fiction will begin to creep into the scientific article on "Electromagnetic pulse." Misguided Wikipedia policies of the past have led to articles (such as this article on 1 December 2009) which seem to show video game rules as being actually equivalent to real and powerful nuclear weapon effects. There is a need to have a separate article about the occurrence of electromagnetic pulse in fictional/gaming situations so that it can be clearly distinguished from the occurrence of electromagnetic pulse in reality. (This has been a problem in Wikipedia for many years). X5dna (talk) 10:30, 1 December 2009 (UTC)

New article on Electromagnetic pulse in fiction and popular cultureEdit

There is now a new article called Electromagnetic pulse in fiction and popular culture.  This new article is the place for all fictional and video game references to electromagnetic pulse. Please do not put fictional references in the scientific article on electromagnetic pulse. X5dna (talk) 04:56, 14 January 2010 (UTC)

Citation needed???Edit

I removed the "citation needed" tag after the phrase "Typical modern scenarios seen in large numbers of news accounts and opinion articles . . ." in the "Post-Cold War attack scenarios" section. A Google search today for "electromagnetic pulse" in news articles shows 2,580 news articles and 17,718 blog postings about electromagnetic pulse for a total of 20,298 possible references that could be used here. Although not all of these possibilities would be appropriate for references here, a large number of them would be. Including only the most highly appropriate references would still leave hundreds of highly relevant examples. Citations are not needed for things that appear in news and opinion articles on a daily basis. These "citation needed" tags for obvious things like this are simply time wasters. X5dna (talk) 02:28, 5 December 2009 (UTC)

EMP Mechanics incorrectEdit

"The E1 pulse is the very fast component of nuclear EMP. The E1 component has an intense electric field that can quickly induce very high voltages in electrical conductors. E1 is the component that can destroy computers and communications equipment and is too fast for ordinary lightning protectors."

This is not entirely accurate. The incident electric field does not induce currents in conductors. In fact, the boundary conditions on an electric conductor dictate that the tangential component of the incident electric field is zero, and the normal component induces a surface charge density (assuming for the sake of academic argument that the electric conductor is perfect - zero resistivity).

What induces a current in an inductor is a tangential MAGNETIC field. However, because in normal space a time varying electric field is necessarily coupled with a time varying magnetic field that is orthogonal to it, an incident electric field pulse comes with an orthogonal magnetic pulse for free, and this is what induces the potentially damaging currents in electronics. It is nonetheless the incident magnetic field, and not the incident electric field, that is the direct cause of coupled current in electric conductors.

-- (talk) 13:51, 16 February 2010 (UTC)

I changed the term electric field to electromagnetic field so that it would be technically correct with reference to E1 (since the previous post is correct with respect to some details of the E1 mechanism). E1 currents can be induced from both the electric and magnetic field components (depending upon a number of factors). It is important to note, however, that it is excessive voltage that exceeds rated the breakdown voltages of devices and equipment -- and not excessive current -- that initiates most of the E1 damage. X5dna (talk) 04:04, 19 February 2010 (UTC)

Soviet Test 184Edit

The entire section is based in gossip and gossip of gossip, and some sparce information that it is not conclussive.

Sorry but gossip can't be used to fill a incomplete story. -- (talk) 16:19, 12 July 2010 (UTC)-- (talk) 16:19, 12 July 2010 (UTC)

I've read technical journal articles and scientific conference reports and other writings about the Soviet K Project and Test 184, and I can't find any justification for the claim that this section of the article is based on gossip.  Although much is unknown about these events, the published reports from various sources, including some not referenced in this article, are all pretty consistent with each other and with known facts about nuclear electromagnetic pulse. X5dna (talk) 02:39, 26 July 2010 (UTC)


I put much of the more concise, older version of the introduction to the article back in place. Most of the material that had been moved to the new and extremely long introduction to the article (for the past two weeks or so) was material that was questionable or confusing anyway. If needed, that deleted material is readily available from the article history, and can be added back in to the appropriate parts of the article (very carefully) as needed. X5dna (talk) 02:31, 26 July 2010 (UTC)

Usefulness as a military weaponEdit

Would the deliberate use of high altitude nuclear explosions (for EMP effects) have much utility from a military standpoint (terrorism aside) ? During the cold war it was sometimes suggested that a "pure case EMP attack" (i.e without any bombing of military or civilian targets) was possible in order to inflict economic/infrastructural damage on an enemy. However were such an attack to occur it would have likely to have lead to retaliation in kind or escalation to fullscale nuclear warfare. In a cold war scenario it would have been difficult to use EMP in most parts of Europe without affecting neutral and friendly countries as well. Initially EMP might have been regarded as a way to prevent retaliation to a surprise attack by disabling an enemies means of counterattack but as awareness of the phenomenon grew measures were taken to "harden" crucial military hardware against such effects. Therefore the only likely effect of an EMP attack would be to hamper civil defence and recovery/reconstruction efforts after the war is over causing even more difficulty and misery for civilian survivors. (talk) 20:50, 10 August 2010 (UTC)

Questionable Addition of 11 August 2010Edit

Someone has added a paragraph to the article stating that the destruction of consumer electronics would be the greatest danger to the average person from an EMP event. This contradicts all of the the published studies by EMP experts which have found that the greatest danger would be the lack of food and water. The food distribution systems in industrialized countries relies completely upon computerized inventory systems, electric and electronic temperature control equipment, and a functioning transportation system. Water supplies for all but a small minority of people depend totally upon functioning electric water pumps and electrical and electronically-controlled water purification systems. Consumer electronics are of little consequence to people who are dying because of a lack of food and drinkable water. X5dna (talk) 13:29, 11 August 2010 (UTC)

popular news (USA Today)Edit


Is there any meta-analysis about the US discussion on this matter? The vast discussion is IMHO a remarkable phenomenon, given the fact that any attacker could yield much more destruction or "terror" if he simply ignited the same bomb over a city. The fascination for having (only) the electric devices shut down should give interesting insight into americas heart. At least a paragraph "in the media" or "public discussion" might make sense. --Bernd.Brincken (talk) 23:09, 19 February 2011 (UTC)

I don't believe that anything about the current EMP controversies in the United States belongs in this particular article. It is possible that new articles should be written about "The United States EMP Commission" or "The United States Congressional EMP Caucus" or "EMPact America." A summary of current EMP controversies might be appropriate in those articles, but not this one.
It should be noted that the core of the current controversies is the one that you have mentioned, and then (perhaps without realizing it) advocated one side of that controversy. Because the food distribution system in the United States is almost totally dependent upon data processing and electricity, many people in the United States government have stated the belief that more than 200 million U.S. residents would starve to death during the first year after a maximally-effective EMP attack, and that they would not fare much better after a severe solar storm of the magnitude of the 1859 event. The point of controversy is the question of at what level food distribution could resume, and water and sewer service could resume, after an EMP event. The largest EMP non-profit organization, "EMPact America," was started by the owner of a small regional food distribution company who was concerned about that question. Food, water, sewer service and home heating (not consumer electronics) are at the core of the controversy.
The U.S. EMP Commission spent several years trying to come up with an objective meta-analysis of this subject incorporating all of the available data. Much of the EMP Commission work is freely available on the internet[1]. Most of the writings about EMP in the popular press make no reference to the work of the EMP Commission.
It should also be noted that many people have already objected to the extent to which this article relies on United States writings on EMP, although United States writings comprise at least 90 percent, and probably closer to 99 percent, of the authoritative and unclassified reference material that is available on the subject. Including any of the current United States controversies in this article would simply prompt a barrage of outraged comments on this discussion page, and would make this article into an even greater target of vandalism than it already is.
There is already a separate article about Electromagnetic pulse in fiction and popular culture, that cites many of the early popular articles written about this subject, as well as the novels describing death by starvation after an EMP event. X5dna (talk) 07:52, 20 February 2011 (UTC)
Thanks for your detailed comments. A separate article like "EMP in the US public debate" might thus make sense. --Bernd.Brincken (talk) 14:14, 22 February 2011 (UTC)

Confusing or Unclear?Edit

I have removed the "confusing or unclear" tag from this article. The article has been extensively re-edited since that tag was put in place. Also, whoever added that tag provided no explanation at all as to why it was added.

Electromagnetic pulse can be a complex subject to understand. Please put specific areas of confusion on this discussion page. I'm sure that specific points of confusion can be addressed. Some graphic animation would be useful, but I doubt if anyone has the time or resources to produce the necessary animation. Perhaps we can make this a much more easily understood article, though, if readers would address specific points of confusion on this discussion page. X5dna (talk) 09:07, 19 April 2011 (UTC)


Is it pronounced "Emp" —Preceding unsigned comment added by (talk) 03:05, 12 May 2011 (UTC)

The abbreviation is almost always, although not in every case, pronounced as the three letters separately (E-M-P). The military acronym HEMP, however, is usually pronounced "hemp" as a one-syllable abbreviation. X5dna (talk) 04:54, 12 May 2011 (UTC)

Excessive VandalismEdit

Editing of this article really needs to be restricted to registered editors. The vast majority of unregistered users making recent edits are clear cases of vandalism. The quantity of this sort of vandalism is driving away legitimate editors from Wikipedia altogether. It is tiresome to be constantly reverting vandalism rather than making real improvements to articles. X5dna (talk) 18:48, 20 May 2011 (UTC)


Do EMP's remain in the Earth's magnetic field after a bomb explosion or do it dissipates? I mean, how long do EMP's remain active? When a nuclear missile or bomb explodes EMP's are released, on which distance depending upon the explosion altitude, that much I know but how long does it last. Freedom Fighter 1988 (talk) 05:46, 9 September 2011 (UTC)

The high-intensity E1 component of a nuclear EMP is over in less than one millionth of a second. The longest lasting component is the E3 component, which typically peaks within one minute and the Earth's magnetic field returns to normal within a few minutes. Non-EMP effects of a high-altitude nuclear explosion may last much longer. Interference to radio communications may last for a few hours (depending upon a large number of variables), and artificial radiation belts may last for years. See that article on artificial radiation belts for more information. The radio propagation interference and the artificial radiation belts that can destroy satellites are completely separate from the EMP effects, which is why they are not covered in this article. X5dna (talk) 00:02, 13 September 2011 (UTC)
Thank you very much for the information, it helped me a lot. Freedom Fighter 1988 (talk) 16:08, 13 September 2011 (UTC)

Question : Concentric Blimp/Balloon EMP ? A decent metaphor for non-nuclear EMP concepts ?Edit

Conceptually and theoretically only (obviously), if several large conducting balloons were filled to high pressure with an insulating gas like sulfur hexafluoride (SF6), were charged and had large induced magnetic fields, and then were rapidly popped, would this generate a substantial amount of magnetic flux ? (Presumably, the surface area of the magnetic fields would rapidly contract ?) Is this a decent analogy or metaphor for the generation of magnetic fields and rapid decrease in it's area ? Alternatively, is this metaphor misplaced or misleading - for example are there important features relating to symmetry, or shape or direction of the flow that are getting lost in such an analogy or metaphor? If so, how would you describe the basic concepts of these physics phenomena to laypeople in a clear manner using simple down to earth metaphors and models ? — Preceding unsigned comment added by (talk) 20:33, 22 October 2011 (UTC)

United States vs. British spellingEdit

Someone recently changed about half of the spellings of "metre" in this article to "meter". This half-and-half version of spelling standards not only violates the Wikipedia: Manual of Style, it just makes the article look really sloppy. Also, when there have been other revisions made since the half-and-half change, it is really a lot of work for another editor to make everything consistent again. As a U.S. resident myself, I prefer the U.S. spellings, but this article has used the British spellings for a very long time now. If you believe that it is necessary to make a change in spelling standards, please state the reason here, and make ALL of the changes. Don't just leave the article a jumbled mess. X5dna (talk) 09:11, 25 December 2011 (UTC)

Effecects on satellites of that timeEdit

When I was reading some soviet books on in-space EMP tests, I stumbled at some informations about these tests damaging multiple satellites of that time, both US and russian (and there weren't *that* many at the time. Anyone got more info about this? — Preceding unsigned comment added by (talk) 20:26, 8 May 2012 (UTC)

Copyright problem removedEdit

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first paragraphEdit

first paragraph needs to specifically state that it can induce excess currents in electronic devices that are turned ON at the time. article needs a seperate section to discuss more about methods used for sheilding from emp. — Preceding unsigned comment added by Gawdsmak (talkcontribs) 19:32, 6 October 2012 (UTC)

If you look at the archives page of this discussion page (linked at the top of this page), you will see that the numerous problems associated with including specific EMP effects have been discussed for years. A large part of the problem is that any section on EMP effects tends to have numerous EMP myths constantly added. One of those myths is the belief that EMP only affects devices that are turned ON. This myth was specifically addressed in a technical report written for Oak Ridge National Laboratories in 2010. Also, electronics technology is changing so fast that a team of engineers would be required to constantly monitor any section on specific EMP effects. There are already Wikipedia articles on related specific topics such as Voltage spike, Surge protector and Electromagnetic shielding. X5dna (talk) 15:02, 9 October 2012 (UTC)

Erroneous November 4, 2012 additionEdit

The reference cited in the addition of November 4 to the Electromagnetic Pulse article provides no justification for the statements that were added to the article. In fact, Figure 3 in the reference from the Army Communicator article contradicts the material that was added to the article. Note that the frequency components of EMP go out beyond 100 MHz according to Figure 3 of the cited reference at:

That article from Army Communicator is from 1987, meaning that it is 25 years old. A reference to 25 year old electronics technology would generally be inappropriate, but that article is actually pretty good. Most of the technology described in the article has not been outdated, although better EMP protection techniques are now available.

The problem with the November 4 addition to the Wikipedia Electromagnetic Pulse article is that the magnetic shielding described is designed for frequencies of less than about 300 Hz. and is generally ineffective at frequencies above 100 KHz. So this leaves the frequency components of EMP that are between 0.1 MHz and 100 MHz completely unprotected. See the descriptions of the frequency range of magnetic shielding alloys at:

Also see the Wikipedia articles on Electromagnetic shielding and Mu-Metal.

For additional information about the frequency spectrum of a nuclear EMP, see pages 33 and 34 of the technical report at:

X5dna (talk) 03:42, 8 November 2012 (UTC)


what about EMP from an asteroid-impact? i´m pretty sure this effect exist. — Preceding unsigned comment added by (talk) 18:18, 26 December 2012 (UTC)

Hmm, got any Reliably Sourced material about these nuclear explosion asteroid impacts? HammerFilmFan (talk) 00:49, 22 January 2013 (UTC)
I suspect that the original poster has read speculations about the effects of a small chunk of antimatter hitting the upper atmosphere. Under the right conditions the matter/antimatter annihilation at the top of the atmosphere would release a gamma ray burst that would in turn produce an electromagnetic pulse. I don't know of any reliably sourced information about this either, though. X5dna (talk) 14:03, 22 January 2013 (UTC)

January 30, 2013 RevisionsEdit

I reverted the revisions made on January 30 by Luisloureiro for several reasons. First, the additions were inappropriate for the introduction to any article, and would have belonged in explanations later in the article. The addition to the introduction made the introductory section extremely confusing to the average reader. Introductory sections are supposed to be simple and concise. Second, the subject matter of the additions applied more to other Wikipedia articles, such as Electromagnetic radiation and health. The top of the current article states that "This article is about the general weapons effect. For other uses, see the more specific topic."

The nature and effects of bursts of electromagnetic radiation that occur incidentally during the normal course of commercial or experimental activity are not appropriate to this particular article (although they may be quite relevant and important to other Wikipedia articles). There are other Wikipedia articles about many aspects of electromagnetic radiation. Finally, the cited reference was added in a manner that did not conform to Wikipedia standards. In addition, the cited reference was not in English, and therefore not appropriate to the English-language version of Wikipedia without some sort of unusual justification. X5dna (talk) 02:12, 30 January 2013 (UTC)

6 April 2013 editsEdit

An IP deleted some information with a dead link reference, I don't like this ¦-[
There are reports of "super-EMP" nuclear weapons that are able to overcome the 50,000 volt per metre limit by the very nearly instantaneous release of a burst of gamma radiation of much higher energy levels than are known to be produced by second-generation nuclear weapons. The reality and possible construction details of these weapons are classified, and therefore cannot be confirmed by scientists in the open scientific literature.
Ref: (Statement, Dr. Peter Vincent Pry, EMP Commission Staff, before the United States Senate Subcommittee on Terrorism, Technology and Homeland Security. March 8, 2005
The EMP Commission sponsored a worldwide survey of foreign scientific and military literature to evaluate the knowledge, and possibly the intentions, of foreign states with respect to electromagnetic pulse (EMP) attack. The survey found that the physics of EMP phenomenon and the military potential of EMP attack are widely understood in the international community, as reflected in official and unofficial writings and statements. The survey of open sources over the past decade finds that knowledge about EMP and EMP attack is evidenced in at least Britain, France, Germany, Israel, Egypt, Taiwan, Sweden, Cuba, India, Pakistan, Iraq under Saddam Hussein, Iran, North Korea, China and Russia.
Many foreign analysts–particularly in Iran, North Korea, China, and Russia–view the United States as a potential aggressor that would be willing to use its entire panoply of weapons, including nuclear weapons, in a first strike. They perceive the United States as having contingency plans to make a nuclear EMP attack, and as being willing to execute those plans under a broad range of circumstances.
Russian and Chinese military scientists in open source writings describe the basic principles of nuclear weapons designed specifically to generate an enhanced-EMP effect, that they term "Super-EMP" weapons. "Super-EMP" weapons, according to these foreign open source writings, can destroy even the best protected U.S. military and civilian electronic systems.
All nuclear weapons can produce EMP as a secondary effect, but the effect can be enhanced by special weapon design.
--Chris.urs-o (talk) 08:06, 7 April 2013 (UTC)

The IP user who made these 3 deletions violated several Wikipedia policies as stated in WP:LINKROT, which states, among other things, "Do not delete cited information solely because the URL to the source does not work any longer." If anyone wants to add this information back into the article, the updated reference to use for what is now a dead link is:

X5dna (talk) 12:09, 7 April 2013 (UTC)

New QuestionEdit

This article discribes the effect of an EMP attack on electronics, but it doesn't describe the direct effect on human, animal & plant life. Does a HEMP have no physical effect? Would the radiation releaced affect anyone or anything on the ground? How low does a EMP detonation need to be to hear a blast, feel a shock wave? — Preceding unsigned comment added by CycloneSteve (talkcontribs) 01:44, 17 April 2013 (UTC)

The article doesn't mention any HEMP effect on humans, plants or animals because none have ever been found.
Military personnel below high-altitude nuclear explosions were all wearing radiation badges. Also there was a lot of radiation monitoring equipment. No immediate alpha, beta or gamma radiation or neutron radiation was measured at ground level. The big problem was the extremely bright light flash (which has caused eye damage), especially for nighttime detonations. See the article on Operation Fishbowl. The altitude necessary to hear a blast is dependent upon a large number of variables. In reports of the low yield 20 km. high test called Tightrope, which was the last of Operation Fishbowl, the declassified reports don't mention any sound being heard below the detonation point. X5dna (talk) 16:49, 17 April 2013 (UTC)
@X5dna: Just throwing this in for discussion, what about people with 'implanted' electronics, like pacemakers and cochlear implants. I presume these are becoming much more common, even since 2013. If EMP stuffs your pacemaker ...? You could be dead from EMP. 220 of Borg 02:44, 2 August 2015 (UTC)
Some EMP testing was done on pacemakers in the 1970s and again in 1988-89. The results were rather inconclusive. From what I remember, the tests often showed some upset (false triggering) but rarely permanent damage. With the technology having changed so much during the past quarter-century, and the lack of any ongoing testing, we just don't know the effects of EMP on implantable medical devices. As in so many other areas, the electronics has gotten more sensitive to EMP, but the increased use of cell phones and other RF devices has necessitated the use of increasingly high-quality internal shielding of the devices.
The greatest immediate danger to human life is likely to be to those in hospitals on electronic life support machines. X5dna (talk) 18:32, 16 August 2015 (UTC)

Wrong title - move or copy to new home?Edit

This article is misnamed. It focuses almost entirely on HEMP, with a few ragged pointers to other kinds (for example the section supposedly on on the general "Characteristics of nuclear EMP" almost immediately talks of the E1 pulse generated in the "upper atmosphere", so is really about the "Characteristics of HEMP").

There are many types of EMP. Off the top of my head I have come across:

  • NEMP
  • HEMP - a form of NEMP tailored to cause maximum damage
  • LEMP from a lightning discharge
  • NNEMP from electromagnetic weapons
  • ESD - an electrostatic discharge event typically takes the form of a small high-impedance EMP
  • Power switching and shorting can cause EMP events of various kinds.

Nor is there much in the article about protection, test and measurement, such as the damped sinewave model of induced signal in the victim. Fair enough, that could be treated as EMC, but it sill needs summarising and linking.

Frankly, this article needs splitting with the lion's share going to a new article on High altitude electromagnetic pulse and the rest forming the basis of content more directly relevant to the article name.

The question is, is it better to move this whole misnamed thing and start afresh, or to create the new article page and cut-paste the bulk of it across? — Cheers, Steelpillow (Talk) 16:43, 22 May 2013 (UTC)

I cannot disagree with anything that you are saying, but what you are suggesting would be an incredible amount of work to accomplish and to maintain. There was a major re-consolidation and splitting of EMP-related articles in 2009. That was a huge amount of work.
It continues to be a lot of work to maintain the split. For example, people keep wanting to add fictional material to this Electromagnetic Pulse article, even though there is a separate and lengthy article on Electromagnetic pulse in fiction and popular culture.
Most people come to this article looking for information on NEMP, HEMP or NNEMP.
There do need to be separate articles on "LEMP," "EMP in the U.S. Public Debate," and "EMP Protection, Test and Measurement." The latter two articles, especially, would be very lengthy and difficult to write and maintain.
As discussed in one of the earlier sections above, the subject of EMP protection would be especially difficult since the EMP susceptibility of critical infrastructure and other important electronic items in the world economy is changing dramatically year by year. Any comprehensive document on EMP protection would be obsolete by the time it is completed.
It has always been a problem that people want to add references to EMP protection documents from 25 to 40 years ago as evidence of the EMP susceptibility of today's electronics, oblivious to the profound implications of Moore's law for EMP sensitivity. X5dna (talk) 03:37, 23 May 2013 (UTC)
Thank you for that. My background is as a test engineer in the wider field, I have little interest in HEMP hype and especially not in fiction. I am disappointed that the EMP in Fiction article does not go back beyond 1980, for example it has no mention of the EMP attack in one of the Thunderbirds puppet TV shows, aired I guess during the 1960's, and that the article does not better distingiush or discuss the types of EMP in popular awareness. But that's a side issue.
Back on topic, I take heart that Wikipedia is an encyclopedia not a text book. Furthermore it is a living resource, ever changing. The fact that we cannot achieve high standards first time round should not stop us from making something a bit less awful than it is now. A journey of a thousand miles begins with a single step, yadda yadda. This is the spirit in which I made my limited suggestion for splitting this article.
On closer inspection, the whole thing is focused on weaponry, in fact on NEMP, and for the most part HEMP, with just one short section on NNEMP weapons. The idea that this constitutes an encyclopedic article on the EMP phenomenon is simply laughable, it really is. We cannot leave things as they are. Indeed, it is crystal clear that this article needs to be moved and a new article created in its place, with just the section on NNEMP being cut/pasted back here.
With regards to maintainability, I am not suggesting we create pages for each and every aspect of EMP. But I would hope that each aspect can find a relevant home rather than an irrelevant one.
I'll try and write something to kick off the replacement article before any formal attempt at a move. If you like, keep an eye on User:Steelpillow/Test. — Cheers, Steelpillow (Talk) 11:13, 23 May 2013 (UTC)
OK, I wrote something that IMHO is better than nothing, please see User:Steelpillow/Test. But I am one of those 25-year-out-of-date folks so I have not attempted to add any references. Feel free. Meanwhile I think the current article is best moved (over redirect) to Electromagnetic pulse weapon because the NNEMP secion does seem to belong there rather than in my rewrite. Any objections before I make a format request for the move? — Cheers, Steelpillow (Talk) 13:39, 23 May 2013 (UTC)
The differences between nuclear EMP and non-nuclear EMP are so extreme, especially in terms of their radius of damage (as well as their frequency components) that I would rather see them as separate articles.
I won't have time, myself, to do much on Wikipedia for the next few weeks; so I'll leave it to others regarding how to handle the re-organization. X5dna (talk) 03:30, 24 May 2013 (UTC)

Proposed article move and re-creationEdit

Following the above discussion I propose to move the current page to Nuclear electromagnetic pulse because that is what it is primarily about.

I have drafted a replacement article on the Electromagnetic pulse at User:Steelpillow/Test, which I propose to cut/paste back into this article (Moving it across is bad because that would bring a lot of my test page's old history with it).

To tidy things up, I also propose to delete the section on NNEMP weapons from the new Nuclear EMP article. The section has found a home in my draft, so overall it will effectively just stay on this page.

Any objections?

— Cheers, Steelpillow (Talk) 12:51, 25 May 2013 (UTC)

Just remember that the vast majority of people looking for Electromagnetic Pulse will be looking for "nuclear electromagnetic pulse," so a note about the location of the Nuclear Electromagnetic Pulse article needs to be at the top of the page on the new EMP article.
Also, there are hundreds of links within Wikipedia to the current Electromagnetic pulse article. Most of those links presume that the article will be about nuclear electromagnetic pulse.
Click on the "What Links Here" link in the Tools section on the left side of the current Electromagnetic Pulse article. All of those wikilinks in other articles will need to be fixed if the current article is renamed. (There may be a semi-automatic way to do this since the problem must have arisen before.)
Also, many Wikipedia editors will probably object to the lack of references in the first 60 percent of your proposed EMP article. It needs more references.
Finally, it might be much easier to just add a note at the top of the page of the current article saying that "This article is about nuclear electromagnetic pulse. For the general subject of Electromagnetic pulse, see the article Electromagnetic Pulse (general principles)." Then "Electromagnetic Pulse (general principles)" would be the name of your new article. This would save you from having to modify hundreds of wikilinks scattered throughout Wikipedia.
Good luck on however you decide to do it. X5dna (talk) 14:04, 25 May 2013 (UTC)
Lots of those "What links here" links are from articles referencing EMP generally or things like lightning and other non-weapons phenomena. Leaving them all pointing at the wrong content is wholly unacceptable = a massive cleanup is already on our hands. Might as well create a decent article structure while we are at it. But yeah, I'll add a hatnote pointing to the NEMP article, good idea that. — Cheers, Steelpillow (Talk) 18:32, 25 May 2013 (UTC)

Do references need references now?Edit

An anonymous editor added several "citation needed" tags to a quotation from a U.S. government report written for Oak Ridge National Laboratories. That report was already cited in this article along with a web link to the original Oak Ridge report. I have never before encountered the assertion in a Wikipedia article that an authoritative quotation from a public domain reference should have references within the cited reference. If someone disagrees with the Oak Ridge government report, they should state why Oak Ridge National Laboratories is not an authoritative source on nuclear physics, or else they should take the matter up with the government laboratory in a different venue. Actually, many of the misconceptions which the Oak Ridge report was addressing were popularized in earlier versions of this very Wikipedia article, and some the the "Citations needed" can be found above on this very talk page. X5dna (talk) 06:38, 1 August 2013 (UTC)

Once again, an anonymous editor has altered a direct quotation from a U.S. government report. If you think that you know more about this subject than physicists who are employed by, or are under contract to, a U.S. government laboratory, please state the reasons for your greater level of expertise, and then cite more authoritative references instead. Do not, however, alter direct quotes unless you can cite evidence on this talk page that the quotation in question is actually a misquotation. X5dna (talk) 06:39, 23 September 2014 (UTC)

Vacuum tube versus solid state electronicsEdit

This section makes a general claim about vacuum tube based equipment being less vulnerable to nuclear EMP than newer solid state equipment. However, the only citation for this paragraph is from 1981. The phrase "newer solid state equipment" is surely no longer accurate in this context. — Preceding unsigned comment added by BillBucket (talkcontribs) 18:05, 20 January 2015 (UTC)

I completely agree about the problem of using references from 1981. There are newer and more accurate references available. I will dig them up when I have time.
In general, though, this is a rather complex subject. Modern solid-state devices are more than a million times more sensitive to destruction from voltage spikes than vacuum tubes. This does not mean that the overall circuits are that much more sensitive. Many components used in vacuum tube circuits were thousands of times more sensitive than the vacuum tubes themselves.
Also, as solid-state devices are becoming more sensitive to breakdown, more protection devices are being added to the circuits, especially where they connect to the outside world. (Devices added to protect against electrostatic discharge will not necessarily be very helpful with electromagnetic pulse, though.)
In 1981, even though the solid-state devices themselves were hundreds of times more resilient than the solid-state devices of 2015, the lack of circuit protection in the commercial and industrial electronics of 1981 made the overall solid-state circuitry of the time extremely fragile. X5dna (talk) 09:28, 25 January 2015 (UTC)
@BillBucket and X5dna: I fixed 'Bills' link from the text as it wasn't doing right to this discussion. There seems to be a lot of un-sourced info & possible OR regarding this isue on the page. Theoretically the integrated circuits (IC). etc used today are more susceptible to EMP because the 'tracks' and conductors within the semiconductor material itself have become extremely thin (sub-Micrometre (μm), less than a thousandth of a millimetre) as the computer microprocessors for example, have packed more and more into a smaller space. Chips that had 100,000 transistors, now literally have billions of them in the same or less areas and can be damaged by 50 volts (Or less). Operating voltages supplied to the chips have also fallen, I'm not sure if that is a factor at all, though. The actual operating voltage & current at the semiconductor junction level are also likely to have been reduced substantially. Some devices, known as Field-effect transistors or "FETs' could, even 25 years ago, be damaged by stripping a piece of sticky tape off a roll (hence statically charging it) and waving it near the transistor.
Valves, despite being more physically fragile, are more ablr to survive excess heat, voltages and currents than semiconductors. Despite being 'fragile', valves have been made physically robust enough (metal envelopes, rather than glass IIRC) as long ago as WW2 to be used in proximity fuses in cannon shells.
A lot of what I said is also along the lines of what X5dna said, but it also assumes that the device is unprotected by a Faraday cage or similar. Much military electronic hardware used to be in very robust metal cases which, if properly earthed should go a long way to protecting the internal electronics, theoretically! 220 of Borg 02:34, 2 August 2015 (UTC)
@220 of Borg and X5dna: Thanks, you both make good points. Keep in mind that while shrinking electronics does makes them more sensitive to electrical damage, it also reduces the cross-sectional area, i.e. the device absorbs less EMP energy proportional to its reduction in area. Obviously, many external components connected to these devices won't shrink (e.g. antennas). Compared independently of the common factors, modern devices themselves are perhaps not more susceptible to EMP, despite being more susceptible to voltage spikes from the similarly sized external components. For instance comparing a tube based communication radio with a modern mobile phone, while perhaps not an entirely fair comparison, the tube radio will absorb far more energy than the mobile phone. I'm not positive if there is a point where an EMP would destroy one and not the other, but it's worth considering. BillBucket (talk) 21:08, 3 March 2016 (UTC)

Fact check: U.S. casualties from a nuclear HEMP attack?Edit

Recently some U.S. Senators questioned Energy Secretary Moniz about the potential effects of an Iranian nuclear EMP attack on the United States. Ted Cruz, for example, puts U.S. casualties in the "tens of millions". He referenced the work of the EMP Commission during this discussion. Does anyone know where this figure comes from? I have not read the 2008 and 2004 EMP Commission reports, but I searched through them using a number of different queries and couldn't find a basis for this figure.

Jim Woolsey cites testimony of the "chairman of the EMP commission" for "90 percent of Americans would die within 12 months" of a nuclear EMP attack. Woolsey also coauthored a 2014 Wall Street Journal article that states "The EMP Commission, in 2008, estimated that within 12 months of a nationwide blackout, up to 90% of the U.S. population could possibly perish from starvation, disease and societal breakdown." In other news articles, I have seen a figure of "70 to 90 percent dead" attributed to the chairman of the EMP Commission. But I can't find the actual quote. The closest I got is the July 10, 2008 House Armed Services Committee testimony of Dr. William Graham, chairman of the 2008 EMP Commission, who was asked a question about a novel called One Second After, which considered a HEMP attack over Nebraska that killed 90% of the U.S. population a year after the attack. Graham said that the novel's estimates were "in the correct range" and that 10% of the population could probably survive in a "basically rural economy" caused by an EMP attack.

Is this off-the-cuff answer regarding a novel the only basis for the "90% of the U.S. population would die" figure? And is that figure, in turn, the source of Cruz's "tens of millions of Americans would die" figure? Can anyone shed some more light on these numbers? Ketone16 (talk) 15:15, 1 August 2015 (UTC)

I haven't seen any references to this in any open EMP Commission reports. This matter was discussed in Congressional Hearings with EMP Commission members. Transcripts of those hearings are available online. Those discussions were in terms of the carrying capacity of the affected civilization. For example, if we suddenly had available only 1870s technology and communication and food and water distribution systems, it is reasonable to assume that a country could only support the population of 1870, so a die-off would occur until that population level was reached. That, at least, was the assertion of some EMP Commission members at those hearings.
I don't believe that information like this is appropriate for this particular article. There probably should be an article on the "United States Electromagnetic Pulse Commission" on Wikipedia. A law has been passed re-establishing the EMP Commission. Funding for the new U.S. EMP Commission will begin on July 1, 2016 and will continue through at least June 30, 2017. X5dna (talk) 13:49, 16 January 2016 (UTC)

Burst heightEdit

The article should make an attempt to spell out, in terms as concrete as possible, what kind of EMP effects are generated, if any,

  • in an air burst at a height optimised for overpressure against soft targets (i.e. a few hundred or thousand metres);
  • in a ground burst;
  • in an underground burst.

Would there be any appreciable/significant EMP at all in these kinds of scenarios, where the burst height is geared to maximise the damage caused by the other weapons effects? --Cancun (talk) 11:32, 10 January 2016 (UTC)

You are correct that more needs to be written in this article about the effects of low-altitude EMP. The only thing that is mentioned in the article is about the EMP effects of the 1945 Trinity test.
Explaining low-altitude effects will require scanning in a diagram from a U.S. government nuclear weapons textbook.
That, and gathering the references, will take me some time. Also, there is not very much available for reference material on low-altitude EMP except for that one text. I will do my best, though, as soon as I can find the time. (Basically, the answer is that low-altitude detonation EMP effects are roughly limited to the blast area, except that wires and cables inside of the blast area can conduct the pulse fairly far beyond this blast area depending upon how far the wires and cables extend.) X5dna (talk) 13:30, 16 January 2016 (UTC)
So how about underground bursts like in the film 'Broken Arrow'?--Cancun771 (talk) 13:58, 21 January 2016 (UTC)
Underground nuclear explosions cause an EMP within the underground chamber. Although rock and soil are rather poor electromagnetic shielding materials (compared with most metals), there is so much of the rock and soil between the surface and the underground explosion point that the EMP is quite weak at the surface. This is evidenced by the fact that secret underground nuclear tests are sensed by seismic disturbances, not by the satellites that are capable of detecting the EMP from above ground nuclear explosions. (The EMP scene in the film "Broken Arrow" is just silly.) X5dna (talk) 05:41, 28 January 2016 (UTC)

EMP or HEMP?Edit

The article begins with a clear distinction between EMP and HEMP, but then becomes muddled and seems to deal mostly with the latter and very little with the former. Also, it says that "The term 'electromagnetic pulse' generally excludes optical (infrared, visible, ultraviolet) and ionizing (such as X-ray and gamma radiation) ranges" but gamma radiation crops up over and over again in the subsequent text and illustrations.

Your first question is essentially identical to the one asked by Cancun, immediately above. Your second question is an easy one to answer. The gamma rays from the nuclear weapon are responsible for nearly all of the electrons getting knocked out of atoms in the atmosphere. The electrons moving at relativistic speeds then create the electromagnetic pulse. Remember that nuclear EMP is a secondary effect that is created outside of the weapon itself. That secondary effect starts when gamma rays slam into atoms, knocking out the electrons. This creates a pulse across the radio frequencies. Gamma radiation is the primary effect (originating inside of the weapon). EMP is the secondary effect (originating outside of the weapon). (Some EMP is created without gamma radiation, but that is a relatively very minor effect.) X5dna (talk) 13:14, 16 January 2016 (UTC)

Watch Dying MythEdit

In the article, it states that watch are "much too small" to be affected by the EMP.

Earlier above, it says that Hawaii experiment delivered about 5 kV/m pulse strength, which induces about 10 megavolt of electric potential over 500 nanoseconds in 1 mm long conductor parallel to the EMP propagation vector. This far exceeds breakdown voltages of semiconductor electronics, so it may permanently damage all internal circuitry just by irreversibly eroding semiconductors. Additionally, with common resistance of digital chips of 50 kiloohm, this will result in producing thousands of watts worth of heat dissipation energy during this short surge, which is all but sure to melt extremely small internal circuitry. It's worth mentioning that internally, chips also feature significant length of conductors, usually devoid of electromagnetic shielding. It also says that targeted pulse can peak out at 50 kV/m. Thus even in wrist watches, there's sufficient amounts of conductors to cause permanent damage from EMP. — Preceding unsigned comment added by (talk) 10:05, 7 February 2016 (UTC)

It is not this article that makes the claim about watches, it is a report written by some of the top electromagnetic experts in the world for Oak Ridge National Laboratories. If the scientists at Oak Ridge National Laboratories are a dubious source of information, perhaps you could suggest a more competent authority. Your "dubious - discuss" tag is on a direct quotation from a U.S. Government report from Oak Ridge. If you have questions about their competence, you should take the matter up with the scientists at Oak Ridge and their contractors. X5dna (talk) 16:14, 8 February 2016 (UTC)
I also question the arithmetic of the anonymous commenter. A pulse of 5 kilovolts per meter yields a maximum induced voltage of 5 volts per millimeter. X5dna (talk) 17:49, 9 February 2016 (UTC)

"Thousands of Watts" of heat, dumped even just over 500ns, would raise the temperature of a 1mm*0.1mm*0.1mm copper conductor by 15000K (per kW), resulting in explosive vaporisation. Seems unlikely. (talk) 13:26, 15 February 2016 (UTC)

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Broken Link in SourcesEdit

A 2010 technical report written for the US government's Oak Ridge National Laboratory included a brief section addressing common EMP myths.[1]


  1. ^ Report Meta-R-320: "The Early-Time (E1) High-Altitude Electromagnetic Pulse (HEMP) and Its Impact on the U.S. Power Grid" January 2010. Written by Metatech Corporation for Oak Ridge National Laboratory. Appendix: E1 HEMP Myths

This link is broken, it goes to an "under construction" page at ORNL. Can someone hunt down another copy of this PDF or figure out where on ORNL's page it got shuffled off to? (talk) 14:20, 30 May 2016 (UTC)

There were actually 3 broken links in this article caused by (yet another) re-shuffling of important links by Oak Ridge National Laboratories. I've got all three links fixed and going to non-ORNL links to the original PDF of the ORNL reports.
If there is anyone at Oak Ridge reading this, please STOP shuffling your report locations around like this. It happens every few years at the Oak Ridge web site, and it causes all sorts of problems for Wikipedia, as well as thousands of others who rely on important Oak Ridge reports. X5dna (talk) 13:14, 12 June 2016 (UTC)

These reports made for Oak Ridge National Laboratories by Metatech are cited many times throughout Wikipedia. They have been moved from the Oak Ridge site to the FERC (Federal Energy Regulatory Commission) web site. For future reference, here are their current locations (as of early 2017):

Executive Summary:

Report Meta-R-319

Report Meta-R-320

Report Meta-R-321

Report Meta-R-322

Report Meta-R-323

Report Meta-R-324

X5dna (talk) 21:10, 14 April 2017 (UTC)

ANI NoticeEdit

  There is currently a discussion at Wikipedia:Administrators' noticeboard/Incidents regarding an issue with which some editors of this page have been involved. The thread is Dr. Ronald Cutburth. Your input at ANI is very much welcome. --Guy Macon (talk) 20:12, 3 December 2016 (UTC)

Return to "Nuclear electromagnetic pulse" page.