Talk:Scanning electron microscope

message: Is there any reason the image isn't showing up on this page?  The larger version doesn't seem to be working either.  Might be I'm just missing something?  --  TomPreuss 13:34, 5 Aug 2004 (UTC)
replies: text: I don't think there's anything wrong with the formatting of the page, it'd show the image if the image existed - I get a 404 not found message when I try to look at the image directly. I guess the image needs to be uploaded to Wikipedia again. Average Earthman 15:59, 5 Aug 2004 (UTC)
replies: text:  That's pretty odd though.  What do you think could cause that to happen?  --  TomPreuss 13:03, 6 Aug 2004 (UTC)
thread_title:  Ant picture broken? 

message: Shouldn't this page be listed under SEM? It's a pretty common abbreviation. --Michaeltoe 22:09, 4 Feb 2005 (UTC)
thread_title:  Scanning Electron Microscope = SEM 

message: The use of a dedicated backscattered electron detector above the sample in a "doughnut" type arrangement, with the
That is all: the paragraph in the section 'Detection of backscattered electrons' ends abruptly. Seems like there's some half-editing... I can now see the paragraph fully, and no one has edited it!! Perhaps there was a problem in the browser I was using(in my college). Firefox proves itself to be THE best. :)
SundarKanna 20:03, 26 December 2005 (UTC)
thread_title:  
Why does the paragraph end abruptly?
 

message: I removed the template  because the French article lost its featured article status. Stefane 07:47, 21 March 2006 (UTC)
thread_title:  The French article is no more featured 

message: I came across an orphan about OIM (apparently stands for orientation imaging microscopy). Can some one try to verify the information in it? Here: Orientation imaging microscopy (which is where I had to move it to make way for an "OIM" disambiguation page. — User:Donama 04:33, 17 May 2006 (UTC)
replies: text: Fixed. 24.211.234.99 22:30, 15 October 2006 (UTC)
thread_title:  Anybody who knows about SEMs? 

message: Can somebody give me the construction and the electronics involved in electron microscopy? —Preceding unsigned comment added by 220.225.87.34 (talk • contribs) 06:25, 11 June 2007 (UTC)
replies: text: It consists of an electron gun commonly made of tungsten and cathode because of its high melting point.a grid is placed nearer to the electron gun which is used to accelerate the primary eletrons.a magnetic condensor lens and scanning coils is placed nearer to the grid .sample is placed next to the scanning coil a collector is followed by a video amplifier and cro .the scanning coil is connected to the cro and it is then connected to the scan generator. —Preceding unsigned comment added by 117.193.98.168 (talk • contribs) 02:19, 17 November 2009 (UTC)
thread_title:  Construction 

message: The reference to Alan Nelson's patent is irrelevant as there has never been any implementation of this approach to an environmental SEM either in laboratory equipment 
or in commercial instruments, and no published reference to a refereed journal exists.  In contrast, the patent:
U.S. Patent No. 4,823,006, filed Feb. 19, 1988. Integrated electron optical/differential pumping imaging signal detection system for an environmental scanning electron microscope. Inventors: G.D. Danilatos, G.C. Lewis. Assignee: ElectroScan Corporation.
describes the first commercial ESEM imlementation by ElectroScan.  The latter was based on prior Danilatos works as listed in http://www.danilatos.com.  In addition to the differential pumping and electron detection techniques described by the first Danilatos reference provided in the present entry, the commercial ESEM has made extensive use of the newly invented system of a gaseous detection device as comprehensively described by:
Danilatos, G.D. (1990). Theory of the Gaseous Detector Device in the ESEM in Advances in Electronics and Electron Physics, Academic Press, Vol. 78:1-102.
The Alan Nelson patent inappropriately employs a series of apertures with trapped air in the cavities between them.  As a result, the electron beam would suffer significant losses before it can be usefully employed in the specimen chamber.  At any rate, Alan Nelson by no means should be referenced as a contributor to the development of ESEM, let alone as an initiator of this technology.  In contrast, Danilatos preceded with his first patent and papers on ESEM in 1979.  It is therefore proposed to amend the references accordingly.
Esem0 05:40, 8 July 2007 (UTC)
thread_title:  References to be amended 

message: I've been looking through some of the imaging articles, and many appear to be missing major concepts fundamental to the instrument.  For example, SEMs are known for their amazing depth of field, yet this term is not used at all in this article.  Is there something I don't know about SEMs or Wikipedia and imaging articles that is a reason for omitting this?
KP Botany 02:06, 4 October 2007 (UTC)
thread_title:  Depth of Field 

message: it would be very nice if resource for downloadable SEM images On an archived bundle (such as rar or zip)
also put here as the resource for people yo get Free SEM images on a specific category, such as human cells or parasitology Etc.
ive been looking anywhere to get such resource, and nothing better than here. But i wish a can find The free image bundled as i mention.  —Preceding unsigned comment added by Kuplukjaya (talk • contribs) 07:06, 25 March 2008 (UTC)
thread_title:  it would be very nice if resource for downloadable SEM images also put here 

message: This edit changed a fair bit of text, and seems to have removed some info, as well as adding some. Can someone look at this? Should it simply be reverted? —Pengo 01:11, 30 March 2008 (UTC)
thread_title:  Removed content 

message: There are many poor quality SEM images on Wikipedia for some reason.  I removed some from the gallery for this article, because there are a sufficient number of better quality or useful images.  The one of the topo/atomic number contrast should also be removed when a better image comes up.
The first one I removed is of the polyester.  This image has serious charging artifacts, creating the ruinous line across the middle of the image, it's in focus almost nowhere, and it has lousy depth of field (of course, since it's in focus almost nowhere).  A longer working distance, a smaller aperture, a smaller probe size, lower KV, better coating, many things would have made this a better image.  It's fine for the polyester fiber article for now, but a better one should be captured or found, as this one has too many problems with it to be used in an encyclopedia for anything other than an article on SEM artifacts (which it would be good for).
The diatoms are out of focus.  There's no point to the image.  It's not in focus anywhere in the depth of focus of the image.
The red blood cells should be removed also, when they can be replaced with a better image.  Red blood cells are easy to shoot on an SEM, and this image is far too noisy to be considered for production anywhere outside of Wikipedia--it's too old.  However, because red blood cells look totally cool on SEM (versus TEM), it's okay to leave this very noisy image in for now.  They're a standard.  
The nematocyst is too low resolution to be of any use.  It should be replaced, also.
The Drosophila melanogaster body is very poorly preserved, rather than life-like, there's excessive charging to the point of putting a bright white lightening bolt through the image, and the carbon dag substrate consumes an unwieldy portion of the image.  However, this is a basic subject in SEM, like red blood cells.  Its compound eye is completely out of focus, also.  
The asbestos fibers should be photoshopped to remove the charging artifacts, if left in.  The picture is not compelling or illustrative of anything other than the fact that SEM is used to look at asbestos fibres.  I think it is rather common.  
Probably the same public domain sources could be searched for better images.
An SEM image should be in focus.  This does not require an expert microscopist to discern.  It's either in focus or it's not.  TEM images can be much more subjective and demanding of expert eyes to tell quality.  Especially with biological specimens, if it looks out of focus, if the insect is collapsed and dessicated, it's not a good image.  It's more difficult with materials specimens, but there are few of any of these of any quality on Wikipedia.
--Blechnic (talk) 06:27, 8 April 2008 (UTC)
replies: text:  Then you should replace rather than remove if you are concerned about image quality. Otherwise you are depriving readers of information. Peterlewis (talk) 06:36, 8 April 2008 (UTC)
replies: text:  Precisely what information have I deprived anyone of by removing an unacceptable micrograph?  Can I upload pictures of my cat and use it, no matter how low quality, in the article on cats?  No.  The same thing should not be acceptable with micrographs.  I left plenty of bad ones without leaving the worthless in the article.  They contain no information without pointing out to the readers that they are useless due to artifacts which render them of too low quality to be proper micrographs.  --Blechnic (talk) 06:51, 8 April 2008 (UTC)
replies: text:  PS In addition, people with good micrographs may just see an overly full gallery.  They won't want to add good images in with the low quality ones, or they may not even look beyond the number of micrographs, thinking Wikipedia is full of SEM images. It's not.  --Blechnic (talk) 06:53, 8 April 2008 (UTC)

text: I think you are being over-critical. I am a microscopist myself, and would be happy to use any of the images you deleted. If you have better ones or more showing other details, then put them in. But you cannot just delete what is already there. Peterlewis (talk) 07:06, 8 April 2008 (UTC)
replies: text:  Yes, if the images are completely unworthy due to artifacts that could not be published, they should be removed.  I am skeptical that you are a microscopist and would leave an image like that of the blurry, out of focus, no depth of field polyester with all the charging and a charging artifact slicing the image almost in half top to bottom, the blown out asbestos, the flattened flies, the out of focus diatoms.  Leaving junk in is an invitation not to find much better.  Especially compared to the newer micrographs.  There are plenty of images left in the gallery that leaving the junk in is not necessary.  --Blechnic (talk) 07:10, 8 April 2008 (UTC)
thread_title:  Removed images from gallery. 

message: : Re the caption on the photoresist about the semiconductor industry: the purpose of mentioning their importance in the industry is that the image is of a semiconductor photoresist.  Yes, they're important (high res FE guns) in many industries, but these are just notes about the particular images in the gallery, so the high res comment is specific to this excellent micrograph. --Blechnic (talk) 20:10, 13 April 2008 (UTC)
thread_title:  Image captions 

message: SEMs don't have objective lenses.  The signals from the object are collected by various detectors and images formed from the detection of these signals not from the final lens.  The final lens or focusing lens is not an objective lens.  --Blechnic (talk) 02:53, 23 April 2008 (UTC)
replies: text: Good point. An SEM's objective lens is for focussing the beam. Provided the column can generate a beam with sufficiently small diameter, an SEM could in principle work entirely without condenser or objective lenses, although  it might not be very versatile or achieve very high resolution. One might also mention that, unlike optical and transmission electron microscopes, magnification in the SEM is not a function of the power of the objective lens. It results from the ratio of the dimensions of the raster on the specimen and the raster on the display device. Assuming you are working with a fixed size display, higher magnification results from reducing the size of the raster at the specimen, and vice versa. The x,y scanning coils therefore control magnification, not the objective lens.Plantsurfer (talk) 08:27, 23 April 2008 (UTC)
replies: text:  Add it to the article, don't tell me back here!  However, this whole area of how the microscope work needs developed, so I'm not certain if it wouldn't be better to outline a battle plan rather than piecemeal fixing things.  --Blechnic (talk) 16:47, 23 April 2008 (UTC)
thread_title:  Objective lenses in SEM 

message: The article cites . However, I wasn't able to find this article in the journal's archive. Is there some mistake? ––Bender235 (talk) 09:23, 12 August 2008 (UTC)
replies: text: The fact that it was published as an abstract may explain it. JCB's archive only lists the abstracts of full papers. You need to refer to the paper copy. Plantsurfer (talk) 09:51, 12 August 2008 (UTC)
thread_title:  Non-existent article? 

message: It seems like the article Electron microprobe has substantial overlap with this one. In fact, between this article and the EDS article, I think almost everything in Electron microprobe is covered, but better. Should Electron microprobe be merged and then deleted? Or should we decide that parts of this article should be moved to Electron microprobe and vice-versa? I don't know, but I'm hoping someone here will do something about this. Thanks!! :-) --Steve (talk) 04:39, 30 January 2009 (UTC)
replies: text: They are two different instruments, although they have entirely overlapping functions.  The SEM is almost always equipped with EDS, but not always with WDS, while an EPMA always comes with multiple WDSs and an EDS.  Also an EPMA has a light microscope integrated for focusing for the WDS.  There are other differences, even though they can both accomplish pretty much the same things.  The EPMA article needs a lot of work, but it is a specific instrument, with its own history, versus the SEM.  Almost every geology department of a university will have an EPMA and a TEM.  All of them want an SEM in addition, but not all of them have their own SEM.  I don't think that EPMA should be deleted.  Maybe parts of this article could be moved to EPMA, and a link to the main article on EPMA indicated at the top, with merely a couple of paragraphs here describing how the two instruments are closely related.  --KP Botany (talk) 03:00, 31 January 2009 (UTC)
thread_title:  May I draw your attention to the article [[Electron microprobe]] 

message: Did they have to coat the snowflake with gold before scanning?  Would be nice to mention it in the caption since the coating-of-gold was a surprise to me when I visited this article.  Tempshill (talk) 06:36, 7 February 2009 (UTC)
replies: text: Yes. Bill Wergin used sputtered gold or platinum coatings on his snow/ice specimens. Plantsurfer (talk) 15:11, 7 February 2009 (UTC)

text: Thanks for asking the question, Tempshill.  I added a note to the image caption for other readers.  The snow crystals are usually captured on a cooled copper plate (-100 and something degrees C), then sputter coated with platinum in a cryo-sputter coater (for lack of a better name), then imaged in the cryo-SEM.  --KP Botany (talk) 11:52, 8 February 2009 (UTC)
thread_title:  Snowflake 

message: I'm an amateur, but in my experience with gold or carbon sputter coating, the thickness is a few nanometers.  In the "biological samples" section, it says: "However, the coating has a thickness of a few micrometres."  I think this is a typo, but I'm unfamiliar with biological samples so I thought I'd check here before I changed it. Jermor (talk) 20:51, 19 February 2010 (UTC)
replies: text: While I never worked with bio-samples either, the statement is certainly in error (micrometer coating would be intransparent; and all sources say nanometers), and thus I changed it to nm. Materialscientist (talk) 05:28, 20 February 2010 (UTC)
thread_title: Micro or Nanometer Coating Thickness

message: Is there also not in existence a transmission scanning electron microscope? If so, can someone more knowledgeable write upsomething about it?
Old_Wombat (talk) 09:23, 28 October 2011 (UTC)
replies: text: We have scanning transmission electron microscopy, but it does need much work. Materialscientist (talk) 09:41, 28 October 2011 (UTC)
thread_title:  Another kind of SEM? 

message: I strongly believe all altered (MEANS COLORED) micrographs should be removed.  — Preceding unsigned comment added by Vniizht (talk • contribs) 22:07, 3 February 2012 (UTC)
replies: text: See earlier discussion of this below.  Some SEM pictures do come coloured for very good reasons, and the colouring is not done by hand but by the instrument.  Such pictures can be acceptable for publication if the protocol and justification are both clear.Plantsurfer (talk) 12:14, 10 December 2012 (UTC)
replies: text: Thanks. I've added a first section on the use of color in SEM pictures; it needs work, but the issue clearly needs to be addressed. I'll add some citations next. -- Dan Griscom (talk) 13:52, 10 December 2012 (UTC)
replies: text: 3/4 of the references provided on color refer to internet blogs and listservers which are not reliable external sources, i.e. not acceptable per wiki policy. They should be deleted. The first reference from a refereed journal is fine. Two such additional references have already been suggested in the continued discussion "To Plantsurfer about colored pictures" below.--Esem0 (talk) 01:31, 12 December 2012 (UTC)
replies: text: Thanks for catching that. -- Dan Griscom (talk) 02:19, 12 December 2012 (UTC)

text:  And thanks to whomever added more information on the use of color to display information captured by the SEM, rather than Photoshopped in by the researcher or press agent. I do believe, however, that many or even most of the color images the public sees are hand-edited. I'd love to see more information on this, as it would be important information for a visitor. -- Dan Griscom (talk) 02:19, 12 December 2012 (UTC)
thread_title:  No colored pictures! 

message: 1. 300 V - 1kV is a new "normal" voltage for SEM. Low voltage and in-lens SEM is a way to go now. 10 kV is a way to hight voltage even for traditional SEM. Too strong edge effect and too high volume of signal generation. I myself do not go above 5 kV for most applications.
2. For at least 15 years there were no new SEMs with CRT. We cannot stick to explanations of image formation with CRT scopes any more. Time to move forward.
So, your "undo" of my editing looks too outdated. 
I am waiting for your reply; otherwise I will reverse it back.
Thanks,
Chivesud (talk) 15:30, 17 February 2012 (UTC)
replies: text: Chivesud, sorry for delay - hectic days. I agree that image formation with CRT scopes is not relevant anymore, but I do disagree with the high voltage comment - this all depend on the user, and for inorganic samples, higher voltage usually offers better resolution (charging effects aside), thus most non-biologists by default go to nearly the highest microscope voltage (say 20 keV) - just my observation. Materialscientist (talk) 00:44, 23 February 2012 (UTC)

text: As an experienced user of SEMs since shortly after the first one was  installed in Scotland in the late 1960s I agree with Chivesud on this. A 30kV beam stimulates signal generation from depths within the specimen several hundred times greater than the resolution of a modern FESEM, swamping the signal from fine surface detail and it follows from this that the use of high kV is almost always counterproductive if the aim is maximum resolution. Only if the aim is to stimulate x-ray emission or to detect dense objects such as colloidal gold labels beneath the surface of a specimen using the Backscattered electron signals is high kV necessary. It is probably because non-biologists make greater use of analytical modes that they regard high kV as the default. It is irksome to have to switch back and forth between high-res and analytical settings, so the default will be the setting that gets most use. For highest resolution any specimen will have an optimum accelerating voltage in the range 2-5 kV where the best combination of signal to noise and resolution can be obtained.  In addition, very short working distances are required for maximum resolution, and most microscopes cannot focus a high kV beam at shortest working distances because the objective lens power required is excessively high.Plantsurfer (talk) 17:49, 18 March 2012 (UTC)
thread_title:  To: Materialscientist and Mike Rosoft. Let's do not stick to the previous century tradition 

message: Hi Plantsurfer,
Colored pictures ARE NOT SUITED FOR SCIENTIFIC PUBLICATIONS. Period.
Please, do not revert again my editing on the colored pictures.
Thank you,
Chivesud (talk) 01:58, 24 March 2012 (UTC)
replies: text: Please provide reliable sources for this strong statement. Materialscientist (talk) 02:15, 24 March 2012 (UTC)
replies: text: Hi Chivesud, I do not disagree with you that the majority of coloured SEM images are false-coloured and that the colouring is purely arbitrary embellishment and is usually without scientific justification. Nevertheless there are valid uses for such images even in scientific publications. One such example of the publication of false-coloured SEM images appears in the following paper in The Plant Cell: http://www.plantcell.org/content/23/4/1337.full.pdf+html?sid=82d6ac36-70f6-4624-b224-ef1cd9a7b25c. page 1339 Other legitimate uses are in the publication of 1) anaglyph stereo images 2) mapping of x-ray data onto an image or 3) in other situations where multi-channel information is being presented, such as a BSE or cathodoluminescence image, superimposed on a topgraphical secondary electron image. Modern SEMs such as the Hitachi 4700 and 4800 have the capability to combine signal channels into a colour image for just this purpose.  Let  me know if you have any trouble seeing the pdf - if so I could send it to you by email. Plantsurfer (talk) 16:24, 24 March 2012 (UTC)

text: It is all gets a bit complicated these days, because so many imaging techniques (such as confocal microscopy) combine separate data channels into one image, and not only are the gain or contrast likely to be different in each channel, but the colours assigned to each may well be arbitrarily chosen.  This can apply to astronomical images too - if you look at Astronomy Picture of the Day you will find innumerable examples where x-ray or radio images are merged with visible-light images.  Nature (the journal) is obvioiusly concerned to prohibit arbitrary falsification of images by editing with e.g. Pxxxxxxop, and the spirit of the thing is to preserve information integrity.  However, the question of whether a photograph truly represents reality has always been an issue in scientific photography.  The first departure occurred when the choice of emulsion was made (contrasty and slow or fast and soft), the second when the emulsion was developed - any manner of response curve could be cooked up by suitable choice of developer chemistry, time and temperature  and the third departure occurred when the negative was printed - hard or soft paper - the choice was not usually the scientist's but the departmental photographer's.  People fiddle with images using e.g. clone tools in Photoshop and think they are doing something novel, but that is far from the case. The manipulation that a professional photographer could get up to in the darkroom was capable of doing that 100 years ago, and you don't need to look too deeply into Photoshop to see that its tools are derived from darkroom tricks, implemented in digital form.  Consider unsharp mask sharpening, for example. Plantsurfer (talk) 20:02, 3 April 2012 (UTC)
replies: text:  In further support to Plantsurfer, may I add that color is extremely useful in superimposing two or three different information signals like here,   here and  here. No computer processing was involved but plain superimposition of successive images carrying SE and BSE information, i.e. meaningful topographic, material/composition information (see also: Danilatos, G.D. (1986b) Colour micrographs for backscattered electron signals in the SEM . Scanning 8:9-18. Or Danilatos, G.D. (1986c) Environmental scanning electron microscopy in colour. J. Microsc. 142:317-325). Displaying all this information simulataneously in B&W would be utterly confusing.--Esem0 (talk) 03:17, 28 October 2012 (UTC)
thread_title:  To Plantsurfer about colored pictures 

message: I think the few words spared for Manfred von Ardenne do not make justice for the father of scanning electron microscope. Specifically, the phrase "but never made a practical instrument" portrays a denial for his great achievements. He actually constructed a prototype SEM and produced the first ever scanning electron micrographs as reported in the second part of his "Elektronen-Rastermikroskop". He was not a manufacturer to develop and produce a machine for the general public. This does not deserve him any negativity after the world has enjoyed the outcomes of his innovation for so many decades. We are not qualified judges to state that "he never made a practical instrument" except to state the opposite. He was actually both a great experimentalist and builder of electron microscopes, and a great theoretician. He is the equal to Ruska but not easily recognized as such.--Esem0 (talk) 13:33, 9 August 2012 (UTC)
replies: text: Better historical account for SEM is now provided. --Esem0 (talk) 04:04, 26 October 2012 (UTC)
replies: text: Are there any surviving images taken by the instruments developed by the SEM pioneers Max Knoll and Manfred von Ardenne? If so, can they be added to the article?  It would also be of interest to have examples of early images produced by the Cambridge group.Plantsurfer (talk) 08:29, 26 October 2012 (UTC)
replies: text:  There are in the relevant references but one has to obtain good digital copies of them from the original journals and (worse) has to upload them with relevant permissions for wiki use.--Esem0 (talk) 10:15, 26 October 2012 (UTC)
thread_title:  Manfred von Ardenne 

message: Does anyone have or know of a bona fide multichannel color SEM image that can be used in the article without copyright problems. Plantsurfer (talk) 12:23, 13 December 2012 (UTC)
replies: text: You can find lots of images with explanation in multichannel SEM imaging and until such images might be released for wikipedia use.  --Esem0 (talk) 06:00, 14 December 2012 (UTC)
thread_title:  Color SEM image 

message: Search results of the article: 9 counts for "an SEM" and 7 counts for "a SEM". It should be consistent and changed to "an SEM", according to grammar rules and for example the entry for "indefinite articles" in Wikipedia: "The form an is used before words that begin with a vowel sound (even if spelled with an initial consonant, as in an hour), and a before words that begin with a consonant sound (even if spelled with a vowel, as in a European)"Basshannes (talk) 11:41, 17 November 2015 (UTC)
replies: text: Unified as "an SEM", which is the dominant form in scientific literature, AFAIK. Materialscientist (talk) 11:44, 17 November 2015 (UTC)
thread_title:  An SEM or a SEM 

message: Can someone clarify the following?
  "...eliminate the chromatic aberration otherwise inherent in the electron microscope"
Chromatic aberration is a potential defect in glass lenses, not in an SEM.  — Preceding unsigned comment added by 208.59.128.48 (talk) 12:05, 24 October 2016 (UTC)
replies: text: Just as in the light beam that illuminates the specimen in a light microscope, the electron beam consists of electrons with a range of energies, usually with a Gaussian distribution. The electron lenses cannot focus the electrons of different energies to the same extent, so chromatic aberrations occur in the images made by simple electron lenses that result not in colour fringes but in loss of resolution. Plantsurfer 12:29, 24 October 2016 (UTC)
thread_title:  CA 

message: An individual editor's expertise in instrumentation for the semiconductor industry is not sufficient to establish that particular information is reliable for Wikipedia. Please provide a reliable source. "The Citation needed template is intended for use when there is a general question of the verifiability of a statement, or when an editor believes that a reference verifying the statement should be provided." Sucb a source probably contains more useful information about SEMs in the semiconductor industry, and I can't find one. --2600:387:6:807:0:0:0:6A (talk) 12:11, 26 May 2017 (UTC)
thread_title:  Industry standard 

message: The source does not say eggshells can be put in SEM with little further treatment, whatever that means, it says this Southwestern US collection of 600 year old eggshells stored for 40 years were rinsed with distilled water and carbon coated before being examined on the SEM. --2601:648:8503:4467:B8A4:9B4E:66AB:4469 (talk) 13:02, 26 May 2017 (UTC)
thread_title:  Eggshells in SEM 

message: That spider kicked me from the chair. Maybe another picture or just a leg?  — Preceding unsigned comment added by Dnvuma (talk • contribs) 13:02, 19 October 2019 (UTC)
thread_title:  Spider