Wikipedia:Reference desk/Archives/Science/2021 June 6

= June 6 =

Antibodies of all COVID vaccines are same?
We have 6 major COVID vaccines, so antibodies in it are same or different? Rizosome (talk) 02:29, 6 June 2021 (UTC)
 * The vaccines differ in what exact parts of the spike protein they target, but with some overlap. I assume the same will be true for the resulting antibodies (i.e. you can possibly determine the vaccine given from a full spectrum of antibodies present, but not, in general, based on the presence or absence of one particular antibody type). --Stephan Schulz (talk) 11:05, 6 June 2021 (UTC)

I have a separate question. Given there are however many different covid vaccines, are there any selectivity among them? Example: if you have diabetes, or have high/low blood pressure, then you are preferred this 1 over that? But it seems, you choose which vaccine you want. That sucks. 67.165.185.178 (talk) 03:26, 7 June 2021 (UTC).

'Quad' stereographic photography
I was just looking through random pages, hoping to find an image that might benefit from retouching, and I discovered this extraordinary photograph of General Dennis T. Kirby taken in the early 1860s. Crossing my eyes it appeared to be a pair (or two pairs) of stereographic photos. Just to make sure I opened the image in Photoshop, created two copies which I aligned, and flicking between the two layers I could clearly see that they were indeed stereoscopic.

Upon further inspection, however, I realized that all four images were taken at the same time; the images on the left were taken from slightly to the right and the images on the right were taken from slightly to the left (hence being viewable in 3D by crossing your eyes), but also the images on the top were taken from slightly below where the images on the bottom were taken from (and you can actually tilt your head 90° and cross your eyes to view them in 3D).

Bearing in mind that cameras produce upside-down/back-to-front negatives, what we're seeing here is the result of a camera with four lenses controlled via a single shutter release - a sort of 'quad' stereographic camera - from over 150 years ago. I've been fascinated by photography and stereography for most of my life but I've never heard of such a camera nor seen such photographs. Does anyone here have any idea about them? (Pinging User:C.Suthorn because I know he has an interest in this sort of thing.) nagualdesign 04:33, 6 June 2021 (UTC)


 * I have never heard or seen anything like this. However there are cameras that take photographs like this (see image). These are for taking 4 passport fotos at the same time, not for a stereoscopic effect.


 * --C.Suthorn (talk) 06:45, 6 June 2021 (UTC)
 * It doesn't really surprise me that there are modern cameras that do this. What really fascinates me is that they were doing this in the 1800s. (Apologies for referring to you as "he", I had no idea that you prefer to be called "them", but please don't edit my posts.) nagualdesign 16:57, 6 June 2021 (UTC)


 * Yes, such a camera was used to take my passport photos at least once, years ago. Our government requires two identical, professionally taken photos to be submitted, and this was a way of producing them simultaneously.  (For the reasons explained above, they weren't actually quite identical, but apparently nobody worried about that.)  I think the photographer cut the four photos apart and I got to keep the extra two.


 * Side comment: that bold black / gray "nagualdesign" thing is really distracting, to the point where I had trouble reading one thread where you posted several times.


 * --184.145.50.201 (talk) 06:56, 6 June 2021 (UTC)
 * It's a shame that they get cut into separate photos. I think the coolest bit about them is the 3D effect.
 * That bold black/gray "nagualdesign" thing is my signature. You're going to have trouble reading this thread in a minute when I post multiple replies at once! Perhaps you could try crossing your eyes? nagualdesign</b></b> 16:57, 6 June 2021 (UTC)
 * I know it's your signature. That's what I'm complaining about. --184.145.50.201 (talk) 21:03, 6 June 2021 (UTC)
 * Vandalizing their signature isn't going to lead to a positive outcome for you. DMacks (talk) 21:31, 6 June 2021 (UTC)
 * "Vandalizing"?? Never mind, I'm done with this. --184.145.50.201 (talk) 00:03, 7 June 2021 (UTC)
 * I mis-attributed the target of your disruptive edit (inserting an external link in your own sig was the disruption contrarary to signature standards, not damaging someone else's sig. This is the edit in question: diff. My appology for mis-stating what you were doing that was not-appropriate. If you have a concern about someone else's sig, talk to them directly, or then pursue at other notice boards. WP:POINT won't help. DMacks (talk) 00:10, 7 June 2021 (UTC)
 * And my apology for the disruption; it was not a spam link, but it was a misdirected paste and before posting I should have previewed and noticed and fixed it. --184.145.50.201 (talk) 04:45, 7 June 2021 (UTC)
 * @184.145.50.201 Bit weird complaining about my signature, which I've had for over a decade with no complaints until now, while pasting a spam link into your own signature, contrary to WP policy. Anyhoo, if you want to discuss this further feel free to leave a post on my talk page. <b style="font:1.3em/1em Trebuchet MS;letter-spacing:-0.07em"><b style="color:#000">nagual</b><b style="color:#BBA">design</b></b> 00:24, 7 June 2021 (UTC)


 * Four-lens cameras were relatively common for direct-positive photographic processes back in the US Civil War era. Not for stereoscopy, but simply because direct-positive photos (like tin-types) can't be copied, so it was handy to be able to give the customer four copies of the same photo. here is an example camera.
 * However, the LOC Catalog says this one was shot to wet-plate negatives. So, they could have made as many prints as they wanted from a single negative.
 * ApLundell (talk) 07:39, 6 June 2021 (UTC)
 * Now we're talking! That camera really does look the part but, as you say, this was shot using the collodion process, making things even more complicated. I suppose there's no reason that such a camera can't be used, or adapted for use, with wet-plate negatives though.
 * As I understand it, tintypes also need to be kept in a dark envelope while being placed in the camera. I made the mistake earlier of mentioning multiple shutter releases, when of course with these old cameras you slid a cover out from in front of the plate. I suppose the main difference with using a wet plate in that camera would be the post processing. <b style="font:1.3em/1em Trebuchet MS;letter-spacing:-0.07em"><b style="color:#000">nagual</b><b style="color:#BBA">design</b></b> 16:57, 6 June 2021 (UTC)

Thanks everyone for your comments. I'm not going to mark this as resolved just yet as there may be more insights to be had. Here comes that signature again... <b style="font:1.3em/1em Trebuchet MS;letter-spacing:-0.07em"><b style="color:#000">nagual</b><b style="color:#BBA">design</b></b> 16:57, 6 June 2021 (UTC)


 * If they intended to make a lot of prints of particular photo, I guess a four-up camera still makes sense.  Imagine the time and labor involved in making 1000 prints compared to the labor of making 250 prints and cutting them. ApLundell (talk) 21:17, 7 June 2021 (UTC)
 * Yes, the more I've thought about it the more I realize that taking multiple photographs at once was primarily (or solely) to make things easier and quicker, and that the stereographic effect was simply a by-product of the process. Still, it's great that we have all this 3D data about people who lived so long ago. With modern coding techniques you could easily convert them into accurate 3D models, and even create an app to view them from slightly different angles by tilting your smart phone. I'll mark this question as resolved. Cheers. <b style="font:1.3em/1em Trebuchet MS;letter-spacing:-0.07em"><b style="color:#000">nagual</b><b style="color:#BBA">design</b></b> 03:15, 9 June 2021 (UTC)

RL10 nut types
In the photo File:RL-10_rocket_engine_(30432256313).jpg, we can see some detail of the fastners holding together various high-pressure seals, such as those around the turbopump assemblies. Both the nuts and bolts appear to have fluted multilobular heads (perhaps with rounded flutes, a bit like inverted Torx fasteners). I can't see specifically the shape (the photo is detailed, but not quite *that* detailed). They don't seem to be any of the types listed at list of screw drives. Presumably they're some kind of high-performance aviation grade head (one maybe used in other aircraft parts, such as jet engines). Can anyone identify the type? 51.7.144.6 (talk) 21:55, 6 June 2021 (UTC)

No expert but either external Torx which have 6 points or 12 point external drive. BMWs use the external torx in some places. Greglocock (talk) 23:37, 6 June 2021 (UTC)


 * Those are spline nuts. Not listed at Nut (hardware). There are probably other names for them. They have fluted pockets that securely fit the special sockets used on them. Similar to an F1 wheel nut. Several of the lower ones look a little different because they've been safety-wired to prevent loosening and therefore have the holes for the wire.
 * There are also a few castellated nuts near the bright white circular object. --DB1729 (talk) 05:18, 7 June 2021 (UTC)
 * And upon further thought, I believe Greglocock is correct. What you're seeing are called external Torx. DB1729 (talk) 05:55, 7 June 2021 (UTC)
 * Link: External Torx. Our article Lug nut mentions a "spline drive" type, without explaining what that means. --Lambiam 07:14, 7 June 2021 (UTC)