Wikipedia:Reference desk/Science

Welcome to the science section
of the Wikipedia reference desk.

skip to bottom

Select a section:

• Computing
• Entertainment
• Humanities
• Language
• Mathematics
• Science
• Miscellaneous
• Archives

Want a faster answer?

Main page: Help searching Wikipedia

   

How can I get my question answered?

• Select the section of the desk that best fits the general topic of your question (see the navigation column to the right).
• Post your question to only one section, providing a short header that gives the topic of your question.
• Type '~~~~' (that is, four tilde characters) at the end – this signs and dates your contribution so we know who wrote what and when.
• Don't post personal contact information – it will be removed. Any answers will be provided here.
• Please be as specific as possible, and include all relevant context – the usefulness of answers may depend on the context.
• Note:
  • We don't answer (and may remove) questions that require medical diagnosis or legal advice.
  • We don't answer requests for opinions, predictions or debate.
  • We don't do your homework for you, though we'll help you past the stuck point.
  • We don't conduct original research or provide a free source of ideas, but we'll help you find information you need.

Ready? Ask a new question!

How do I answer a question?

Main page: Wikipedia:Reference desk/Guidelines

• The best answers address the question directly, and back up facts with wikilinks and links to sources. Do not edit others' comments and do not give any medical or legal advice.

See also:

• Teahouse
• Help desk
• Village pump
• Help manual

July 17

Five-year survival rate for cancer

In general, when five-year survival rates for diseases are calculated, do the statisticians pay attention to unrelated deaths? Let's say I get diagnosed with a rare type of cancer (so one person's death can mathematically affect the small sample size), and as I'm leaving the doctor's office, I get run over by a reckless driver. Do I drag down the five-year survival rate for my type of cancer? Nyttend (talk) 00:47, 17 July 2026 (UTC)

it depends. If observed survival rate is being calculated, the cause of death doesn't matter, only survival. So you would be included as you suspected. If relative survival rate is being measured, you arr included but in comparison to the general population, who are also being killed on random events. Your unexpected death is balanced out by someone else's unexpected death. If specific cause rate is being measured, you are excluded because you did not die of that specific cause. You mention this in relation to cancer, but it shows up more in vaccines where people confuse rates to push narratives for social media clicks. ~2026-39968-68 (talk) 02:20, 17 July 2026 (UTC)

Overwhelmingly, cancer studies report a relative survival rate. So, while people in the cancer cohort will have car accidents, that is compared to the general population which also has car accidents. That is why the rates are percentages. They are a percent of the general population. Something like 70% means the survival rate for the cancer cohort is 70% of the general population. The benefit with doing it this way is that the analysts don't skew the results by trying apply rules about which deaths are included and which are not. Then, they have to work out when a person would die if they didn't die from some other cause. ~2026-35239-54 (talk) 11:07, 17 July 2026 (UTC)

Comparing relative to the general population also accounts for deaths that are only indirectly caused by cancer. Suppose brain cancer causes problems with balance and vision. That reasonably leads to poorer identification of emergent situational threats and ability to move to safety. So we have a a pedestrian getting killed by a bad driver because they didn't realize the car was coming towards them and then stumbled back into the street trying to get back on the curb at the last minute being an increasingly likely scenario due to cancer. I would think this should be counted as a reduced overall survival due to cancer, but cannot be direclty traced to the cancer itself in any specific indiviual's death.

Take it a step further: common side effecs of chemotherapy include all sorts of neurological damage, including with to vision and balance, and do have a greater statistical likelihood of falls and similar accidents. Given old folks are both more likely to have cancer and more likely to have worse outcomes from falls themselves, if grandpa has cancer, he is less likely to survive even if the cancer is not the direct cause of death itself. DMacks (talk) 15:39, 18 July 2026 (UTC)

Then let's imagine that there's a convention for people with a rare kind of cancer, and the attendees represent something like 50% of those with this cancer in a country. A gas line ruptures and causes the whole building to explode, and everyone inside (patients, dining staff, support workers, maintenance staff, etc) is immediately incinerated. Aside from the topic of the event that they're all attending, these people's deaths have nothing to do with their illness. Nyttend (talk) 12:06, 20 July 2026 (UTC)

From Nyttend's morbid Thought experiment we draw the wisdom that Correlation does not imply causation. No participants were injured in this experiment. ~2026-39925-22 (talk) 15:39, 20 July 2026 (UTC)

Obvious xkcd, for those who haven't seen it. DMacks (talk) 21:46, 21 July 2026 (UTC)

Well, people without cancer also sometimes get run over … —Antonissimo (talk) 00:59, 18 July 2026 (UTC)

A single additional random accidental death could distort the survival rate numbers in a small enough sample size. At population levels or in samples of multiple thousands, it doesn't make a difference. -- Avocado (talk) 20:58, 18 July 2026 (UTC)

I think it is also important to recognize that people undergoing treatment for cancer have a higher rate of accidental falls, and of suicide. Also, these five year survival rate studies have an issue with patient retention. Best practice is to only make comparisons to groups of patients getting the other treatment(s). Abductive (reasoning) 17:45, 19 July 2026 (UTC)

Of the 987 patients in the group receiving the novel treatment, 212 were alive at the end of the five-year study, while of the control group of 1024 patients receiving the traditional treatment, 210 were alive. What formula should the study use to report the five-year survival rate with the novel treatment? Or should survival rates not be reported at all?  ​‑‑Lambiam 07:58, 20 July 2026 (UTC)

A recovery rate with documented change in symptoms is a meaningful verification of a novel treatment but a survival rate alone, possibly in spite of ineffective treatments, is not a reliable measure. ~2026-39925-22 (talk) 15:48, 20 July 2026 (UTC)

The question was about how statisticians determine survival rates, not about which measures are best practice when reporting on comparisons between treatments. Still, I fail to see why reporting on five-year survival rate in a controlled study should be deprec(i)ated.  ​‑‑Lambiam 09:38, 22 July 2026 (UTC)

July 19

Altimeters

Do aircraft commonly (also) have metric altimeters in countries which measure altitude in feet? And how common is to measure altitude in meters in such countries? --40bus (talk) 17:08, 19 July 2026 (UTC)

Didn't you ask this same question a year or two ago? ←Baseball Bugs ^{What's up, Doc?} carrots→ 17:48, 19 July 2026 (UTC)

I don’t remember asking such a question.

Well it was 2024, see here. Heights are in feet except above China.Shantavira|^{feed me} 07:53, 20 July 2026 (UTC)

Similar things were asked on more occasions. I remember commenting that in Europe, gliders often have metric altimeters (and also vertical speed in metres per second, airspeed in kilometres per hour). This also applies to historical aircraft, as before 1945, European aviation (except in the UK and Ireland) was metric. After all, Europe (except the UK and Ireland, except some ballooning) metricated before the start of aviation. And modern glass cockpits can be converted between metric and imperial with the push of a button. PiusImpavidus (talk) 09:21, 20 July 2026 (UTC)

It’s a bit more nuanced. Altitudes and flight levels are reported in feet worldwide, including Europe. Russia and China have historically used meters for some altitudes and flight levels, but most commercial operations use feet. The altimeter itself doesn’t use feet or meters internally. It uses barometric pressure. ATC assigns altitudes in feet, but also gives a pressure setting. In the U.S. and Canada, the pressure is given in inches of mercury (inHg). In Europe and most of the world, it’s given in hectopascals (hPa). Pilots set the altimeter to the assigned pressure (e.g., 29.92 inHg or 1013 hPa). Once everyone is using the same pressure reference, their indicated altitudes will be consistent relative to each other, which is what matters for separation. ~2026-35239-54 (talk) 16:24, 20 July 2026 (UTC)

Still, ATC will tell a flight to maintain 3000 feet, not to maintain 90 kPa.  ​‑‑Lambiam 19:40, 21 July 2026 (UTC)

On initial approach, ATC will usually (I don't know of an exception) give out the air pressure such as "QNH 1017" or "Altimeter 29.92" and then the instruction "Descend and maintain 3000 feet." The first is to calibrate the altimeter. The second is the actual altitude. But, it still remains that with very rare exception, feet is used as the altitude unit. I've seen China and Russia used as examples where feet is not used, but that appears to be changing. Their major airports have switched to feet to standardize with the rest of the world. ~2026-35239-54 (talk) 19:56, 21 July 2026 (UTC)

Aviation is weird.

Over the past 231 years, almost all of the world metricated, but aviation, which started metric in most of the world, is one of the few (if not the only) things that demetricated. That gives us such rules as: take you altitude in thousands of feet, multiply by three, multiply by some correction if the lift-to-drag ratio of your aircraft isn't the standard, and you get the distance from your destination in nautical miles to start your decent. In metric (or FFF or any other consistent unit system), just take your altitude, multiply by your lift-to-drag ratio and you get the distance. Apparently the rule above assumes a standard lift-to-drag ratio of 18.2:1. In the same manner, in road, rail and water transport, slopes are always expressed as a ratio (1:150, 0.7%, 7‰), the tangent of the angle, which for shallow slopes is the same as the angle in radians, but aviation uses an angle in degrees. This makes it non-obvious which is steeper, a 3.5 degree glide slope or an 18:1 lift-to-drag ratio (the former is steeper, so you need your flaps to increase drag).

Meteorologists talk about the 300 hPa level when referring to the higher part of the troposphere. PiusImpavidus (talk) 09:18, 22 July 2026 (UTC)

But pilots don't need to do any calculations when they've Bitching Betty or Grumbling Gary nagging them about the exact approach angle. ~2026-35239-54 (talk) 12:05, 22 July 2026 (UTC)

How common is to measure aircraft and ship speed in km/h instead of knots? --40bus (talk) 07:36, 24 July 2026 (UTC)

For inland shipping (rivers, lakes, canals), km/h seems pretty common. At sea, it's mostly knots. Amongst aircraft, gliders often use km/h. I don't know about ultralights and airships, but others seem to use mostly knots these days. km/h used to be more common. PiusImpavidus (talk) 19:52, 24 July 2026 (UTC)

July 20

Obscure catalog entry name that closely resembles the Wolf–Rayet catalog

While co-writing someone else's draft about a W Ursae Majoris variable (Draft:V523 Cassiopeiae), I discovered a reference to a designation of the star as "Wr16" (not to be confused with the Wolf–Rayet star catalog entry WR 16):

Jeong, Jang-Hae; Kim, Chun-Hwey; Lee, Yong-Sam (2010-06-15). "Photometric Observations of the Contact Binary System V523 Cassiopeiae". Journal of Astronomy and Space Sciences. 27 (2): 81–88. doi:10.5140/JASS.2010.27.2.081. ISSN 2093-5587.

SIMBAD's entry on this star lists this name as well (under the catalog "SV*"), but has no information about the catalog. What is SV*? Would the "Wr16" designation require a hatnote from WR 16 to V523 Cas once the draft is published? –LaundryPizza03 (dc̄) 06:29, 20 July 2026 (UTC)

"Wr" probably refers to Weber (1958), [1]. Would have to precess the coordinates to J2000 to be sure. --Wrongfilter (talk) 06:41, 20 July 2026 (UTC)

July 22

Do people become passive aggressive from being bullied, or from being unloved or what?

Do people become passive aggressive from being bullied or being unloved, or what? Or is it behavior pattern opurtunistically picked up on by an unhappy person, or conceivably, by a happy, untroubled person?Rich (talk) 01:53, 22 July 2026 (UTC)

There are some clues in Passive-aggressive behavior. ←Baseball Bugs ^{What's up, Doc?} carrots→ 01:59, 22 July 2026 (UTC)

IMO, resentment and opposition to the demands of people in positions of authority^[2] can be natural and healthy, and is not in itself a sign of a clinically troublesome personality trait. Given the fact that people in positions of authority are generally in a position to deliver vindictive retaliation in response to perceived defiance of their authority ("insubordination!"), it is prudent not to express one's resentment and opposition openly but use instead, for example, a one-person slowdown.

Note that "Passive–aggressive personality disorder" has been removed from the DSM since the DSM-5 of 2013, IMO rightly so. That said, for people suffering from a personality disorder, which can have many causes, coping mechanisms can become sealed in, and these mechanisms can include those used for the "passive aggressive" label.  ​‑‑Lambiam 08:06, 22 July 2026 (UTC)

Maybe the OP (who can't spell, BTW) would prefer active aggressive, such as bringing a gun into work and shooting up the place. ←Baseball Bugs ^{What's up, Doc?} carrots→ 11:11, 22 July 2026 (UTC)

"Active" aggressive is not a thing. There are three categories discussed in psychology: passive-aggressive (hides hostile behavior), assertive (expresses needs openly without hostility), and aggressive (expresses hostility openly). ~2026-35239-54 (talk) 11:55, 22 July 2026 (UTC)

How does that make shooting up the workplace somehow better? ←Baseball Bugs ^{What's up, Doc?} carrots→ 13:31, 22 July 2026 (UTC)

You're the only one here who thinks that. Bugs, you need to stop lying about what has been asked. DuncanHill (talk) 14:00, 22 July 2026 (UTC)

Your comment makes no sense. ←Baseball Bugs ^{What's up, Doc?} carrots→ 14:37, 22 July 2026 (UTC)

It makes total sense. You're asking someone to defend a position they never stated. Classic straw man. You're the only one who's mentioned guns and shooting up workplaces. -- Jack of Oz ^{[pleasantries]} 21:20, 22 July 2026 (UTC)

I merely asked whether the OP preferred "active" aggression rather than "passive" aggression. Still waiting for an answer on that. However, the OP's core premise is flawed. As if passive aggression is somehow driven by something that's wrong with them, rather than by a toxic environment they find themselves in. That's why I recommended the OP read the article on passive-aggressive. ←Baseball Bugs ^{What's up, Doc?} carrots→ 23:32, 22 July 2026 (UTC)

In fact, the tone of the OP's question reminded me of the gunnery sergeant's comment in Full Metal Jacket, where he berates the troubled private as to whether he didn't get enough motherly love when he was an infant - just before the private guns him down. ←Baseball Bugs ^{What's up, Doc?} carrots→ 23:44, 22 July 2026 (UTC)

The OP asked about possible causes of passive aggressive behavior. You responded that by asking that question, the OP likely wants people to get guns and shoot up workplaces. As pointed out, your response is out of place, likely based on context you are personally attaching to the question that others are not. ~2026-39968-68 (talk) 01:18, 23 July 2026 (UTC)

-> Hmm I guess the private did not get enough motherly love then, but I haven't seen the momovieBut I have some explainig to do, even though I didn't do anything wrong this time.

...Once again I failed to read the article on passive aggression before posting, because I was so upset thatt a person I know is a genius at underhanded cuts, and a friend called it passive aggressive. So I went ahead and posted, and then perused the science reference desk, noticing Greglocok's rather cranky response. Feeling rather cranky myself, I believe I was justified in replying to Greg, both at the ref desk and on his talk page. As I said, I was right to do so, but I don't think Greg is bad, just having a bad day like I have sometimes. And to be clear, Grelokok was being directly cranky, not underhanded, not passive aggressive...passive aggression is not something everyone has experienced, I'm sure. Anyway, Baseball Bugs, you might not have seen real passive agression from someone yet, it can be unbelievable, although I don't know for sur. But I haven't forgotten how much I owe you for forgiving me when I attacked you personally when I thought I was having another heart attack! It shows you have a big heart. Rich (talk) 01:30, 23 July 2026 (UTC)

I don't recall that incident, but obviously you certainly would! I hope you are well now. :) ←Baseball Bugs ^{What's up, Doc?} carrots→ 01:50, 23 July 2026 (UTC)

Here's the clip from Full Metal Jacket I was talking about. This is where private Pyle's apparent compliance with a bullying sergeant turned from "passive" aggression (i.e. apparent compliance) to "active" aggression.[3] I'd have to argue that "passive" aggression, while unpleasant, can also be rather more civilized than "active" aggression. ←Baseball Bugs ^{What's up, Doc?} carrots→ 01:56, 23 July 2026 (UTC)

I would also say that Greglocock's comments to you, on the subject of extinction, were rather snippy. ←Baseball Bugs ^{What's up, Doc?} carrots→ 01:59, 23 July 2026 (UTC)

actually the comments were directed at the OP of that thread. While snippy, Gregs remark wasnt underhanded. Rich (talk) 02:32, 23 July 2026 (UTC)

yeah, I'm better, no heart attacks or heart symptoms Rich (talk) 02:35, 23 July 2026 (UTC)

Excellent. Where there's life, there's hope. As to the extinction thing, you're right, it was directed at the original poster. But still over-the-top. ←Baseball Bugs ^{What's up, Doc?} carrots→ 02:38, 23 July 2026 (UTC)

Right and let's bear in mind that what clinicians call passive aggressive might be much more extreme and unpleasant, like my recent experience, than the pattern of an unhappy employee unwilling to perform an unethical action requested by his employer.Rich (talk) 06:12, 23 July 2026 (UTC)

The reply just above was supposed to be a reply to Lambiam, don't know why it went down here. Rich (talk) 06:13, 23 July 2026 (UTC)

A reply to a contribution at indentation level N will have indentation level N + 1 and is placed after all earlier replies, or replies to replies, and so on, to the aforesaid contribution. All of these have an indentation level of at least N + 1. There is no earlier spot where your reply would have fit. Anywhere else would mean inserting it between one contribution and an existing reply to that contribution.  ​‑‑Lambiam 13:50, 23 July 2026 (UTC)

You've hinted at the backstory that triggered your initial question. Maybe you could tell us more, albeit without saying who or where this happened. ←Baseball Bugs ^{What's up, Doc?} carrots→ 23:24, 23 July 2026 (UTC)

i better not.Rich (talk) 18:31, 24 July 2026 (UTC)

July 24

Far-away astronomical object naming

Draft:1E 2259+58.6

Does this name comply with standard naming for such astronomical objects? The draft mentions three categories into which it will be placed if moved to mainspace, and I didn't see any contents with similar names. The current name makes me think of the awkward form of scientific notation used by simple calculators to represent large numbers. Nyttend (talk) 04:37, 24 July 2026 (UTC)

The name is compliant. "1E" indicates the catalogue, in which the object was found, in this case the first Einstein Observatory catalogue. The remaining numbers give the coordinates (equinox B1950, to be precise), first right ascension (22 hours 59 minutes), then declination (+58.6°). The declination is rather short and the decimal point seems to be omitted in most of the literatur, but otherwise the name is fine. --Wrongfilter (talk) 05:22, 24 July 2026 (UTC)

Per WP:COMMON NAME, we use the name that is "most commonly used", which may be non-obvious for something that is not a household thing, and that has in fact many designations (including 1RXS J230109.7+585242, 2E 2259.0+5836, 2E 4673, 2XMM J230108.1+585244, INTREF 1098, MITG J2301+5852, PSR B2259+58.6, PSR J2301+5852, and SRGA J230109.9+585254).

We have an article by the abbreviated name 1E 1048−59 for what SIMBAD names as 1E 1048.1-5937. We also have 1E 0317+186, 1E 1207.4-5209 and 1E 161348−5055, and several more 1ES ...'s.  ​‑‑Lambiam 06:08, 24 July 2026 (UTC)

July 25

arxiv.org timestamp

[4] The metadata for this article says 2008, but the v1 pdf says June 2022 and v2 says November 2024. Any idea what's going on? Is this a normal thing with with arxiv preprints? The references section of v2 doesn't have anything later than 2007 iirc, so I don't think the paper has been updated. I got the link from the article transformation optics but haven't checked when it was added. It's definitely a good introductory article. ~2026-41486-45 (talk) 07:51, 25 July 2026 (UTC)

The LaTeX source file (which is what the authors upload to arXiv) presumably has the command \today, which is replaced by the current date when the source file is compiled to pdf. So June 22 and November 24 was the last time the pdfs were produced from the original source files (which date back to 2008). What this tells us is not to use \today in material that is to be published. --Wrongfilter (talk) 08:05, 25 July 2026 (UTC)

Indeed, the source file has:

\title{Transformation Optics and the Geometry of Light}
\author{Ulf Leonhardt$^1$ and Thomas G. Philbin$^2$\\
$^1$School of Physics and Astronomy, University of St Andrews,\\
North Haugh, St Andrews KY16 9SS, UK\\
$^2$Max Planck Research Group 
Optics, Information and Photonics,\\
G\"{u}nther-Scharowsky Str.\ 1, 91058 Erlangen, Germany
}
\date{\today}
\maketitle

 ​‑‑Lambiam 11:08, 25 July 2026 (UTC)

Wow thanks. That explains. ~2026-41428-07 (talk) 18:30, 25 July 2026 (UTC)

July 31

[Neuroscience?] Why can I read nonfiction but struggle badly with fiction and primary texts?

Why can I read nonfiction but struggle badly with fiction and primary texts?

I have very little difficulty reading nonfiction when it concerns something I genuinely want to understand. Fiction, narratives, and older primary texts are another matter. Even when I recognize that they may be worthwhile, I quickly start feeling as though I should be doing something more useful. If the material does not hold my attention immediately, I may also become tired while reading it.

This was not always a problem. I read stories more easily when I was younger, but sometime in early adulthood my reading habits shifted heavily toward informational material. I now tend to collect books about whatever subject currently interests me and can read extensively when I feel that I am learning something concrete.

This has recently become noticeable because I have developed an interest in philosophy. I enjoyed an introductory ethics class and did well in it, but I find many original philosophical works extremely difficult to tolerate. I can read explanations, summaries, and contemporary discussions of the same ideas without much trouble. With the primary texts, however, my attention quickly drops and the reading begins to feel unnecessarily slow.

I have ADHD and autism, although I do not want to assume that either condition completely explains this. My attention is strongly interest-based. When a topic captures me, I can explore it independently for years. I have gone deeply into areas such as music production, technical hobbies, electronics, security, and hands-on computer projects. At the same time, I often burn out when I try to turn an interest into a rigid, structured curriculum.

I also have difficulty studying simply because I have decided that it is time to study. I am working on that as I continue college, but there is a large difference between deliberate studying and the intense focus that happens naturally when something catches my attention.

Is this mainly a problem of attention, motivation, reading preference, or the feeling that fiction and primary texts are not immediately productive? Has anyone experienced a similar split between being able to read nonfiction deeply while struggling with stories or original works? Rottentortoise (talk) 01:35, 31 July 2026 (UTC)

No idea about the psychological causes but yeah, assigned readings can be tedious. What helped me in school was to take notes while reading, on a pad of paper alongside the book. I'd read a paragraph from the book and write a one-sentence summary of it in the notes, then repeat. That required mentally processing the content of the paragraph to be able to summarize it, so it kept me paying attention. It also usually let me recognize important points so I'd mark those with a "*" or whatever in the notes, write down verbatim quotes if I thought I'd use them in the class paper based on the book, that sort of thing. It thus just became a matter of plodding through the assignment until reaching its end. It was much slower than reading something just because it was interesting, but probably resulted in deeper understanding, so it worked out ok. ~2026-42295-00 (talk) 03:02, 31 July 2026 (UTC)

I think this is probably quite a common experience. In my teens and twenties I routinely read two or three novels a week, plus various monthly short-story magazines, plus a good deal of non-fiction.

Now, in my sixties, I always have a couple of novels on the go but rarely finish more than one per fortnight. However, I consume considerably more non-fiction both as books and magazines, and as YouTube (etc) lectures and podcasts, particularly about science and history.

Fiction for its own sake has somehow come to seem a bit less engaging than it used to be, although reading fiction with a further purpose (such as assessing whether it deserves entry in some specialist list or publication) adds motivation. I exploit this by keeping a journal in which, when I finish a book, I write a few-hundred-word summary of it, and my assessment of its qualities.

That said, a really good storyteller can still grip me to the level of reading through the night. Perhaps you could adopt new approaches to finding writers and works which will really appeal to you. One strategy might be to look at lists of works shortlisted for various literary awards, both general and genre. Hope this helps. {The poster formerly known as 87.81.230.195} ~2026-41275-62 (talk) 06:26, 31 July 2026 (UTC)

In general, one's attention span unconsciously tends to create a balance between effort and motivation. When reading fiction, the motivation may be lacking. With primary philosophy texts, the effort to wade through the thicket can exhaust the most motivated reader. In any case, this book may capture your attention.  ​‑‑Lambiam 09:35, 31 July 2026 (UTC)

Electromagnetism before relativity

Say after Maxwell's equations but before the Michelson-Morley experiment or postulates of special relativity. So Luminiferous aether was a viable theory. Did the concept of spacetime make any sense then? Would it have used a Euclidean metric signature? Do any (in retrospect) obvious paradoxes arise? Has anyone worked such a thing out, including in the modern era? Thanks. ~2026-42295-00 (talk) 04:46, 31 July 2026 (UTC)

It would have made no particular sense to use a Lorentzian metric signature such as (− + + +). Also with a purely Euclidean metric on Newtonian absolute space and time, one needs a conversion between temporal and spatial distances. Although c is a reasonable choice, it is counterintuitive to the human experience that two co-spatial events merely one second apart would be as distant as two simultaneous events separated by almost 300000000 metres. And, at the time, there was no reason to assume that speeds exceeding c were excluded, so this particular choice of conversion factor would still have been perceived as somewhat arbitrary. There would have been no practical or theoretical use of such a metric, so it appears rather unlikely that anyone would have seriously proposed it.  ​‑‑Lambiam 08:25, 31 July 2026 (UTC)