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.
I've been looking into tech to scan for animals in a yard. Normal IR won't work. It is the wrong bandwidth. The IR scanners I've found are rather expensive - and they don't even have screens anymore. They use your phone for the UI. They are just the camera. For the task of just a yes/no sensor - is there a warm body in that direction? How cheap of a device can I get? What is it called? ~2026-16820-81 (talk) 17:01, 18 March 2026 (UTC)[reply]
If it's just detecting the presence of a (warm) body in a given direction, why not just wire up a digital infrared thermometer (IR gun)? cmɢʟeeτaʟκ(please add {{ping|cmglee}} to your reply)17:38, 18 March 2026 (UTC)[reply]
The question "is there a warm body in that direction?" suggests that you want to control the direction. I presume, though, you mean, "in the (fixed) direction" of the yard. There are many IR motion detectors on the market, from cheap to expensive. It is not easy, though, to find enough technical details to see if they will be satisfactory for your purpose. I presume you want a good sensitivity but no alarms for every scurrying squirrel and also not for every time the sun starts shining onto the yard. ‑‑Lambiam17:51, 18 March 2026 (UTC)[reply]
I would like to be able to point it at a bush and know if there's a hedgehog in there. Point it at a tuft of grass. Is there a hedgehog in there? Point it at the pile of leaves in the corner. Is there a hedgehog in there? When I know the yard is safe, I can mow without worry of mowing over another hedgehog that just rolls in a ball instead of running away. It is a laziness device - instead of stamping around kicking through all the grass, I want to stand on the porch and just point. ~2026-16820-81 (talk) 18:07, 18 March 2026 (UTC)[reply]
Another hedgehog :( ... it does sound like an infrared thermometer is your cheap option. I suppose hedgehogs lurk in piles of leaves because they provide insulation, though, which will spoil this plan. The scanning system mentioned in that article sounds useful (one thermometer plus a rotating mirror), though I don't know what industrial equipment source you'd need to buy it from. It would take advantage of the hedgehogs staying still. Card Zero (talk)18:55, 18 March 2026 (UTC)[reply]
As I thought - this is all rather expensive. I'll keep working on the rake and duct-tape system. I can't mow near the fence easily, but the rake bumps them away before the mower gets to them. ~2026-16820-81 (talk) 19:20, 18 March 2026 (UTC)[reply]
Hedgehogs enter through small gaps in fences or hedges and dislike walking on sharp gravel. That suggests a passive defence of your yard. Hedgehogs proceed by pushing their sensitive snout forward to sniff. That suggests the low-tech solution of an electric fence BUT there are animal rights supporters and even wildlife rescue groups who discourage it. ~2026-16372-61 (talk) 23:25, 18 March 2026 (UTC)[reply]
The OP doesn't say they want to exclude hedgehogs, but rather to detect and by implication avoid injuring them. In the UK hedgehogs are viewed with affection, and are desirable in gardens (they are excellent pest controllers and do no significant damage). Many people regularly feed them and purposely leave or actively construct suitable hibernacula in their gardens. {The poster formerly known as 87.81.230.195} ~2026-76101-8 (talk) 01:56, 19 March 2026 (UTC)[reply]
The FOV on those is about 70 degrees. To identify an object in the distance, it needs to be about 5 degrees. I've been learning a lot more than I wanted to learn about infrared sensors. Passive infrared won't work, period. They identify movement. A tehermopile may work, but the FOV has to be small because they average everything they see. So, you are pointing at mostly cold ground and vegetation, it will average out a tiny animal and you won't get a reading off it. A thermal array can compare one point in the distance to other points - it is a collection of narrow FOV thermopiles for the cheapest models. I am going in a different direction now. I was staring at a lamp shade designed to help keep you from knocking over the floor lamp. Instead of bars, the shade is held on with springs. If I had a big metal ring mounted around the mower on springs, I could still press it close to the fence or a wall, but if I hit a hedgehog with the ring, hopefully it will scurry away. ~2026-16820-81 (talk) 12:50, 19 March 2026 (UTC)[reply]
According to an article I read this morning about a hedgehog hospital expansion, hedgehogs respond to ultrasound by curling up in a ball and staying still. Ultrasound deters most other animals though. Of course, you'd think the lawnmower is enough to scare most animals away. If I heard something huge and noisy coming at me, I would likely move away. ~2025-42594-02 (talk) 15:24, 20 March 2026 (UTC)[reply]
But you are a human who knows what machines are. A hedgehog has not evolved to comprehend or instinctively respond appropriately to such recent innovations, which is why they also get run over on roads a lot. It's hard to think in non-human mindsets, and visualise evolutionary timescales. {The poster formerly known as 87.81.230.195} ~2026-76101-8 (talk) 10:03, 27 March 2026 (UTC)[reply]
@KnightMove T-Rex fossils are relatively common as it had a wide range. Also it was of impressive size: Although some other theropods might have rivaled or exceeded Tyrannosaurus in size, it is still among the largest known land predators, with its estimated bite force being the largest among all terrestrial animals. By far the largest carnivore in its environment. And it lent its name to a popular band. Shantavira|feed me17:47, 21 March 2026 (UTC)[reply]
Cabazon Dinosaur "Mr. Rex" There were (are?) children's jokes in which a tyrannosaurus is addressed as "Mr. Rex". Also, one of the enormous Cabazon Dinosaurs, a roadside-attraction completed in 1981, is named "Mr. Rex". These may have contributed to the epithet being sealed in. ‑‑Lambiam06:37, 22 March 2026 (UTC)[reply]
I would guess that the imagery of the meaning of the full binomial ("tyrat lizard king" or, more poetically "king of the tyrant lizards") was the major factor. It would parallel "king of the jungle" for lions and (later) "king of the monsters" for Godzilla. On a side note, the late appearance of "T-rex" is due to that form being incorrect. The correct T. rex was used at least as early as the second paper on the species (I've seen it, but not the first) and would have been implied to anyone familiar with the usage of such names. User:Khajidha (talk) (contributions) 17:24, 22 March 2026 (UTC)[reply]
I confess I don't have a source to support this suggestion, but it may be simply that the species name is short. Omitting it would only save a few characters, so it got to stay. People are...if not lazy, then let us say parsimonious.
Look at the common model organisms in the biology lab. It's usually Saccharomyces and almost always Drosophila for yeast and fruit fly folk, but E. coli and C. elegans for your workhorse bacteria and nematodes. Communicate sufficient meaning in a manageable number of characters. TenOfAllTrades(talk) 22:56, 22 March 2026 (UTC)[reply]
The last guy to ask this question was a bit of an asshole, but the answers he got may (or may not) be of interest. We didn't get to an answer that time either. Matt Deres (talk) 00:12, 23 March 2026 (UTC)[reply]
Thanks - indeed I should have browsed the archives before. Well, then there wouldn't have been the additional suggestions. :-) --KnightMove (talk) 08:23, 23 March 2026 (UTC)[reply]
Reviewing Newspapers.com (pay site), the first time I'm seeing "Tyrannosaurus" and "Tyrannosaurus Rex" (sic) are in articles from November of 1905. There are also comments about it being "the real king of beasts". The first mention of "Triceratops ... belonging to the group of Ceratopsidae" is in January of 1890, with no species name given. ←Baseball BugsWhat's up, Doc?carrots→ 12:14, 23 March 2026 (UTC)[reply]
How does something with a much simpler brain experience stimuli? How would it think? What would it feel like to be a nematode with 300 neurons, or a fruit fly with 100,000 neurons? Would it just be like some kind of reflex machine, and you'd have very little actual autonomy outside of doing what you must in order to survive? Furthermore, what would it be like to experience life as something with a brain far more complex than a Human's? New emotions? Greater control over the mind?
We have no idea and even no idea on how to get an idea. There is no commonly agreed definition of consciousness, neither scientifically nor philosophically, and the relation between the physiological processes (whose internal communication goes not only across neurons but also uses the endocrine system) and the resulting subjective experiences is very poorly understood. The current human experience has been shaped over millions of years in an evolutionary process driven by reproductive fitness. A hypothetical race of transhumanoids, with a zillion times more neurons and an experience shaped by whatever would shape it, will not be able to describe their experiences in a way we could even begin to understand. See also our article on "What Is It Like to Be a Bat?". ‑‑Lambiam06:23, 21 March 2026 (UTC)[reply]
That's an interesting read. I feel fairly certain (based on no particular evidence) that animals are every bit as self-aware as we are (or think we are). Our veterinarian, discussing our pets, put it this way: "They live in their own little worlds." And in some ways, that describes humans also. ←Baseball BugsWhat's up, Doc?carrots→ 06:41, 21 March 2026 (UTC)[reply]
I'm reminded of this quote from Hitchhiker's Guide to the Galaxy: "[a human] no more knows his destiny than a tea-leaf knows the history of the East India Company [to describe Arthur Dent's ignorance of his own fate]." But consider the flip side: How much does the East India Company know what it's like to be a tea-leaf? ←Baseball BugsWhat's up, Doc?carrots→ 06:45, 21 March 2026 (UTC)[reply]
The hypothesis about a zillion-fold increase in neurons, saying that this would cause a wild shift in understanding, a super-human experience inaccessible to regular humans with their ordinary number of neurons, is a big assumption. It's similar to the superintelligence concept that's often bandied around in the context of predictions about AI (by those with AI to sell). Since, as you say, we don't really know what we're talking about when we talk about consciousness, it would be extrapolation from no data to say that superintelligence would bring more of this undefined thing, consciousness. Or even more intelligence. Card Zero (talk)11:29, 21 March 2026 (UTC)[reply]
That's a good point. What can we infer about brains of higher complexity than ours? Is it just impossible to assume anything, when like @Lambiam said, the human experience (and brain) "has been shaped over millions of years in an evolutionary process driven by reproductive fitness"? Combined with the fact that so much of human intelligence is developed postnatally, on the basis of "experiences", does it just come down to "it depends"? Fzinu (talk) 17:22, 21 March 2026 (UTC)[reply]
I gave the experience of the putative transhumanoids as "shaped by whatever would shape it". This may involve minds "designed to order". Customized designs of the nervous and endocrine systems can have possibly very different architectures than the human one, giving, for example, rise to a "hive mind" within an individual specimen. I did not say that it would bring "more" of consciousness or intelligence. All I tried to say is that there would be no shared vocabulary for them to communicate to us "what it is like" to have a hive mind (or whatever), not because it is different, but because there are no words for "what it is like" in human language. Compare trying to describe the sensation of seeing a sunset to a person who is born blind. ‑‑Lambiam20:40, 21 March 2026 (UTC)[reply]
AOPA (a U.S.-based non-profit for pilots) actually produces what they call 'pinch-hitter' and 'companion copilot' program materials, aimed at the non-pilot companions of private pilots, providing some very basic instruction on what to do if the pilot with them becomes incapacitated in flight. This is obviously more of a concern for smaller, private, general-aviation aircraft than for airliners, as small GA aircraft usually don't have a second pilot in the right-hand seat (and because medical requirements are looser for private pilots). TenOfAllTrades(talk) 18:32, 26 March 2026 (UTC)[reply]
The transitive property of inequality says that if x < y < z, then x < z. In the context of time, with x representing the present, it would follow that the future of the future is still the future. Likewise, with z representing the present, it would follow that the past of the past is still the past. If y represents the present, then it would follow that the past is also the past of the future and the future is also the future of the past. Of course, even the present could be considered the past of the future (e.g., today is "tomorrow's yesterday") and the future of the past (e.g., today is "yesterday's tomorrow").
But the future of the past could be past, present or future. If a≠b and b≠c we can't conclude anything about a≠c. You can think about a tree, and whether something is further from the root, the leaf is further than the branch it is on, but perhaps you cannot compare one branch to another. For a mathematical article look at Ordinal number and Well-order. Or even more generally at Relation (mathematics). ≠ is a kind of relation as is = <, > ≤ or ≥. Graeme Bartlett (talk) 06:58, 27 March 2026 (UTC)[reply]
The binary relation denoted by "<" in a strict total order is (by definition) transitive. So are the weaker binary relation "≤" and the binary relation of equality on any domain, usually denoted by "=".
There are many physical quantities whose ranges of measures have a total order, such as mass or energy, temperature, entropy, and so on.
In the usual models of spacetime, all four dimensions of any reference frame possess a total order. It is not preserved by transformations between the reference frames of different observers. The time dimension is special, though: there is a partial order, called "causal precedence", on the set of events, (see Causal structure), and this order is respected by the (total) order of any specific reference frame and is preserved by transformations between the reference frames of different observers. Like for total orders, the relation "<" of a strict partial order is also transitive. ‑‑Lambiam10:14, 27 March 2026 (UTC)[reply]
On Field's metal, Cerrolow 136, etc. there is a table entry for "Bi-Pb-Sn-Cd-In-Tl". I can find no references for it. I can find Bismuth Lead Tin Cadmium Indium Alloy[1] but that's the closest I could find. Can anyone find a reference to it? --Guy Macon (talk) 22:12, 27 March 2026 (UTC)[reply]
It is called "alloy Y". See this reference for support of existence: Kulbachinskii, Vladimir A.; Ezhikov, Nikolai S.; Lunin, Roman A.; Bulychev, Boris M. (3 March 2020). "Superconductivity in alkali-doped fullerides with wood's metal and heterofullerides with two different alkali metals A (1) A (2) MC 60". Fullerenes, Nanotubes and Carbon Nanostructures. 28 (3): 168–172. doi:10.1080/1536383X.2019.1686615. Graeme Bartlett (talk) 23:39, 27 March 2026 (UTC)[reply]
Also in this paper: Ezhikov, N. S.; Bulychev, B. M.; Lunin, R. A.; Kulbachinskii, V. A. (1 January 2021). "Superconductivity of potassium and rubidium heterofullerides modified with low-melting alloys". Low Temperature Physics. 47 (1): 51–54. doi:10.1063/10.0002897. by the same people. Graeme Bartlett (talk) 23:50, 27 March 2026 (UTC)[reply]
I don't think alloy Y is really a name for the Bi-Pb-Sn-Cd-In-Tl alloy. Rather Y is just a simple single letter term for the alloy coming from the Y in alloy just like W is a simple single letter term for Wood's metal the sources have used. I only checked the first but it says "In this work, fullerides were investigated in which two alloys with low melting T were intercalated — Wood’s metal (denoted W) and alloy (Y), containing Bi; Cd; Pb; In; Sn; Tl (Tm ¼ 41.5 °C) thallium and iron triad metals" strongly suggesting this is the case IMO. BTW there's no reference that I saw of where they found out about alloy Y nor for that matter Wood's metal, I assume it's not needed since they specify the exact composition (they specify the percentages later) and melting point of alloy Y, and Wood's metal is so well known that it isn't needed. Nil Einne (talk) 10:39, 29 March 2026 (UTC)[reply]
I could only find the abstract online, not the entire paper. Is it your impression that this was a custom alloy used in that lab only, or is this something that someone else might have been able to purchase and use? If the former, we shouldn't list it under "Similar alloys". Also, are the percentages of each metal and temperature we list the same as those in the paper?
Finally, only the eutectic alloys have a single melting point, but the table entries for the non-eutectic alloys all have a single number instead of a range. For example, it says the melting point of Rose's Metal is 98°C (208 °F) but the Rose's metal page says it is between 94 and 98 °C (201 and 208 °F). And don't get me started on the melting point and composition of Galinstan. That one is a real mess that I plan on working on once I get the easy ones right. --Guy Macon (talk) 03:35, 30 March 2026 (UTC)[reply]
The whole paper(s) is available online with Wikipedia library. I can confirm there is no reference for the Bi-Pb-Sn-Cd-In-Tl in them. If you search, you can find companies that claim to sell Bi-Pb-Sn-Cd-In-Tl. So it is likely real. You could email the authors of the two papers to ask how they found out about it, hopefully not from Wikipedia. It could be that previous papers are in Russian and not easily located online. Perhaps a search using the Russian names for the elements could come up with something. Graeme Bartlett (talk) 04:23, 30 March 2026 (UTC)[reply]
The symbols for the elements in the Russian literature are identical: one or two letters from the Latin alphabet with the first letter capitalized. Perhaps adding search terms like сплав (alloy) will help ‑‑Lambiam09:04, 30 March 2026 (UTC)[reply]
According to this article, myriapods, the class containing the millipedes, have seven-segmented walking legs. Our article on millipedes agrees: "The legs are composed of seven segments, and attach on the underside of the body." This means there are six internal joints, one between each adjacent pair of segments, plus one connecting the coxa (the most proximal segment) with the thorax (body) of the millipede. ‑‑Lambiam01:27, 30 March 2026 (UTC)[reply]
