Science desk
< March 6	<< Feb \| March \| Apr >>	March 8 >

Welcome to the Wikipedia Science Reference Desk Archives
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.

March 7

Charged black hole, color charge

Can the charge in a charged black hole be color charge?Rich (talk) 02:26, 7 March 2019 (UTC)[reply]

When speaking of black holes in the context of general relativistic models, since general relativity does not describe color charge, no by definition. Beyond that, then since strong interactions are short range, I don't see how you would even measure the color charge of a black hole, assuming it could have a net one, which seems hard given color confinement. Someguy1221 (talk) 02:44, 7 March 2019 (UTC)[reply]

okay. Well if magnetic monopoles turn out to exist, would gener relativity allow a black hole to have magnetic monopole charge?Rich (talk) 04:35, 7 March 2019 (UTC)[reply]

Black holes can have any conserved charge: electrical, barionic, magnetic, etc. Ruslik_Zero 04:49, 7 March 2019 (UTC)[reply]

So if color confinement fails to always hold, does what you're saying mean that at least as a thought experiment, a black hole could have a net color charge?Rich (talk) 04:27, 8 March 2019 (UTC)[reply]

What about "isospin charge?" Could a black hole have that?Rich (talk) 04:31, 8 March 2019 (UTC)[reply]

As far as I know, to give a black hole color charge, you would have to dump a free quark into it. Attempting to separate two existing quarks at the event horizon should have the usual bouncing baby consequences. Wnt (talk) 22:16, 8 March 2019 (UTC)[reply]

How to calculate rate of flow in a pressurized gas?

I'm looking at working on a simplified simulator for gasses in an enclosed space and have been having trouble finding straightforward formula for calculating the rate of movement of gasses between areas of different pressure. For instance, from a heated side of a room to a cooler side or through a pipe. So far any explanations I've managed to find have been far beyond my level and much more in-depth than I'm ideally looking for. I'm certain information regarding my problem exists but as I'm operating a bit out of my field here I'm not sure where to start. If anyone could point me in the direction of some simplified formula for modelling gasses, it'd be very much appreciated.

Mediokrek (talk) 02:28, 7 March 2019 (UTC)[reply]

What would you say your level is? Someguy1221 (talk) 02:48, 7 March 2019 (UTC)[reply]

I can understand math and formulas just fine. The issue is when I start getting lost in the weeds with a ton of specific terminology or laws that I'm not familiar with. Mediokrek (talk) 03:45, 7 March 2019 (UTC)[reply]

The more general the question, the more general the answer. With the correct parameters and certain things staying constant, it is easy to calculate flow between two spaces that is forced through an orifice (with very specific size parameters), for example. You can also fairly easily calculate the flow out of a pressure vessel. I would focus on a very specific case and start working from there. Kees08 (Talk) 03:50, 7 March 2019 (UTC)[reply]

Geology - Htee Pwint Kan Umbrella Pond (copy of Feb. 15 discussion + a new video clip)

What is the geological term that categorizes the Htee Pwint Kan Umbrella Pond (19°31′56″N 97°11′29″E / 19.53222°N 97.19139°E / 19.53222; 97.19139 Loikaw, Kayah State, Myanmar)? Etan J. Tal^(talk) 09:04, 15 February 2019 (UTC)[reply]

On the basis of the picture shown here, they appear to be small mud volcanoes, but there isn't much to go on. Mikenorton (talk) 09:51, 15 February 2019 (UTC)[reply]

I found this 2002 article from the Journal of Asian Earth Sciences on the geological history of Myanmar and Kayah State in specific.

I also found Geographical study of tourism development in Loikaw District Kayah State, a neat geological review article published by several local Myanmar geology researchers. They have much to say on the overall geography, including many lakes and pond features created by the local limestone geology; but nothing specific on the "Umbrella Pond".

Fascinatingly, they cite us - (Wikipedia) - so if the local geology experts are coming here for answers, we'd better do a good job on this question!

Nimur (talk) 21:40, 15 February 2019 (UTC)[reply]

Thank you for your effort to help. Though I have not found a concrete answer for my query I will continue to look out for a comprehensive and referenced answer. Etan J. Tal^(talk) 09:59, 16 February 2019 (UTC)[reply]

This is my OR, but I think that they might be carbonate mounds (tufa) formed as water from underground percolates up into that lake. Mikenorton (talk) 22:47, 16 February 2019 (UTC)[reply]

Here is a video clip which may help to decipher... Etan J. Tal^(talk) 06:56, 7 March 2019 (UTC)[reply]

Systemic vs Invasive infection

I'm trying to create a section in the article Saccharomyces cerevisiae about pathogenicity of the species. In this review, for example, systemic infections caused by S. cerevisiae are described. Meanwile this one treats invasive infections. I have no medical training, but it appears to me that both articles speak of the same thing: the fungus infests blood. To what extent terms "systemic infection" and "invasive infection" are interchangeable (if they are)? And in the case of a fungus pathogen aren't they both synonymous to "fungemia"? Эйхер (talk) 17:34, 7 March 2019 (UTC)[reply]

Yes, I think they are very close in meaning. Ruslik_Zero 09:46, 8 March 2019 (UTC)[reply]

The first source you cite is older and less standards-based (seems to focus on multi-organ, hematogenous dissemination); the second source you cited includes a broader range of infections when it defines "invasive" thus: "We only considered proven infection, based on the definitions of the Invasive Fungal Infection Cooperative Group of the European Organization for Research and Treatment of Cancer-Mycosis Study Group of the National Institute of Allergy and Infectious Diseases cooperative group [19]: fungemia, isolation from normally sterile fluids (e.g., pleural and synovial fluids), and deep-site infections either histologically proven for sites susceptible to colonization (lungs, peritoneum, esophagus) [20, 21]. We did not include asymptomatic patients with only 1 organism isolated from the peritoneal cavity after digestive perforation or surgery, or from urine, oral swab, stool, or vaginal swab specimens, because such patients were more likely to have colonization rather than true infection [20-22]" Similar but somewhat distinct. — soupvector (talk) 04:37, 10 March 2019 (UTC)[reply]
- @Soupvector:, Have I, then, got it right that the concept of "invasive infection" (as used in the latter study) completely includes the concept of "systemic infection" (as used in the former study) as a special case? I. e. that any systemic infection is invasive (but not vice versa)? Эйхер (talk) 12:49, 10 March 2019 (UTC)[reply]
  - agree. — soupvector (talk) 17:41, 10 March 2019 (UTC)[reply]
    - Thank You very much! Эйхер (talk) 17:30, 11 March 2019 (UTC)[reply]
      - Эйхер, I can provide some more concrete insight here as to the overlap. "Invasive" does not as a literal matter, completely subsume "systemic" in this context, no--though a description of a given infection that reaches to one often reaches to the other. To put a finer point on the individual descriptors as they relate to pathogens, "invasive" infections are those which start from the compromise on one given anatomical feature or physiological system and then spread aggressively from there, whereas systemic infections are those for which the observable effects are effecting multiple of the body's important physiological systems, such that there is a broad effect on the body overall. So in a sense, an invasive infection may or may not lead to a systemic infection, but the context in which you hear it is often backwards-looking ("the infection was invasive, presenting within 48 hours as..."), such that it almost always does end up referring to how a systemic infection came about. Does that clarify the relationship between the two terms somewhat? Snow ^{let's rap} 02:39, 12 March 2019 (UTC)[reply]
        @Snow Rise: Rather I get even more confused. Can You give an example (real or imaginary) of an infection that IS systemic but NOT invasive? Эйхер (talk) 05:59, 12 March 2019 (UTC)[reply]
        Well, I think I may have failed to pull apart the distinction adequately: more or less all infections are going to be "invasive" to some extent, so whether a given infection is described as invasive is a matter of context and the degree of its invasiveness. The same is true to some extent for the degree to which an infection is systemic. So, most systemic infections will indeed be invasive to some extent and vice-versa, but the meaning of each descriptor is based on a a different analysis: if an infection is (particularly) invasive, then it means that it got into the system quickly or progressed into different tissues and systems quickly, whereas if an infection is (particularly) systemic, it means that multiple physiological systems are involved (regardless of whether the infection was rapid or not, or involved a route of infection that would otherwise be idiomatically described as invasive. In order to understand these two terms, one has to understand the difference between how they technically could be used, and the circumstances in which they typically are used.

So, for example, suppose one has a depressed immune system and skin lesions due to an underlying condition. If one of those lesions is thereafter the site through which staph bacteria invades the body, that is a circumstance in which the resulting infection might be called "invasive": the infection was a route that usually not open to a pathogen of this sort, but for a compromise in the health of the individual in question, and as a result, it stands a chance of moving into parts of the body which it would normally have a hard time invading and causing a lot of damage as a consequence. This would be classified as an invasive infection, but you might think of this as meaning "uncommonly/particularly" invasive. Now suppose that staph infection progresses into septicemia, and leads to infection of several organs--the infection is now systemic, but again, you might think of the term as "particularly systemic".

But again, it's important to remember that while you could discuss a particular infection interms of how invasive it is and your average physician would understand more or less what you were getting at, in practice the term is used more idiomatically to describe particular infections resulting under specific conditions. So in my example above, the staph infection is invasive because that same type of bacteria commonly infects the skin without necessarily posing serious risk to the infected individual (especially if treated aggressively), but on those particular circumstances it can infiltrate deeper into the body and imperil more vulnerable parts of the body and the life of the individual altogether. Therefore it is an invasive form of infection by a fairly common pathogen. Likewise, while any infection is going to be "systemic" in some vague sense (at a minimum, every infection can be defined as infecting multiple physiological systems), the practice in medicine is to reserve this term for when a given individual's health is suffering broad deleterious effects from the infection--so to again fall back on my example above, once the staph bacteria have infected the blood and spread to organs (say the brain, for example), the infection and its effects are definitely systemic. Snow ^{let's rap} 07:47, 12 March 2019 (UTC)[reply]

Indiscriminately answering lawn fires with water: arson risk?

Suppose surveillance cameras and a computer-vision system were used to detect fires on a lawn, with no ability to distinguish types of fire, and programmed to turn on sprinklers as the first response when a fire was detected. Would this allow arsonists to deal more damage than otherwise possible by starting one of the kinds of fire that shouldn't be fought with water (like a grease or electrical fire)? Would it help if the system still called the fire department on any fire that survived a few minutes of watering? Neon Merlin 21:46, 7 March 2019 (UTC)[reply]

I'm curious how you could get an electrical fire on a lawn. ←Baseball Bugs ^{What's up, Doc?} carrots→ 00:42, 8 March 2019 (UTC)[reply]

A fault with the Under-soil heating? Most such systems use pipes carrying warm liquid (such as water or water + glycol), but some have used electrical wiring, as mentioned in this item and this Wikipedia article. {The poster formerly known as 87.81.230.195} 2.123.27.125 (talk) 13:40, 8 March 2019 (UTC)[reply]

What percentage of lawns have under-soil heating? ←Baseball Bugs ^{What's up, Doc?} carrots→ 17:22, 8 March 2019 (UTC)[reply]

No idea, but we're discussing a hypothetical situation posited by the OP, not existing ones in the Real World™. Also, define "lawn." {The poster formerly known as 87.81.230.195} 2.123.27.125 (talk) 02:22, 9 March 2019 (UTC)[reply]

The obvious thing that comes to mind is that there is a lovely sunset and all the lawn sprinklers in town come on to put it out ... leaving no water for the fire department should a real fire occur. (cf. moonrise over Norway...) Wnt (talk) 04:52, 8 March 2019 (UTC)[reply]