Science desk
< January 18	<< Dec \| January \| Feb >>	January 20 >

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

January 19

Electric hobs

Domestic electric hotplates used to usually have coiled elements, like those in the first picture. Nowadays they have solid plates like those in the second. In my experience the older type are quicker to both heat up and to cool down, allowing better control of whatever it is one is cooking. Why the change? Thanks, DuncanHill (talk) 02:05, 19 January 2022 (UTC)[reply]

Cleaning? Sagittarian Milky Way (talk) 02:29, 19 January 2022 (UTC)[reply]

I'll second that. I remember as a student a lot of rented accomodation had that type of cooker, and under the elements was a difficult to get to place with the charred remains of many years of students' cooking -- Q Chris (talk) 10:37, 19 January 2022 (UTC)[reply]

Induction cooking manya (talk) 07:33, 19 January 2022 (UTC)[reply]

No it's not. Bazza (talk) 11:20, 19 January 2022 (UTC)[reply]

I would not even call the second one "modern". I had to replace my oven/hotplate unit two years ago and all electric options in the store had a vitroceramic (flat) surface rather than apparent metal. I suppose the metal-only design is less expensive to produce and low-end appliances might still do that, but at least where I looked (France, near Paris, multiple house appliances / electronics stores) the vitroceramic design has become standard. Vitroceramic is easier to clean but I suspect the real reason is design. Tigraan^{Click here for my talk page ("private" contact)} 11:47, 19 January 2022 (UTC)[reply]

They're still on sale: see here. Martin of Sheffield (talk) 12:06, 19 January 2022 (UTC)[reply]

Ceramic hobs are rather out of my price range. DuncanHill (talk) 02:16, 20 January 2022 (UTC)[reply]

I'm not sure I'm prepared to grant the premise of the question. The choice of exposed- versus sealed-coil electric elements seems to be one of style and regional preference, rather than a distinction of 'old' versus 'new'. For example, have a look at the products offered by a major U.S. retailer. It's apparent that exposed-coil elements are the preferred - possibly the only - option for a raised resistance element. (Though, as Tigraan notes, vitroceramic and induction cooktops are becoming de rigeur.)

The enclosed elements have the benefit of being somewhat easier to keep clean, as food and liquids cannot drop into the recessed 'pit' beneath them. On the other hand, exposed elements would be more 'responsive'--able to heat and cool more rapidly.

I can't say why the preference would seem to be different on one side of the Atlantic versus the other, but I note that Google Image searches for "electric hob" find almost exclusively enclosed elements, whereas "electric stove" or "electric range" brings a mix that leans much more toward exposed elements. TenOfAllTrades(talk) 14:31, 19 January 2022 (UTC)[reply]

Would you care to check your URL? I get "Access Denied You don't have permission to access "http://www.homedepot.com/b/Appliances-Ranges-Electric-Ranges-Single-Oven-Electric-Ranges/4/N-5yc1vZc3q6Z1z0jzgl/Ntk-EnrichedProductInfo/Ntt-electric%2Bstove?" on this server. Reference #18.17ce7a5c.1642603684.28522a73". I'm not sure it is regional. Coiled element hobs seem to be the cheapest, then solid hobs, then the exotics (ceramic, induction). Martin of Sheffield (talk) 14:50, 19 January 2022 (UTC)[reply]

I can't comment on the function of the URL; it still works fine for me (Google Chrome, Windows 10, and still works if incognito). Here's a simpler one that seems to be essentially the same result: https://www.homedepot.com/s/electric%2520stove. TenOfAllTrades(talk) 19:45, 19 January 2022 (UTC)[reply]

Nope. Perhaps "homedepot" don't want to talk to anyone outside your country? Is that the USA? Martin of Sheffield (talk) 20:12, 19 January 2022 (UTC)[reply]

Home Depot isn't a random website, it and competitor Lowe's are the USA's duopoly of house stuff big box "shops". Like other US big box stores they're usually an ocean of parking spaces at a roughly box-shaped building about 0.1 miles wide and having only one very tall storey (maybe cause some of the less New York City-like parts of USA have a significant population percentage that would get claustrophobic otherwise?). If you have enough F-350/450/3500 trucks (common US cars, like a big SUV with an 8 foot roofless boot) you could probably get everything you need to turn an empty field into an average fully rentable+furnished house in one unannounced shopping trip. I don't know if they have enough but I know that they rent the public pickup trucks too. Maybe even bulldozers. Not sure on that one. But if they have no shops in England and few website viewers would pay the huge shipping cost (you can get electric stoves in England after all, with the right plug, even the close part of Alaska costs extra) then they may not want you using their bandwidth. Sagittarian Milky Way (talk) 01:34, 20 January 2022 (UTC)[reply]

The Home Depot links don't work for me either. DuncanHill (talk) 02:13, 20 January 2022 (UTC)[reply]

Doesn't work for me either. Possible that they don't ship to Europe, can't be bothered to conform to GDPR and so block all non-US users. Rmvandijk (talk) 11:55, 20 January 2022 (UTC)[reply]

Apparently the UK is still under GDPR, or a UK law with the same effect in practice, if someone far from both EU and anywhere they sell to can access then your promising GDPR hypothesis is very likely true. Sagittarian Milky Way (talk) 15:23, 20 January 2022 (UTC)[reply]

Home Depot works for me in NZ so it probably is just GDPR. www.kmart.com however doesn't work for me. I thought it was intentional and they just decided to block anyone outside the US or whatever but they do hae an international landing page [1] It seems it is or was the same in Australia at one time [2] so it's possible it's trademark related. Nil Einne (talk) 09:09, 26 January 2022 (UTC)[reply]

The German article tells me that the solid cast-iron hobs became predominant (in Germany or central Europe, I guess) in the 1920s, so the term "modern" really is a bit of a stretch. Personally, I think I've only ever seen the open type in the US. --Wrongfilter (talk) 18:22, 19 January 2022 (UTC)[reply]

Well as the link I posted shows, they are still on sale in the UK from a leading white good supplier. Martin of Sheffield (talk) 18:31, 19 January 2022 (UTC)[reply]

This discussion has been interesting to me largely because I had been unaware of the word hob for this item. I'd have called it a "cooktop" or a "range", or possibly even imprecisely an "oven" (referring to the whole unit, not just the top). Is "hob" the normal word in the UK? Is it colloquial? What would you call it when speaking carefully? --Trovatore (talk) 02:25, 20 January 2022 (UTC) [reply]

Yes, in the U.S., the word "hob" is pretty much unknown. I am familiar with it because I am in the kitchen countertop business. The appliance is called a "stove" in common American usage if it has a oven, or a "cooktop" if no oven is included. The formal industry term for a "stove" is a "range". In the U.S., the coil heating element is common for inexpensive, entry level stoves, but more expensive units have other types of heating elements, which are called "burners". Cullen328 (talk) 02:34, 20 January 2022 (UTC)[reply]

So "stove" is the other word I might use, sure. The house I grew up in had cooktop separate from oven rather than in a single unit, and I think I called them both the "stove".

It also sounds as though some of the participants use "hotplate" to mean cooktop (or maybe just a single burner?). To me a hotplate is a standalone single burner, generally low-powered, that allows college students to heat up soup in their dorm rooms without too much chance of burning the place down. --Trovatore (talk) 02:41, 20 January 2022 (UTC)[reply]

In the U.S., "hotplate" refers to a small, inexpensive portable appliance, not to an appliance that would be permanently installed. Cullen328 (talk) 02:44, 20 January 2022 (UTC)[reply]

Yes, that's what I meant. But it doesn't seem to be how some above are using it. --Trovatore (talk) 03:10, 20 January 2022 (UTC)[reply]

The hob is the top part of the cooker, it contains hotplates (or gas rings, sometimes called just rings, if it's a gas hob) which are the things that get hot underneath sauce- and frying-pans. There are four hotplates visible in the picture at the top of this section. The oven is the box-like part of the cooker which gets hot and is used for baking and roasting. The whole thing is a cooker, and may include a grill, in which food is cooked under radiant heat. You can have separate hobs, ovens, and grills. A stove is powered by coke, coal, or wood, and may just be a room-heater, not a cooker. A range is either a posh, modern, huge cooker, or an old-fashioned (usually coke, coal, wood, or gas powered) thing you'd find in a farmhouse or the 19th Century, and which would be used for both cooking and heating water for washing day, and which the proud housewife or the put-upon skivvy would polish with black lead. DuncanHill (talk) 03:30, 20 January 2022 (UTC)[reply]

Many NYC rentals have gas ranges and portable hotplates are good for the subset of renters who wish to avoid paying two-digits of bucks just to use a few bucks of gas. For the price of only two coils 3 people can cook every day under bright fluorescent and have a normal (non-mini) fridge and take long showers under 25 watts and watch VHS or free SDTV on 27" electron gun in the dark all evening (this was a long time ago) and use only 120 kilowatt-hours per month (one-third the New York City average). What's a white good? Sagittarian Milky Way (talk) 04:02, 20 January 2022 (UTC)[reply]

White goods (I don't think I've ever seen "white good" until today) are cookers, fridges, freezers, washing machines, tumble dryers, and the like. Wikipedia calls them major appliances. To my ears a "major appliance" sounds like something Bloodnok might have to adjust DuncanHill (talk) 05:06, 20 January 2022 (UTC)[reply]

Yay, my first guess was right. If that had been an American term a third of the country would be rubbing it in peoples' faces to try to irritate them while some of the rest would call the original a phrase of oppression as bad as the N-word. Sagittarian Milky Way (talk) 06:02, 20 January 2022 (UTC)[reply]

What's the name of this device?

I want name of this device. I think it's used to lift heavy objects. Rizosome (talk) 06:59, 19 January 2022 (UTC)[reply]

It looks like some kind of "toe jack" to me. 41.165.67.114 (talk) 08:05, 19 January 2022 (UTC)[reply]

It could be associated with the motor trade, but the base does not look substantial enough to me. The alternative is agricultural, variously known as a "cabin ratchet" or "farm jack". See cabin ratchet* or farm jack* for examples. *Found via the internet, I have had no dealings with these firms and make no recommendations. Martin of Sheffield (talk) 08:39, 19 January 2022 (UTC)[reply]

I seems that the base is meant to be bolted to the floor. Also, part of the device has been removed; is it the motor lying on the floor? The toothed structure looks to me more like a rack, meant to engage with a gear, forming a linear actuator allowing for controlled motion in either vertical direction. (A ratchet is for motion in one direction.) --Lambiam 10:06, 19 January 2022 (UTC)[reply]

I don't think the base is meant to be bolted down, that curved thing at the front looks more like a stabiliser leg. The bolt on the right may well be for another leg that is missing. I agree about the ratchet vs rack-and-pinion, but that is because it looks as though it is designed for motor operation rather than hand operation. It would be interesting to know what used to be bolted to the working face. Martin of Sheffield (talk) 10:25, 19 January 2022 (UTC)[reply]

Whatever was bolted to the exposed face must have moved the pinion (mounted in the wide vertical slit) and, unless operated by manual power, contained a motor. So I think we are looking at the backside; the load being hoisted was then at the other side. --Lambiam 22:09, 19 January 2022 (UTC)[reply]

That white stuff splashed around the bottom of it looks like it is a rock drill of some sort. If you fastened that drill lying behind it back onto the plate that slides up and down the rack, it would look a bit like this https://www.machinio.com/listings/55550554-small-portable-borehole-mining-hydraulic-hard-rock-drilling-machine-in-shanghai-china Just a Guess!!49.197.155.118 (talk) 07:29, 20 January 2022 (UTC)[reply]

The rock drill theory neatly explains the rounded recess in the foot of the device, also seen in this rock drill machine. I imagined the part on the floor was meant to be mounted vertically on the exposed plate, but did not identify it as a heavy-duty drill, which it plausibly is. --Lambiam 14:14, 20 January 2022 (UTC)[reply]

Rack-and-pinion lift? --Lambiam 10:19, 19 January 2022 (UTC)[reply]

I am satisfied with multiple answers here. Rizosome (talk) 09:11, 20 January 2022 (UTC)[reply]

Resolved

Why more (ecological) forest generally means more rain?

Please suffice an explanation aimed for non-chemists / non-meterologists.

Thanks, 79.176.222.75 (talk) 12:26, 19 January 2022 (UTC)[reply]

This article published by Yale University does a good job of explaining the role that forests play in moderating local climate; including their effect on rainfall. --Jayron 32 13:30, 19 January 2022 (UTC)[reply]

Also suitable amount of rainfall, temperature, and sunshine get you a rich ecosystem like a rain forest. It's not that a forest causes rain, it is that rain causes a forest. 85.76.87.150 (talk) 16:18, 19 January 2022 (UTC)[reply]

Actually I read that also, forests cause rains, in general, especially if there is enough forest, in a given area. I read that in the past but never got an explanation. 79.176.222.75 (talk) 17:06, 19 January 2022 (UTC)[reply]

Both are correct; it's a complex system, the climate, and while rainfall does lead to forests, forests do also cause an increase in rainfall; the article I linked has some explanations as to why. --Jayron 32 17:20, 19 January 2022 (UTC)[reply]

In addition to the transpired water mentioned in Jayron's article above, this article (reporting this paper) says that rainforests also produce their own cloud condensation nuclei. Alansplodge (talk) 21:21, 20 January 2022 (UTC)[reply]

Is there a difference between "(ecological) forest" and other forest? —Tamfang (talk) 02:07, 21 January 2022 (UTC)[reply]

I don't know but possible distinctions could be forests that can't grow there naturally without human help like a indoor, watered or fabric-shaded one and places like clear cuts, Times Square and some golf courses that were, would be or will be forest if given the chance. I know there's an ecological term for what a place "ought" to be or will end up as without human intervention. Sagittarian Milky Way (talk) 02:58, 21 January 2022 (UTC)[reply]