Wikipedia:Reference desk/Archives/Science/2017 July 5

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July 5

Early sunsets

At this time of year, where in the United States is the earliest sunset? Not the "first" sunset (the spot where it's after sunset when the rest of the country is at least slightly in daylight), but the earliest time on local clocks. It shouldn't be too hard to calculate the earliest in each time zone, but comparing locations in different time zones is more difficult; you can't easily compare Needles, California with easternmost Maine without a table, for example, and accounting for the eastern tip of Hawaii's Big Island (both close to the equator, with little "benefit" from it being summer, and probably rather far east in its time zone, plus no daylight saving time) compared to either of them is downright impossible, I suppose, unless you've calculated it out. All I could find with a Google search was stuff talking about eastern Maine (because it has the "first" sunsets in the country), or stuff that somehow came up even though it wasn't USA-related. Nyttend (talk) 01:09, 5 July 2017 (UTC)

PS, this assumes PM sunsets; no weirdnesses with DST-affected midnight sun somewhere in Alaska with 12:07 AM sunsets or anything like that, please. Nyttend (talk) 01:14, 5 July 2017 (UTC)

The Old Farmer's Almanac used to be the go-to source for this sort of thing. But one's not handy. I wouldn't think there's much variability based on longitude. Anyway, you may find these links of interest: (earliest sunset 2015 was on December 8), calculator... But this is a question you might ask them, there. - Nunh-huh 01:44, 5 July 2017 (UTC)

(edit conflict) I'm too lazy to bother with the actual calculations. But as a starting point we could look for places that extend far eastward from the central latitude of their time zone, and are far enough north for seasonal effects to produce early winter sunsets. Based on those criteria, a quick look at my big U.S. wall map with time zone boundaries suggests eastern Maine still looks like a good bet. Shock Brigade Harvester Boris (talk) 01:48, 5 July 2017 (UTC)

But as I say, "at this time of year"; if you're correct in saying that longitude doesn't have a big effect, Maine won't have much of a chance, since its northern location gives it a big bonus over somewhat-farther-western places farther south, like metro Miami, Florida. Nyttend (talk) 02:29, 5 July 2017 (UTC)

Miami is a LOT farther west than Maine. --Jayron32 02:54, 5 July 2017 (UTC)

Gah, I don't know how I overlooked your qualifier. Maybe because I'm stupid and careless? Shock Brigade Harvester Boris (talk) 04:00, 5 July 2017 (UTC)

Understood, but I was responding to "I wouldn't think there's much variability based on longitude", and I'm not clear how differences due to longitude (thirteen degrees, in this case) compare to differences due to latitude (nineteen degrees, in this case) around the times of the solstices. Nyttend (talk) 03:04, 5 July 2017 (UTC)

Going by clocks is not the best approach, especially if a state does not honor daylight saving time. But Maine might well not be the answer anyway because it's much farther north than Florida. Your best bet would be to find online newspapers for, say, Augusta, Maine and Miami, Florida, to see what tomorrow's sunrise and sunset times are. ←Baseball Bugs ^{What's up, Doc?} carrots→ 03:08, 5 July 2017 (UTC)

What do you mean? That's the whole point of my question: at the beginning of summer, where in the country is the local-time-of-day at sunset the earliest? Or put another way, if you work 9-5, where in the country do you have the shortest period of time between leaving work and sunset? It's intentionally an interaction of the astronomical phenomenon and the legal definition of time. Nyttend (talk) 04:37, 5 July 2017 (UTC)

Yes, longitude makes a big difference. Compare the easternmost point (point A) in one time zone to the easternmost point (point B) at the same latitude in the time zone west of it. Ideally being one twenty-fourth of the way around the world, they have the same sunset time on local clocks. But now move slightly east of point B, just across the time zone boundary, to point C—the sun goes down at the same actual time at C as at B, but one hour later than B on local clocks. so the two points A and B in the more eastern time zone have a clock difference of one hour for sunset. Loraof (talk) 03:27, 5 July 2017 (UTC)

Here is a cool map showing the position of the terminator (day/night boundary) as a function of the time of day for today (or any other day you choose). The latitude effect is very prominent, as we would expect for a date near one of the solstices. For the U.S. Eastern Time Zone it looks like the Miami area is earliest, followed very closely by eastern Maine and Cape Cod. Notice Miami is actually west of the theoretical longitude of its time zone, about 81 W versus 75 W. The Panama City, FL area, which is just barely inside the Central time zone, should have an earlier local time for sunset than Miami since it is east of its time zone center, about 86 W versus 90 W. Earliest of all might be the very southeast corner of California (just across the border from Yuma, AZ). Among all the southeast-corner-of-time-zone possibilities it looks like it has the largest eastward longitude offset from the theoretical center of its time zone, around 114.5 W versus 120 W. Shock Brigade Harvester Boris (talk) 04:00, 5 July 2017 (UTC)

Move to Hawaii. 7pm sunset. And the Big Island is not rather far east in it's time zone – Hawaii's time zone sucks ass. The entire Big Island's west of the center of UT-10 by several degrees and Honolulu's in the UT-11 ship time zone. Honolulu's UT-10 instead of UT-11 or UT-10.5 like it was till '47 (very accurate) probably to be closer to CONUS. Just like Alaska. But day and night already hardly matters by Anchorage's latitude so they have a better excuse. The Eastern ~25 miles of Maine would be Atlantic Time if the boundary was accurate but it seems unnecessary to add a 5th Lower 48 time zone just for 2% of Maine. Sagittarian Milky Way (talk) 04:58, 5 July 2017 (UTC)

Google can be your friend. I just googled the following and got these results:

"sunrise time in bangor maine today" - 4:56 AM

"sunset time in bangor maine today" - 8:24 PM

"sunrise time in miami florida today" - 6:35 AM

"sunset time in miami florida today" - 8:16 PM

So, if my arithmetic is correct, that's about 15 1/2 hours of sun for Bangor and about 13 3/4 hours of sun for Miami. ←Baseball Bugs ^{What's up, Doc?} carrots→ 10:35, 5 July 2017 (UTC)

Users who want a "reliable source" for sunrise and sunset can cite the website of the U.S. Naval Observatory, and if you like reading fine print, pay special attention to the sunrise and sunset data information for lawyers. I like this blurb, because it really puts in perspective how different communities conceive of truth- and fact- ... regular people would probably all agree on when the sun sets; scientists would quibble over the technical and practical details; and lawyers would write a deposition and keep accurate records so they could blame the fact of sun-set on a specific statement by a particular witness. Nimur (talk) 13:20, 5 July 2017 (UTC)

Is ethanol the same as 95% grain spirit?

I use 95% grain spirit to control the alcohol level in liqeuer making but it is harder to find now that I do not go to Europe very often (I live in England). I see ethanol advertised for use in spirit stoves and I know that grain spirit alcohol is also ethanol. But is the ethanol used in spirit stoves the same as the ethanol in 95% grain spirit, and is it safe to use in the mixing of an alcoholic drink?

Thank you. Gurumaister (talk) 16:26, 5 July 2017 (UTC)

Alcohol that is not intended for consumption is commonly called "denatured." See if the advertised ethanol is denatured. If so, you shouldn't consume it. It will taste bad and/or be poisonous because of the additive(s) used to denature the alcohol. In general, if no alcohol tax was paid on the alcohol, it isn't fit to drink. 209.149.113.5 (talk) 16:36, 5 July 2017 (UTC)

@Gurumaister: We should have an article on denatured ethanol. The stuff used is ridiculous - I remember seeing one bottle with ingredients that included aviation gasoline. Obviously bureaucrats should not be allowed in a kitchen, let alone a food chemistry lab - why don't they go pick on the gas stations instead? Gasoline makes better fireworks cheaper, plus carcinogenic benzene... Our article ethanol goes over commercial purification methods, though it has a tag requesting confirmation. Looking at some Google hits about the same thing leads, oddly, to dope forums like [1][2] - I hope the British spy state hasn't gotten around to throwing people in gaol for reading a post with links to places like that - I was hoping they would suggest some optimizations for the small user, but the main thing they claim is that you can use ordinary salt instead of potassium carbonate and I have no idea if that's true.

Just in case you have something other than liqueurs in mind, DO note that people don't generally drink 100% ethanol because it is NASTY - it pulls water out of things like, oh, the membranes of your throat. It's way better to get drunk on a bottle of champagne than to go to the hospital over a container of lab ethanol.

I wasn't aware of the 'denatured' issue. Thank you. Gurumaister (talk) 16:37, 5 July 2017 (UTC)

• "Grain spirit" or Everclear is basically unavailable in the UK. Lab grade ethanol is hard to obtain and it's now appearing as an explosives ingredient (!), when you enquire about the newly created "Explosives Precursor Licence" (as always, implementation of this is devolved to local police forces who've been inadequately briefed on what's covered, so are inconsistent between regions). The paperwork burden in doing so is so awkward that commercial suppliers will only deal in quantities at the oil drum size. It's also notable that many of the general reagent dealers don't carry ethanol.

The only practical option for a small producer is to buy retail vodka, already taxed. I suggest Finlandia as the cheapest and purest that's widely available. There's a little water in this, compared to Everclear, but that's not a big issue for making liquers. Andy Dingley (talk) 16:55, 5 July 2017 (UTC)

@Andy Dingley: I just checked and I didn't find a single hit on Google for ethanol "Explosives Precursor License". I can believe there would be some fire safety rules for working with large amounts of nearly pure ethanol, but does it actually affect the small user, or does it just hinder the distribution of it? Wnt (talk) 20:21, 5 July 2017 (UTC)

Well you won't, it's not one of the listed substances (check the Home Office site) - but some police forces don't seem to be aware of this, and are being creative in their interpretation of what is included. Chlorates and perchlorates are (and reasonably so), but nitrates aren't. Yet black powder shooters (and black powder, rather than Pyrodex) are being pushed to require one of these too. Andy Dingley (talk) 20:33, 5 July 2017 (UTC)

As above: Don't use spirit stove alcohol. Not only is it denatured (having a bitter chemical added) but in the UK it contains 10% methanol – which will send you blind. Finlandia (as mentioned above) is not a bad bet and commonly available. May not be 95% grain spirit (only 40%) but hey... so alter your recipe for your liqueur. One doesn't want to drink 95% grain spirit without diluting it quite bit anyway. Analytical (or as AD refers to as 'reagent' ) is also not a path to go down. One doesn’t actually have to buy a whole drum since it can be purchased in much smaller Winchester bottles. But apart from the paper work -it is analytically pure, thus is more expensive. Phone up the Polish, Finnish and Russian embassies – don't be shy. Their job encompasses more than just issuing visas. They are also there to promoted trade. (they also speak very good English and are familiars with all our idioms). Just tell them you need to to know the nearest stockist of the strongest alcohol you need in order to make your liqueur. Aspro (talk) 19:16, 5 July 2017 (UTC)

Where in the UK will sell a single individual (or commercial woodworking workshop) a single winchester of drinkable-grade ethanol? It's several years since I bought my last (ethanol / methanol mix, but without pyridine stenching agent or purple dye) and it's increasingly difficult to replace it. Andy Dingley (talk) 19:28, 5 July 2017 (UTC)

Depends on what you need to use it for. Suppliers like [3] have a Customer Service number at right-hand top of their web site. They might even be able to supply it in a Boston round (bottle). The people that man these phones love to be helpful and suggest the best alcohol for your use. Used to work for a while in R&D and then moved on to being an Industrial Buyer, where scientists ask me to get them all manner of things of which I had little clue about. Customer Service or the Tech Desk people, quickly made sense of my ramblings and guided me as to what to order. Some of this was for MOD defence work which required complicated paper work – they sorted out that for me too. Their job is to server the customer and will be willing to help you too. If you don't ask - you don't get! Currently, in the UK, straight ethanol is about 18 pounds sterling per litre with duty paid. So a Winchester will be about £45. You mention (for some reason that I can't fathom) a woodworking workshop. The best alcohol treatment for wood, is to shape the wood into casks and fill them with a really good single malt whisky, then store, until temptation overcomes willpower... Hope all this helps in some very small way. Aspro (talk) 00:39, 6 July 2017 (UTC)

Shellac? Sagittarian Milky Way (talk) 01:42, 6 July 2017 (UTC)

Yes. Using typical purple meths (methylated spirit) in a hot summer will exceed exposure limits for pyridine (and is disgusting). Spreading out a solution in meths over a wide surface and then waiting for it to evaporate? How could it do otherwise. Also purple meths will give a haze to blonde shellac.

Fisher, BTW, wouldn't sell to me when I last spoke to them. Many of my workshop solvents came from Fisher (but indirectly), but they're not interested in having me (as a tiny purchaser) as a customer. Andy Dingley (talk) 10:59, 6 July 2017 (UTC)

Do embassies really do that? I bought a huge amount of delicious Polish chocolate at a discount store some years back for a small fraction of the cost of American "chocolate" ... have never seen it again. Maybe I should make a call... Wnt (talk) 20:25, 5 July 2017 (UTC)

Lets leave politics to one side. Embassies are staffed by emissaries of the country they belong to and represent. They may not take kindly to time wasters but if you have genuine enquiry then they are always happy to help. Think you may have had the privilege to have sampled chocolate made the traditional way where it stirred for days in order to give it the quality that you appreciated. The Dutch chocolate makers do this very well too. For all the Embassy staff know, you may popularize one of their countries exports. Which in some-ways you have already done, by pointing out that American Chocolate is mostly just bland brown stuff. Do give them a call to find out where you can buy more. Aspro (talk) 01:31, 6 July 2017 (UTC)

Origin of 4160 volts

I recently was wandering the utility area of a building in the US (end-user mains are 120 V), and saw some electrical conduits marked "4160 V". What is the origin of this voltage? Not the basis for choosing this voltage for specific applications, but why is this value a standard? It seems like an unusual number, and I can't figure out what transformer configuration would supply it. DMacks (talk) 16:37, 5 July 2017 (UTC)

A North American standard for three-phase electrical power is 208 V, e.g. [4]. I note that 4160 V is exactly 20 times higher that 208 V, which might explain why it was chosen. Dragons flight (talk) 18:34, 5 July 2017 (UTC)

And where 208 comes from it that it's the standard 120 multiplied by ${\sqrt {3}}$; that's how three-phase power works. --76.71.5.114 (talk) 21:22, 5 July 2017 (UTC)

A web search pulls up this - it's a company's site, but the forumers sure sound like they know more than I will. This search suggests there were bureaucratic reasons to do no more than that voltage in 1998. This company lists it as the highest "standard medium voltage" variety, and does describe it as three-phase. But millions of HVAC and electrical workers know more about this than I do. Wnt (talk) 20:37, 5 July 2017 (UTC)

4160 volts, three phase supplies are provided for motors and heavy equipment such as well pumps over 500 hp[5]. Equipment for 4160V is considerably more expensive than 480V equipment but the necessary conductor size is about 1/10 of that required for 480V equipment and 480 to 4160 V transformers are available. Blooteuth (talk) 22:56, 5 July 2017 (UTC)

Thanks all! The relationship to 208V was the detail that I hadn't found. And it makes sense (in hindsight) that it would be from the 3-phase voltage because it's used in high-power motors. DMacks (talk) 09:43, 9 July 2017 (UTC)

Pledge of Allegiance

moved to Humanities desk for obvious reasons - please make further comments there. Wnt (talk) 20:28, 5 July 2017 (UTC)