Wikipedia:Reference desk/Archives/Science/2012 March 8

= March 8 =

Humifider as Candle
Help settle a debate! What would happen if instead of adding plain water to a humidifier, I poured in a wee bit of lemon juice, or vanilla or some other lovely scent? Would the room smell nice?72.74.134.42 (talk) 02:23, 8 March 2012 (UTC)


 * Sure, I don't see why not, the water amd aromatics will evaporate, but they'll also probably leave behind nasty residues which will build up and eventually break the humidifier, if not set it on fire. So, in short, sounds like a terrible idea, unless the humidifier is specifically designed to accept "scented" liquids and can be cleaned after use. Vespine (talk) 02:40, 8 March 2012 (UTC)


 * Ok, i probably spoke too quick! Have a look at Humidifier and it appears the more common one is a "cold mist humidifier" which sounds like it wouldn't catch on fire. As long as you rinse and clean the wick, I still don't see why it wouldn't work with a bit of lemon juice in there. I'd be surprised if the instructions didn't even mention what you could couldn't put in the reservoir. Vespine (talk) 02:44, 8 March 2012 (UTC)


 * It depends on the type. A humidifier which heats the water to make it evaporate is the most robust (but also uses the most electricity).  For that type, adding a scent should work fine, as long as it doesn't contain an oil, since the oil becomes flammable when the water evaporates (technically the oil is flammable all along, but all that water vaporization will keep the temperature below the combustion point of oil).  I'd also be reluctant to add a scent in an alcohol base, as alcohol vapor is highly flammable.  So, if you have a water-soluble scent, go for it.


 * If you have an ultrasound humidifier, don't add anything, as any foreign substances on the vibrating membrane will cause it to stop working. You even have to use distilled water in those, as the salts in tap water will become vapor, too, and the area is then covered with salt dust as a result (which is also bad to breathe.) StuRat (talk) 03:05, 8 March 2012 (UTC)


 * I habitually use a low-tech equivalent, utilising a diffuser as seen in the top illustration of the Aromatherapy article. Instead of putting only scented oil into the dish of the diffuser (as some do), I fill the dish almost full with water (usually from a just-boiled kettle to speed up initiation) and drip a few drops of one or several scented (usually essential/concentrated) oils into the water, which is kept gently evaporating by the tealight.
 * Unlike with using oil only, this has the advantage of additionally lightly humidifying the room, and provided the dish holds more water than a tealight can evaporate before burning out, it eliminates the risk of the diffuser becoming dangerously hot, as it might once a smaller oil-only charge has evaporated leaving the tealight still burning but with no evaporation to keep it cooled.
 * Oil combinations can be chosen according to mood or other preference: I find using combinations including eucalyptus and/or tea tree and/or thyme, etc, while I sleep best ameliorate mild cold symptoms – yes, I agree this could be at least partly placebo effect, but it still works and it smells pleasantly to boot. {The poster formerly known as 87.81.230.195} 90.197.66.156 (talk) 14:45, 8 March 2012 (UTC)


 * One other thing that you might want to consider is that the residue may begin to mold. So regular cleaning may be required to prevent this.  Dismas |(talk) 21:19, 8 March 2012 (UTC)


 * I'm fairly certain that you are NOT supposed to use the tea candle aromatherapy diffusers with only oil in it, you'd essentially be making a little deep frier. You fill 3/4 with water and a few drops of essential oil, that's how they are supposed to be used. If you inadvertantly let it evaporate all the way out and the candle is still lit, DO NOT refil it! Put it out and let it cool down first. Vespine (talk) 21:32, 8 March 2012 (UTC)


 * Incidentally, this post inspired me to add some artificial vanilla to the giant pot of water I keep simmering on the stove all winter (to keep the relative humidity around 40% inside). So far it seems to be working well. StuRat (talk) 05:36, 9 March 2012 (UTC)

What are these triangle metal plates hanging from power lines?
Image - http://imgur.com/Jz475

There is one of these metal plates hanging from the line between each pole. No other lines are attached. What are they called and what are/were they used for? — Preceding unsigned comment added by 184.17.124.154 (talk) 03:38, 8 March 2012 (UTC)


 * They look to me to be some sort of warning sign - an indication that the cable is there? Where are the poles? Along a roadside, across the road, or elsewhere? AndyTheGrump (talk) 03:41, 8 March 2012 (UTC)
 * Theres nothing of significance close to these poles, just a road parallel and some farmland. Nothing out of the ordinary. The plates look weathered so the line are probably very old, could be something not used anymore. — Preceding unsigned comment added by 184.17.124.154 (talk) 03:48, 8 March 2012 (UTC)
 * I've often seen them in similar settings, always on the lowest wire and in the middle of each consecutive catenary. I assumed it was some sort of "don't hit this wire while you're working in this area" warning--a large object, more visible than a thin wire. DMacks (talk) 04:58, 8 March 2012 (UTC)


 * Quite. Also, equipment falling in to § 95-229.6. Definitions paragraph one, must have a warning sign (paragraph five) to tell operators not to use the equipment under these lines. --Aspro (talk) 20:01, 8 March 2012 (UTC)


 * It looks like a wire marker meant to be most highly visible in infrared/night vision devices so that helicopter crews can avoid them. Since they would entangle the rotors, "Wire! Wire! Wire!" is called out to prevent catastrophe. I cannot find anywhere this is covered in our flight hazards or safety articles. Dru of Id (talk) 10:01, 8 March 2012 (UTC)
 * Wire strike protection system is a defensive system. Dru of Id (talk) 10:08, 8 March 2012 (UTC)
 * Could be a warning for Crop dusters too. Mingmingla (talk) 20:26, 8 March 2012 (UTC)


 * I can hardly believe I'm about to ask something that sounds like the sort of thing David Icke would come up with, but it's in New Scientist so it must be true... Could the thing you saw be a spy plane charging its batteries? - Cucumber Mike (talk) 21:28, 8 March 2012 (UTC)


 * Much more prosaically, I believe they serve to stabilize the lines in windy conditions, damping harmonic vibration. There are a variety of weights, flaps and such for that purpose.  Acroterion   (talk)   21:51, 8 March 2012 (UTC)
 * Agree. This link calls them anti-galloping devices to prevent wire fatigue. Rmhermen (talk) 22:07, 8 March 2012 (UTC)
 * Aha! That's got it! They are indeed wind dampers, specifically Wright Vibration dampers, as invented by Curtis M. Wright. Here's the patent. Thanks need to go to this site for the tip-off. Note that they're normally used on phone lines, not power lines (hence why they can be metal). - Cucumber Mike (talk) 22:27, 8 March 2012 (UTC)

Mars
You see I'm watching Nova Science now and it's about Mars,so I wonder;exactly how long would it take us to reach Mars?98.71.63.61 (talk) 20:12, 8 March 2012 (UTC)


 * Depends. Check out the table in Exploration_of_Mars and then head up to the top of the article - especially the Launch windows section - to understand that sometimes it is closer to us, sometimes further away. Short answer: seven months or more. --Tagishsimon (talk) 20:16, 8 March 2012 (UTC)


 * Or a bit less, perhaps 5 months, if you just want a flyby, and don't need to maneuver into orbit or land. StuRat (talk) 20:53, 8 March 2012 (UTC)


 * Ah,Thank You My good Friend.98.71.63.61 (talk) 20:36, 8 March 2012 (UTC)


 * Furthermore, the Russians recently completed a simulated Mars mission lasting 520 days, consisting of 250 days 'travelling' to 'Mars', 30 days 'on the surface' and 240 days 'travelling' back again. So travel time seems to be about 8 months. - Cucumber Mike (talk) 21:04, 8 March 2012 (UTC)


 * That's is very interesting,about 8 months,okay thank you.98.71.63.61 (talk) 21:08, 8 March 2012 (UTC)