Wikipedia:Reference desk/Archives/Science/2019 February 15

= February 15 =

Geology - Htee Pwint Kan Umbrella Pond
What is the geological term that categorizes the Htee Pwint Kan Umbrella Pond (19.53222°N, 97.19139°W Loikaw, Kayah State, Myanmar)? Etan J. Tal(talk) 09:04, 15 February 2019 (UTC)


 * 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)


 * 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)
 * 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)
 * 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)
 * HteePwintKanUmbrellaPond.webm

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

Upper bound on heat loss through an open door?
I need to prove to a roommate that leaving the door to our unheated garage open, for 30 seconds at a time once or twice per week, won't make a noticeable difference to our heating bill. How can I obtain a quick upper bound on the heat loss? Or failing that, can I at least prove that it's not (as he claims) worse than having it open for 3 seconds 10 times as often during normal use? (The inside temperature is between 20 and 23°C, and the outside temperature doesn't drop below -5°C at the affected times of day.) Neon  Merlin  23:11, 15 February 2019 (UTC)


 * This one might get you started, or you could run an experiment with the door closed to learn how long the heater operates when it kicks on. Then try it with the door open under your normal usage. How long does the heater operate under both conditions? The question implies a ratio that might indicate a corresponding increase in energy cost. Multiply the expected cost increase by the number of open-door events in your billing cycle. Tamanoeconomico (talk) 05:15, 16 February 2019 (UTC)


 * Estimate or measure the speed of air getting in (e.g. stand in the doorway and notice it feels like a 10 mph breeze), multiply by the area of the doorway to compute the volume of air per second being moved. Use the ideal gas law to figure out the energy difference between that much cold air and that much warm air.  That energy has to be paid for from your heating bill to heat the cold air back to the warm temperature, so you can compute the cost from the $/BTU (or per therm or whatever) that you pay.  That rate should be stated on your bill. 173.228.123.166 (talk) 07:57, 19 February 2019 (UTC)