General science thread
January 30th, 2017 at 1:52:55 PM permalink | |
Face Member since: Oct 24, 2012 Threads: 61 Posts: 3941 | Just to clarify, I'm not sure that the "breaking of the crystals" has anything to do with the reaction. I've only had them a few days so no in-depth testing, but... the best way I can explain (if it's even correct) is to compare it to gum. The pack is like gum. It has the ability to release heat just as the gum has the ability to release flavor. If you were to chew gum to "activate" it and then just suck on it, it loses its flavor very quickly. You can still taste it slightly, but the real punch doesn't come until you agitate it more to get to the flavor stored inside. The pack seems similar in this regard. If you don't break them up, it gets stiff and is quite warm, but not hot. Agitating it doesn't seem to "activate" it, rather it seems to just get the stuff on the outside (which has lost some heat) mixed back in and allows the stuff on the inside (which still has all its thermal energy) on the outside where you can feel it. That make sense? And Aye, I tried other ways of activation. My very preliminary hypothesis was that the act of boiling added enough energy to break down the bonds of the solid of the pack, but whatever liquid it was was very unstable. An intro of energy, in this case kinetic from the cap, was enough to start the chain reaction, similar to striking a blister of nitroglycerine with a hammer. I didn't get too crazy as I'm really digging this miracle, but I punched and flicked it in an attempt to introduce the same snap of energy, but it was for naught. The cool liquid stayed liquid and cool. Fortunately I took a puck to the calf last night. Time for more testing =) Be bold and risk defeat, or be cautious and encourage it. |
January 30th, 2017 at 1:59:22 PM permalink | |
Nareed Member since: Oct 24, 2012 Threads: 346 Posts: 12545 |
If you boil anything, you add energy to it. How much you add depends on how much it can absorb. Once added, though, the energy will go somewhere. In the case of heat, it will go to the thing next to it if it's colder, unless the energy can be stored in a form other than heat. Consider a rechargeable battery. It absorbs electromagnetic energy when you charge it, but it doesn't store it as electromagnetic energy. if it did, the battery would discharge in short order (unless it were perfectly insulated). Instead it converts electricity to chemical energy, which is more stable and can be discharged (to power your phone) in a more measured way over a longer time. Donald Trump is a one-term LOSER |
January 31st, 2017 at 9:34:19 AM permalink | |
rxwine Member since: Oct 24, 2012 Threads: 202 Posts: 21269 | If you want to help search for archeological sites, now you can.
Only in Peru, so far. http://www.bbc.com/news/technology-38812526 "Facts are whatever I say they are." - Trump |
January 31st, 2017 at 12:53:21 PM permalink | |
Nareed Member since: Oct 24, 2012 Threads: 346 Posts: 12545 | This is interesting: http://www.symmetrymagazine.org/article/sign-of-a-long-sought-asymmetry The results are very preliminary and not, yet, statistically significant. But they suggest where to look. This might, in time, lead to an explanation as to why there is a lot of matter and only a little anti-matter. cosmological theories suggest they should have been appeared in equal amounts at the Big Bang. Donald Trump is a one-term LOSER |
February 1st, 2017 at 3:28:23 AM permalink | |
odiousgambit Member since: Oct 28, 2012 Threads: 162 Posts: 6002 | this is some gadget you got from some store or the internet, right? I in fact cannot get such to come up in google. LCD technology that drives thin-screen displays may be related to what this stuff is, a variety callled a thermotropic crystal. The science behind it seems to be the Boltzmann Distribution. https://en.wikipedia.org/wiki/Thermotropic_crystal ............. https://books.google.com/books?id=X8u8BdIKRQ8C&pg=PA122&lpg=PA122&dq=crystal+to+liquid+gives+off+heat&source=bl&ots=b5qti1oR0o&sig=0WTvWo10fDmMsEAqjGSMooQs2aI&hl=en&sa=X&ved=0ahUKEwijgauD3-7RAhXhdpoKHfahAp8Q6AEIMDAD#v=onepage&q=crystal%20to%20liquid%20gives%20off%20heat&f=false I'm Still Standing, Yeah, Yeah, Yeah [it's an old guy chant for me] |
February 1st, 2017 at 12:01:09 PM permalink | |
rxwine Member since: Oct 24, 2012 Threads: 202 Posts: 21269 | BATBOT (were you told bats will fly down and get tangled in your hair?) "Facts are whatever I say they are." - Trump |
February 1st, 2017 at 2:30:04 PM permalink | |
Face Member since: Oct 24, 2012 Threads: 61 Posts: 3941 |
It was a gift from a friend who acquired it from one of those MLM sex toy parties lol. I reckon it's for "sensual massage", but it does up torn ligaments a treat! Be bold and risk defeat, or be cautious and encourage it. |
February 1st, 2017 at 4:54:47 PM permalink | |
odiousgambit Member since: Oct 28, 2012 Threads: 162 Posts: 6002 |
https://en.wikipedia.org/wiki/Heating_pad The most common reusable heat pads contain a supersaturated solution of sodium acetate (3H2O CH3COONa) in water. Crystallization is triggered by flexing a small flat disc of notched ferrous metal embedded in the liquid. Pressing the disc releases very tiny adhered crystals of sodium acetate into the solution which then act as nucleation sites for the crystallization of the sodium acetate into the hydrated salt (sodium acetate trihydrate). Because the liquid is supersaturated, this makes the solution crystallize suddenly, thereby releasing the energy of the crystal lattice. The use of the metal disc was invented in 1978. The pad can be reused by placing it in boiling water for 10–15 minutes, which redissolves the sodium acetate trihydrate in the contained water and recreates a supersaturated solution. Once the pad has returned to room temperature it can be triggered again. Triggering the pad before it has reached room temperature results in the pad reaching a lower peak temperature, as compared to waiting until it had completely cooled. ![]() I'm Still Standing, Yeah, Yeah, Yeah [it's an old guy chant for me] |
February 2nd, 2017 at 3:29:03 AM permalink | |
Pacomartin Member since: Oct 24, 2012 Threads: 1068 Posts: 12569 |
I will put in a spoiler. Primary products for Back, Foot , and Neck & Shoulders are $75, but there are smaller products like a pocket warmer for $13. http://www.clickheat.eu/The-Products/CategoryID/7/ProductID/26.aspx |
February 23rd, 2017 at 9:13:49 AM permalink | |
Nareed Member since: Oct 24, 2012 Threads: 346 Posts: 12545 | NASA announced yesterday the discovery of a system with seven "Earth-like" rocky planets, some of which are in the star's "goldilocks zone," where liquid water can exist and temperatures are compatible with life as we know it. This is all very nice, but don't get too excited. The star is a red dwarf (need I say more?) Sure it makes sense to set some SETI assets to listen, but temper your expectations. What's really nice was Google's doodle today for celebrating the new. It's a short animation showing Earth looking through a telescope while the Moon peers over its shoulder. It's the cutest thing you'll see all day. Donald Trump is a one-term LOSER |