Erina

I use the single compound to avoid all the other stuff in normal washing powder. However, I did work out the cost and it's about the same: On average I go through 1.25Kg of Bicarbonate of Soda in a single month: • 2tbsp /wash 2tbsp = 0.030g *33 = ~1kg 1/33 of the cost of 1/5 of £14 = (£14.00 / 5 = £2.80) / 33 = 0.084p ! I was just wondering what chemical process was going underway when the Sodium Carbonate hit the water?

Receiving a Galileo Thermometer for Christmas this year I was unimpressed by the range of which the internal vials reacted to the ambient temperature. Some research on the matter led me to to understand that the density of the liquid in the vials is uniform, only the tags with the temperature inscription vary and so it should be trivial to adjust the temperatures they react to. I say trivial, but that would involve emptying the surrounding solution and that would be beyond my ability. However, I would care to know if there is an outlet in the UK/EU of whom sell vials, or the tags themselves, that react to the a temperature range from zero to eighteen degree celsius? Alternatively, what would the tags be made from and what would be the specific weights to temperature need to be, if worst comes to the worst and I have to mill some of my own?

I use Bicarbonate of Soda (NaHCO₃) in my washing machine for my clothes as an alternative to commercially available washing powders. Whilst living in London and thus in a "hard water" region I read that converting NaHCO₃ into Sodium Carbonate (Na₂CO₃) would dissolve better in "hard water", but I have since come to find that all it does is collect and crystalise on contact with <30ºC temperature (i.e. cold) water. The Crystals can be coaxed back into mixing with water if the water is heated up (I usually wash my clothes on a 40ºC cycle anyway), but wanted to know why they crystalise? nb. I convert my NaHCO₃ -> Na₂CO₃ in the oven at 230ºC for 1hr.

Thanks for the information, I just wanted to know about the science of heat transfer, not the practicality of fitting it.

Irregardless of the cost, what about heat transfer through 30mm of silicone please?

I meant 30mm

I am trying to understand if heat transfer from an electric or water underfloor heating system through silicone flooring can be done efficiently, given it's heat resistant properties? There will likely have to be the usual insulation layer(s) between the heating system and the silicone surface, and I don't expect the silicone (think cooking utensils) to be more than 300mm thick. Thanks in advance !

Thanks for the references and info!

I don't suppose it is, but as the title suggests, can the human guts acid safely dissolve spider's silk if digested? I like to eat berries from the trees, when in season, and sometimes there may be some spider's silk in the general area. I know that it can withstand a lot of direct force/pressure for it's thickness, but how well does it fair when in stomach acid? Thanks!

John Cuthber: I knew I'd get picked up on the plasma thing, clearly I don't know what I'm talking about, it just popped into my mind. dimreepr: That was an issue that I consoled myself with by leaving the body hunt to the firemen (robot scouts), while the method I am looking to research solely focuses on putting fires out with minimal damage to non-human life i.e. physical goods.

The problem is that water causes huge damage comparable to that of fire. Like using a cloud of plasma as a carrier for electricity, there must be a simple method of flooding a room with gas (covering all exposed surface areas easily) and then changing its properties to cool down. What data is available, or can be surmised, to cool down e.g. a table with the following properties: Length: 21 5/8 "Width: 21 5/8 "Height: 17 3/4 "Max. load: 55 lb Table top: Particleboard, Fiberboard, Acrylic paint, ABS plastic, PaperLeg: Particleboard, Fiberboard, Foil ref: http://www.ikea.com/us/en/catalog/products/20011413/ This furniture is highly combustable, so how long would it take to cool this down in a 6ft x 6ft room with a fire that had taken alight the table's surface, it now producing considerable black smoke? What kind of gas would be a good carrier, how would it be cooled and for how long would it take to all hot area, perhaps then to it's core if necessary?

It is the widely held belief that to put an already raging fire out the only thing that works is water. While CO2, Nitrogen and Halon gases will starve a fire, they don’t reduce the heat. Even in enclosed environments where a fire has consumed all of the available oxygen and fades out leaving combustable gasses, once a firefighter opens the door a sudden rush of oxygen simply reignites the smouldering embers again, possibly with greater ferocity, as the materials on all surfaces in a room give off their own combustable gasses (pyrolisation) when reaching a certain temperature. If an externally applied container could be used to mimic the enclosed environment, with oxygen expunging gasses pumped in to maintain the fire in a suppressed state, with a separate gas used as a carrier for a coolant to reduce the temperature, mimicking water? What gas can be be used to cool a material so that fire cannot function, or gas used in tandem with a technique to steadily reduce temperature to avoid the harsh use of water to cool high temperatures?

I was actually waiting several days for an official email reply until taking you up on your advice and telephoning, to which I learned the rubber is made from a vulcanised synthetic food-grade material, and therefore likely robust against diluted acids (they couldn't tell me exactly what it was though). The lady did highlight that the containers were not designed as a storage medium, rather for dispensing, and so I would be using them for an alternative purpose to what they were designed for. Since we last spoke I have it on assumed authority that outside of the scientific world it would only be hydrochloric acid that glass would have long term issues with, not likely a dilute 5% concentration of acetic acid. The company I was in contact with only mentioning the guarantee their supplier gave them regarding their glass containers, which was by no means a measure of their durability under the conditions I was interested in. Further research yielded positive results regarding a 304 Stainless Steel tap (https://www.amazon.co.uk/dp/B06XPG2CLS?psc=1) rated by the BSSA (British Standard Steel Association) to conclude: "The 304 types are normally considered as suitable grades for most applications, including handling and storage", long term stationary storage is just what I need! So I now feel that I have enough information to be confident enough to put the system together. Many thanks!

Ah, thanks! Silicone looks to be standing up to it's reputation, that's good. But I'm unsure yet what type of rubber I am dealing with..

I get five litre quantities of White Vinegar (5% Acetic acid) in HDPE (High Density Polyethylene) containers and have been assured their stability for up to one year. While this is comforting, it's also not an issue as I will go through that allowance in around a single months domestic use. I would however, like to have a more practical management system and am looking into using a drinks dispenser: http://www.kilnerjar.co.uk/index.php/kilner-range/drinking.html?p=1 This container is mostly comprised of glass, and in a size that I can keep everything in one place, as now. With a tap at the bottom I avoid miss-pouring from the spout of the plastic container as oxygen passes through too rapidly and the flow becomes unpredictable, but that is a metal tap and is comes with silicone gaskets. Finally the top (natural/synthetic?) rubber gasket also concerns me, even if not in contact with the vinegar itself. 1. What affect over time will a constantly replenished, yet ever decreasing, concentration of 5% acetic acid have on a glass container? Will it erode the glass, or cause it to become unstable over time? 2. There are several after-market taps that are of a better quality to the one provided in the example product I offered, which come in both stainless steel and brass versions, all with very good reputations, they also require silicone gaskets and I wonder what the acid will do to these materials over time, given that conditions will mostly be standing, only at times passing solution? 3. I am unsure if the rubber seal used at the top (sandwiched beneath a thick glass lid) is natural or synthetic, but in both cases I wonder how the rubber would react to the fumes from the acid in the air trapped inside the jar? I have checked company literature and they don't mention anything of it, yet it's not designed for the purpose that I am interested in using it for, however there are plenty of chances that it will be used (for short periods) with lemon juice infused water. Finally, the wildcard: I also plan to keep Apple Cider Vinegar (with Mother: cellulose substance made up of various Acetobacter bacteria) in a separate container, which has a similar acidity (but not as much as I understand it) but will be accessed a lot less frequently, lasting anything up to six months, but in an ever decreasing quantity of course. Many thanks for the help!

So when somebody says that grilling smoke is worse than cigarette, it's not true? Is there much proof, from unbiased sources, that second hand smoke causes cancer? Thanks.

Are the carcinogens, carried in smoke, from BBQ meat more detrimental to one's health than second hand smoke from a cigarette? I understand that grilling meat is different to barbecuing it, I've even read that smoke from burnt toast is bad, so, how much scientific proof is there of this? I've been around online but I can't find anything concrete, anybody know? Thanks.

Polytetrafluoroethylene, or Teflon, is wonderful for cooking with. Right now however the people at DuPont are releasing a new and improved version in different colours and probably without the health side effects. However, I am interested to know if Polytetrafluoroethylene can be engineered at the nano level so that not even bacteria can grapple to a surface, this then means that no surface would require anything more than just a wipe of a damp cloth to clean it. Not only this, but of any material or one unlike Polytetrafluoroethylene which could be applied to say toughened glass and used as a kitchen surface. Am I on the right track, basically can bacteria (bad-germs) be made to not stick to a surface?

I am looking to find a way to make two harmless Class 1 lasers collide to create a dot in mid air. My theory (completely un-scientific you understand) is that a laser will carry on forever until it's stopped, but that at Class 1 the beam (body) itself is invisible from the naked eye without particulates. However the dot is always seen, this of course when hitting an object that absorbs light. My theory was that if I could collide two lasers then they would be cut off and as they strike would form a dot in mid air. Now, I've been told that photos do no such thing, no collision and thus no mid air exposure. I've not tried it myself as I only have one red dot Class 1 laser, shame. But, I was looking at this: "Delbrück scattering, the deflection of high-energy photons in the Coulomb field of nuclei as a consequence of vacuum polarization has been observed. However, the process of scattering of light by light, has not been observed.[1] In both cases, it is a process described by Quantum Electrodynamics (QED)." ref: http://en.wikipedia.org/wiki/Delbruck_scattering AND some bits and bobs on "Using High-Power Lasers for Detection of Elastic Photon-Photon Scattering" ref: http://www.2physics.com/2006/03/photon-photon-scattering.html and so was wondering what people thought here. I am open to alternatives, lasers which can emit something other than photos that can be seen by the naked eye, are safe and generally achieve what I am looking for. Thanks.

Hi, I'm no scientist you must understand, but everything is science it seems (or the stuff I dream and would like to build). However, such things which are yet to be built are such that they come up against the laws of physics and it is that reason I am here, to find out how to circumvent those laws and make something new. BTW the sign up process was pretty smooth, asking for a lot of help, a lot of the time, means I've born the scars of a few poly designed registration forms.