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  1. #41
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    Default Re: This one is for Acebird

    Not according to the source I found on Nucleation. All it takes is one impurity. that crystal then "Build on each other". Notice also it says "Absence of impurities". Not absence of most impurities". Here is this on Supercooling with additional comments on the necessity of Pure water. And a bit on how that would be achieved.

    "A liquid below its standard freezing point will crystallize in the presence of a seed crystal or nucleus around which a crystal structure can form creating a solid. However, lacking any such nuclei, the liquid phase can be maintained all the way down to the temperature at which crystal homogeneous nucleation occurs. Homogeneous nucleation can occur above the glass transition temperature, but if homogenous nucleation has not occurred above that temperature an amorphous (non-crystalline) solid will form.

    Water normally freezes at 273.15 K (0 C or 32 F) however it can also be "supercooled" at standard pressure down to its crystal homogeneous nucleation at almost 224.8 K (−48.3 C/−55 F). [2][3] The process of supercooling requires that water be pure and free of nuclei such as having undergone reverse osmosis, however the cooling itself does not require any specialised technique. If water is cooled at a rate on the order of 106 K/s, the crystal nucleation can be avoided and water becomes a glass."

    It is interesting how some individuals only want to see or hear that which agrees with them. Sort of like forming a theory and then gathering only the information that makes it look correct.
    Stand for what you believe, even if you stand alone.

  2. #42
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    Default Re: This one is for Acebird

    Quote Originally Posted by BeeCurious View Post
    It's physics...
    I am sorry Einstein died before I got a chance to speak with him on this.
    Brian Cardinal
    Zone 5a, Practicing non-intervention beekeeping

  3. #43
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    Default Re: This one is for Acebird

    If the water has to be absolutely pure, then why does this also work on bottles of coke and beer? -js

  4. #44
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    Default Re: This one is for Acebird

    Don't know I've never seen it happen. Not certain it does. Need to ask the people that claim the water has to be pure. or claim that it even happens. The OP asked for an explanation for it. I have found two. Took about 10 minutes of searching to find them. go to the source and see if you can find out more. Could be both sources for pure Water where pour choices of words. I didn't write them so can't say how accurate that is. All I know is they both say it.
    I practice slight of hand or illusion. that is why the hand in the OP video stand out to me. you use your hands to do certain things so you have to have them in certain positions for the manipulations. Could be coincidence but I doubt it. the way he holds that bottle is anything but natural.

    I am tending toward the Nucleation idea though. To many people saying they have had it happen to them.

    I found this in regard to Beer or Soda.

    In the case of our beers, when we strike the bottle, the gas bubbles that form immediately give the supercooled liquid a nucleus around which to freeze. It is possible to supercool water bottles in the same manner, but I've found it much easier with glass bottles of beer than plastic bottles of Diet Coke.

    This video shows what woudl appear to be several groups of crystals forming throughout the bottle. http://www.youtube.com/watch?v=8wVzrSke6vY
    Stand for what you believe, even if you stand alone.

  5. #45
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    Default Re: This one is for Acebird

    Quote Originally Posted by Acebird View Post
    I am sorry Einstein died before I got a chance to speak with him on this.
    He would have liked that...
    BeeCurious
    Trying to think inside the box...

  6. #46
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    Default Re: This one is for Acebird

    As to the purity question, you would only need to have absolutely pure water if you wanted to get the temp all the way down to neg40. It seems logical to me that it would be a sliding scale, the more impure the easier nucleation is. Relatively clean bottled water can probably get down close to neg 40, tap water maybe only neg 30, etc. At some point the water would be impure enough to nucleate at the melting point.

  7. #47
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    Default Re: This one is for Acebird

    Water freezes at the temperature water freezes at. The difference is the absence of anything for it to start freezing on. a seed for the crystal. That is what all the information is saying. Supercooled is any temperature below the freezing temperature of the liquid. So for water -1C is supercooled. after that is does not matter how cold it gets. If it has the means to crystallize it would.
    Stand for what you believe, even if you stand alone.

  8. #48
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    Default Re: This one is for Acebird

    So, even though temps here have been well below freezing since yesterday, why is the open and partly consumed bottle of water sitting in my truck still liquid?

    Is my refrigerator freezer cold enough to do this demonstration? Does it matter whether the container is standing tall or laying on its side? Do I have to let the bottle stand still for a period of time after bringing it home from the store? Or, can I do this w/ a refilled bottle of tap water? I don't like to buy water.
    Mark Berninghausen "Ships at a distance have every man's wish on board." Zora Neale Hurston

  9. #49
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    Default Re: This one is for Acebird

    From what I read... Put a bottle of spring/filtered water in your freezer along with a bottle containing tap water. When the tap water is frozen try the exercise with the other bottle.
    BeeCurious
    Trying to think inside the box...

  10. #50
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    Default Re: This one is for Acebird

    Quote Originally Posted by sqkcrk View Post
    I don't like to buy water.
    Scale it down Mark. Do you have a frying pan with a glass top. Boil the water and take the cover off and let the condensate drip into an ice cube tray. When you get one full put tap water in another one. When the tap water freezes drop a grain of something into the one that isn't tap water. Maybe a toothpick will work.
    Brian Cardinal
    Zone 5a, Practicing non-intervention beekeeping

  11. #51
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    Default Re: This one is for Acebird

    Quote Originally Posted by Acebird View Post
    Scale it down Mark. Do you have a frying pan with a glass top. Boil the water and take the cover off and let the condensate drip into an ice cube tray. When you get one full put tap water in another one. When the tap water freezes drop a grain of something into the one that isn't tap water. Maybe a toothpick will work.

    sqkcrk,

    The scratched plastic will not work from what I read. The scratches will accommodate the formation of crystals...

    Just enjoy the videos on YouTube. Do a search for "supercooled water".

    You also have a Mythbusters video for the boiling water version : https://www.youtube.com/watch?v=1_OX...e_gdata_player
    BeeCurious
    Trying to think inside the box...

  12. #52
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    Default Re: This one is for Acebird

    The reason it only freezes to slush-

    Say you have a container with 100 grams of water supercooled to -20 C, The specific heat of water is 1 calorie per gram per degree so 2000 (100 times 20=2000) calories have been removed from the water since it was at the freezing temperature (0 C). Now you drop in a grain of sand or shock the container and freezing begins. The heat of fusion of water is 80 calories per gram so each gram of water that freezes gives out 80 calories which can only heat the contents of the container. After 25 grams of water freeze (25 times 80=2000) the temperature of the water rises to 0 C and freezing stops. This explanation assumes no heat is lost or gained to the surroundings which since the reaction takes only a short time is mostly true. If you want a $2 word the reaction is adiabatic.

  13. #53
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    Default Re: This one is for Acebird

    Whiskers. I don't think the water gives off 80 calories of heat per gram in the process of freezing. It uses 80 calories per gram to do the work of freezing. Heat is energy. energy does work. the arranging of water molecules into crystals is work. So the water must still have enough heat energy to do this work or it is getting it somewhere else. The surrounding air would be one source of gaining that heat.

    I did see where the energy of compression (which would explain the tapping of the container) would start the process. Water does not compress so the energy transferred to it through the tapping would be free to do other things than compress the liquid. Make crystals for example.

    A calorie is not 'Heat" It is "Energy" and one way to measure it is by temperature change. But that does not mean that only heat is energy.

    With that a calories is often defined as you have above. but it is not accurate. here are two definition of a calorie.

    The small calorie or gram calorie (symbol: cal)[3] approximates the energy needed to increase the temperature of 1 gram of water by 1 C at standard atmospheric pressure (101.325 kPa). This is approximately 4.2 joules.
    The large calorie, kilogram calorie, dietary calorie, nutritionist's calorie or food calorie (symbol: Cal)[3] approximates the energy needed to increase the temperature of 1 kilogram of water by 1 C. This is exactly 1,000 small calories or approximately 4.2 kilojoules.

    Notice pressure is part of the equation. It would require 0 calories for water to freeze in a vacuum. 80 calories per gram at normal atmospheric pressure. That is energy used to form crystals. It is not released. So either the water still contains this much energy or that much energy is transferred to the water. tapping of the container would be adding energy. at least enough to get the process started. The remaining energy could still be in the water or is being drawn in from the surrounding air via heat.
    Stand for what you believe, even if you stand alone.

  14. #54
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    Default Re: This one is for Acebird

    Daniel-

    As the water freezes it gives up energy (heat) because the crystal is a less energetic state than the liquid. On the other hand it takes energy to break the crystal bonds and melt the ice.

    The definition of the calorie states standard temperature and pressure since the specific heat of water isn't constant. As you state about 4.2 joules 4.21 actually. At around 30 C it goes down to about 4.18. Then starts to climb again (graph here- http://physics.info/heat-sensible/).

    I was surprised that the initial manipulation of turning the bottle over didn't start the freezing. I've seen this demonstration where the freezing was started by dropping a grain of sand into the water.

    Allow your kids, if you have them, to play with this stuff. Someplace out there is the next Newton. If we can just avoid diagnosing him (her) as ADD and forcing him into some standard mold.

    Bill

  15. #55
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    Default Re: This one is for Acebird

    Great link Whiskers, thanks.
    Brian Cardinal
    Zone 5a, Practicing non-intervention beekeeping

  16. #56
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    Default Re: This one is for Acebird

    Quote Originally Posted by whiskers View Post
    ....snip...Allow your kids, if you have them, to play with this stuff. Someplace out there is the next Newton. If we can just avoid diagnosing him (her) as ADD and forcing him into some standard mold.

    Bill
    Bill, my grandchildren are coming to visit next week, what demonstration do you think would have the greatest impact on them?
    Lee Burough
    I try to learn from my mistakes, and from yours when you give me a heads up :)

  17. #57
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    Default Re: This one is for Acebird

    Lee- I'm kind of with Montessori here, let them lead you, and then help them to go as far along as they can. This experiment we've been talking about here is easy to do and interesting, a beehive has biology for those so inclined, art- in the vein patterns of the wings and the comb itself, logistics- in the management of population and stores, navigation- how the waggle dance draws a map for the others and how the heck do you find your way back through a windy and thus constantly warping world to home. And you have bees to show and knowledge to discuss with them.

    I believe you need to be interested to be successful especially if your own happiness is a factor in your measurement of success. If Beethoven and Newton had been forced to swap places I doubt we would have either the music or the calculus but who knows, both were geniuses.

    Have fun with your grandkids.

    Bill

  18. #58
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    Default Re: This one is for Acebird

    And the answer is:
    http://www.newton.dep.anl.gov/askasc...1/gen01625.htm
    Name: Joshua
    Status: student
    Age: 20s
    Location: N/A
    Country: N/A
    Date: 7/26/2004



    --------------------------------------------------------------------------------
    Question:
    --------------------------------------------------------------------------------
    I am a soldier stationed in Iraq currently, and the rest of my unit and I love ice water, but have a puzzling question. When we put bottles of water into the freezer they dont entirely freeze, until we remove them and open them up or give them a shake. Then the bottle of watter will turn to either a slushy consistancy or solid ice. How is this possible, we cant explain how a bottle of water wont turn to ice in a freezer, but it will when removed and exposed to temperatures above 100 degrees F.

    sincerly, PFC Joshua A
    Baghdad Iraq


    --------------------------------------------------------------------------------
    Replies:
    --------------------------------------------------------------------------------
    Joshua,

    To answer your question. I've really only seen this with cola products that are near their freezing point and ONCE the can is opened then you will see AND FEEL the water crystals forming upon release of the ~ 5 atmospheres of pressure in the can of Coke or Pepsi. However, this is because of a HIGH pressure that NOW is A LOW pressure that resides in the can. You may say, who cares. Well, have you ever looked inside a COLD 2 liter bottle of carbonated coke / pepsi as you uncapped the bottle? If so, (and if the cola was not already 'flat') you would have noticed the IMMEDIATE nucleation of CO(2) (carbon dioxide) evolving from it's dissolved state in the sugar water to a gaseous state ....again...WHO CARES? Well, it may well be that your nearly freezing water could be quite close to 32 deg fahrenheit (33 or slightly higher) already and it just hasn't had the required NUCLEATION SITES to form crystals. AGITATION WOULD CERTAINLY INVOKE IMMEDIATE FREEZING. This, in my opinion, is the reason why you see / feel water crystals in the coke / pepsi example;

    1.) less dissolved constituents within a liquid will increase the freezing / melting point.

    2.) these evolving gas bubbles (CO2) in the bulk of the coke / pepsi will PROMOTE THE EASIER FORMATION OF WATER (ICE FORM)

    Water explanation: Needless to say, the water is near or at 32 deg F. I am willing to bet that it is your agitation (movement / sloshing) of the water that will cause the initial nucleation of sites for which water crystals may grow. Please keep in mind that the 100 deg F will NOT HAVE AN IMMEDIATE EFFECT. The plastics that store that water have GREAT THERMAL insulation...I dont care how thin the walls are. The dominant factor (for the first few minutes) ARE DEFINATELY THE FIRST NUCLEATION SITES FOR WHICH CRYSTALS CAN BE CREATED.

    ** Warning do not try below experiment **

    ** The importance of the understanding of NUCLEATION SITES IN MICROSCOPIC CRYSTAL and BUBBLE FORMATION ** ::

    Please consider the other end of the spectrum as well. If you've ever heard of SUPER HEATING OF WATER IN A MICROWAVE don't do it. But the idea IS THE SAME. I darn near burned my hands attempting the verification of this little factoid of life. If you were take a very very new and PITLESS / SCARLESS / NEARLY PERFECTLY SMOOTH / BRAND NEW PYREX PIECE OF GLASSWARE then PLACE (ideally) ion free water ... either from reverse osmosis / drinking water inside. Put in microwave and set for HIGH for a sufficient time that you think would be needed to bring the above mass of water to a boil. However, in MOST cases, you will NOT see the water boil. WHY? Furthermore, you can bet that you will have superheated water (above 212 deg F @ 1 atmosphere)...HOW?

    Why? Because there are no sites or impurities in water bulk or on the side walls of the pyrex for nucleation of bubbles to occur. But, you will continue to heat the water since the only mechanism to release heat is by the boiling off (two meanings here) of energy.

    How? Well, if you are continually bombarding the water molecules with microwaves and adding thermal energy and NOT allowing it to release, YOU WILL HAVE A SUPERHEATED STATE OF WATER...Not too stable.

    Lastly and most importantly...IF YOU SUSPECT THIS TO BE THE CASE, DO NOT TOUCH !! IF YOU AGITATE OR PUT IN A SPOON (NUCLEATION SITES) THE WATER WILL VIOLENTLY release it's energy down to the highest possible temperature it can stably maintain and still be a liquid (212 deg F). I hope that this 'novel' has been helpful in explaining to you why I THINK that the cause of all of these phenomenon are FROM LACK OF NUCLEATION SITES AND / OR LACK OF AGITATION.

    Best regards and take care,

    Darin Wagner
    Ernie
    My websitehttp://bees4u.com/

  19. #59
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    Default Re: This one is for Acebird

    so, there
    Is it solipsistic in here, or is it just me?

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