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  • experiment

    Something's been missing in my life lately, and this morning I realized what it was- I haven't experimented with anything for awhile, just to see if, or what, or why, -

    Anyway, I came across an aluminum baseball bat and I got interested in how it's constructed, the thickness of metal, etc. I cut the handle off at the end of the tapered section, and was happy to see about a .125 or so wall thickness. Then I thought, gee, how much water would it take to fill this?- my aim really was to measure the wall thickness throughout as best I could, and I was going to do this by a water displacement method. Enaway, I ended up filling it, and with hot water as that happened to be the tap that I turned on. Ok, so it took 550 ml to fill it, semi useless information, who cares. Then I thought, gee, what if I cooled this whole thing now, the metal's going to contract and some water will spill out the top. Whooppee ding. So I'm cooling it- the surprise part was that the water level actually dropped inside the narrow neck of the bat. Now I'm thinking.

    So what has happened? Did the metal expand as it cooled, allowing for a slightly increased internal volume- did the metal shrink ( as I assumed would happen) but the volume of water shrink even more? How much expansion/contraction does water go through with temperature changes? Obviously it expands as it cools past the freezing point, and it expands greatly as it heats past the boiling point, but what of the range between?

    Ok, that's my thing for today.
    I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-

  • #2
    Cant give you specs although i know who will, all i can say is my comparison with car cooling systems and the size of the purge tank, low when cold and high when hot, all the aluminum Rad. cores and the aluminum engine block (subies and honda's), yet when these parts cool in compairison to the water/ethlene glycol its the liquid that goes though more expansion and contraction, about a pint to a quarts worth...

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    • #3
      I dont know any of the coeficients for it, but the water probably "contracted" more than the aluminum did. Water, in a pure state and free of oxygen will continue to shrink in volume well below 0 degrees celcius. This state of super-cooling is rare in water because it must be pure to prevent the growth of ice crystals. [<edit> and it must be under pressure! ] This is the technique behind making ice for ice sculptures - it undergoes various agitations to remove and dissolved oxygen and it is pressurized and super cooled before it is allowed to freeze to form a clear, almost glass like ice block. Anyway, even tap water will continue to decrease in volume until abot 4 degrees celcius.
      Last edited by Fasttrack; 09-09-2006, 04:49 PM.

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      • #4
        I knew that but did not realize they do that for ice scuptures very "cool"

        does this make the Ice colder? there is a simular discussion in the making of ice cream the old fashioned way, adding salt to ice releases colder temps or removes heat so the center cream that it surounds freezes...

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        • #5
          Well technically you can cool solid ice as cold as you want it, all the way until it reaches a point of super-fluidity but you need a really really good "freezer" to be able to remove enough energy to reach that point. If you add some kind of solute to the water, like salt, and then freeze it, it will freeze at a lower temperature but it will then melt sooner. When you add salt to the old-fashioned ice cream makers you'd be adding it to the ice that is around the outside of the ice cream. Because of osmotic pressure, the water wants to mix with the salt and dissolve it but this can only happen when the water is in liquid form. To melt it requires heat so when you add salt to an ice-cube your really just speeding up the process of melting to pull more heat out of the surrounding area. In fact, you can get bad cold burns from an icecube and salt if you put some salt on an icecube and press it against your palm for a few seconds. Basically adding salt just makes the ice pull the heat out of the ice-cream much faster. Since it can pull from the ice-cream faster than it pull heat through the insulation from the outside air, the temperature of the ice-cream actually drops below the freezing point of water while the ice on the outside is melting. Just a chemical refrigerator.

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          • #6
            Does the water come out when you swing at the ball ?

            .
            .

            Sir John , Earl of Bligeport & Sudspumpwater. MBE [ Motor Bike Engineer ] Nottingham England.



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            • #7
              I dont know any of the coeficients for it, but the water probably "contracted" more than the aluminum did. Water, in a pure state and free of oxygen will continue to shrink in volume well below 0 degrees celcius.
              Waitaminute Fasttrack. You need to review your physics. Water continues to contract until just before freezing and then begins to expand before it freezes. Supercooling it makes no difference as this happens at (a moment while I look it up)... Ah yes, 4 degrees celsius. At this temperature water has minimum volume and expands as the temp goes in either direction.

              Water is a very strange compound and can exist in numerous forms, gas, liquid, and many forms of ice and strange in between states.

              This is an excellent web page that explains in detail the 63 anomalous properties of water.

              http://www.lsbu.ac.uk/water/anmlies.html
              Free software for calculating bolt circles and similar: Click Here

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              • #8
                Just curious. How would filling it with water, either cold or hot help you measure the wall thickness of the bat?

                "my aim really was to measure the wall thickness throughout as best I could, and I was going to do this by a water displacement method."

                I have always though they might make a neat exhaust pipe.
                Gene

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                • #9
                  As I wuz taught, the harder you apply the surface of a slider to a slidee, the harder it becomes in overcoming friction twix the two. Not so with ice. Frozen water (ice) exhibits the opposite physic, otherwise ice skates won't work.
                  G

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                  • #10
                    OK...????

                    Sooooo....When you're up to bat, and someone throws you a slider.....The right tool is a .125 wall aluminum bat filled with supercooled liquid???

                    What alloy would that Al bat be to take best advantage of this phenomenon??



                    Never mind, I'll go back to the shop now.

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                    • #11
                      Darnit, now I have to go and buy one the things. i see them for a couple of bucks apiece at the local Goodwill store.

                      I would cut the ends off and see if I could tune it to some musical note.

                      With a bunch of them tuned in a diatonic scale.......hmmmm.
                      Gene

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                      • #12
                        Hence my line: "Anyway, even tap water will continue to decrease in volume *until* about 4 degrees celcius."

                        Evan - perhaps i was splitting hairs but...

                        My mistake earlier - i was thinking only of super-cooling under pressure. I did not make that clear; indeed i had not distinguished between the differences of super-cooling and super-cooling under pressure in my mind. Perhaps you missed this from that site:

                        "The result is a shift in the temperature of maximum density to lower temperatures. At high enough pressures the density maximum is shifted to below 0آ°C (at just over 18.84 MPa). "

                        As density is a measure of moles of water per volume - an increase in density when the amount of H20 molecules (i.e. moles of water) remains constant, the volume will decrease.
                        Last edited by Fasttrack; 09-09-2006, 04:52 PM.

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                        • #13
                          Dang! Now I have to go back and get a few more of these elcheapo kids bats. I suddenly have a need to make an organ.

                          Far as measuring the wall thickness using water, I would have totally immersed the bat part in water in a slender container, then filled the container to some level that I marked on it. Then I would carefully remove the bat and pour all the water back into the container. Mark the level again. Then fill the container back to the first mark, then pour the water into a measuring container until the lower mark is reached. The amount of water in the container would correspond to the volume of material in the bat part. Then measure the surface area of the part, apply a correction factor based on the expected wall thickness, then some more math to get the actual average thickness.

                          I realise that this method is fraught with errors, but that's the way I envisioned doing it.
                          I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-

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                          • #14
                            Darryl - you don't happen to be an engineer do you? Thats the kind of expierement i'd expect from science teachers or engineers or others who may be very brilliant. Its great in theory but not so easy in practice... I've had a couple of those ideas...

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                            • #15
                              Step away from the bat! Do you know how many poor, defenseless children have been hurt by baseball bats? Not to mention supercooled bats modified by unlicensed bat butcherers!

                              MUCH safer to teach them how to play Jarts in a responsible manner.[][]
                              Milton

                              "Accuracy is the sum total of your compensating mistakes."

                              "The thing I hate about an argument is that it always interrupts a discussion." G. K. Chesterton

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