more curved icicles
in [Design]
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From: Archimedes' Lever on 4 Apr 2010 02:03 On Sat, 03 Apr 2010 16:28:10 -0700, John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >On Sat, 03 Apr 2010 14:48:20 -0500, John O'Flaherty ><quiasmox(a)yeeha.com> wrote: > >>On Sat, 03 Apr 2010 11:08:26 -0700, hamilton <hamilton(a)nothere.com> >>wrote: >> >>>On 4/3/2010 9:40 AM, John Larkin wrote: >>>> >>>> ftp://jjlarkin.lmi.net/Curvies_1.jpg >>>> >>>> ftp://jjlarkin.lmi.net/Curvies_2.jpg >>>> >>>> >>>> John >>>> >>>LOL, how did you get them to do that ?? >>> >>>;-) >>> >> >>It looks as if the edge of the snow curves down as it slowly slides >>off the roof, and since it never quite melts, it curves right around. > >Yes. > >John Likely more to it than that, and you just do not know it.
From: George Jefferson on 4 Apr 2010 03:11 "John O'Flaherty" <quiasmox(a)yeeha.com> wrote in message news:ip6fr5t6lhnratlak658o7om86i3gb5q9e(a)4ax.com... > On Sat, 03 Apr 2010 11:08:26 -0700, hamilton <hamilton(a)nothere.com> > wrote: > >>On 4/3/2010 9:40 AM, John Larkin wrote: >>> >>> ftp://jjlarkin.lmi.net/Curvies_1.jpg >>> >>> ftp://jjlarkin.lmi.net/Curvies_2.jpg >>> >>> >>> John >>> >>LOL, how did you get them to do that ?? >> >>;-) >> > > It looks as if the edge of the snow curves down as it slowly slides > off the roof, and since it never quite melts, it curves right around. Sort of. There was a lip formed by the snow before it moved down which allows any droplets to curve inward. As they do this, if they re-freeze(being colder because of the warmer roof) they extend the lip inward. This happens repeatedly. The reason why you do not get a solid lip formed is because initially there will be areas that form that are built up more than others(either due to the non-uniform temperature of the root or crevices being cut away from the droplets or whatever). As the droplets form they gain momentum which carries them around(which I think is what you meant). But because of the crevices and surface tension they form the long spikes. One could artificially do this by creating a some sort of curve like http://chestofbooks.com/crafts/mechanics/Cyclopaedia/images/Marking-Out-Involute-Curves.jpg which gives a path for the droplets to follow. With enough momentum and time(to initially ice over the curve to reduce friction) one could create all sorts of odd phenomena. Using a circuit one could have the droplets come right back to themselves(or almost). One could then remove the artificial support if they wanted. Anyone got a large storage freezer to try this? ;)
From: John Larkin on 4 Apr 2010 10:57 On Sat, 03 Apr 2010 23:03:40 -0700, Archimedes' Lever <OneBigLever(a)InfiniteSeries.Org> wrote: >On Sat, 03 Apr 2010 16:28:10 -0700, John Larkin ><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: > >>On Sat, 03 Apr 2010 14:48:20 -0500, John O'Flaherty >><quiasmox(a)yeeha.com> wrote: >> >>>On Sat, 03 Apr 2010 11:08:26 -0700, hamilton <hamilton(a)nothere.com> >>>wrote: >>> >>>>On 4/3/2010 9:40 AM, John Larkin wrote: >>>>> >>>>> ftp://jjlarkin.lmi.net/Curvies_1.jpg >>>>> >>>>> ftp://jjlarkin.lmi.net/Curvies_2.jpg >>>>> >>>>> >>>>> John >>>>> >>>>LOL, how did you get them to do that ?? >>>> >>>>;-) >>>> >>> >>>It looks as if the edge of the snow curves down as it slowly slides >>>off the roof, and since it never quite melts, it curves right around. >> >>Yes. >> >>John > > >Likely more to it than that, and you just do not know it. Explain it to us. John
From: krw on 4 Apr 2010 20:57
On Sat, 03 Apr 2010 21:53:36 -0700, John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >On Sat, 03 Apr 2010 23:26:37 -0500, "krw(a)att.bizzzzzzzzzzzz" ><krw(a)att.bizzzzzzzzzzzz> wrote: > >>On Sat, 03 Apr 2010 16:30:46 -0700, John Larkin >><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >> >>>On Sat, 03 Apr 2010 14:20:50 -0500, "krw(a)att.bizzzzzzzzzzzz" >>><krw(a)att.bizzzzzzzzzzzz> wrote: >>> >>>>On Sat, 03 Apr 2010 09:40:57 -0700, John Larkin >>>><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >>>> >>>>> >>>>>ftp://jjlarkin.lmi.net/Curvies_1.jpg >>>>> >>>>>ftp://jjlarkin.lmi.net/Curvies_2.jpg >>>>> >>>> >>>>You must get some wind up there. >>> >>>It's not wind doing this. The snow on the pitched roof does a slow >>>glacier sort of creep, and curls as it crawls over the edge, taking >>>the icicles with it. >> >>Are the two pictures of the two sides of the house or one side from two >>directions. Now I see what you're talking about; a totally different process >>than I was assuming (and had seen before). Cool. > >Both shots were from the same south-facing window, looking east and >west. Maybe the sun on the sloping roof makes the snow creep and curl. >I've looked at a lot of other houses in the neighborhood (all the >construction is very similar... draconian HOA rules) and I haven't >seen this anywhere else. Interesting. Is your cabin unique in direction, shading, or anything obvious like that? Maybe your insulation isn't quite right or your roof isn't ventilated well enough? It might be worth an investigation. >The icicles are clearly growing as their bases curl, resulting in the >curved shapes and branches. Tricky timing. It would make sense that the icicles would form as the glacier slides. Neither will tend to happen at -40F. ;-) >Neat planet we live on. Sure. But sometimes nature is speaking to you. Check your attic. |