[time-nuts] Lifetime of glass containers
Joseph M Gwinn
gwinn at raytheon.com
Mon Jun 15 20:07:48 UTC 2009
time-nuts-bounces at febo.com wrote on 06/15/2009 03:56:42 PM:
> Not to charge in, but I've looked at ordinary window pane glass in very
old
> buildings and you can actually see the rippling effect that occurred
over
> time, showing the "flow" of the glass toward the lower edge of the pane.
One
> presumes that the panes were relatively uniform when installed 120 years
> earlier. Sounds liquid to me.
It's hard to say because the panes were not flat to begin with. Window
glass was then made by manually blowing a big cylinder and then cutting
the hot glass and unrolling the cylinder onto a flat charcoal surface. The
ripples are largely parallel to the axis of that original cylinder.
Modern window glass is made by pouring a sheet of molten glass out onto
molten tin, where the glass floats and flattens itself. The glass sheet
is pushed steadily away from the glass pot, cooling as it goes until hard
enough to cut into sheets. <http://en.wikipedia.org/wiki/Float_glass>
Joe Gwinn
> Dave
>
> ----- Original Message -----
> From: "Hal Murray" <hmurray at megapathdsl.net>
> To: <time-nuts at febo.com>
> Sent: Monday, June 15, 2009 12:23
> Subject: [time-nuts] Lifetime of glass containers
>
>
>
> dave at uk-ar.co.uk said:
> > Or as someone else suggested, use a Glass container. So long as you
> > don't want it to last for many 100's of years, as Glass is not a
> > solid, it is a "super cooled fluid" and as such it flows like Ice over
> > time, just that it takes much much longer to do so!
>
> As best as I can tell, the glass-is-a-liquid story is bunk.
> http://en.wikipedia.org/wiki/Glass#Behavior_of_antique_glass
>
> I was going to ask if anybody had tried to measure it. That seems like
> something a time-nut would know about.
>
> The astronomers have been running tests for years. Their
> mirrors don't seem
> to sag enough to notice, and they are very good at noticing tiny
> distortions.
>
> --
> These are my opinions, not necessarily my employer's. I hate spam.
>
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-
> bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
> The following line is added for your protection and will be
> used for analysis if this message is reported as spam:
>
> (Raytheon Analysis: IP=64.34.164.147; e-from=time-nuts-
> bounces+gwinn=raytheon.com at febo.com; from=dgcarlson at sbcglobal.
> net; date=Jun 15, 2009 7:57:28 PM; subject=Re: [time-nuts]
> Lifetime of glass containers)
More information about the Time-nuts_lists.febo.com
mailing list