"Ifff you go out in the sun today..." Better make sure your camera/lens is metal!
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From: Robert Coe on 17 Jul 2010 20:51 On Sat, 17 Jul 2010 19:58:02 -0400, "Peter" <peternew(a)nospamoptonline.net> wrote: : "Robert Coe" <bob(a)1776.COM> wrote in message : news:98p346hl4t9752r9774j6db5ioq0b1brjf(a)4ax.com... : : > Rich, did you sleep through high school physics? An object isn't black : > because it absorbs IR; it's black because it absorbs all *other* wavelengths : > and *radiates* in the IR band. That's why if you lay different-colored cloth : > squares on snow, the black square sinks into the snow fastest and the : > white square sinks hardly at all. Canada gets plenty of snow in the : > winter, so they must have showed you that in the seventh grade. Did you : > play hooky that day? : : Uhm! Black is the absence of color. Which is another way of saying that a black object absorbs all visible wavelengths (and reflects none). Which is what I said. Your point is ??? Bob
From: Peter on 17 Jul 2010 21:19 "Robert Coe" <bob(a)1776.COM> wrote in message news:mmj4469l67f7hcf6lvijf880vbglh61io1(a)4ax.com... > On Sat, 17 Jul 2010 19:58:02 -0400, "Peter" <peternew(a)nospamoptonline.net> > wrote: > : "Robert Coe" <bob(a)1776.COM> wrote in message > : news:98p346hl4t9752r9774j6db5ioq0b1brjf(a)4ax.com... > : > : > Rich, did you sleep through high school physics? An object isn't black > : > because it absorbs IR; it's black because it absorbs all *other* > wavelengths > : > and *radiates* in the IR band. That's why if you lay different-colored > cloth > : > squares on snow, the black square sinks into the snow fastest and the > : > white square sinks hardly at all. Canada gets plenty of snow in the > : > winter, so they must have showed you that in the seventh grade. Did > you > : > play hooky that day? > : > : Uhm! Black is the absence of color. > > Which is another way of saying that a black object absorbs all visible > wavelengths (and reflects none). Which is what I said. Your point is ??? Since when does black radiate in any band? -- Peter
From: Peter on 18 Jul 2010 19:47 "John A." <john(a)nowhere.invalid> wrote in message news:oem446l8nkqaqjn2mstig2ojidkmkujsf1(a)4ax.com... > On Sat, 17 Jul 2010 21:19:05 -0400, "Peter" > <peternew(a)nospamoptonline.net> wrote: > >>"Robert Coe" <bob(a)1776.COM> wrote in message >>news:mmj4469l67f7hcf6lvijf880vbglh61io1(a)4ax.com... >>> On Sat, 17 Jul 2010 19:58:02 -0400, "Peter" >>> <peternew(a)nospamoptonline.net> >>> wrote: >>> : "Robert Coe" <bob(a)1776.COM> wrote in message >>> : news:98p346hl4t9752r9774j6db5ioq0b1brjf(a)4ax.com... >>> : >>> : > Rich, did you sleep through high school physics? An object isn't >>> black >>> : > because it absorbs IR; it's black because it absorbs all *other* >>> wavelengths >>> : > and *radiates* in the IR band. That's why if you lay >>> different-colored >>> cloth >>> : > squares on snow, the black square sinks into the snow fastest and >>> the >>> : > white square sinks hardly at all. Canada gets plenty of snow in the >>> : > winter, so they must have showed you that in the seventh grade. Did >>> you >>> : > play hooky that day? >>> : >>> : Uhm! Black is the absence of color. >>> >>> Which is another way of saying that a black object absorbs all visible >>> wavelengths (and reflects none). Which is what I said. Your point is ??? >> >> >>Since when does black radiate in any band? > > You've never heard of black body radiation? > > Heck, even black holes apparently radiate. The very definition of black is the absence of radiation. You are mistaking imperfect black, for pure. Hawking has stated that possible emission of radiation by black holes it's just theory. At present, black holes are theoretical. It is possibly due to to some as yet undefined quantum effect. Until there is scientifically accepted proof I will go with my working definition. -- Peter
From: whisky-dave on 19 Jul 2010 08:44 "Peter" <peternew(a)nospamoptonline.net> wrote in message news:4c43953d$1$5557$8f2e0ebb(a)news.shared-secrets.com... > > > The very definition of black is the absence of radiation. You are > mistaking imperfect black, for pure. Hawking has stated that possible > emission of radiation by black holes it's just theory. At present, black > holes are theoretical. No they existed they have been 'seen' from observing matter falling in to them, they also radiate gamma radiation. >It is possibly due to to some as yet undefined quantum effect. Until there >is scientifically accepted proof I will go with my working definition. There seems to be lots of proof that black holes exist, they have even measured them. > > > > > -- > Peter
From: Peter on 20 Jul 2010 11:34
"Wolfgang Weisselberg" <ozcvgtt02(a)sneakemail.com> wrote in message news:59ufh7-nk.ln1(a)ID-52418.user.berlin.de... > Peter <peternew(a)nospamoptonline.net> wrote: > >> The very definition of black is the absence of radiation. > > ITYM reflection. > > Just because usual black stuff radiates warmth on earth and > you cannot see it, that doesn't mean no radiation. I am usually reasonably precise in my language. If there was any ambiguity I cleared it up. Reread you own statement. Believe what you will, I have said all I care to.. -- Peter |