A Possible and Very Stupid Flint

[naama_gat at hotmail.com]

No: HPFGUIDX 22849

--- In HPforGrownups at y..., joym999 at a... wrote:
> --- In HPforGrownups at y..., meboriqua at a... wrote:
> > Okay, Penny's question about classes after exams inspired me to 
> post 
> > something that I noticed a while back from PoA.  If this is a 
> Flint, 
> > it is not only pathetic that I noticed it, but might enable me to 
> gain 
> > membership to the L.O.O.N. society.
> > 
> > At the end of PoA when Harry and co. are taking their finals, they 
> > return from their Herbology final "with sunburnt necks" after being 
> > "in the greenhouses under a baking-hot sun" (ch. 16).  If I am not 
> > mistaken, aren't greenhouses completely made of glass?  Unless some 
> of 
> > the panels are made of mesh or something to let a breeze in, there 
> is 
> > no way they can get sunburnt necks through glass.  Sweaty necks, 
> yes, 
> > but not sunburnt ones.
> > 
> > How's that for nitpickiness?
> > 
> 
> As nitpickiness, I would say that it is excellent, and that Jenny is, 
> by any definition of the word, a true LOON. (That is a compliment.  
> Really it is.)
> 
> As science, however, I do not think it is accurate. [Joywitch takes 
> off witches hat, puts on nerd glasses and enters professorial mode.]  
> Sunlight consists of a wide spectrum of electromagnetic waves which 
> range in frequency/wavelength from the infrared (which feel hot) to 
> the ultraviolet, and all the visible frequencies in between.  Sunburn 
> is caused mostly by the ultraviolet waves, IIRC.  Some glass, such as 
> car windshields, eyeglasses, etc. is coated to keep out UV rays, but 
> most glass is not.  Plants live by converting sunlight to usable 
> energy (photosynthesis), and they require waves from the ultraviolet 
> part of the spectrum to do their photosynthesis stuff well.  So, the 
> glass used in greenhouses would not be likely to have UV coating, 
> hence you should be able to get quite a nice sunburn by hanging out 
> in it for a few hours.
> 
> But why would their necks be sunburnt?  Do they all have short hair?  
> Even if they spent most of the time bending over their work, wouldnt 
> their arms and legs also get sunburnt?  Or do they always have to 
> wear those wizard robes, even in the hot greenhouse?  And if they 
> have to wear their robes, why dont they have to wear their hats, 
> which could keep them from getting sunburnt necks?  And is there no 
> limit to how far we can take this nitpick?
> 
> --Joywitch, who should be working on the contest instead of being 
> LOONy


>From my very very vague memory of Biology classes I think that plants actually do not 
utilize UV light but other parts of the spectrum. 
OK, I did a small search and I'm right - cholorophyll absorbs visible light with peaks at 
red and blue. Also, from what little I've just read on the net, regular glass does deflect 
most of the UV radiation, although not all (because of the ozone hole Australia gets more UV 
radiation than England, so the chances of getting sunburn under glass are probably much 
higher there). 
So, I think the nitpick stands. It doesn't seem likely to me that in Britain you would get 
sunburnt when working for a few hours in a greenhouse.


Naama, nitpicking scientifically