On 20-2-2009 19:22, Orchid XP v8 wrote:
>>> [A fact which our Java lecturer disputed. He was trying to claim that 
>>> the range of a single-precision float is "oh, more than the number of 
>>> atoms in the universe", and thus you don't really need 
>>> double-precision.]
>>
>> One of the reasons why I am happy that I did not know of CS when I 
>> started at uni. They started a year before and somehow that message 
>> did not reach me in time, otherwise I might have studied CS. While 
>> studying physics I did a few courses at the CS department and was 
>> invariably struck by the quality of the lecturers. Did I tell the 
>> story of the teacher that could not write down the equation for a 
>> straight line?
> 
> Heh. Well, I guess if what you happen to be doing doesn't involve that 
> equation, there's no particular reason to know it. 

He was giving a lecture where he needed it. Does that count?

> But yeah, generally 
> neither the students nor the lecturers, frankly, knew what they were on 
> about. [With some notable exceptions.]

That is why I advise people that are intelligent and interested in 
computers to study a real science, like physics or chemistry.

>>> I'm not quite sure how that's relevant here though.
>>
>> The number of atoms in a given volume of gas at standard pressure is 
>> constant, hence the weight of a volume of N2 is 7 times that of H2 and 
>> O2 8 times. So why did you expect a few percent?
> 
> Because oxygen is only slightly further down the periodic table than 
> hydrogen? I would therefore imagine one atom of oxygen is not "that 
> much" heavier.

So you can't compute 3x9 in your head *and* you have failed to 
understand the fundamental concept behind the periodic table. Your 
future in academia becomes bleaker every post. ;)

> 
> (I had also assumed that because they're slightly bigger, there'd be 
> slightly fewer of them per unit of volume...)

http://en.wikipedia.org/wiki/Atomic_radius (where the calculate radius 
of oxygen is even less than that of hydrogen)

And the radius of the atom is largely irrelevant for gasses as you could 
have known if you paid attention when the gas laws were introduced ;)

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