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Comments:
<0> DanF_DrC, hmm, good call. Different frequencies and polarizations and junk.
<1> size constraints and direction
<1> cell phone antenna for instance
<2> is there a standard on what +/- should mean?
<2> does it imply definite bounds or one std deviation?
<1> Failure02, no expert but I think it depends on what people mean. mostly std dev I would think
<0> Ive seen both. Never heard of a std, but I would think the former is more common.
<0> heh, maybe not :P
<2> would there be any reason for some other convention?
<2> (i can't think of one)
<1> sharp boundary would be one
<2> what's a sharp boundary?
<1> if nothing is outside the +-
<2> ok. that's what i meant by definite bounds
<1> std dev is something like 90% is within the +- but not certain
<1> yep
<2> it's fun reading about different estimations for the hubble constant, with different values way outside of eachother's error margins :)
<1> yep. human competence is largely a shared delusion
<0> Failure02, heh, Ive seen those plots. Quite funny.
<1> that said one could imagine that the conclusions are right under the ***umptions of known theory and that the disparity is evidence of an incomplete theory
<1> something similar seems to be the case with the gravitational 'constant' as well
<3> is universe in the middle of nothing?
<4> klerfayt, you shocked all the physicist in here profoundly
<3> I'm not physicist
<4> me neither
<3> is Universe finite or infinite?
<5> klerfayt, the space is infinite the stuff in it is not.
<6> klerfayt: honestly, we do not know
<3> space=nothing ?
<6> klerfayt: but a good answer might be that even if it was infinite, we could never actually find out since our available resources (including space) is always a finite subset
<6> klerfayt, not all think that space is nothing :)
<6> (Feynman may have been one of them? Not sure if I remember correctly)
<3> what makes all uncertain is the fact that we never know how much we know of everything
<6> something about particles that nearly randomly pop into existence and cancelling themselves on the average (in vacuums)
<6> sure
<7> night all
<1> sleep well
<7> sleep well :)
<8> hi everyone
<8> what is water made up of? 2 hydrogen molcules + 1 oxygen?
<0> water is a molecule
<6> hazey: are you serious? http://en.wikipedia.org/wiki/Water
<8> kanzure: im serious. we are not all as advanced as you
<8> kanzure: can man of nature create MORE new water?
<8> or is the water we have today the same water that was here from start of earth?
<6> hazey: the water here did not necessarily atomically bond during the formation of the Earth
<6> hazey, water is a basic chemical that many know of and is easy to learn about, it's perhaps the first molecule any child usually knows of
<8> when was the last water created?
<0> last water molecule?
<8> kanzure: we have water shortgage in Australia! Why cant they just make more water?
<8> MindHack: yes!
<8> MindHack: can man of nature create MORE new water?
<8> MindHack: can man OR nature create MORE new water?
<5> they can, but it takes energy.
<0> sure, but where are you going to get the stuff to make the water?
<6> lots and lots of energy
<6> where are you going to get the hydrogen?
<0> and the energy, as darkgreen put it
<8> I read on wiki that water is composed of two hydrogen atoms and one oxygen atom.! So why cant man just make more water in the labs?
<8> MindHack: I read on wiki that water is composed of two hydrogen atoms and one oxygen atom.! So why cant man just make more water in the labs?
<6> because we do not know how to make hydrogen, nor oxygen
<8> MindHack: cant they get hydrogen atoms and oxygen atoms to create more water?
<8> kanzure: ah ok
<8> kanzure: well that explains that :P
<6> heh'
<8> kanzure: can they take it from elsewhere?
<8> kanzure: can man take oxygen atoms and hydrogen atoms from elsewhere and make water?
<0> hazey, sure, but hydrogen is rare on earth. Needs to be extracted from other places, which takes lots of money.
<5> rocks to water only $500 a drop.
<6> hm,
<6> doesn't the sun have a good source of hydrogen?
<8> MindHack: where is hydrogen located?
<0> kanzure, nah, barely any in there :P
<6> kanzure: hazey: when was the last water created?
<6> guyNamedBill: that should be a kickban
<8> darkgreen: they can extract water from rocks?
<0> hazey, most industry gets their hydrogen from petroleum, and you probably know how rare that is
<8> MindHack: ok
<5> hazey, if human kind was desperate enough, it would find a way.
<8> MindHack: so the water I drink today, may be the exact same water that has been getting around for 1000's of years on earth?
<0> darkgreen, nah, I think we'd be dead, but thats just me :)
<0> hazey, sure
<8> MindHack: heh
<0> hazey, most of it
<8> MindHack: so you mean the water I drink today, could have been the same water that was lying in a pool of vomit 4000 years ago?
<0> there is a chance that there are water molecules in you right now that never p***ed through a human being.
<0> sure
<5> hazey: http://eo.ucar.edu/basics/images/usgs_water_cycle.jpg
<8> darkgreen: cheers!
<0> now how old are you hazey ?
<8> MindHack: well that changes my view on recycle water! in Australia, they are going to recycle sewage water! but its already been around in dirty places since the beginning of Earth anyway, right?
<8> MindHack: I am 42
<0> HA!
<8> MindHack: am I right?
<0> yeah
<8> MindHack: ok
<0> sewage water has been recycled for ages. Not sure when they started
<8> intwresting
<8> i never knew this stuff
<8> MindHack: the water that I drink out of taps, who knows where its been :P
<0> I try not to think about it :P
<6> 42? have you been living in what, Australia?
<8> MindHack: 5000 years ago the same water I drink now, could have been sitting in a pile of dog poo and been evoprated into the air and then fell as rainwater! correct?
<5> Certain europee'en folks drank their own .. after a heavy night of drinking, to shall we say; go for another round.
<0> kanzure, Id hate to post this to bash.org......but......
<0> :p
<8> kanzure: in Sydney
<6> hazey: yes, dog poo.
<8> kanzure: thats interesting! so the water I drink today out of taps could have been goodness knows where :P
<6> yes
<8> intersting thought :P
<5> MindHack, your not going to post this on bash.org are you?
<8> i was very ignorant about this
<8> this is very interesting indeed
<0> darkgreen, nah
<6> hazey, there's more ;)
<8> for some reason I thought new water is created all the time
<5> It is
<8> kanzure: for some reason I thought new water is created all the time by nature.! how wrong I was :P
<6> hazey, not only this for water, but for all atoms, molecules, compounds, people, galaxies, planets, etc.
<6> although people are able to reproduce, luckily
<0> hazey, some water is freshly created through chemical reactions
<8> kanzure: so no new atoms are every created from stratch? so what makes up my body, could have been atoms floating around somewhere else in universe?
<8> MindHack: some water is freshly created through chemical reactions? How much per year?
<8> MindHack: what are those chemical reactions made up of?
<6> hazey, I can not answer that. Many atoms have been reused many times. This is evident by the fact that we haven't hit any sort of equillibrium state.
<0> hazey, no clue. Most water on earth has been around for the long haul Id say
<8> MindHack: what are those chemical reactions made up of that create the new water?
<6> hydrogen, oxygen
<0> hazey, not sure, Im no chemist. Have hydrogen peroxide at home? That for example bubbles. When it bubbles, it releases pure oxygen gas, and when its done bubbling COMPLETELY, it turns to pure water
<6> I don't think you understand this, hazey.
<8> MindHack: isnt man and animal poo just made up of atoms?
<6> hazey, try #chemistry
<5> bzzzz
<8> kanzure: sorry, didnt realise I was in wrong channel for this topic
<8> thanks though
<8> bye
<6> not really, atoms are physics, so are chemical reactions
<6> you could probably talk about anything in here, but it'd get you banned at some point :-p
<0> hazey, as for atoms forming. That happens in stars mostly, because you need lots of heat to make that work.
<0> hazey, on earth, new atoms are formed in atomic bombs and radioactive processes, but other than that they stay pretty unchanging. Its only the molecules that rearrange themselves.
<0> hazey, this is the difference between chemical and nuclear reactions.
<8> so the bottom line is... the tap water we drink today is mainly made up of the same water that has been around since the beginning of the Earth?
<0> almost all of it, yeah
<8> MindHack: about 99%?
<0> might be a small portion that came from cometary fragments hitting the earth, reactions that liberated oxygen and hydrogen atoms that have never become water
<0> I dont know the number.
<8> MindHack: roughly?:P
<0> I dunno. very roughly
<0> its things like that that science is hard pressed to find numbers for
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