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I've been wondering about similar topics, so hope this is not considered off-topic. How would wind and waves on Titan compare to Earth. Instead of swimming how would sailing be effected? PS: Gian - if this is too far astray from your query let me know I'll start something else.

An engineer's view: It's not really a question of thermodynamics, I suspect. And it's not just relative. I think you want to know more about the humidity of the air, and the air movement. Relative temperature will have an impact, but not as much as humidity and wind. Then add in sea spray. Which means I'm with mistermack.

I wasn't sure how to explain it but as usual studiot you are all over it. The power of a wave in the ocean decreases quickly with depth. Until the bottom is closer and you create surf. I would think, no more than gut feel, power from waves is likely to be low efficiency for power production.

Same as studiot. Note that most domestic solar panels don't deal with partial shading at all. It de-rates many systems so that the whole panel may as well be in the shade. There are commercial systems that have dealt with this issue but I doubt they are easily available for domestic. Height itself makes no difference. Angle to the sun obviously does.

Guys, I thought I should revisit my thanks here. You give a perspective that simply doesn't come from a uni subject on basic chemistry. Hey, you offered me a quantum physics "rabbit hole" to chase. And I appreciate it. In time, in time. Right now an issue I had in Chemistry has evaporated. Go to to say thanks, no honest really thanks, for that.

Cheers Swansont

Thanks guys, as usual dropping questions here leads to interesting discussions I had not considered. Note that (at this stage) my studies are chemistry, not quantum - though without doubt this is starting with "sub atomics" and in particular the actions of the electron. [clearly moving toward chemical bonding.] This said - swansont, if Pauli exclusion relates to energy and spin (can I leave out orbital angular momentum for now?), the the 1s and 2s orbitals (for example) can never be other than excluded as they are different energy levels to start with? This would cover the matter for all orbitals that appear to share space/volume. In terms of "position is not a quantum state" my visualisation gets caught again - what happens when molecules - or make it simpler, two monoatomic elements meet. More specific, noble gases so we are not dealing with bonding complications. The electrons simply don't notice the orbital space of the other when they "rub shoulders"? studiot I must be reading those diagrammes incorrectly - Fig 9 seems to me to clearly show the 1s and 2s orbitals overlapped. Or that their is a probability of the 2s orbital with an electron positioned (that word again) in the 1s orbital probability.

Guys, I'm having trouble with another really basic concept so I hope you can sort me out. Let's just look at the spherical orbitals. In the usual diagrams the 1s orbital completely is inside the 2s orbital. But Pauli excludes this. Is the 2s orbital actually a sphere with a (1s size) hole inside of it? This overlap can be carried through to the 2p etc orbitals. In a massive atom that inner sanctum of 1s volume, against Pauli, could get very busy. Cheers

Now that is interesting though have to say beyond my current knowledge ability. So we create a new nucleus by forceably removing a neutron proton [self edit]. Presumable the "un-required" electron simply matches?

Thanks guys - apologies at not responding earlier - we've had some family health matters that changed my focus for a bit. Int ereseted in the comment that a nucleus being a soup of quarks - sounding like an modern update on the plum pudding model of the atom. (Ok, not really but interesting anyway.) Are their any thoughts on "why"? Why does carbon do C12 and C14, for instance?

I'm trying to fathom what is happening when an atom has additional (or fewer!) neutrons than the number of protons - different atomic isotopes. Generally I understand that chemical properties are set by the quantity of protons/electrons and the relationship or "closeness" that the electron orbit has to the valence electrons. (Happy to have my clumsy language corrected). Why does/can a nucleus adopt additional or fewer protons - at all? Then it seems to make a little sense that the more massive nucleus might have "space" for additional protons - why does it happen with hydrogen? What are the differences in chemical properties for different isotopes and why? I understand as an overview, there are no practically discernable differences in chemical properties, albeit there is radioactivity in the larger isotopes. In detail however, that isn't the answer is it? In Hydrogen, between 1H, 2H and 3H there is an incredible proportional difference in atomic mass of 200% or 300%. I have read that reaction times can be different. Anything else?

OK, Studiot, as usual is completely right, a bit of heat will go a long way in these circumstances. At near freezing, I'd suggest opening the window will do naught. BUT, if there is a human inside breathing, you have a little humidifier in the system in these conditions. Mate I haven't experienced this much personally, one though a trip where I crossed the arctic circle in winter, and that same trip further south in very cold conditions. Sleeping in a car north of the acrtic circle in winter my breath was easily creating enough humidity that I had freezing on the windows inside the car. Opening the windows solved the issue. OK down to say -5 but if it's getting colder live with the frost. Try a little heater, but at near freezing it doesnt need much breathing to create high humidity. Nor does it need a lot of heat to solve it.

Well no, and I would have assumed in celebs that it wasn't natural. Of course there is racial harmony and mixing these days, but that would be a different issue wouldn't it>

So previously known/proven? Still they seem have shown this through the genome which is amazing. Black skin blue eyes would look odd today!

The effect of air flow: If your campervan is indeed 80%RH, and outside is say, 40% - opening the windows will certainly help. But it is not because airflow is impacting humidity, is because you are replacing the humid air with drier air. The human body moderates temperature by radiation and as it gets hotter by evaporation - sweat. If we have a hot humid environment, the air does not have much capacity to take up a lot of moisture. The boundary layer (for want of a better term) close to the skin becomes saturated. In this case, air movement will help, because new air is dryer than the old boundary air (even if it is humid). So evaporation is more effective. If it is a dry heat then air movement wont do anything - for practical purposes. If it is cool and humid it also wont pick up a lot of moisture because the max vapour pressure of moisture is low - even if it is cold and dry it doesnt have the capacity to pick up much moisture. A heater will work if the source of the humidity is simply the internal air. If you have an independent moisture source, say something got wet - the heater wont do much. Think about hiring a small dehumidifier. It's like a small air-conditioner but has a set point below the due point to extract moisture. They can be quite effective. Maybe run it for a week then return it.

Sydney Harbour Bridge. No doubt there are plenty of claims for "longest span" and the like, wiki says it was the Harbour Bridge until 2012. Prototype built in Newcastle UK (I think), the final version was inspired by Hells Gate in New York. Completely dominates Sydney harbour and is an annual focus each New Year's Eve.

Ifit If the partial pressure of water vapor in air approaches 100% (ie we approach 100% RH) water will drop out of the air. The easiest way to force this is by cooling. If it is -3 the water drops out as ice. Snow or hoar frost or ice crystals etc. If it is above 0 it is dew, or rain, or mist, etc. The device used to work out air temperature/moisture vapor/condensation etc is the psychrometric chart. They are not hard to find on the net, and it is reasonably self evident how to use the thing. As a note, if it is cold and humid, we tend to describe it as "clammy". Hot and humid as "muggy". I'm not sure of the health issues you are looking for, and it's not an area I have any more info than the uninformed. Humidity and de-humidification is something I might be able to help with. Sometimes it's done with dessicant crystals, ie direct absorption, but the traditional method is to over cool the air well below dew point where the moisture condenses and drops out as condensation, dew if you prefer (so there is a lessor absolute quantity of water vapor in the air, even though it is 100% RH) then re-heat it. With less water vapor, the RH has reduced. It's pretty energy inefficient. Oh, the effect of wind movement is a different thing again, but generally impacts perception rather than the actual "humidity". I can run through that if that is what you are looking for.

Studiot Hope you are still happy to talk on an old thread. Let me try to pull together what I think I have picked up so far. A molecule's reaction to EM depends on it's structure, shape and bonding. CO2 is a linear molecule so it's vibrations are waggling and stretching. These motions make it unresponsive to the visible spectrum but responsive to IR. Non-linear molecules don't react to IR (but do react to visible light?) - which covers water. I would however have thought that nitrogen and oxygen were also linear? Specifically to CO2 there are three frequencies - am I reading that graph correctly? Asymmetric being something close to 3900-3400; symmetric 2400 and bending 900? Can those frequencies be related to the vibration modes called waggling and stretching? I follow part only on the resonance discussion - the aerial analogy doesn't help me as my understanding of an aerial is as rudimentary as molecular vibration. Though I note the discussion that the increased energy is not related to electron states - without following this too closely, it would then relate to movement between parts of the molecule - ie the bonding. Anyway, hope you have your red pen ready. [ps to the many other posters here, I am not ignoring your content which has also been very interesting. Fire away at will! I am just going to avoid flights of fancy such as arguing about waves in the in absence of a medium, etc. Studiot has laid out a path that connects with me is all.] EDIT: in the chem tube pictorial of CO2 vibration, the graph indicates several specific levels that I take to be energy levels ie VB = 0; v = 1; v = 3; Dissociation. I had thought this to be like electron energy levels, in steps, but clearly NOT electrons. Do the vibrations come in energy steps also? And does dissocation mean what it says? I would have that would require extraordinary energy but the step doesn't look huge.

Thanks Strange. As an interested novice (interested observer lol) this was an "AHA!" moment for me.

Browsing my favourite Christmas gift - the Feynman Lectures - I remembered this thread. So. This is Richard Feynman, original lecture from, I think, 1961, "The relation of Physics to other sciences". Lack of space also prevents our discussing the relationship of physics to engineering, industry, society, and war, or even the most remarkable relationship between mathematics and physics. (Mathematics is not a science from our point of view, in the sense that it is not a natural science. The test of it's validity is not experiment.) We must, incidentally, make it clear from the beginning that if a thing is not a science, it is not necessarily bad. For example love is not a science. So if something is said not to be a science, it does not mean that there is something wrong with it; it just means that it is not a science.

Apologies on the delayed response - Studiot, plenty of things arising, lol. I need to wrap my head around the info before asking for expansion. back at work, with exams cominng means I'm a bit time poor. Just wanted to say thanks for now.

OK another interesting topic seemingly come to an end. Could I ask, as at least one non-expert who has been viewing this thread with interest, could someone complete the loop? Studiot - you proposed working through this with classical wave theory. Is it possible to finish that thinking? Cheers guys.

Haha! I did realise that Planks constant was a unit, but I also thought that it was a an actual number. So, not the case. Cheers

HallsofIvy Sorry mate, I hadn't checked in as I simply thought it was a case of a specialist dumping on a basic novice. SO have to say I was very wrong in that assessment and thank you for your response. FWIW I wasn't suggesting that all irrational numbers are prime square root, pie being an obvious example. In fact I would of thought that there are many, many irrational numbers, more than rational I guess.Yes I AM interested in the relationship of polynomials to transcendental numbers. But education must prevail for a while before it means much more to me than an abstract observation. I'll get there. With persistence. By the way, maybe someone here can answer a question I asked of a maths lecturer earlier this year but without clear response. Is plank's number irrational? I get that "plank-bar" would be due to the involvement of pie, but what about planks number itself? (apologies to Vovka for the hijack.)

I said I wasn't an expert. I also did not say it was "the definition" but "pretty much a definition". This might not be math, but it is English. I guess that verbal qualifiers can be tricky things. Out of interest, can you name a root of a prime that is rational? Genuine interest if the answer is yes.