Kaeroll

Hi all Have a quick question... I'm writing up my year's project work, and shockingly enough it involves a handful of straight line graphs. Excel kindly provides me with a line of best fit and its corresponding equation, along with a value called R-squared. (Mine is 0.537... not too good) I know this is a measure of how good the fit is, but I'm not sure how to explain this in my write-up. I won't need detail on it, just a brief statement to the tune of "The correlation isn't very good". How should I refer to this R-squared value? I know very little about statistics. Cheers Kaeroll

Gas from your hob and oxygen from the air?

Fantastic. Thank you very much. Kaeroll

Hi, Thanks for your reply. That confirms my interpretation. I'm not sure how to explain it though - I'm not familiar with second order effects (I believe it came up once in a lecture on 2D spectra... I switched off). I take it this effect is the cause of the abnormal intensities? Cheers Kaeroll

I second this. It also works for irritating housemates.

Handy way to remember this: when you grab your pizza from the oven without oven gloves, which way does the heat flow...?

Hi all, I have a problem interpreting a spectrum I ran recently. It's a simple proton NMR of 2,3-dimethylbutan-1-ol. I don't have access to a scanner so unfortunately I can't post the spectrum here, but a near-identical version is available at sdbs. (Which, by the way, is an excellent resource) If anyone's interested in helping with this problem I recommend accessing it there. Its CAS no is 19550-30-2. I've assigned (hopefully correctly) all peaks other than the peak at 3.5ppm. On my spectrum it appears to be a doublet of quartets, with non-binomial intensities, but I'm not sure. From one end to the other, I see two peaks of roughly equal intensity, two of double intensity, all with equal J values; this is followed by a larger gap, and then the first multiplet's mirror image. I believe this peak arises due to the protons in the [math]CH_{2}OH[/math] group being coupled to the proton at C2, and then further coupled due to the methyl group at C2 (i.e. coupling beyond three bonds). If the intensities were binomial I'd be convinced this is so. Can anyone offer any advice as to why it's non-binomial, or where I'm wrong? Cheers Kaeroll

That's actually a very nice point. Think I might borrow that one off you.

I came to that conclusion about thirty seconds after making that post. Apologies for any confusion to the OP...

I think homeopathy thrives off a trend against intellectualism and authority. This is just a personal observation, I have no other sources to back this up, but I believe we currently live in a society where the 'experts' and those in a position of authority - be it legal, medical, scientific, etc - are mistrusted on principle. The prevalence of conspiracy theories (9/11, HIV, etc) seems to support this. In this country there's been a trend against vaccinations after the MMR controversy. A minority of parents shunned all vaccinations for their kids because "THEY" hadn't researched them properly, or whatever. I think homeopathy buys into this kind of sentiment; "THEY" don't want real, natural remedies like homeopathy to hit the market because it will put THEM out of business. Doesn't matter that a battery of tests show it's ineffective - of course "THEY" would say that! I realise my above point is fairly poorly articulated... it's a thought I'm still sitting on for a while. Responses welcome though.

Unfortunately, in this country at least (the UK), critical thinking skills seem to be at an all-time low. I dread to think of the situation in the average American household.

Indeed! The internet is a wonderful place, truly the intellectual lubricant science has always needed. My current work focuses on reversing the trend of darkening of toast, which I believe may be related to entropy and the arrow of time. I don't want to bore you with the details, so in brief I am testing various substances as a sort of protective layer. So far, my results are inconclusive; marmalade has proved ineffective, and I found Marmite actually increases the rate of disappearance!

I'm guessing you're meant to use the boiling points as a guide to polarity, assuming the molecular weights are all within a tight range. I would tentatively suggest that cyclohexane is more polar than benzene due to the symmetry of benzene, but I've not seen any data on this so it's merely speculation. Edit- scrap the second half of that post. I'm wrong. Need coffee before posting here...

I discovered this is not a good idea about eight hours after that post. I still feel a little rough... though I wasn't actually sick. Never, ever again. (You only turn 21 once though...)

Au contraire! I too have been investigating the phenomenon of dark toast. I observed that in the presence of certain housemates with a penchant for burnt pizza, dark toast left unattended becomes completely invisible. Interestingly, the only remaining fragments (or 'crumbs') are light or at most semi-dark. The obvious interpretation is that the housemate has eaten the toast - but I extracted a sworn statement from the subject that this is not the case. Most interesting.

Well... regardless of the numbers, this very post is proof that one can have 21 shots of vodka over four hours (not one, ah well) and still be able to type coherently. Experiments: why science is fun.

Seems that alcohol's a bit of a theme in here, but here goes... If one were to consume, say, 21 shots of vodka (or an equivalent spirit) over an hour, roughly what would one's b.a.c. be? I have absolutely no idea how to work this out, even to a ballpark estimate. I'm aware it depends on a lot of variables but hey, run with it. Kaeroll

He'll be here all week here, folks. Try the fish.

Murphy's law dictates, amongst other things, that buttered toast lands butter side down.

Yes, elimination would likely compete. The product ratios depend strongly upon reagents and conditions though. I'm not sure about your second question. What alcohols and alkyl halides are you thinking of? Those conditions should allow the substitution reaction to occur. Again, the product ratios are dependant upon the reagents and conditions, but KOH should be a good enough base to effect the substitution.

Stop being funny. I can't give reputation points fast enough to keep up, and feel bad going off-topic just to say "zing!"

Home experiment: strap a piece of buttered toast to a cat's back (butter side up) and drop from a height. Murphy's law vs. Darwin.

Did I ever tell you I love you?

You're the mod. Use your stick of moderation to put an end to it.

This demands one response and one response only: Tits or GTFO.