exchemist

I'm intrigued to see that the "thorn", present in Old English, is something used in Icelandic. The other characters I don't recognise. However I must agree with Markus that if you are interesting in discussing science, as opposed to striking an affected linguistic pose, you are better off sticking to the English alphabet. I've just tried to read your post and gave up in annoyance after only a paragraph.

Ssh, don’t tell Lara Knowles.

Good point, and yes, we had that discussion with that person who had a bee in his or her bonnet about microwaving silica gel, some months ago.

Why do you think mineral crystals are fractal in nature?

OK, yes I know that fractals exhibit the same patterns at different scales. But how is that applicable to systems as different as a mineral crystal and a living organism?

Your statement seems to be meaningless. To start with, what is this "complexity definition of invariance of scale"? Where can we find it? Can you recite what it is? Next, having established that, if we can, you need to explain what you mean by patterning, diversity and complexity being related due to this.

OK. Where would scale come into this? Or is this about “scale” , i.e the degree, of complexity?

What “phenomenon” are you talking about, and in what way do you think invariance of scale applies to it?

According to my recollection from the lubricants industry this phenomenon applies to sliding surfaces, rather than just a static contact. It leads to what is known as adhesive wear (as opposed to abrasive or corrosive wear). With sliding surfaces, microscopic asperities come into contact, causing very high pressures and temperatures at the contact zone which leads to microscopic welding of the surfaces at these points. As the sliding continues, these microscopically welded areas are torn asunder. Often this does not occur at the point where the weld formed, so that material is torn out of one or both surfaces. It is often the practice to use dissimilar metals in bearings, chosen so that the welds are weaker than the parent metals. This encourages the adhesions to break without tearing lumps out and thus preserving the surface. (One example is in worm gears, where the worm is usually steel and the gear wheel is bronze. Worm gears have an extremely high rate of sliding relative to rotation, so the issue can be quite acute in such gears.) The purpose of lubricants of course is to keep the surfaces apart and prevent this from happening. It is common practice to add anti-wear or extreme pressure agents - often sulphur/phosphorus containing organic molecules - to lubricants where the nature of the motion does not ensure a constant pressurised film of lubricant to do this, another classic example being the cam followers in an engine. The anti-wear agents decompose under local temperature, adsorb on the surface and form a protective but weak layer, that easily breaks without damaging the parent surface. However one does also get "cold welding" of clean flat metal surfaces brought into static contact. This occurs especially with surfaces exposed under vacuum, so that no oxide layer has a chance to form: https://en.wikipedia.org/wiki/Cold_welding.

Not if all our grandparents had it, surely?

All the features you list are common to a vast range of creatures, so would not be part of this 1-4% you are enquiring about. So we share DNA all of these, even though we are not directly descended from any of them. It is often said we share 50% of our DNA with a banana, even. But my understanding is the 1-4% relates to DNA features found in homo sapiens neanderthalensis but NOT found in homo sapiens sapiens of African origin. As for where it comes from, one needs to keep in mind that H sapiens sapiens and H sapiens neanderthalensis appear to have interbred. So they are not fully separate species. Therefore, if, like me, you are of N European ancestry, it is likely you have some ancestors who were Neanderthals, rather in the way that I have one Welsh great-grandmother.

Thanks, that's helpful. What occurs to me about the graph is that they have chosen a scale and a range that makes the effect look as small as possible. We are in reality concerned with the range from 280ppm (the level at the end of the c.19th) to ~400ppm +/- 50 for scenarios in the recent past, today and the near future. So be useful, the graph should be scaled to show the effects within that range. On that basis it would be clearer that, even assuming the chart is correct, which I can't verify, the effect of an increase from 400-450ppm would be about 50% of the increase from 350-400ppm. So less rapid, sure, but still very substantial, and nowhere close to reaching some sort of asymptote of course.

On another forum a climate change denier posted this graph: At first glance it looks like no more than the expected exponential reduction in intensity with concentration of the absorber predicted by the Beer-Lambert law. Has anyone come across this being used as a counterargument to climate change science, is the implication true that further increases should have a proportionately lesser effect and what relevance does that have to the models used to predict climate change?

Re your first, apparently yes. Re your second, no, but that has nothing to do with anything physical.

As this is the person who once tried to convince members of another forum that you can be strangled by your own thymus gland in cold weather, nothing is off the table. 😄

I thought it was copper chromite that was commonly used as a decarboxylation catalyst.

I note the introduction of a new topic, in an irrelevant manner. This is a tediously familiar pattern.

I don't think you need to be that extreme. I have washed items with strong colours at 40C for years, with absolutely no trouble. But I would certainly not try 60C, at least not in a mixed wash. That's for whites and cream-coloured things (I have some sheets and towels that colour) only - plus those notorious maroon towels, which I have to do on their own, or with red items - I have some red polo shirts. (Towels really do need 60C or they can get smelly after a bit.)

No, you know me better than that.😆

And here comes the next item, in the drip-feed of crap to keep the roundabout of pointless dialogue spinning: dinosaurs.

As does the deliberately erratic spelling, color and colour in the same sentence, phisics (really?) etc. Timewaster.

Do you mean this? 1mm every 5secs would be 1.2cm/minute, so it would take 25mins for your feet to advance 1ft along the bath, by which time I’d have thought the water would be getting cold. But I suspect the phenomenon may involve some unnoticed feedback between the apparent weight of your legs and your muscles, i.e. not a pure physics problem. You may subconsciously relax progressively as your feet move and more of the weight is supported by the water. But it’s a speculation. It could also be some kind of slick-slip due to the movement of the skin, I suppose.

Haha, like “Motor Daddy and the Motor Boat” on sciforums, perhaps. That too became a standing joke.

Was that one of Theorist’s?

Aha, thanks very much. So would it be fair to say QFT is the mathematical underpinning of QED? I suppose it also plays the same role in QCD, doesn't it?