jab2

Zinc actually corrode easier than iron. Galvanizing iron or steel protects it because the corrosion is first confined to the zinc layer as it acts as a sacrificial anode, that is until the zinc has been corroded away. The corrosion product of zinc is Zn(OH)2. Some reading: http://www.totalmateria.com/Article40.htm http://www.totalmateria.com/articles/Art60.htm http://www.ce.sc.edu/deptinfo/members/faculty/ray/web1/Ugrad/ECIV%20303/Corrosion/Set2%20Chemistry%20of%20corrosion.pdf Oeps, exchemist beat me on the draw.

Yes, the "light" travel as photons through space, only when it interact with the eye and the optical signals are processed by the brain do we experience the sensation we call "colour".

Something that is often neglected in discussing vision is that what the optical sensors in the eye experience are not equal to what the brain makes us think we see. Our brain not only take input from the eyes to form a "picture" but other stimuli and even historic information too, thus giving us a picture vastly richer in detail that what was passed down the optical nerves. For a species who has grown up with paper we will nearly always see paper as white, even if the light iluminating it is not what we call "white light", because we "know" from experience paper is white. So even if the paper is not illuminated with white light our brain "adjust" the information to still tell us it is white. This is why camera manufacturers must build a white balance feature into their cameras as the camera sensor show what it "sees" without adjustment, thus white paper that is not white. Take a photo of the same piece of paper under sunlight, fluorecent light, and tungsten light without the colour balance adjusted, and see how the colour of the "white" paper differ. So to get to your question of "white" and "colourless", I think we call light which is a mix of all frequncies "white", simply because we have decided to call a surface which reflect all frequencies in the same ratio as the incoming light "white". Vision is actually a facinating field. We "see" so much more than what the eye see.

Craig, very much so. Many years ago I was observing a blind person navigating the passage (think you Americans call it hallway) in a house. He was told his room is the second door left and the bathroom the first door right, and given a description of the rooms, and where the furniture, toilet, bath, etc are. I asked him how he manages that and he said, "I see by sound". He had me closed my eyes and showed me what he meant. For the untrained ear it is difficult, but once you know the principle, it is not that hard to navigate in the dark inside a structure with hard (reflecting) surfaces. He started by having me make click sounds as I move down the passage, but once you get the hang it is even possible to hear the "hole" of a doorway just by ambient noise. Later you start getting a sense of the topology of the rooms too.

I was just sent a link to photos taken by the LROC of the moon landings sites by a friend. Wonder what the denial explanations to this will be.

I find the list rather curious, or rather the choice of words. My training is analytical chemistry and I worked for a number of years making, or rather testing, military explosives and propellants. I'm not in the trade anymore, but still have a healthy interest in the subject. My other interest is nuclear physics, and the history of nuclear weapons. So I have a long history of Google searches on these subjects. Have I triggered a response somewhere yet? I'm positive of that, but since a background check would most likely ID me as not being a threat (OK, one never know with the stories one read about the rather disjointed thinking of your TSA), I cannot believe the number of words which is missing from that list. There are no reference to any chemical name of a major explosive, indeed it does not even have the general name of the explosives, and the worst, it does not even have the word, explosives, by itself. Really, this can't be the correct list, or some people are dead at their desks. :blink:

Using FF too, and the link wors for me. Little off topic. I'm not a great fan of roses, but find the "old", "native" rose species, which has a more simple flower structure than garden roses, quite attractive. I notice a few states have a Rosa as State flower, and all of a rather simple structure. Wonder if one can obtain them in the trade. That said, only flowers with mega potential are carried by the trade here, and it is rather impossible for an individual to import plant material to South Africa. Looking at the drawing of the Indian Paintbrush (Castilleja Linariaefolia) of Wyoming, it reminded me of our Mimites Cucullatus, a totally unrelated plant. Looking at the pictures on the Castilleja page on Wikipedia there is however no resemblance between the two. The photo of C. Lanata however bare some resemblance until one look closely.

This bunch was on request from a friend to post some of my plant shots. I'm now using Adobe Lightroom to catalog my photos so are busy getting ID together. So most probably there will be IDs in future.

So is this thread dead, or what? OK, with most of you in the mids of winter I assume flowers is not too high on the priority list, but then there is always flowers from elsewhere. There are a few members who know a little bit about the South African floral splendor, or rather the flowers of the Cape Floristic Kingdom. The CFK is the smallest of the 6 floral kingdoms recognized in the world and is blessed with a extreme diversity of species of which 69% are endemic. The area is about 46 000 sq Km and has over 9000 species. Table Mountain (Cape Town) has more species than the whole of the UK. Of the genus Erica the CFK has over 600 species, where the rest of the world has 26 species. For more info read this wikipedia page. To illustrate some of this splendor I have posted a number of images to a public album on Facebook. So have a look here and enjoy my garden in nature. PS: Please let my know per PM if you have difficulty in viewing the FB album.

So is this thread dead, or what? OK, with most of you in the mids of winter I assume flowers is not too high on the priority list, but then there is always flowers from elsewhere. There are a few members who know a little bit about the South African floral splendor, or rather the flowers of the Cape Floristic Kingdom. The CFK is the smallest of the 6 floral kingdoms recognized in the world and is blessed with a extreme diversity of species of which 69% are endemic. The area is about 46 000 sq Km and has over 9000 species. Table Mountain (Cape Town) has more species than the whole of the UK. Of the genus Erica the CFK has over 600 species, where the rest of the world has 26 species. For more info read this wikipedia page. To illustrate some of this splendor I have posted a number of images to a public album on Facebook. So have a look here and enjoy my garden in nature. PS: Please let my know per PM if you have difficulty in viewing the FB album.

Interesting. I grew up with an Afrikaans word, karfoefel, which loosely meant what a boy and girl do, which they should not do, when out of sight of the elders. Acts not necessarily of the sexual kind yet, but definitely leading to it. Could it be related, as listening to some people, one can call their bedroom antics a commotion. :)

I guess I did, since you only mentioned it AFTER your "They assume it because it is true." statement to Banjofrog which was the trigger of my initial response. In SA the age of consent is16 years. I'd say we are on the same wavelength here. Maybe my use of the word sex is not strictly correct since English is not my mother tongue, but I see sex as copulation between consenting people who both get a stimulation benefit. If one partner is under duress in my book I would describe it as rape, not sex. Yes, but measured by the norms of current western societies, it would be disruptive to the benefits that a tight, caring family are suppose to give.

According to what data? Here in SA it is not uncommon for girls in the poorer communities to be sexually active at 12 years of age. Would it scar such girls emotionally considering they enter into sexual relations by free will with their peers? If your life is a hell because of poverty, the high of sex is just about the only high you know, and it is free. So can feeling good be harmful? Now if this 12 year old move to a sexual relation with a 20 year old, what would be different to the relation to scar her emotionally? And if she turns 30 and have a relationship with a 38 year old, still the same age difference, would it still be harmful? Make no mistake, I do not condone it when youngsters are sexually active, but the issue is not so clear cut as society wants to make it. During the Middle Ages the age of girls on marriage, and therefore their sexually active age, was way lower than what society deems acceptable today. Was the average Middle Ages women more traumatized than today's woman fighting for a place in the corporate world? Nature is not perfect, but it is sometimes worrying that we try to out think nature and want to prescribe to it. Eg our diet today is totally off from our digestive system design, with very visible results. But back to the subject. Would nature be so far off the mark that it enters a girl into her reproductive cycle, yet her brain is still not ready for 7-9 years to deal with the issues of reproduction, thus somehow have to juggle hormonal needs with abstinence for 8 years?

I assume it is because the end result of the manufacturing process give a mixture of chain lengths, and since there would be not a huge difference between performance for end use between the different lengths, separating them will be senseless and an unneeded expense.

Sakhel, as you most probably know the Eusapon range of products are made by BASF as surfactactants and degreaser for the leather manufacture industry. (I do not know if it is cross industry used too). The Technical Data Sheet in my book state it IS a ethoxylated fatty alcohol with a small amount of solvent. Neither product is identified, but this is in line with most propitiatory products we use in the leather industry. If you are concerned about the environmental or health status of the product, the best is to contact your local BASF representative and post the question to them. If you have a legal obligation to know the constitution of the product, they will supply it.

Closeup of a female conebush ( Leucadendron spp) cone showing individual flowers. Leucadendron are a genus of the Proteaceae family. The cone is about 15mm in length. Pardom the shallow depth of field.

After a short drive in the Klein Karoo region of South Africa I shot the following. See my album at http://scienceforums...display__detail

OK, taking a back check. Eucomis is what we call the pineapple lilly. Very pretty flower. I have one in a pot and will try and get a picture when it flowers. Well it is time I hijack M's thread and show a few SA species of flowers. See my album at http://scienceforums...display__detail