is blood blue before it touches air?
138869
Blood is red. Blood is ALWAYS red. There is a misconception that blood may at some point be blue because in biology text and models blood leaving the heart is frequently represented as blue because it has been oxygenated. Why blue for oxygen - it comes from the Greeks who realized there was oxygen in the sky and mistakenly thought oxygen gave the sky its blue color. There is also the common cliche "Blue blood" someone who is rich.
74137
Neither is blue. \n\nThe SKY\nThe blue color of the sky is due to Rayleigh scattering. As light moves through the atmosphere, most of the longer wavelengths pass straight through. Little of the red, orange and yellow light is affected by the air. \n\nHowever, much of the shorter wavelength light is absorbed by the gas molecules. The absorbed blue light is then radiated in different directions. It gets scattered all around the sky. Whichever direction you look, some of this scattered blue light reaches you. Since you see the blue light from everywhere overhead, the sky looks blue. \n\nThe Sea.\nParticles and solutes can absorb light, as in tea or coffee. Green algae in rivers and streams often lend a blue-green color. The red sea has occasional blooms of red Trichodesmium erythraeum algae. \nParticles in water can scatter light. The Colorado river is often muddy red because of suspended reddish silt in the water. Some mountain lakes and streams with finely gound rock, such as glacial flour, are tourquise. Light scattering by suspended matter is required in order that the blue light produced by water's absorption can return to the surface and be observed. Such scattering can also shift the spectrum of the emerging photons toward the green, a color often seen when water laden with suspended particles is observed. \nThe surface of seas and lakes often reflect blue skylight, making them appear bluer. [[[ Montana reflection.]]] The relative contribution of reflected skylight and the light scattered back from the depths is strongly dependent on observation angle.
522474
normally blue because the oxygen diffuses blue light most.
592905
The sky is blue partly because air scatters short-wavelength light in preference to longer wavelengths. \nWhere the sunlight is nearly tangent to the Earth's surface, the light's path through the atmosphere is so long that much of the blue and even yellow light is scattered out, leaving the sun rays and the clouds it illuminates red, at sunrise and sunset.\n\nso\n\nAn old weather predicting adage rhythmically states: \n\nRed sky at night, Sailors' delight.\nRed sky in morning, Sailors take warning. \n\nHumidity in the air is indicated by red skies at sunset-- red sky at night-- or, at sunrise-- red sky in morning. The forming raindrops scatter the short-wavelength blue light so that only the long-wavelength red light reaches the observer.
518383
The "oxygen saturation" is measured with a pulse oximeter that is non-invasive and just attaches to your finger.  It tells us the percentage of your hemoglobin that is completely bound with oxygen.  The device is actually a type of "sphectophotometer" if you ever studied chemistry.  A previous writer is correct in saying that it basically ensures that your body is well oxygenated.  It is obviously a very important monitor that is required in all anesthetics given.  Before the days of measuring oxygen saturation, anesthetists had to go by such signs as the color of your lips, etc.  which is not nearly as accurate.  In addition, the appearance of blue lips (or cyanosis) is a very late finding and means that the oxygen levels are dangerously low.  Pulse oximetry, together with other monitors has made anesthesia safer than it ever had been before.
285388
bright red in the beginning....it should look fresh (without sounding gross)\n\nas your period comes to the end...it should look a little darker...the blood is older and has been exposed to more oxegen.\n\nrest assured that both are normal
357307
Cells are colorless, so if we want to see them, we need to color them.\nMethylene blue basically stains membranes, so you can use it to distinguish one cell from the other, sometimes you can get a light stain in nucleus, but mainly stains external membranes in vegetable cells, the called cell wall (not present in animal cells)
434873
i dont know what u mean by the second question but for blood, i just make a tiny circle and make it red so it looks like blood.
145430
I would say red.  The brighter red the colour of the blood, the more oxygen it carries. The darker its color, the less oxygen it carries.  Arterial blood is generally a brighter red because it has recently passed through the lungs. Venous blood is generally a darker red because it has passed through the capillaries where the oxygen is transferred from the blood to the tissues.\n\nSome people think that blood inside the body is blue but this myth probably started when someone drew a chart of the human blood system and colored the arteries red and the veins blue. This myth has been around a long time and seems to have a life of its own.
364291
Haemoglobin, which is made red by the presence of iron. Just think of your blood as rusty.
419726
The blue color of the sky is due to Rayleigh scattering. As light moves through the atmosphere, most of the longer wavelengths pass straight through. Little of the red, orange and yellow light is affected by the air. \n\nHowever, much of the shorter wavelength light is absorbed by the gas molecules. The absorbed blue light is then radiated in different directions. It gets scattered all around the sky. \nOn Earth, the sun appears yellow. If you were out in space, or on the moon, the sun would look white. In space, there is no atmosphere to scatter the sun's light. On Earth, some of the shorter wavelength light (the blues and violets) are removed from the direct rays of the sun by scattering. The remaining colors together appear yellow. \n\nAs the sun begins to set, the light must travel farther through the atmosphere before it gets to you. More of the light is reflected and scattered. As less reaches you directly, the sun appears less bright. The color of the sun itself appears to change, first to orange and then to red. This is because even more of the short wavelength blues and greens are now scattered. Only the longer wavelengths are left in the direct beam that reaches your eyes.
398109
Blood is NEVER blue... Your veins are gray, with red blood within, it appears blue.\n\nYour face loses color due to the lack of hemoglobin, which is present in blood.\n\nThree things determine pigment.\n\nKeratin-Yellows\nMelanin-Browns\nHemoglobin-Reds\n\nEveryone has all three of these pigments present in their skin, when a light-skinned person deprives an area of oxygenated bloodflow, the red tint is removed due to the lack of hemoglobin.\n\nHope this helps!
27910
first of all, to Paranoid Princess:\n\nwhoa, whoa WHOA.  just a minute.  the sky is not blue because there's liquid oxygen in the upper atmosphere.  that's just retarded and you shouldn't go presenting bizzare mis-truths as fact when they *aren't* fact.\n\nhere is a profile of temperatures at various altitudes:\nhttp://www.windows.ucar.edu/tour/link=/earth/images/profile_jpg_image.html\nas you can clearly see the lowest temperature is about -100C.  oxygen liquefies at -182C at normal pressures (reference: http://www.ucc.ie/ucc/depts/chem/dolchem/html/elem/elem008.html ), and even lower temperatures at the low pressures in the upper atmosphere.  PLEASE don't present some bizarre fiction as truth to someone who isn't well-informed enough to know that you're simply fabricating nonsense from thin air.  if you have simply been misled by someone else, at least try to do a marginal amount of research before answering a question on something you don't know much about.\n\nthat said, to the original asker:\n\nthe sky is blue because of a phenomenon called "rayleigh scattering", which occurs because the molecules of air (mostly N2 and O2) happen to be the right size to scatter blue light in all directions.  some of this blue light reaches your eye after being re-scattered again by a second molecule, sometimes all the way across the sky.  \n\nthis is also why the sky turns red at sunset - at low angles, the sunlight has to travel a longer distance through the atmosphere, and by the time it reaches your eye, a lot of the blue light has already been scattered away, leaving yellow orange and red.  (i have yet to hear any explanation of why the sky doesn't turn green between daytime and sunset, though.  still tryin' to figure that one out.)\n\nanyway here are some home/school experiments designed to illustrate rayleigh scattering:\nhttp://www.physics.brown.edu/physics/demopages/Demo/optics/demo/6f4010.htm\nhttp://www.chaosscience.org.uk/dem/public_html/article.php?story=20050222224622239\nhttp://teachers.web.cern.ch/teachers/archiv/HST2002/smallexp/krug/Rayleigh.htm\nhttp://bulldog2.redlands.edu/facultyfolder/deweerd/research/scattering-AJP.pdf\nhttp://www.ktca.org/newtons/9/sky.html\n\nalso, a nice page illustrating rayleigh scattering:\nhttp://hyperphysics.phy-astr.gsu.edu/hbase/atmos/blusky.html\nand a slightly more advanced version:\nhttp://world.std.com/~mmcirvin/bluesky.html
142088
Bruises, also known as contusions or ecchymoses, are what develop when your skin gets smashed for some reason but not broken. The soft tissues are damaged, the little vein or capillaries under your skin rupture and the blood puddles up under your skin. That's why a new bruise is red. It's all that nice red blood pooling up.\n\nEventually your body goes to work and starts metabolizing the spilled blood. After a couple of days, the bruise will look black or blue. By the sixth day, it goes all greenish on you, and then a few days later, it will turn sort of yellowish brown. It all has to do with the chemical changes involved in metabolizing that blood and getting things fixed up in there. \n\nAnd the reason that older people seem to bruise more easily is that their veins and capillaries and so forth grow more delicate with age and are more easily ruptured. \n\nhttp://www.azcentral.com/news/columns/articles/0105clay05.html
386818
Sounds like you may be starting.  Sometimes the blood can take on a brownish tint.
95744
Because the air particles reflects different colors from light. The blue color wavelengths are so long that we see them without seeing the other colors.\n\nAt least that's what I remember, I think.\n\nAnd the sea looks blue because of the reflection from the sky. If you run your sink, the water is not blue. D:
90472
It's not the reflection of the ocean. \nSky is blue because the blue wavelenght of sunlight is scattered by oxygen and nitrogen molecules in the air. This is known as Rayleigh scattering. The absorbed blue light is then radiated in different directions. It gets scattered all around the sky so wherever you look, some of this scattered blue light reaches you.