aman Posted December 31, 2002 Posted December 31, 2002 Is dark skin an advantage in space against radiation? Would black astronauts be safer on a Mars voyage? Just aman
Matzi Posted January 1, 2003 Posted January 1, 2003 I think it is defintely so, though I suppose the protection is mainly better against UV radiation. I would doubt that dark-skinned people are more resistant against alpha-radiation for instance. I do not know exactly what kind of radiation is of significance for astronauts but the NASA and the other organisations will certainly have considered this already.
fafalone Posted January 2, 2003 Posted January 2, 2003 The radiation danger in space is very extreme. they would be better protected, but it doesn't matter anyway. if 2 people have a nucelar bomb dropped on them, the one with body armor is better protected, but they're both screwed anyway. the space suits astronauts wear make skin color irrelevant anyway because of the protection they offer.
Ahmad Posted January 3, 2003 Posted January 3, 2003 Besides that, pigmentation only protects you from visible light spectrum, not from UV radiation.
Matzi Posted January 5, 2003 Posted January 5, 2003 Originally posted by Adam First man was not black , thanks. I still would not exclude that. I mean why shouldn't the first man have been black?
Soulja Posted January 5, 2003 Author Posted January 5, 2003 Originally posted by Matzi I still would not exclude that. I mean why shouldn't the first man have been black? Exactly. You cannot go out making statements as if they were fact with nothing to support yourself. As Nietzsche said "There are no facts, just interpretations". Anyway in Logic we call what Adam has said as a "non-argument" because it has no basis what so ever. Just Soulja
Matzi Posted January 5, 2003 Posted January 5, 2003 I do totally agree with you (eventhough I think Nietsche's quotation might be mostly refering to philosophy). Additionally, there are certainly more arguements against Adam claim. I mean, where did "the first human" live? Can we answer this question yet (will we ever?)? Certainly not. Besides, I think it is now widely accepted than man evolved from primates. Most of thm have dark skin (now), haven't they? They have this dark skin because it's of advantage for them. So why shouldn't the first human which, since we believe it evolved from primates, must have lived in some geographical neighbourhod to these primates have also adapted this kind of protection (why should he have gotten rid of it?)? Many questions to be answered...
Soulja Posted January 5, 2003 Author Posted January 5, 2003 Originally posted by Matzi I do totally agree with you (eventhough I think Nietsche's quotation might be mostly refering to philosophy). Additionally, there are certainly more arguements against Adam claim. I mean, where did "the first human" live? Can we answer this question yet (will we ever?)? Certainly not. Besides, I think it is now widely accepted than man evolved from primates. Most of thm have dark skin (now), haven't they? They have this dark skin because it's of advantage for them. So why shouldn't the first human which, since we believe it evolved from primates, must have lived in some geographical neighbourhod to these primates have also adapted this kind of protection (why should he have gotten rid of it?)? Many questions to be answered... I think philosophy and science go hand in hand. As for Nietzsche's quotation, i have commented on it before, here is a little slice of what i said: Nietzsche said “There are no facts, just interpretations.” A fact is defined as “Something demonstrated to exist or known to have existed, something believed to be true or real”. So if there are no facts, nothing exists or is believed to exist or, is true or is real. The definition of nothing is “Something that has no existence, not anything.” The first word of the definition is ‘something’. The word ‘something’ indicates that ‘nothing’ is a thing. And a ‘thing’ is of existence. So logically this evidence would prove that ‘nothing’ exists, but there is a contradiction when it has ‘no existence’. So we have a paradox, a logical contradiction. The evidence that nothing exists is the ‘something’. And the evidence that it has no existence is the ‘no existence’. So it is impossible to prove or disprove that “There are no facts, just interpretations,” but in the second part of the definition it says “not anything”. Anything is defined as “Any object, occurrence, or matter whatever.” So if nothing exists, than no object, occurrence or matter exits. This proves that if there are no facts this world is not real. This proves that it is logically possible for nothing to exist. If we look back at the definition of a fact it says “something believed to be true or real”. The definition of belief is “to accept as true or real” and real is “Existing objectively in the world regardless of subjectivity or conventions of thought or language.” This proves that if there are no facts, nothing is believed to be true or real. Therefore, a fact does not have to be true, just believed to be true. This means that in order for there to be no facts, no one must believe in anything. People do believe in things though, this proves Nietzsche’s statement wrong.
Matzi Posted January 5, 2003 Posted January 5, 2003 Hm, I still think that especially in sciences there are at some point of time facts that we discover. In a way these facts must have resulted from interpretations, there you are right. And I see the problem: When becomes an interpretation a fact? I think everyone has to see it his way... To the existence thing: Is it - philosophically - possible to prove that something is incorrect? I mean, philosophy cannot ever result in a definite and undoubtable answer (wouldn't this be a fact?), at least that's what I learned at school. So "prooving that existence is not real" or something similar to that is in a way only an idea.
Ahmad Posted January 6, 2003 Posted January 6, 2003 An entity is your interpretation of something. If your interpretation is not fomulated correctly, then what you are percieving as a thing is actually nothing. We call it a thing because this is what we first would think is, but that's not actually what it is. After proving that it cannot exist, then it must be considered as nothing. Now, don't confuse the definition of the word 'nothing' as it would be written, seen, or even percieved, with a non-existing thing. Note: if your interpretation of something is absolutely correct, then that is a fact. A basic set of facts must exist in the first place for us to be able to conclude new ones. If we interpret our observations, then we are taking our observations as facts. BTW, it is too hard to write philosophy in English when it is a second language! I wish I could write more, but I know I will be misunderstood.
Matzi Posted January 6, 2003 Posted January 6, 2003 Originally posted by Ahmad [...]BTW, it is too hard to write philosophy in English when it is a second language! I wish I could write more, but I know I will be misunderstood. I know what you are talking about.
kenel Posted January 22, 2003 Posted January 22, 2003 Two well preserved, recently discovered, ancient skulls were found in Europe. The French paleoanthropologists carbon dated, and proved the skulls to be nearly Six Million years old, which is 1 million years older than the previously thought "original man". This challenges the "out of Africa" theory, and could prove that man was not originally from Africa (or black). <source: article from Laurie Goldman of Popular Science>
Glider Posted January 22, 2003 Posted January 22, 2003 Originally posted by Ahmad Besides that, pigmentation only protects you from visible light spectrum, not from UV radiation. Melanin does protect against UV radiation. Tanning is a defence mechanism; pale skins burn, tanned skins are protected. This is the basis of the main theory concerning the advent of white skin. Vitamin D is produced through the action of sunlight (UV) on the skin. This is our ONLY source of vitamin D. Black skin takes around 4 times the intensity of UV to produce the same amount of vitamin D as white skin. This is fine in equatorial regions. However, as the species migrated north, the intensity and duration of sunlight reduced. Those individuals with paler skins then had an advantage over those with darker skins, as they could maintain levels of vitamin D where those with darker skins could not. The problem of vitamin D deficiency still exists in dark skinned people who live in more northern regions, and is pronounced in some individuals, notably those who, in line with their religion, spend a great deal of time completely covered. Problems associated with vitamin D deficiency are hair loss, a loosening of the teeth, rickets and skin problems. In the UK for example, a white skinned person synthesises sufficient vitamin D only from around June, to about halfway through september. The amount of vitamin D produced in that time has to last the individual througout the winter when the sun (even when it's out) is too low in intensity and duration.
Piccolo Posted February 2, 2003 Posted February 2, 2003 I dont wanna sound racist lol but if the first man was black why isnt he extinct since they evolved into other races.
PogoC7 Posted February 2, 2003 Posted February 2, 2003 I watched a show on Discovery about the beginning of the human race. They say we began in Africa, then moved to the middle east, then troughout the globe. So if we began in Africa. Maybe he has Black. The Discovery found the first human was a black women. http://dsc.discovery.com/convergence/realeve/realeve.html The show was called "The Real EVE"
Piccolo Posted February 2, 2003 Posted February 2, 2003 I saw something similar to that, it showed that their was more discoveries older than the woman they found.
Mastermold Posted February 2, 2003 Posted February 2, 2003 It is a misconception to believe that just because an ancient organism evolved, they should be extinct. Primates gave rise to homo-sapiens, but the primates of 6 million years ago were much different than the primates of today. The point is that if the first humans were black (which most evidence shows), then many black humans would live through lineages that did not undergo "random mutations" that gave rise to favorable conditions in other humans such as whites or asians. (Pardon my non-PC tone, but we are all inelligent people... absolutely no offense is meant) But that also does not mean that black people are necessarily LESS evolved, it means that they received other random mutations or natural selection favored them in other ways. Any organism alive today is a true testament to its ancestral strength because it evolved from a single lineage beginning with the first single celled organisms. Also, an interesting note is that UV radiation damages genetic material in a very distinct way. The energy allows bonds to form between pyrimidine bases (Cytosine and Thymine) in DNA, and this severely interferes with DNA replication, which in turn initiates DNA repair, or cell death. But the scary thing is that millions of skin cells would experience that damage and most if not all would fix it or just die. But there are the rare exceptions where if a gene is damaged, it destroys the cell death process and causes mutant replication and cancer. I don't spend a lot of time in the sun.
aman Posted February 2, 2003 Posted February 2, 2003 There's a tribe in Africa that can be traced as our earliest common starting point and it's people are very unusual because of all their diverse racial characteristics. All are dark skin but some could be Chinese, American Indian, or even very tan caucasions. They still are nomads and speak with a clicking language. There was a special on NOVA last week about it. Just aman
Piccolo Posted February 2, 2003 Posted February 2, 2003 Abobo was the first man in Africa he was discovered recently by Nintendo.
Aardvark Posted February 20, 2003 Posted February 20, 2003 Just a quick note, primates have white skin, shave a chimp and have a look. Also black skin's probably not primarily an environmental adaptation to the sun. Current theory suggests skin colour is more dependant on sexual selection. An example being Tasmanian Aboriginals who lved in a relatively cool shaded climate and yet maintained just as dark skins as Aboriginals in Northern tropical Australia. As for the question, did the first true humans have dark skin, personally i doubt it but no strong evidence either way.
Glider Posted February 21, 2003 Posted February 21, 2003 Originally posted by Aardvark Just a quick note, primates have white skin, shave a chimp and have a look. Then shave a gorilla and compare. Gorillas are primates too. There's a tribe in Africa that can be traced as our earliest common starting point and it's people are very unusual because of all their diverse racial characteristics. All are dark skin but some could be Chinese, American Indian, or even very tan caucasions. They still are nomads and speak with a clicking language. These are the bushmen of the kalahari. They are thought to have the longest unbroken genetic lineages of all humans on earth (i.e. have had to contend with almost no external interference by other peoples), and have remained largely unchanged in their ways for millenia. Unfortunately, they are in danger of extinction due to modern interference and the spread of farming (as are so many other things). In physical characteristics, they are short, and as you mention, have a variety of skin tones. However, they are thought to have migrated South from Eastern Africa at about the same time as other people migrated North. As they have an unbroken lineage back to that time, they may be regarded as most closely resembling our common ancestors, but in their own way, they have changed as over the thousands of years too, and they share with everybody else the common lineage originating in Eastern Africa.
Sayonara Posted February 21, 2003 Posted February 21, 2003 Originally posted by Glider Then shave a gorilla and compare. Gorillas are primates too. And yet gorillas live in the jungley shade. How strange.
Glider Posted February 21, 2003 Posted February 21, 2003 Very true, as do chimps. However, these animals have in common a fairly comprehensive covering of hair, which homo sapiens lack (or at least most of them). They also have different skin structure and chemistry to humans, which means they are not strictly comparable. Other animals (e.g. dogs, cats, horses and so-on) also show differences in skin pigmentation. The patterns of melanin production in these animals occurs for different reasons than in humans. They also have different skin structures and chemistry to humans. For example, horses have sweat glands and sweat through their skin, dogs don't. As I mentioned earlier, one of the functions of human skin is the synthesis of vitamin D. In the skin, the precursor substance, 7-dehydrocholesterol, is converted to cholecalciferol (vitamin D3) in the presence of UV radiation. In the liver, cholecalciferol is converted to 25-hydroxycholecalciferol. Then, in the kidneys, this substance is changed into 1,25-dihydroxycalciferol (calcitriol), the most active form of vitamin D that stimulates the absorption of calcium and phosphorous from dietary foods. Whilst we need a degree of UV exposure to produce sufficient vitamin D, too much results in burning and can lead to skin cancer. Tanning (the production of melanin) is a defence against this, and provides protection against UV radiation, thus in darker skins, more UV exposure is required to produce the same amount of vitamin D than in lighter skins.
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