That gives you upper and lower limits of oxygen to allow a burning flame to propagate.chrismb wrote:Can you explain these numbers, please?Giorgio wrote:Flammable limits of oxygen in air by VOLUME:
Lower: 4.0%
Upper: 75.0%
Sometimes a picture is worth thousands of words
Again, symbiotic or instinctive farming (as with ants) or naturally necessary or instinctive fire use as with a as yet identified stupid alien species don't count. We can make a judgement call. We are pretty smart after all.chrismb wrote:Sure, but if you were arrive here on earth and the only signs left by humans were pieces of burnt stuff, then how would you distinguish that from something that happened naturally?Skipjack wrote:Chris, I think you would be surprised about how organized ants are.
Anyway, I would say that you should reconsider the "fire" definition that seedload and I brought forth. There really is not other animal that is using fire like humans are.
A planet might conceivably have an excess of oxygen and flammable gases, and fire is/was something to be avoided. I don't think it is a distinguishing feature.
It's my understanding that the SETI search is now focusing on laser pulses being transmitted between stars, since they would have a much better chance of getting through than radio waves.
There is the paradox of brain development requiring cooked meat, which in turn requires brain development to build a fire.
There is the paradox of brain development requiring cooked meat, which in turn requires brain development to build a fire.
CHoff
Are you sure? SETI are an organisation looking for radio-signals from extra-terrestrial life. I was told that their interests do not cover all possible methods for detecting ET, only radio transmissions.choff wrote:It's my understanding that the SETI search is now focusing on laser pulses being transmitted between stars, since they would have a much better chance of getting through than radio waves.
There is the paradox of brain development requiring cooked meat, which in turn requires brain development to build a fire.
Intelligence
It is surely an arguable point and the line at which someone draws it will be subjective, but for good reasons I would say that unless I found a species that farmed its own nutrients, rather than plucking them from the environment, then I would tend not to associate that with 'intelligent life'.
I would place the bar higher. A species is intelligent if there is some form of communication or interpretation through which it could argue it's own case.
I would place the bar higher. A species is intelligent if there is some form of communication or interpretation through which it could argue it's own case.
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CaptainBeowulf
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- Joined: Sat Nov 07, 2009 12:35 am
I'm not sure about that. In humans it worked that way because cooking the meat allowed easier chewing, so the jaw muscles stretching all the way around the head could become thinner and longer. That in turn allowing the skull to get a lot bigger. But something with a different shaped head (or brain located elsewhere in its body) might be able to develop a much larger brain without needing to get smaller jaws/jaw muscles.There is the paradox of brain development requiring cooked meat, which in turn requires brain development to build a fire.
IIRC, a number seafoods are very good for the brain and brain development, and we do find very old middens of shellfish/clam/mussel shell scraps where humans have been in the last few tens of thousands of years. Maybe this pattern goes way back millions of years, and seafoods might have been a major factor rather than cooked meat generally.
The arguement was that for primates to develop brains from the size of a chimp to a modern human would require an easy to digest high energy cooked animal protein diet. The rational being that a diet of raw meat or raw vegetables requires too much energy to digest, leaving too little energy to support large brain evolution.
But of course building a fire and cooking meat is a multistep process that requires intelligence, the kind that only a large brain provides in the first place. Hence the paradox, the primitive man doesn't have the brains to cook the food to build the brain to cook the food.
A researcher in Austrailia is looking for laser light transmission between galaxies.
But of course building a fire and cooking meat is a multistep process that requires intelligence, the kind that only a large brain provides in the first place. Hence the paradox, the primitive man doesn't have the brains to cook the food to build the brain to cook the food.
A researcher in Austrailia is looking for laser light transmission between galaxies.
CHoff
Cooked meat supply is easily satisfied by frequent lightning lit brush fires raging across the savannah that used to be where the Sahara is now. See? Even this ape figured that one out in 20 seconds.choff wrote:The arguement was that for primates to develop brains from the size of a chimp to a modern human would require an easy to digest high energy cooked animal protein diet. The rational being that a diet of raw meat or raw vegetables requires too much energy to digest, leaving too little energy to support large brain evolution.
But of course building a fire and cooking meat is a multistep process that requires intelligence, the kind that only a large brain provides in the first place. Hence the paradox, the primitive man doesn't have the brains to cook the food to build the brain to cook the food.
A researcher in Austrailia is looking for laser light transmission between galaxies.
I am aware of that ONE researcher, who also claims he already detected a laser signal. Most SETI researchers remain focused on radio. I think they are both wrong, technological cultures go through technological singularities too quickly for us to detect either type of signal. There arent enough civilizations close enough for us to detect either type of signal that are within 100 years of our own point of development.
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CaptainBeowulf
- Posts: 498
- Joined: Sat Nov 07, 2009 12:35 am
Hmm... I understand that part of the argument, but I don't entirely agree. Basically, I could see a person surviving quite well on a diet of raw fruits, vegetables, nuts and sushi. A vague memory of that part of the argument is what prompted me to mention seafood - it seems to have a high amount of the nutrients needed for brain development, without necessarily needing to be cooked. So, maybe eating seafood came before cooking...The arguement was that for primates to develop brains from the size of a chimp to a modern human would require an easy to digest high energy cooked animal protein diet. The rational being that a diet of raw meat or raw vegetables requires too much energy to digest, leaving too little energy to support large brain evolution.
I also like the learning to cook meat by finding meat cooked by brush fires idea. I think that's probably a large part of how cooking started.
But basically, I don't see any great mystery - something with the mental capacity of a borderline Australopithecine/Homo Habilis/Erectus could probably evolve without cooking, but would then be smart enough to learn to cook. Cooking then helps it get from Homo Habilis/Erectus brain capacity to Homo Sapiens brain capacity.
Looking for laser communications is also something we should do, while bearing in mind that they could have developed even more efficient communications based on principles we don't yet understand.