iron

water is an important part of star formation. if there isn't enough no star.

guh, i had my annual performance evaluation today. so i'm drinking tonight. heavily. but hey, at least it also means two raises this month (merit and cost of living). anyway, moving on...



yeah for sure LOL. "social darwinism" bears about as much resemblance to Darwin's actual work as Nazism does to any empirical archaeology on the Proto-Indo-European peoples, not to mention Stalinism to Marx's work, and i wouldn't be surprised to hear other examples of political tyrants co-opting the work of well-intentioned philosophers (the literal-etymological meaning of which is 'lover of knowledge).



so i'm still curious about ammonia. nitrogen isn't quite as, uh, "right wing" as oxygen, but it has been suggested before in "alternative biochemistry." check out this wikipedia link - it's not a bad contribution to this discussion:

alternative biochemistry

taking a step back, what did you think of my idea of "life" defined (at least a first criterion) as a reiterative system? forget development (i.e., natural life) for a second - does this seem like a relatively encompassing definition of life? does it make room for too much we wouldn't want to call life? if so, what other critera could we add to arrive at a satisfactory definition of life? or does it leave out something you can think of?

also, on a totally random note, i've always wondered why technetium is synthetic, why it has no stable isotopes. i guess i'm just curious about what makes one isotope stable and another not. on the whole i'm not poorly-read when it comes to physics, but i've had some trouble finding an answer for this. i was just curious if anyone else knew, even just an hypothesis.

non carbon life will probable stay with in the family.

the family being in the up and down line in the periodical table.


one of which i believe is silicon.

I read the article. It mentioned some of my concerns. The oxidation cycle didn't occur to me (and it should have), but it does make sense. The ammonia and Nitrogen dioxide atmospheres make the most sense and I could see that working with a planet that has liquid ammonia. The one problem mentioned is the Cold temperatures. That would reduce reactivity and solubility. Also, if its that cold out there, I would wonder if enough solar radiation is making it to the planet to power life. All in all, I would dare say its possible. Not likely, but possible.



I went back and re read you post, and I think I might need a little bit more clarification on what you mean (sorry I'm kinda slow today). Are you talking about a system that essentially can self replicate or something a little more complex beyond self replication, like responding to stimuli?

There's really a fine line for "life" and it seems like it can be contested a lot. Generally I go by the old school definition of life: A system that has the capacity for metabolism, growth, reaction to stimuli, and reproduction. Its really cut and dry, but I think it works quite well as its very specific yet very open.

i had that definition in... what was it, middle school? it's good, but i think it fails to account for: things that don't grow, but could still be considered living (viruses, for example), and things that don't die and therefore might not reproduce, and it also obfuscates the difference between reaction to itnernal vs. external stimuli.

upon reflect, this line of thought is, on my part, influenced by an assumption proceeding from our previous talks of intelligence, that something which is intelligent must be considred alive. but that's an a priori assumption that needn't be necessarily true.

there is a possibility of a type of life form on earth.


that is clay.

I think it has some potential. It certainly passes Occam's Razor. It has been proposed (I believe it was Richard Dawkins) that the only true "organism" is DNA itself, and that all creatures, even complex multicellular creatures, are tools of the DNA, which "understands" that even though each individual gene isn't involved in the eventual step of procreation, working as a complex unit gives an advantage to the DNA as a whole. This closely resembles your definition here. It certainly seems like a workable theory, to me at least.

that certainly sounds like it could be Dawkins' idea - i'm not thoroughly familiar with his work, but i know the name. it kind of reminds me of the idea that multi-celluar organisms can be viewed as colonies of highly-specialized single-celled organisms.

i think i've got an idea brewing about life and intelligence related to this discussion, as well as growing from it. but i don't think this idea is ripe enough to even yield some interesting questions, so i'll come back to this later today.



i've read something similar, but i'm not sure that we'd be talking about the same thing; so i'm inviting you to elaborate.

okay, i'm going to think on the fly. as i said, my interest in the definition of life extends or is interrelated to my interest in intelligence. so i'm going to take a step back and talk about intelligence.

while there are many people theorizing about intelligence, there are three major thoeries i know of. the first is the classical theory, which basically views intelligence as a single trait. it's not very good at explaining qualitative differences in intelligence, i.e. what makes one person a good musician and another a good mathematician.

the next major theory is Howard Garder's theory of multiple intelligences; this theory origianlly itemized 7 types of intelligence. in alphabetical order, they are: bodily-kinesthetic, interpersonal, intrapersonal, linguistic, logical-mathematical, musical, and spatial. he subsequently added naturalistic intellignece, and there's a lot of work to add a ninth, existential intelligence (which was also vying against spiritual and moral intellinces). if you're interested in what's meant by any of these terms, check the link. his theory is criticized as being ad hoc, intuitive rather than empirical, and confusing what's better called ability with intelligence, which should point to some deeper characteristic.

the last theory, also the one i think is the most scientifically robust, is Robert Sternberg's triarchic theory of intelligence. this one has more empirical grounding, and it focuses on the processes of thought as the major unit of analysis when investigating the nature of intelligence. basically, he sees three types of intelligence: analytical, creative and practical. i think of his analytical intelligence as 'explicit problem solving,' when all the rules, conditions and laws are known, and it's probably the type of intelligence that most separates us from other animals. practical intelligence is more or less 'street smarts,' adapting your self to the environment and your environment to yourself. creative intelligence has most to do with approaching novel situations and automating familiar tasks; it doesn't necessarily mean you're good in the arts (also, this type of intelligence may be significantly less important to other animals*).

i like this theory because IMHO it's the most grounded in cognitive study of the mind and brain, it views humans as adapting/adaptive organisms in a natural environment, and it maintains a strong distinction between the processes that give rise to behavior and the behaviors themselves (i.e., aptitude vs. ability).

i also like it because it gives me a basis on which to imagine new forms of 'superficial intelligence' (i.e., new 'kinds' of intelligence in the multi-intelligence model). it allows me to view any life form on a spectrum of intelligence (by analyzing the processes that give rise to its behavior). from that, i have a nice framework to imagine 1) how alien life forms might be considered intelligent in some way, without them necessarily being radio-building and starship-piloting creatures, and 2) it allows me to speculate on how future mutation of human genes and anatomy could impact our intelligence.

this isn't to say that i think i can trace the change of a chromosome to a change in brain structure to a change in cognition on a molecular level, but these ideas do give me some basis for speculation (and after all, i'm writing speculative fiction here).

*when i say creative intelligence is less important to other animals, it's by no means to say that they lack creative intelligence. the ground this branch of intelligence has to do with encountering novel situations and problems on the one hand, and automating routine tasks on the other: animals of many sorts obviously deal with both new and old situation and problems. i say creative intelligence is more important to humans because of the role creativity plays in a healthy human psychology. deep down, all humans have what R.D. Laing called "existential anxiety" - basically, we need to have confidence, faith even, in our own existence and that of the world we experience. among other things it does, creativity serves as the 'proof' to our selves of our own existences (by introducing new things into the world, we break old patterns of cause and effect that we can observe - this serves an emotional role; we prove to ourselves that our actions do have real effects on the world, on the one hand, and that we are masters of our selves, our bodies and our actions, on the other hand).

so, i hope this isn't an overwhelmingly long post. obviously enough, the mind interests me greatly - and when it comes to writing sci fi, the minds of the future are just as interesting. so i hope this can spark some discussion on the subject!

it seems that clay either grows or propagate.


i tried to look it up kept getting stuff about people named clay.

Viruses arn't alive as they don't fufill 3 of those requirements. They can't grow, reproduce or metabolize on their own. They have to hijack a cell's machinery to do it.
Also if something doesn't die naturally (no aging) that doesn't mean it will never die. It can still take critical damage. With out the ability to ensure the survival of its species, its ultimately doomed. Also with reaction to stimuli, its implied that it can react to either internal or external or both.

I like the original definition because it doesn't limit us to biochemistry. For example, there could be living things that don't use or have DNA or are based on other chemicals structures, like ammonia. I beleive those 4 characteristics are genuenly unique to living things, and irregardless of intelligence, it could still be alive.

When it comes to intelligence, I think the other problem is, does intelligence = life? Would a computer fit? It certianly fits one of the three triarchic levels (analylitic). We, of course, know they aren't alive by any means, but technically, it seems it could slip through and be included.



Interesting concept. I would tend to think the opposite though. I mean for DNA to be usefull, it needs specifc proteins to decode it. I would assume that the DNA is more of a tool of the proteins, (a guide book if you will) allowing them to self regulate and perform functions other then replicating themselves. Besides, what if we find organisms that don't use DNA?

i never said "life" in my definition had to occur naturally, which means it wouldn't have to necessarily have a means to propogate or ensure species-level survival - though given enough intelligence, it could perhaps assemble a copy of itself.

i guess here's the question: would you consider Data from star treck to be alive? ever see Bicentennial Man?



on the whole i'd tenuously say, yes, computers have a rudimentary analytical intellgence. i mean, if you look at some of the AI experiments we've achieved - chess master-level computers, AI robot soccer teams, even the unscripted AI in GC2 - i think there's enough parity in the underlying processes to rightly describe it as intelligence (with sufficient caveats, such as 'artificial'). AI is hampered mainly by a near-total lack of other forms of intelligence, and a given computational anaysis is only as good as its parameters, which are still dependent on humans for the most part.

The Variable Specific Impulse Magnetoplasma Rocket (VASIMRTM) is an electro-thermal thruster for spacecraft propulsion. It uses radio waves and magnetic fields to ionize and accelerate a propellant. The method of heating plasma used in VASIMRTM was originally developed as a result of research into nuclear fusion. VASIMRTM is intended to bridge the gap between high-thrust, low-specific impulse propulsion systems and low-thrust, high-specific impulse systems. VASIMRTM is capable of functioning in either mode. The Costa Rican scientist and astronaut Franklin Chang-Diaz created VASIMRTM concept and has been working on its development since 1979.

Current VASIMRTM designs should be capable of producing specific impulses ranging from 3,000 to 30,000 seconds (jet velocities 30 to 300 km/s) The low end of this range is comparable to some ion thruster designs. By adjusting the manner of plasma production and plasma heating, a VASIMRTM can control the specific impulse and thrust.


VASIMRTM diagramThe Ad Astra Rocket Company plans to test a ground prototype rocket in early 2008, the VX-200, to demonstrate the required efficiency, thrust and specific impulse. A flight version of the VASIMRTM, the VF-200, is expected to be tested in space in late 2010.

VASIMRTM is not suitable to launch payloads from the surface of the Earth due to its low thrust to weight ratio and its need of a vacuum to operate. Instead, it will function as an upper stage for cargo, drastically reducing the fuel requirements for in-space transportation. The engine is expected to perform the following functions at a fraction of the cost of chemical technologies: 1) drag compensation for space stations, 2) lunar cargo transport, 3) in-space refueling, 4) in space resource recovery, 5) ultra high speed transportation for deep space missions.


WWW Link

i wonder if you could put that on a space plane.

I have a question?

If mass creates gravity, more mass creates more gravity and less mass creates less gravity, is it possible to have negative mass?

The idea being that negative mass would be like an antigravity divice?

i believe there are mathematically valid derivations of various physical equations (relativity and quantum phys.) that predict anti-gravity and matter with negative mass (as well as negative energy).

but just because they're mathematically valid doesn't mean they're physically possible. this is actually similar to when we were discussing 'warp' (the Alcubierre metric). it'd require "exotic matter" (matter with zero, negative or imaginary mass).

if i got my stuff right, the math means it can exist in reality without creating paradox or defying the known laws of physics. it doesn't mean that it does exist, or that (if it doesn't) that it can be created.

i think this is one of those catch 22 thingys

ie


anti gravity=gravity


of course i could be wrong


[edit] Fifth force
Under general relativity any form of energy couples with spacetime to create the geometries that cause gravity. A longstanding question was whether or not these same equations applied to antimatter. The issue was considered solved in 1957 with the development of CPT symmetry, which demonstrated that antimatter follows the same laws of physics as "normal" matter, and therefore has positive energy content and also causes (and reacts to) gravity like normal matter.

WWW Link

just because that type of matter has an "anti-" in front of it doesn't mean it makes anti-gravity (the terms can be confusing). rather than matter and anti-matter, it's better to think of it as matter type A and matter type 1. our universe seems completely made up of matter A. but if our universe were completely made up of matter type 1, it'd be no different at all, and we'd call matter type A "anti-matter." but the two types of matter work exactly alike. that's what the quotation you posted is saying.

the idea of anti-gravity is something else entirely. it's better to start with negative matter, i.e., matter with negative mass. such matter would fall up out of a normal (positively massive) gravity well. positive matter and negative matter would work oppositely from the way mangetic poles work - i.e., opposites repelling and like types attracting. this is different from anti-matter, which still has positive mass and energy.

PS: denyasis, i'm watching Gatacca at the moment and it's making me think of our molecular bio discussions.

I am very suprised my idle pondering actually has some theoretical merrit!

I had no idea there was any theory on the subject, i just casually thought, "hmmm wouldn't negative mass be like antigravity?".

Somone on this forum mentioned a particle at extreme velicity actually increases its mass.... damb boss is asking me to go and do somthingh!

Anyway i have previously mentioned in another post - i was thinking the atom at extreme velocity is increasing its mass relatively speaking because time is overlapping on itself? from the atoms perspective, the rest of the universe would be loosing mass!

Anyway if that is true then what is the oposite of time overlapping? being stretched out?

At any rate, no matter what the reason, if the mass of an atom can be increased, therefore surly it can be reduced?

Or is mass like heat, once you reach absolute zero, thats it, there is no negative temperature or negative mass?

hey guys just in case anyone's following the news, the fires in San Diego county have gotten crazy. i'm okay, as is my home, though i don't know when i might check in again. i'm kind of surprised i still have internet at home. the university where i work was closed for the week. at this point almost 300,000 acres have burned, and the air quality has deteriorated to the point of presenting serious risk in some areas to those with existing lung conditions.

i spent yesterday helping people evacuate in Solana Beach. i'm taking some old books and board games to one of the evacuation sites today before i see if it's okay to head up to the evac zones again. so anyway, i just thought i'd mention it... please find a place in your thoughts/prayers for the thousands of people and families displaced by this disaster.

thanks,
nik

just don't try to fight them with a garden hose

Dyspotic;

Stay safe. I hope your home lasts the fires. All of us here will keep you and everyone else in California in our thoughts and prayers.



No clue. If they could reproduce (ie build an offspring or copy), I would suppose so. If you think about it, I think insect colonies like ants only have a few sexually active members of the colony right? I guess this could be analogus to the "robots" building and maintaining a robot factory, hence rolling the robots out of the fab would be alive.

Physics conduses me so much. Like I really don't get how things like anti-matter and anti-gravity can exist. I'm not contesting any of you, I'm just saying it totally perplexes me, lol.

PS - I probably won't be around either for about a week or 2, but for different reasons. My final (for my certification and my job) is next week followed by graduation the next Monday, so I'll be studying by butt off and then entertaining family, etc. Sorry to disappear on ya'll, and you guys have a great weekend!

Hello! has anyone here figured out the meaning of life yet?

(it's been a long time since I was in this thread)