General Science/History Questions Thread.

[Lago PARANOIA]

How did photosynthesis evolve?

People generally say that agriculture led to a population explosion at the expense of reducing overall quality of life for humans. Why?

At what level of brain mass does consciousness appear? Could you make animals conscious by growing their brains bigger? How much is consciousness related to brain mass?

If someone was to produce an exact replica of you down to the molecule and then they shot and killed you but kept the clone alive, would you still feel something like consciousness?

Is consciousness the highest state of awareness? Will our robot children in the grim darkness of the far future experience some new level of thought, or is this all there is and that our children will pretty much think the same as us but a lot faster? If they will, what will it be like?

If the human brain was a computer, what would the specs be?

Why do some people have an easier time memorizing things than others?

Fuckin' magnets--how do they work?

[CatharzGodfoot]

Photosynthesis is based around moderately complex molecules called pigments, which readily absorb photons of certain wavelengths and release electrons. This basically just happens, so once they exist you have a regular source of electrons. Electrons are basically just a source of energy, and using electrical potential drops as 'waterwheels' is the basis of both photosynthesis and aerobic metabolism.

My best guess as to how the system evolved was that some cell managed to use pigments to generate a potential gradient across a cell membrane, basically creating a battery. By allowing positive ions to flow to the negative side (or vice-versa), a cell can power molecular machinery that creates more useable forms of energy (like ATP). Additional molecules would improve the procedure by gradually and efficiently bleeding off energy from the electron itself rather than relying on the cross-membrane potential.

I'm not a biologist, though (and my wife is asleep), so this is pure armchair conjecture.

[Edit]
What the fuck, Lago?


[*]Consciousness has multiple meanings. I would say that most things that are alive and have brains are conscious part of the time and unconscious others. People call this a sleep/wake cycle. You can't improve the quality of consciousness just by making a brain bigger. Different structures of the brain do different things. More processing is better up to a point[/i], and then it becomes redundant and you need new structures to derive new meaning.
[/Edit]

[Username17]

Catharz is basically right on the photosynthesis angle. I'll throw out another little factoid about it because it's so crazy: Chloroplasts are actually foreign bacteria cells that have been enslaved to produce energy for plant cells in the same way as we have enslaved mitochondria.

If you strike a pigment with a photon of the right energy to be absorbed, it will absorb it and go into an excited and unstable state. It then will revert back to the normal state by giving off energy in some form. So if you tie a pigment to something else, you can generate some electrical or chemical effect from the pigment powering down. Our own eyes work the same way, save that the pigments powering down cause neurons to get signaled instead of proteins being empowered to form sugars out of carbon dioxide and water.

-Username17

[violence in the media]

People generally say that agriculture led to a population explosion at the expense of reducing overall quality of life for humans. Why?

Who says this? Libertarians and survivalists?

If so, I imagine this sentiment comes from a preference for the dynamic of hunting and charting your own destiny versus doing something comparatively dull and repetitive and often at the behest/command of another.

[Blicero]

The period right after the Black Death actually witnessed a comparatively large standard of living for the "common people." Ironically, it took until roughly 1700 or 1800-ish, I believe, for that standard of living to return to its 1350-1450 levels. So no, that's totally false.

The Industrial Revolution gave workers really shitty working conditions, but they still had a much higher standard of living than in centuries past.

[Surgo]

Fuckin' magnets--how do they work?

You probably already know that the magnetic force is "created" (sort of) by moving charge -- ie, a current.

This is really simplified since it's been a while since I took E&M and I don't have time right now to refresh myself via Wikipedia, but magnets work in basically the same way. Some metals, like iron, are configured in such a way so that when you send a bunch of electrons on a loopy journey that resembles a Lissajous figure around the material they'll just keep going and going and going...this is called a bound current or an Amperian current. And like any current, it has a magnetic field associated with it. If you get a bunch of these going in sort of the same direction, they'll add together constructively. And there you go.

If the human brain was a computer, what would the specs be?

Ask IBM, they simulate a cat brain on a computer.

[erik]

If someone was to produce an exact replica of you down to the molecule and then they shot and killed you but kept the clone alive, would you still feel something like consciousness?

If you died then I imagine you would not feel anything. Sensation is a brain function. No brain function, no sensation. The perfect twin would feel whatever it would normally feel. They clone and original are separate entities. I'm not sure I understand the dilemma.

Why do some people have an easier time memorizing things than others?

Most people in fact do not have a vast inherent difference in ability to memorize. Supposedly only 4 people in the world have been identified to actually have superior memory capabilities that are no clearly the result of using memorization techniques. How they do it... is not entirely clear.

For everyone else. The really significant differences come down to techniques used to memorize information..

[Count Arioch the 28th]

Is consciousness the highest state of awareness? Will our robot children in the grim darkness of the far future experience some new level of thought, or is this all there is and that our children will pretty much think the same as us but a lot faster? If they will, what will it be like?

I submit that if they had the same senses as we do, then it wouldn't be vastly different. A being with different sensory capabilities would have a completely different way of thinking. That is only my opinion, I back it up with nothing. But I feel that perception is what makes the difference. Hell, I find a lot of the people here alien and unknowable because of their different life events giving them outlooks so divergent from my own they might as well be from Mars, imagine how different someone's thought processes were if they saw into the infrared or ultraviolet spectrum? If they could sense electrical fields? If they could feel gamma radiation?

[Crissa]

People generally say that agriculture led to a population explosion at the expense of reducing overall quality of life for humans. Why?

Who says this? Libertarians and survivalists?

If so, I imagine this sentiment comes from a preference for the dynamic of hunting and charting your own destiny versus doing something comparatively dull and repetitive and often at the behest/command of another.

Also, bone analysis shows that nutrition on average actually went down, even though the ratio of calories expended to get calories, declined.

Personally, gimme a farm over a living on the edge nomadic situation.

-Crissa

[Quantumboost]

Some metals, like iron, are configured in such a way so that when you send a bunch of electrons on a loopy journey that resembles a Lissajous figure around the material they'll just keep going and going and going...this is called a bound current or an Amperian current. And like any current, it has a magnetic field associated with it. If you get a bunch of these going in sort of the same direction, they'll add together constructively. And there you go.

Pulling from Wikipedia and what I remember from Physics...

Ferromagnetism doesn't have actually anything to do with bound electrical currents. It's a property of electron spins.

Basically, elementary particles each have a number called "spin". Electrons and protons and neutrons have spins of 1/2 or -1/2. Photons have spin 0. Other particles can have other spins, but it's always a multiple of 1/2.

And like the particles were actually spinning, which is probably not at all what's actually happening, a charge which has a nonzero spin also has an inherent magnetic field.

Sometimes atoms have a net magnetic field due to how exactly they're set up, but they usually like to cancel out other atoms' magnetism - like with actual magnets. In ferromagnetic materials, that... doesn't happen. There's something called the exchange interaction that has something to do with the atoms being indistinguishable when you swap them which makes them like to have their spins aligned. And that causes the magnetic fields to line up, so you get a net magnetic field. Some kind of weird quantum thing, I'm not actually clear on how all that works.

Anyway, ferromagnetic materials have all those atoms lining up and combining their magnetic fields Voltron-style, and eventually these aligned atoms come together in "domains" which are microscopic chunks of iron (or whatever) that have a magnetic field of their own. And when those domains are aligned, the iron (or whatever) has a net magnetic field.

You can make them face the same way by sending electrons on a loopy journey like Surgo said.

tl;dr version - "crazy quantum Voltron stuff".

[Count Arioch the 28th]

If so, I imagine this sentiment comes from a preference for the dynamic of hunting and charting your own destiny versus doing something comparatively dull and repetitive and often at the behest/command of another.

I rather like having immunizations and air conditioning and internet and a Taco Bell on the corner, so I won't say that quality of live was better back in the day.

I will say that one of the most disheartening aspects of my adult life is the idea that I'm working my ass off to make someone else rich.

[Blasted]

Surely the solution to making someone else rich is starting your own business.
It's a risk/reward calculation, and you can change your mind pretty much at any time.

[CatharzGodfoot]

Surely the solution to making someone else rich is starting your own business.
It's a risk/reward calculation, and you can change your mind pretty much at any time.

[Zinegata]

People generally say that agriculture led to a population explosion at the expense of reducing overall quality of life for humans. Why?

Agriculture didn't really "reduce the quality of life" for humans. It did result in lower meat intake because people began eating crops more than meat, which was only later partially rectified by the widespread use of herding and livestock.

Essentially, what happened during the Agricultural revolution was a simple transformation. From small numbers of humans eating meat (some of the meat possibly from fellow humans during very lean times), agriculture allowed for a lot more humans to exist eating a reliable plant-based food source.

If you're a die-hard red meat person, sure your "quality of life" would have declined. But for civilization as a whole quality of life improved because it allowed people to specialize, which in turn leads to stuff like technology, which in turn leads to people having actual pots to cook with instead of doing it on fucking a rock.

At what level of brain mass does consciousness appear? Could you make animals conscious by growing their brains bigger? How much is consciousness related to brain mass?

Consciousness, or sentience you mean?

If someone was to produce an exact replica of you down to the molecule and then they shot and killed you but kept the clone alive, would you still feel something like consciousness?

Nope. A human being's "consciousness" is an arbitrarily complex computation mechanism residing in an organic shell. If an exact copy of you was made, it would merely create another copy of the said arbitrarily complex computation mechanism.

These two would operate indepedently in parallel and thus would not have any continuity in consciousness. Unless of course there are stuff regarding ESP or "human souls" that we haven't discovered yet.

Is consciousness the highest state of awareness? Will our robot children in the grim darkness of the far future experience some new level of thought, or is this all there is and that our children will pretty much think the same as us but a lot faster? If they will, what will it be like?

By consciousness do you mean self-awareness?

[CatharzGodfoot]

If someone was to produce an exact replica of you down to the molecule and then they shot and killed you but kept the clone alive, would you still feel something like consciousness?

Nope. A human being's "consciousness" is an arbitrarily complex computation mechanism residing in an organic shell. If an exact copy of you was made, it would merely create another copy of the said arbitrarily complex computation mechanism.

These two would operate indepedently in parallel and thus would not have any continuity in consciousness. Unless of course there are stuff regarding ESP or "human souls" that we haven't discovered yet.

Wait, what do you mean by "continuity of consciousness"? I took it to mean that the copy will have the experience of being the same individual as the original--that there would be no 'glitch' or feeling of having someone else's memories. Clearly they will diverge (the copy won't have the memory of death), but the two are effectively interchangeable at the moment the copy in created.

[Crissa]

There's no evidence that memories are stored in the hardware of the body. So with no continuity of consciousness, there are no memories.

-Crissa

[CatharzGodfoot]

There's no evidence that memories are stored in the hardware of the body. So with no continuity of consciousness, there are no memories.

-Crissa

Crissa, are you claiming to be a Dualist?

[Maxus]

The agriculture thing is only half-right. Modern-day hunter/gather cultures aren't off as bad as you think, their cultures being oppressed out by the rest of the world notwithstanding.

They aren't malnourished. Hell, they tend to pull from so many food sources they aren't in much danger from starving because there's not much they don't know about when it comes to food. In many areas of nutrition (protein, and a few others who are slipping my mind right now), they eat better than we do. It's very exercise intensive, though.

Agriculture, while it produces a lot of food, means we produces only a few kinds of food. And people tend to have to stay in the same spot. Which leads to problems in waste management and disease and if the crops fail, we're screwed.

The quote Lago inquired about is sort of like...taking evidence that most people can recognize the attractiveness of someone of the same gender and saying "This means everyone's bisexual."

[Count Arioch the 28th]

Surely the solution to making someone else rich is starting your own business.
It's a risk/reward calculation, and you can change your mind pretty much at any time.

Depends on the nature of a business. I could enter a perfectly competitive market at any time I collect the capital and leave at any time, but those types of firms never make profit in the long term. If I could start my own monopoly I would make bank, but I would need considerably more capital than a lower-class bum like myself is likely to accumulate in the course of his lifetime.

[Blasted]

Depends on the nature of a business. I could enter a perfectly competitive market at any time I collect the capital and leave at any time, but those types of firms never make profit in the long term. If I could start my own monopoly I would make bank, but I would need considerably more capital than a lower-class bum like myself is likely to accumulate in the course of his lifetime.

Sure, the point was that you could work for yourself, but there's a good chance that you would earn less.

[Count Arioch the 28th]

Depends on the nature of a business. I could enter a perfectly competitive market at any time I collect the capital and leave at any time, but those types of firms never make profit in the long term. If I could start my own monopoly I would make bank, but I would need considerably more capital than a lower-class bum like myself is likely to accumulate in the course of his lifetime.

Sure, the point was that you could work for yourself, but there's a good chance that you would earn less.

There is another option. Working directly for the government. Granted, that's not always the case. To give an example: Municipal Wastewater Treatment is always profitable. Not only in terms of "not losing thousands of people a year to cholera" type of way although that's a big part of it, but in a real concept of dollars and cents. City/County governments rob said plants blind and use it to fund other projects, which run the gamut from public schools and health to buying the Mayor's favorite prostitute a new Lexus.

However, even the idea that the money I am making MIGHT go to something worthwhile to society leaves me with less misgivings than my job for the past 4 years (working for various box stores), where I can guarantee that money isn't going to charity unless it's for a tax break.

[Zinegata]

Wait, what do you mean by "continuity of consciousness"? I took it to mean that the copy will have the experience of being the same individual as the original--that there would be no 'glitch' or feeling of having someone else's memories. Clearly they will diverge (the copy won't have the memory of death), but the two are effectively interchangeable at the moment the copy in created.

I mean that if one of the two dies, his consciousness won't continue with the survivor. Because they are two, seperate, entities who exist in parallel.

Unless the two have some kind of unknown link (i.e. ESP), such as the sort identical twins have claimed to have experienced. But right now that's just wholly speculation.

The agriculture thing is only half-right. Modern-day hunter/gather cultures aren't off as bad as you think, their cultures being oppressed out by the rest of the world notwithstanding.

They aren't malnourished. Hell, they tend to pull from so many food sources they aren't in much danger from starving because there's not much they don't know about when it comes to food. In many areas of nutrition (protein, and a few others who are slipping my mind right now), they eat better than we do. It's very exercise intensive, though.

Agriculture, while it produces a lot of food, means we produces only a few kinds of food. And people tend to have to stay in the same spot. Which leads to problems in waste management and disease and if the crops fail, we're screwed.

The quote Lago inquired about is sort of like...taking evidence that most people can recognize the attractiveness of someone of the same gender and saying "This means everyone's bisexual."

Hunter-gatherer societies however, are enormously fragile. One poor season of bad hunting can mean a good portion of the tribe dying out due to starvation. It also gravely limits the size of such communities, making specialization impossible.

If you're in a hunter-gatherer community, chances are that 90% of your time spent awake is spent just looking for food. Even if you managed to catch an elephant in the morning, chances are you'd still go out and look for more food in the afternoon - because chances are there are some days you won't catch anything at all and you need the surplus to feed your people.

That leaves very little time for stuff like leisure, arts, or technological development. That's why agriculture led to civilization, and is well on its way to wiping out hunter-gatherers.

And quite frankly, I would say that a very large majority of the world's population wouldn't even be able to live under hunter-gatherer conditions.

[Count Arioch the 28th]

And quite frankly, I would say that a very large majority of the world's population wouldn't even be able to live under hunter-gatherer conditions.

There is reason to believe that, because most of the world's population weren't able to live under hunter-gatherer conditions back then either.

[Zinegata]

There is reason to believe that, because most of the world's population weren't able to live under hunter-gatherer conditions back then either.

Somewhat. It would be truer to say that most of the world's population during the hunter-gatherer era never made into adulthood. When food is scarce, people die, particularly the young.

[Maj]

People generally say that agriculture led to a population explosion at the expense of reducing overall quality of life for humans. Why?

I am currently reading The Vegetarian Myth, by Lierre Keith. It's a little on the hippie side, coming from a former vegan, environmentalist, feminist who hates agriculture as vehemently as many people on these boards hate religion, but summed up the explanation is something like this:

The rise of agriculture brought about the ability to have surplus (She makes this surplus synonymous with wealth, and definitionally, with the creation of wealth comes the creation of poverty). A surplus requires the technology to store it, and the [military] might to protect it from those who want it. Thus, agriculture gives rise to civilization. A surplus also means that people can stop killing their babies because there is less concern for famine and inadequate food supply, therefore the population grows. This leads to more agriculture in order to keep up with the population growth, which leads to enslaving large portions of the population to do backbreaking labor (she cites a statistic of 17 hours per week as the average time a hunter-gatherer is required to spend in order to take care of their needs), thus leading to harsh social conditions, and massive environmental devastation as ecosystems are wiped out in order to make way for crops.

Further, she talks about quality of life and health after the consumption of cereal grains became wide-spread. The "diseases of civilization" include arthritis, diabetes, high blood pressure, heart disease, depression, stroke, schizophrenia, cancer, crooked teeth, bad eyesight, and many autoimmune disorders. According to Ms. Keith, evidence of these diseases were not found in the bones of hunter-gatherers. She attributes this to evolution: humanity didn't evolve with grains, therefore our bodies have a difficult time assimilating them.

So, in her perspective, agriculture is the force behind the creation of economic class and slavery, the bajillion hour work day, and imperialism (as you destroy the ecosystem with agriculture, you have to go find and claim/conquer more land in order to be able to keep farming).

And all that sounds just a little nutty when summed up in less than 350 words. She brings up some fabulous points on veganism and why it's not a good idea - ethically or nutritionally - and she talks a lot about environmental and sustainability concerns with farming, especially modern farming. Even if I don't agree with some of her conclusions, especially socially speaking, she has some good insight that's worth gaining.

At what level of brain mass does consciousness appear? Could you make animals conscious by growing their brains bigger? How much is consciousness related to brain mass?

I am currently also reading Why We Believe What We Believe, by Andrew Newberg, MD. Dr. Newberg studies religion and beliefs from a neurological viewpoint, trying to figure out why humans have the ability to form beliefs, and what purpose they serve. Because of his perspective, he speaks of consciousness in terms of the ability to believe.

According to him, it really depends on the kind of brain the creature has. While single-celled organisms can have notions about the world around them, they're usually not much more complex than, "Safe? Yes/no." It's our frontal lobe - with its ability to imagine - that governs consciousness. It's where our core beliefs (likes, dislikes, habitual thought patterns, etc) and dreams reside, and where behavior is initiated. It's also the part of the brain that directs our attention when interfacing with the outside world.