[This is the introduction to chapters III, IV and V out of 12 of the Complexity Lab Manual. It is preceded by a chapter and labs on natural history, and then a chapter on how to build robots to try to mimic life, from the transistors on up, giving us our first hint of the complexity involved. More concrete examples will be inserted in the future.]
Unlike our machinery, life builds itself from the inside out. Tiny robots that build each other and crawl around each other and can make chemical transformation from air to plant to animal flesh. That’s a lot to take in.
Just as we saw how to build robots hierarchically up from simple transistors and motors and pulleys and how to build their behavior hierarchically up from subroutines of subroutines... so does life:
First: our bodies are societies of a trillion amoebas. We start off as a colony of the society of amoebas that is our mother. A group of them settles in her ovary and one of them gives birth.. Well they give birth by splitting in half.. Anyway this colony population grows and as it does the members shape each other, move around each other, build ties, lay down bony scaffolding and fibrous scaffolding to hold themselves all in place. They set up dances with each other, hundreds dancing a heart some lungs, contracting muscles and the conversation that is the brain...
All the while the mother is shipping them food that they grow on and removing their garbage... eventually they are ready to leave as an independent being.
We can actually watch a critter like a snail or roundworm do this under a microscope and make a movie of it.
That these amoeba can do all this... well are they just like people themselves like the mirrors within mirrors? Nearly, but only one cell each. We can watch one of these moving pinpoints in a drop of pond water under a microscope and see that it is in fact a microscopic animal capable of many of the basic behavior of us big animals: swimming, crawling, searching, thinking, hunting food, growing, seeking mates, reproducing, dying. these single cells are the most basic level of organization of life.
Put a strand of algae in a jar of water and air and it grows more of itselves out of thin air! this is chemistry, and what are the parts inside? For we can see stuff streaming around in these little protozoans. How do algae grow themselves out of air water and stuff that leaks out of glass? How does life transform rock and air and water into life?
Some clues: we can grind up these simple critters and do paper chromatography on them you see that the stains soaking upwards on the paper separate into distinct blobs with craft, you can get a hundred or more blobs to separate. Are they distinct kinds of parts the critters are made of?
Chemistry is the most exciting scientific discovery for us living thinking beings. What is it?
The first discovery is that even though the world seems to be made out of an infinite blended variety of colors tastes and textures and smells, in fact we can chemically reduce all these substances into a FEW distinct types. Visit a museum and see a 1000 different mineral forms and colors and textures. From this we can isolate a toolbox of merely about 50 elemental substances that can't be chemically broken down any further. in fact 100s of different minerals, and indeed 99.99% of what's around us can be made solely from the dozen or so most common elemental substances. This is remarkable. These are:
The metallic elementals: Sodium, makes the sea salty. Potassium, used by the batteries in neurons. Calcium, makes bones seashells, limestone. Magnesium, makes chlorophyll green. Iron, the catalyst that can among other things, carry oxygen in our blood from lungs to muscles.
The semiconductors: Aluminum, together with Silicon, make the scaffolding that holds the metals together to make up 95% of all the rocks around us, in fact, all the earth.
The nonmetals: Carbon, the stuff in air that becomes the backbones of wood and flesh. Oxygen, which connects all these and dissolves them in water and burns. Hydrogen, that helps oxygen make water. Nitrogen, the stuff in air that compliments the Oxygen in our chemistry. Phosphorus, storing the energy currency that all life uses, and backbone to our genetic blueprints. Sulfur, the connector that holds iron catalysts in our enzymes to metabolize our food. And Chlorine, Sodium's partner in dissolving in seawater.
And this is the first hint at the essentially digital, discrete nature of the stuff of our world.
The next clue is that we can react simply carbon, hydrogen and oxygen together and get strikingly different compound substances, organic compounds, each with distinct properties. These different substances can be separated from each other and we can burn each sample back up to separate out the elements and see that each compound contains the same PROPORTIONS off each of these three elementals.
Something fishy is going on. through careful experiments and reasoning chemists guessed that these elemental substances came in discrete particles they called atoms and that the different compounds had different properties because the same atoms arranged themselves together in different geometries, either in straight chains or branched ones or rings or even more complicated. Many of the properties of stuff, like color, taste, hardness... come from the way discrete parts arrange themselves in different geometric relationships.
Finally at the beginning of the 20th century we discovered that stuff was in fact made of many discrete parts that we call atoms. The shock is how small they are and how many it takes to make up a blob of stuff. If we imagine one of our amoeba or paramecium with its cilia and vacuoles and all it's behaviors as a robot made of parts, how many parts can there be in there? You can hold in the palm of your hand 600,000, 000,000,000, 000,000,000 molecules of water. This is the Avogadro’s number that you learned in freshman chemistry. It is a painstaking experiment to measure this number. I think that it is one of our most radical scientific discoveries.
Nearly a million billion billion. even I don't know how to imagine that number, so we go hierarchical again: a glass of water is 100 cubes of water the size of sugar cubes, so each cube (cubic centimeter) has (divide the big number by a 100) 10,000, billion billion molecules. Now we can break each of those cubes up into 10X10X10 tiny cubes (draw all those cross hairs on the cube) and get 1000 tiny sandgrain cubes. So each of those has 100, billion billion molecules. now, how big are those tiny paramecium? We watched them in our microscope, they are about a 10th of the length of the side of a sandgrain cube, so we draw crosshairs again and 10X10X10, divide by a thousand again: 100, million billion molecules in the paramecium.
Now if we grind up paramecium and separate out their chemicals like we did with the paper chromatography we find out that some of the substances are a dozen times as heavy as water molecules. Those are sugars and amino acids, and fats. And there are substances that are 100s of times as heavy as those and these are proteins. So there can be 10million billion small molecules and 100thousand billion proteins in the paramecium. Now we are getting somewhere.
To help you visualize this stupendous number, let's do this guided visualization: imagine yourself standing in front of a large apartment building in New York City. a window is maybe 10X20 bricks (200) there are 20 X 20 stories worth of windows on the face of the building (so 400 windows times 200 bricks =80,000 bricks in one face) now just for the hell of it, making a gross overestimate in the number of bricks, imagine the building is solid bricks, so the building is 200 bricks deep, so the solid building would be made of 200X80,000 bricks or 16,000,000. Now there are 5X10 buildings on that block, so that’s 50X and we get 1000,000,000 bricks per block. Manhattan is about 10blocks wide by 200 blocks long so that's 2000 X or 2thousand billion bricks in Manhattan. For the hell of it lets think of 5 boroughs (nowhere near as densely built as midtown Manhattan..) and we have 10thousand billion bricks in nyc.
That's how many of these proteins there are in that tiny dot we watched in the pond water crawling around.
Ok, what are these proteins? Are they like bricks? Well, to cut to the chase, in the past century we’ve actually learned to SEE these proteins, with electron microscopes and x-ray diffraction, to watch them MOVE and change shape with fluorescent microscopy. So here is the story:
What ARE these molecules? After a 150 years of experimenting with them, here's what you can discover in an organic chemistry class. They can sense their surroundings, sense each other, sense essential qualities in each other like size and shape and electrical charge.. They can respond to each other in simple ways. They can attach to each other in specific shapes and replace parts of each other and come apart in specific ways and recombine. They are like parts of machines that don't need mechanics to put them together, because they are in constant motion, jostling, sensing each snapping together by their own internal rules. (kind of like the way each of us is a society of amoebas that sense each other and build with each other their arrangements. However, It is important to note though, that the molecules are MUCH simpler than amoebas, and are not alive, they don't eat and grow and can't perform trial and error chains of thinking). Molecules are springy and vibrate, and wiggle. They can absorb and emit specific amounts of energy that we sense as different colors and as heat. They are kind of fuzzy without discrete boundaries and this is why they can sense each other and attach and come apart.
Going in deeper, we've discovered that it's the dancing of electrons that shape and give dynamics to molecules. These electrons are at the same time discrete dots of charge and also vibrating waves (don't try to wrap your heads around this one, this is the central mystery of quantum mechanics, which after a 100 years since its discovery still puzzles the discoverers of this new kind of physics). This is what makes molecules fuzzy and sensitive and springy and interact with energy and light. It is what makes them utterly different than our clunky inert machine parts.
In a way, these electrons are like the transistors we started with some chapters ago, and the molecules are like the logic gates that we built up, layer upon layer to make our complicated 'thinking' computers. Except, that while our transistors and computer chips could process information, they could not move around and recombine with each other. But molecules CAN do these things. So in essence they are tiny pieces of computer/robots. And in fact the larger ones, the proteins made of smaller parts, the amino acids, DO act as small computers and small robots.
But they are very different than the computers and robots that we design. we use to much one pointed consciousness in our craft, to much thinking about one thing at a time and building one machine at a time from the outside. The protein robots think more like swarms of honeybees or ants or termites and get together in crowds and cooperatively construct machines. And the processes they perform is like a whole bunch of subroutines working on each other simultaneously instead of the way ours do it, executing one at a time.
And of course these protein robots, being so close to the basic level of molecules CAN build each other out of foodstuff, the water air and glass that our algae cells grew themselves from. Because they are made out of proteins.
So here is what life is: at the basic level a living creature is a swarm of 100thousand billion cooperatively coordinating tiny robots, of about 1000 different kinds, constantly interacting, building huge structures out of each other, taking these structures apart, putting them back together, taking each other apart and building new ones depending on the needs of the swarm... this happens incredibly fast: proteins change shape and jostle around millions of times a second.
I want you to meditate for a bit on where we have reached in our journey inward... the levels within levels of mechanisms made out of each other.
Again, imagine yourself taking a few days to wander around New York City, and imagine each of those bricks are one of the thousand different kinds of protein robots in a paramecium, each taking the place of one of these bricks, all swirling around interacting with each other building static and dynamic structures out of each other on the time scales of seconds, minutes, hours. You can watch them reproduce an ENTIRE CITY in a matter of DAYS.
[This is followed immediately by a chapter on how simple energy flow organizes fluids, chemistry into stable, creative dynamic patterns. How life is animated. And then a chapter of math and computer games that show how millions of simple interacting parts can take these dynamic patterns and elaborate them into surprising complexity.
Eventually we survey what we've discovered so far about the chemistry at the origins of life itself. ]
Thursday, April 21, 2011
Tuesday, April 12, 2011
On Hebrew Prayer: Organizing Principles and Surprise
barukh' ata yhvh 'eloheinu melekh ha'olam
"barukh 'ata" means blessed are you. I bless you (well hell, i don't really understand this ENGLISH word 'to bless' we don't really use it every day do we?), i am thankful for you i am in awe of you. You? yhvh (the 4 letters representing the holy name in Tanakh (bible) that traditional Judaism does not pronounce, though in the bible it certainly seems to function as a pronounceable personal name) is presence/miracles (which is what i call that state i am in when i am intensely aware of the miraculousness of existence itself. It is not a state of duality, ME being present TO miracles outside me, but a state of awareness that breaks down barriers between subject/object sensation/action) always available if i cut the tense headchatter worry about time and just be in this moment that is not yet death as long as i am present.
yhvh, presence, as close as breath not just something i feel, but feeling itself, the act, not something outside of me, no duality.
a personal particular name of a presence who came to my people? I suppose whenever one of us has this kind of experience it is experienced as intensely particular.
Now in traditional Jewish prayer we say 'barukh ata adonoi' so as to avoid pronouncing the name meaning blessed are you, our lord. (Some say barukh ata hashem, blessed is the name) Not Lord, Sir. I am not a slave to presence/miracles, presence/miracles is not a big man who has made it in the world, who is more capable than me, who has accumulated more than me.
it is not lord/slave, it is partnership. miracles cannot create without the stable beings we are who can catch energy flow, choosing some miracles and letting others go.
Certainly not a being at all, yet distinctive in some way? definitely presence, that i can remember, name if i want, but no name is the real name. presence/miracles is not outside of me, i can give presence/miracles no pronoun, i can't even talk ABOUT presence/miracles, only each time I want to mention presence/miracles I must BE in presence/miracles. Very similar to 'i will be who i will be' 'whoever i want to be, you can't predict', 'i am the spark who wakes you out of staleness.'
'Eloheinu (our god, 'elohim with the 'our' ending. 'Elohim looks like the plural of El also a word found in Tanakh to represent various middle eastern gods, but is not considered in the Jewish tradition to be plural.) However a friend suggested to me that the form of the word is similar to words like (water) and khayim (life), so we can take it as an all pervading force that you cant split up into pieces, the all pervading not-stuff of the universe, the patterns that make the universe, the physics, the mathematics. perhaps we can coin a new word like 'elohayim.
So if Elohayim is the physics the predictable, then yhvh is the unpredictable, the singularity, the quantum fluctuation that brings the potential of physics into being a universe.
Melekh (king)? what do Malakhim do? rule? push people around? coerce people? no, they are charismatic centers around which people organize THEMSELVES. Malkhut is the organizing principles themselves, the sets of interactions and feedback loops that allow independent agents to interact and self organize into larger processes. Elohayim is the set of principles that allow the multitude of discrete agents in 'olam (the world) to organize into patterns.
Does that work for me personally? For my community? It is a reminder that my mind does not create this world around me, that i myself am a dissipative process of molecules interacting, meaning that energy is flowing through me (not just into me) and this energy flow causes fluids and chemistry to form stable dynamic systems that can catch random fluctuations and create pattern). Can i rally around the patterns of physics and mathematics, do they give my life meaning? Well, what else do i walk with and breath with and how does this elohayim serve as an organizing center for community? why should a gathering of people show recognition of physics and mathematics and the principles of self organizing mathematics that energy flow through interacting particles creates stable creative dynamical systems?
well, for sure, every time a bunch of people want to get together and do something, they should realize how these principles work, that people self organize they are not controlled by a politician, nor should they let themselves be. they should learn the ways of dissipative and inculcate patterns of local interaction.
and of course they should at these intense moments of prayer get out of their petty little mind-worlds, human society world, and realize that there is a larger earth around them a larger set of patterns that gives them the very gravity they move in, the very electromagnetic force that makes atoms, molecules, biology cohere. thankful that the universe is an INTERESTING place, otherwise we wouldn't be.
And why does yhvh and elohayim have to be one and the same? This is one of the cornerstones of the Jewish tradition. One God. This doesn't work for me, I do not see evidence for it. I do not require a neat simple system that collapses all primal organizing principles in my life into one being. so i have to say: baruch ata yhvh who sparks into being, toda l'elohayim melekh who is expansion and organization of the sparks into an 'olam.
"barukh 'ata" means blessed are you. I bless you (well hell, i don't really understand this ENGLISH word 'to bless' we don't really use it every day do we?), i am thankful for you i am in awe of you. You? yhvh (the 4 letters representing the holy name in Tanakh (bible) that traditional Judaism does not pronounce, though in the bible it certainly seems to function as a pronounceable personal name) is presence/miracles (which is what i call that state i am in when i am intensely aware of the miraculousness of existence itself. It is not a state of duality, ME being present TO miracles outside me, but a state of awareness that breaks down barriers between subject/object sensation/action) always available if i cut the tense headchatter worry about time and just be in this moment that is not yet death as long as i am present.
yhvh, presence, as close as breath not just something i feel, but feeling itself, the act, not something outside of me, no duality.
a personal particular name of a presence who came to my people? I suppose whenever one of us has this kind of experience it is experienced as intensely particular.
Now in traditional Jewish prayer we say 'barukh ata adonoi' so as to avoid pronouncing the name meaning blessed are you, our lord. (Some say barukh ata hashem, blessed is the name) Not Lord, Sir. I am not a slave to presence/miracles, presence/miracles is not a big man who has made it in the world, who is more capable than me, who has accumulated more than me.
it is not lord/slave, it is partnership. miracles cannot create without the stable beings we are who can catch energy flow, choosing some miracles and letting others go.
Certainly not a being at all, yet distinctive in some way? definitely presence, that i can remember, name if i want, but no name is the real name. presence/miracles is not outside of me, i can give presence/miracles no pronoun, i can't even talk ABOUT presence/miracles, only each time I want to mention presence/miracles I must BE in presence/miracles. Very similar to 'i will be who i will be' 'whoever i want to be, you can't predict', 'i am the spark who wakes you out of staleness.'
'Eloheinu (our god, 'elohim with the 'our' ending. 'Elohim looks like the plural of El also a word found in Tanakh to represent various middle eastern gods, but is not considered in the Jewish tradition to be plural.) However a friend suggested to me that the form of the word is similar to words like (water) and khayim (life), so we can take it as an all pervading force that you cant split up into pieces, the all pervading not-stuff of the universe, the patterns that make the universe, the physics, the mathematics. perhaps we can coin a new word like 'elohayim.
So if Elohayim is the physics the predictable, then yhvh is the unpredictable, the singularity, the quantum fluctuation that brings the potential of physics into being a universe.
Melekh (king)? what do Malakhim do? rule? push people around? coerce people? no, they are charismatic centers around which people organize THEMSELVES. Malkhut is the organizing principles themselves, the sets of interactions and feedback loops that allow independent agents to interact and self organize into larger processes. Elohayim is the set of principles that allow the multitude of discrete agents in 'olam (the world) to organize into patterns.
Does that work for me personally? For my community? It is a reminder that my mind does not create this world around me, that i myself am a dissipative process of molecules interacting, meaning that energy is flowing through me (not just into me) and this energy flow causes fluids and chemistry to form stable dynamic systems that can catch random fluctuations and create pattern). Can i rally around the patterns of physics and mathematics, do they give my life meaning? Well, what else do i walk with and breath with and how does this elohayim serve as an organizing center for community? why should a gathering of people show recognition of physics and mathematics and the principles of self organizing mathematics that energy flow through interacting particles creates stable creative dynamical systems?
well, for sure, every time a bunch of people want to get together and do something, they should realize how these principles work, that people self organize they are not controlled by a politician, nor should they let themselves be. they should learn the ways of dissipative and inculcate patterns of local interaction.
and of course they should at these intense moments of prayer get out of their petty little mind-worlds, human society world, and realize that there is a larger earth around them a larger set of patterns that gives them the very gravity they move in, the very electromagnetic force that makes atoms, molecules, biology cohere. thankful that the universe is an INTERESTING place, otherwise we wouldn't be.
And why does yhvh and elohayim have to be one and the same? This is one of the cornerstones of the Jewish tradition. One God. This doesn't work for me, I do not see evidence for it. I do not require a neat simple system that collapses all primal organizing principles in my life into one being. so i have to say: baruch ata yhvh who sparks into being, toda l'elohayim melekh who is expansion and organization of the sparks into an 'olam.
Friday, April 8, 2011
On Eating Animals
Life eats life to live. Creatures all the time are domesticating each other, it is the process of symbiosis, parasitism, that's one of life's defining features. mothers give birth to varied children in overabundance as experiments in this grand evolutionary game. delicately crafted creatures that we in no way are capable of crafting ourselves are just food in the scheme of things. our intensely strong consciousness of our very being, personality, individuality , our attachment to this strong sense of self, to the personality of others, these are also part of our mortal animal nature.
this is all very hard for us very conscious clinging to ego beings to take. it has always made it hard for us to take part in this cycling of life on earth. can we choose to take ourselves out of this pattern and not eat animals? i think for some that is a possible route if taking the life of animals causes them personal pain.
however even if 6billion humans become vegetarian, this is not a life of do no harm. we have to deny billions of other animals the right to their own vegetable food, room to live, not to mention the incredible burdens we put on ecosystems as a whole.
one day we will have to come to terms with the fact that we are life, and this is the way life is, it is not a mamby pamby fairy existence. life is gutsy and intricately intertwined with suffering and death. the only way out of this reality is to take the poison koolaid and believe your soul is going to live on some passing comet. (in fact it is this tendency to shy from the horrific reality of life and try to fly away to an idea of an eternal soul in heaven that i find one of the most dangerous aspects of many religions)
The bhagavad Gita has an interesting view on this. Arjuna is a warrior preparing to bring his army to battle. he is standing on a mountain watching both armies prepare. the sight overwhelms him, he begins to imagine all the death and suffering his soldiers will cause, and the families that will suffer when their soldier-fathers don't come back from battle, and... he freezes.
So Krishna comes and takes the whole rest of the book convincing him that there is no other way. if his army does not fight then the enemy army will also cause suffering to his people. Krisha brings him to the very pinnacle of experience of the horrific reality of life with its whirling giant maw of teeth and arms and eyes of creativity through destruction (for that is what the evolutionary process of life on this earth as been for the past 3.6billion years that has produced the myriad crafted beings we are and share this life with) and then brings him back down to his reality, he is a warrior and his role is too fight.
if i worried about every tiny ant i might step on, every animal who suffers in order for my crops to grow, if i worry about every person i may harm in my inept attempts at human interaction, if i worry about every chemical and machine and genetic defect out there that might cause me harm and shorter life, id never get out of the house and live. that is not the way. i was created part of this vast living couldron, and i choose to partake in it.
that's what eating animals is about.
this is all very hard for us very conscious clinging to ego beings to take. it has always made it hard for us to take part in this cycling of life on earth. can we choose to take ourselves out of this pattern and not eat animals? i think for some that is a possible route if taking the life of animals causes them personal pain.
however even if 6billion humans become vegetarian, this is not a life of do no harm. we have to deny billions of other animals the right to their own vegetable food, room to live, not to mention the incredible burdens we put on ecosystems as a whole.
one day we will have to come to terms with the fact that we are life, and this is the way life is, it is not a mamby pamby fairy existence. life is gutsy and intricately intertwined with suffering and death. the only way out of this reality is to take the poison koolaid and believe your soul is going to live on some passing comet. (in fact it is this tendency to shy from the horrific reality of life and try to fly away to an idea of an eternal soul in heaven that i find one of the most dangerous aspects of many religions)
The bhagavad Gita has an interesting view on this. Arjuna is a warrior preparing to bring his army to battle. he is standing on a mountain watching both armies prepare. the sight overwhelms him, he begins to imagine all the death and suffering his soldiers will cause, and the families that will suffer when their soldier-fathers don't come back from battle, and... he freezes.
So Krishna comes and takes the whole rest of the book convincing him that there is no other way. if his army does not fight then the enemy army will also cause suffering to his people. Krisha brings him to the very pinnacle of experience of the horrific reality of life with its whirling giant maw of teeth and arms and eyes of creativity through destruction (for that is what the evolutionary process of life on this earth as been for the past 3.6billion years that has produced the myriad crafted beings we are and share this life with) and then brings him back down to his reality, he is a warrior and his role is too fight.
if i worried about every tiny ant i might step on, every animal who suffers in order for my crops to grow, if i worry about every person i may harm in my inept attempts at human interaction, if i worry about every chemical and machine and genetic defect out there that might cause me harm and shorter life, id never get out of the house and live. that is not the way. i was created part of this vast living couldron, and i choose to partake in it.
that's what eating animals is about.
Tuesday, March 15, 2011
I Have Seen The Future Of Art, and It Is The Jetsons
I was walking around at RPI today in Troy, NY, and came across this EMPAC (Experimental Media and Arts Center) thing.
So what is this all about, this high tech futuristic stuff? It reminds me of that juvenile imagination of the glorious future we used to watch as kids on saturday mornings called the Jetsons. and then i looked harder, and something actually looked familiar. could it be? I had to check:
Yes, it's her! Jane Jetson! Million dollar serious performing arts center and it's modelled after a cartoon's hairdoo. Hopefully I will write a more detailed deconstruction of this hideous piece of architecture shortly.Also, I'm taking up a collection to raise money to ship it off to the moon.
Ok, i realize that's an artist's conception, so i found this photo (see below):
Friday, March 11, 2011
Swirls Of Sexvines In English and French!
SWIRLS OF SEXVINES
swirls of sexvines intoxicating,
night perfumes of flowers
calling moths, enticing them
to mix pollen and imagine
new beings, inviting danger,
eruption of potent species
into the forest.
a memory of aroma of a night
when i feared being only a moth
but my death was death of the universe
locked in my skull,
infested with vines
and sinews of thoughts and longings.
bible verses came to attack
but the jungle rotted them
to ant food.
longing for something to read,
i picked up stars with my tongue
but they stung ,
so i burrowed under leaves
and seeped into roots.
the stars called me
into veins in the night.
i became many, and the rain
washed me into puddles
where i birthed a multitude
of minute beings eating each other,
living in each other's bellies,
stitching the earth together in laughter,
and it keeps growing...
TOURBILLION DE SEXVIGNES
tourbillons de sexvignes
parfum de nuit des fleurs enivrant
appelant phalenes, les inciter a mélanger de pollen,
imaginer des êtres nouveaux, inviter danger,
eruption des espèces puissant dans la forêt,
une mémoire de l'arôme d'une nuit
où je craignais d'être seulement un papillon de nuit,
mais ma mort était la mort de l'univers
enfermé dans mon crâne infesté de vignes
et les nerfs des pensées et des désirs.
versets bibliques sont venus attaquer,
mais la jungle les a pourri en ailments de fourmis.
desirais ardemment pour quelque chose à lire
je ramassé étoiles avec ma langue, mais ils piqué
donc je s'enfouit sous les feuilles
et je s'est infiltrées dans les racines,
et les étoiles m'a appelé dans les veines dans la nuit
et je suis devenu beaucoup
et la pluie me rejetee dans les flaques ou je donné naissance
à une multitude d'êtres vivants miniscules mangent
les uns les autres, vivant dans les uns les autres ventres
brodent la terre ensemble en rient et il ne cesse de croître...
I'm sure i've hopelessly botched the verb tenses, and probably they are not consistant. also i would have to read a bunch of french poetry (in storage) to find the right words with the right connotations.
swirls of sexvines intoxicating,
night perfumes of flowers
calling moths, enticing them
to mix pollen and imagine
new beings, inviting danger,
eruption of potent species
into the forest.
a memory of aroma of a night
when i feared being only a moth
but my death was death of the universe
locked in my skull,
infested with vines
and sinews of thoughts and longings.
bible verses came to attack
but the jungle rotted them
to ant food.
longing for something to read,
i picked up stars with my tongue
but they stung ,
so i burrowed under leaves
and seeped into roots.
the stars called me
into veins in the night.
i became many, and the rain
washed me into puddles
where i birthed a multitude
of minute beings eating each other,
living in each other's bellies,
stitching the earth together in laughter,
and it keeps growing...
TOURBILLION DE SEXVIGNES
tourbillons de sexvignes
parfum de nuit des fleurs enivrant
appelant phalenes, les inciter a mélanger de pollen,
imaginer des êtres nouveaux, inviter danger,
eruption des espèces puissant dans la forêt,
une mémoire de l'arôme d'une nuit
où je craignais d'être seulement un papillon de nuit,
mais ma mort était la mort de l'univers
enfermé dans mon crâne infesté de vignes
et les nerfs des pensées et des désirs.
versets bibliques sont venus attaquer,
mais la jungle les a pourri en ailments de fourmis.
desirais ardemment pour quelque chose à lire
je ramassé étoiles avec ma langue, mais ils piqué
donc je s'enfouit sous les feuilles
et je s'est infiltrées dans les racines,
et les étoiles m'a appelé dans les veines dans la nuit
et je suis devenu beaucoup
et la pluie me rejetee dans les flaques ou je donné naissance
à une multitude d'êtres vivants miniscules mangent
les uns les autres, vivant dans les uns les autres ventres
brodent la terre ensemble en rient et il ne cesse de croître...
I'm sure i've hopelessly botched the verb tenses, and probably they are not consistant. also i would have to read a bunch of french poetry (in storage) to find the right words with the right connotations.
Friday, January 7, 2011
Elementary Algebra Final Exam I Gave Once (or use it as a review!)
BASIC MATH I 38103 FINAL EXAM 12 NOV 1998
COPY DOWN EACH PROBLEM, AND THE PROBLEM NUMBER. (YOU NEED NOT
COPY THE LONG SENTENCES, ABBREVIATE!) SHOW ALL WORK. WRITE
OUT ALL STEPS THAT YOU THINK OF. DON'T DO ANY IN YOUR HEAD.
WORK SLOWLY BUT SURELY AND YOU WILL FINNISH IN TIME. CIRCLE
YOUR ANSWERS. DON'T FORGET TO CHECK SOLUTIONS TO 'SOLVE FOR X'
PROBLEMS. LOOK AT THE ORIGINAL QUESTION WHEN YOU FINNISH A
PROBLEM, TO MAKE SURE YOU'VE ANSWERED THE QUESTION. QUESTIONS
ARE WORTH 4 POINTS EACH (UNLESS MARKED LIKE []) TO MAKE A TOTAL
OF 200 POINTS. THERE ARE 4 PAGES, 57 PROBLEMS.
PART I
1) WHAT IS THE SLOPE OF THE LINE: Y= -3X+2 ? [1]
2) WHAT IS THE Y-INTERCEPT OF THE LINE Y=4X+3 ? [1]
3) DOES EVERY STRAIGHT LINE HAVE A Y-INTERCEPT? [2]
4) GRAPH THE LINE Y= -3
. 3
5) GRAPH THE LINE Y= - ---X + 6
. 2
6) FIND THE VALUE OF THE SLOPE OF THE LINE BETWEEN THE POINTS:
(6,3) AND (-2,3), OR TELL IF THE SLOPE IS UNDEFINED.
7) WRITE THE EQUATION OF THE LINE WITH A SLOPE OF -3/2 THAT
PASSES THROUGH THE POINT (-4,3)
8) WRITE THE EQUATION OF THE LINE THAT PASSES THROUGH THE
POINTS: (4,-5) AND (4,3)
9) WRITE THE EQUATION OF THIS LINE:
PART II
10) DOES EVERY SYSTEM OF EQUATIONS HAVE A SOLUTION? [2]
11) CAN A SYSTEM OF LINEAR EQUATIONS HAVE EXACTLY TWO DIFFERENT
SOLUTIONS? [2]
12) MATCH THE SYSTEM OF EQUATIONS WITH THE CORRECT CONCLUSION:
[9]
A) Y=2X+1 B) X+Y=1 C) X+Y=1
. Y=X+2 2X+2Y=2 2X+2Y=4
1) NO SOLUTION 2) EXACTLY ONE 3) INFINITE NUMBER
. SOLUTION OF SOLUTIONS
. 2
13) IS THE GRAPH OF THE EQUATION Y=X A STRAIGHT LINE? [bonus]
SOLVE EACH SYSTEM OF LINEAR EQUATIONS. DON'T FORGET TO CHECK!
14) BY SUBSTITUTION: 15) BY GRAPHING: 16) BY ADDITION:
. 4X + Y = 14 Y = X - 1 X - Y = 4
. 3X - 2Y = 5 2Y + X = 4 2X - 3Y = 9
[6] [9] [6]
PART III
. -5 6
17) WHICH IS BIGGER 4 OR 3 ? [1]
. 2 2
18) TRUE OR FALSE: (X+4) = X + 16 [2]
19) WHAT IS THE AREA OF THE FLOOR OF A ROOM 10 FT. WIDE, 8 FT.
LONG AND 12 FT. HIGH?:
A) 80 FT. B) 960 SQUARE FT. B) 960 CUBIC FT. C) 80 SQUARE FT.
. 3 2 2 2 0 0
20) ( -3X Y ) *(4X Y) = 21) 4 * 3 =
. -2
22) WRITE 10 AS A DECIMAL.
SIMPLIFY, WRITING THE ANSWER WITHOUT NEGATIVE EXPONENTS.
. 2 -2 0 2 7 -4
23) 4X Y 24) 4X Y 25) (X )*(X ) =
. -------- ----------
. 2 -2 4
. (XY) 12Y X
. 3 2 2
26) (8X - 3X - 4Y) - (-4X + 8X + 2Y) =
. 2 2
27) (X-1) * ( X + X - 1) = 28) (4X-3) =
29) WRITE 0.00821 IN SCIENTIFIC NOTATION
. -5 2
30) WHICH IS GREATER? 8.98 X10 OR 1.001 X10 [2]
. 2
. -X - X
31) IF Y = -------- AND X= -2, CALCULATE THE VALUE OF Y.
. 3
. X
PART IV
32) HOW MANY DIFFERENT SOLUTIONS MIGHT A QUADRATIC EQUATION
HAVE? [2]
33) HOW MANY DIFFERENT SOLUTIONS MIGHT A 3RD DEGREE EQUATION
HAVE? [bonus]
. 2
34) SOLVE X = 4 35) FACTOR: 6X+9 [1]
36) DO THE SOLUTIONS OF QUADRATIC EQUATIONS REFER TO THE POINTS
OF INTERSECTIONS OF CURVED LINES OR STRAIGHT LINES? [bonus]
. 2 3 2
37) FACTOR: 2X - 5X - 3 38) FACTOR: X - 6X - 8X
. 2
39) IS: 3X + 1 = 4 A QUADRATIC EQUATION? SOLVE FOR X.
. 2
40) IS: 5X = X - 14 A QUADRATIC EQUATION? SOLVE FOR X.
SOLVE FOR X:
. 2
41) X +100 = 0
. 3
42) X(X+3) = 2X + 6 43) X -9X = 0
. 2
44) DIVIDE BY LONG DIVISION: (2X - 5X -3) - (X-3)
PART V
45) ARRANGE THE FOLLOWING NUMBERS IN ORDER FROM THE SMALLEST TO
LARGEST: 4 4 4 4 4 4 4
. ---, ----, ---, ---, ---, ---, -----
. 2 1 8 1 4 -1 1
. --- ---
. 2 10
. 4
46) WHERE WOULD THE FRACTION ---, GO IF YOU IMAGINE IT HAS A
VALUE? 0 [bonus]
. 2 2
47) TRUE OR FALSE: X + X X
[2] ---------- = ---
. 4 + X 4
48) TRUE OR FALSE: 6X + 3 9
. -------- = -----
[2] X(X+1) X+1
. 2
. X -3X - 28
49) SIMPLIFY --------------
. 2
. X - 49
. 2 2
. X - 64 X -8X
50) SIMPLIFY --------- - -------
. 2
. 8X + 64 8X
. 3 4
51) ADD: --- + ----- =
. X X+1
. X 2
52) ADD ------ - ------- =
. 2
. 2X+4 X +2X
. 3 4
53) SOLVE FOR X: ----- = ---
. X-2 X
. 6 3X
54) SOLVE FOR X: X + ----- = -----
[6] X-2 X-2
. 1 1
55) SIMPLIFY: X - --- 56) ------ =
. X [2] 1
. --------- ---
. X + 1 2
PART VI
CHOOSE ONE QUESTION AND WRITE ABOUT A HALF A PAGE ON IT. USE
EXAMPLES, EQUATIONS, CALCULATIONS, GRAPHS, ETC... WRITE IN
ENGLISH SENTENCES! [10]
. 0
A) WHY IS 4 =1?
. 2 3
B) WHY CAN'T I ADD X + X = X ?
C) NOW LOOK OVER QUESTIONS #11, #13, #32 AND #36 AND DESCRIBE
THE SITUATION IN DETAIL.
. 4
D) EXPLAIN WHY --- IS UNDEFINED.
. 0
Thank you. I hope you learned more than just some algebra
this semester. I enjoyed your company. Have a jolly winter!
Thursday, January 6, 2011
How Should You Tilt a Bottle To Pour The Liquid Out Fastest?
Blackskimmmer:
engineering question: tube closed at one open at the other. 1"wide, 6 feet long. filled to the brim with water.
what angle below the hoizontal drains it the fastest?
http://sfbay.craigslist.org/forums/?ID=67718622
1)
90 degrees -- upside down would be fastest
Blackskimmmer:
are you sure? the bubbles get in the way.
Zillionaire:
nope. Depends on how stable the tube. The "stickiness" of the water and geometry of the tube determines the angle... I think.
Gotta find the optimum glug, glug frequecy, bubble size and fall rate...
Um... 45 degrees?
Zillionaire:
Start at zero go to 90
Blackskimmmer:
describe the function of angle versus time
Zillionaire:
well... If you did it really fast at the right focal point, you could generate significant cetripetal acceleration. How about infitity degrees per second?
Blackskimmmer:
that's cheating, don't make things complicated yet.
Cyclopia:
Water weighs 1 gram/cc
and is very wet.
It's a good solvent, too.
My favorite beers are about 94% water.
And I am composed mostly of water.
It's good stuff.
1.6)
Blackskimmmer:
second guess the instabilities?
tminus7:
Rayleigh-Taylor instabilities.
http://en.wikipedia.org/wiki/Rayleigh-Taylor_instability
The real reason the water falls out of the tube.
Blackskimmmer:
that article hardly made a lick'o' sense, but i like the idea that crab nebula is RT fingers. my 2nd favorite place in the universe.
well as i aint got no answers to my problem, i'll have to go out and get a tube and experiment myself.
i'll report on it.
why do you say these instablilties is why the water flows out of the tube? in the turbulent regime? or is it just what gets it initiating the flow?
tminus7:
It is what intiates the flow.
Remember the only reason we are talking about this problem at all is that the outside air pressure is pushing the water back into the closed pipe with more force than the water weight pusing out. This is the condition Of RT instability. A low density fluid, air, pushing on a high density fluid, water. The simulation picture in the wiki article, if you turn it upside down is, is exactly the OP's problem. This is for the pipe straight vertical.
One simple proof is the old playing card/ glass of water trick. Place a card over the open end of a glass of water. Hold it and invert the glass. Let go of the card and, magically, the water does not fall out! The card is a stiff solid and changes the conditions away from the RT condition. The card is not free to flow. But it shows the outside air pressure is great enough to hold the water (and card) in the glass. So gravity is insufficient to pull the water out of an inverted glass. You need RT to make it fall!
Blackskimmmer:
aha! you are assuming that the if the water leaves the tube at first without any air flowing all the way to the end first, that the water will have to leave a vacuum at the opposite end, and thus... i'm not sure i understand... ok i understand merely a bubble flowing up through the tube of water but it's flowing up because the water over it is flowing down it, bouyancy and all... i still don't understand how to make a free body diagram with the volume elements to show why things move...
argh.... physics is hard!
ok, at least with the card trick i see that if the water tries to bulge out the upsidown glass with the card, it's gotta leave a vacuum at the top.. so air pressure keeps the card horizontal..
if i replace the card with the surface of the water... (surface tension effects? argghhh).. same problem, so .. you got to get some instability hapening... wow what would a movie be of the shape of the surface of that water the first millisecond that you remove the card (without causing any eddies where it touches... yikes, how to do it clean?)
surface tension IS important. if you do the trick with a hollow glass stirir, the water doesnt come out at all! hmm... what's the cuttof diameter per given hight of column...
yikes! fluids!
2)
Zillionaire:
answer is: 0
Zillionaire:
i mean negative tan(dia/lenth)
Blackskimmmer:
curious suggestion. that's the angle of the triangle from the lip of the tube to the opposite edge.
hmmm... gonna have to try this.
InOldenDays:
Yeah, nice idea, Z.
Angular measure, though: "arctan" instead of "tan".
3)
TheRealTryanJ:
1 degree below hoizontal so it doesnt bulid vacum to prevent water from flowing.
Blackskimmmer:
that's the idea! but how do you know 3degrees isn't faster? tricky problem.
i'm gonna have to go try it later.
4)
Geoloseth:
the angle will have to change in relation to the amount of water left in the tube. In essence you tip it over and once it starts to drain you keep tipping it to the maximum angle before air gets trapped in the tube.
Blackskimmmer:
that's a second version of the question.
5)
Toober:
I'll guess. The glu-glug frequency is a function of viscosity. I'm also not convinced that the recoil due to glugging would be enough to overcome a velocity of the maximum downward angle.
BUT, assuming you want to minimize glugging. That means getting a complete layer of incoming air to the very back of the tube.
So, place the tube at zero degrees horizontal, and draw a line from the lower open lip back to the upper closed lip. (you can figure it out from the dimensions you gave).I'm guessing that that is the minimum tipping angle for non-glugging.
6)
Blackskimmmer:
Ok, here is the report on my preliminary experiments:
well, i didn't get a tube yet, so i used two bottles:
I) louza bottle 1.5" wide mouth, 12" high, 3"wide bottom walls fairly streight
horizontal: 9sec
10sec
it starts off fast and then the last bits dribble out
30deg? about 2 sec, some glugging
45deg: 2sec? some glugging
2.5sec
vertical: 1.5sec
II)beer bottle: 3/4"opening, 4" of 1" neck, 10" tall, 2" at base
horizontal: 20sec, glugging, doesn't empty all the way slows to a dribble etc..
20deg? close to making the line from upper lip to rear bottom end horizontal: 11sec
11sec
45deg: 10sec fairly periodic glugging
9 sec
vertical: 8.5sec nonperiodic glugging? the glugging caused my hand to shake
8.5sec
7.5 sec
8.5sec
dynamic: 10sec
10sec
8 sec starting vertical and going more horizontal at end
10sec
9sec
dynamic maintaining NO glugging: 16sec
18sec
dynamic vertical then horiz then final vertical spill: 9sec
9sec
none of the measurements are precise. to the nearest second because how well could i time when i released the water with my palm? i used my computers clock with seconds. windows XP and IBM thinkpad.
http://sfbay.craigslist.org/forums/?ID=67868883
Blackskimmmer:
wow, i haven't done a physics exp in a while
alot of work!
analysis: while the glugging close to vertical is pretty bad, the speed of emptying between glugs and the speed of emptying at the end (less glugs) seems to more than make up for it.
would be interesting to time precisely the vertical emptying times maybe 100 times and see what kind of distribution i get.
would be interesting to analyse the periodicity of the gluging at various angles.
curious that dynamically changing the angle i couldn't get much better timing!
this is fun. it would be interesting to get a good long cylinder and a stand with a clamp and measure the angle (arcsin(height of rear end/len) more accurately. the longer the tube, the less imprecise my timings will be due to my impreciese "shutter" opening!
Toober:
To standardize:
When I had done similar experiments with students, we used PVC pipe closed-off with a PVC valve that you can cheaply purchase (>$8?) at Home Depot. The experiments we had done were pressure vs. height vs. velocity experiments, but only at 90-degrees vertical.
please consider this response: http://forums.newyork.craigslist.org/?act=Q&ID=67751574
Someday, I'd like to get back to Newtonian experiments.
Blackskimmmer:
yes, i hope to get around to finding some tubing, should be fun.
i suppose if i had glass tubing i could do things like time how long a bubble takes to rise to the top. i recall an exhibit on davinci and one of the things he messed with was the chaotic motion of bubbles...
Toober:
He described bubbles, but only as a part of turbulence (as I recall from my readings).
Blackskimmmer:
this stuff, from:
http://www.esam.northwestern.edu/~miksis/
Computation of Moving Boundary Problems in Fluid Dynamics
Rising gas bubbles play an important role in many physical and biological processes, such as the dynamics of multiphase flows, cavitation processes, and the flow of bubbles in the bloodstream. The rise of gas bubbles and the observation of a path instability has been documented since the time of Leonardo Da Vinci, but questions related to the origin of this instability still exist. CatherineNorman thesis topic was concerned with the development of a level-set numerical method to study the dynamics of rising bubbles. She considered both bubbles rising under an inclined plane and bubble free rising. She considered both cases were there was a film of liquid between the bubble and the plane and classes where there was a three-phase contact line. Hecode allowed for adaptive meshing and she developed a full second-order method.
On the right is a numerical calculation using the level-set code of C. Normann. Here we see a three-dimensional gasbubble rising from rest. The bubble initially rising along the center-line and flattens in the direction it is moving. With increasing distance, a spiraling path instability occurs. Because the bubble is rising inside of a finite channel, the spiraling instability eventually becomes a zig-zag instability where the bubble move back and forth in a center-plane normal to two of the faces.
References
* C.Norman and M.J. Miksis, "Dynamics of a Gas Bubble in an Inclined Channel at Finite Reynolds Number", Phys. Fluids, 17(2), 022102, 2005.
* C.Norman and M.J. Miksis, "Gas Bubble with a Moving Contact Line Rising in an Inclined Channel at Finite Reynolds Number", Physica D, 209, 191-204, 2005.
* C.E. Norman, "A level-set numerical method to determine the dynamics of gas bubbles in inclined channels", Ph.D. Thesis, Northwestern University, June 2005.
another description with davinci quote:
http://ct-cr4.chem.uva.nl/single_bubble/nature.pdf
engineering question: tube closed at one open at the other. 1"wide, 6 feet long. filled to the brim with water.
what angle below the hoizontal drains it the fastest?
http://sfbay.craigslist.org/forums/?ID=67718622
1)
90 degrees -- upside down would be fastest
Blackskimmmer:
are you sure? the bubbles get in the way.
Zillionaire:
nope. Depends on how stable the tube. The "stickiness" of the water and geometry of the tube determines the angle... I think.
Gotta find the optimum glug, glug frequecy, bubble size and fall rate...
Um... 45 degrees?
Zillionaire:
Start at zero go to 90
Blackskimmmer:
describe the function of angle versus time
Zillionaire:
well... If you did it really fast at the right focal point, you could generate significant cetripetal acceleration. How about infitity degrees per second?
Blackskimmmer:
that's cheating, don't make things complicated yet.
Zillionaire:
It is complicated, I would need to know the properties of water and air.
It is complicated, I would need to know the properties of water and air.
Cyclopia:
Water weighs 1 gram/cc
and is very wet.
It's a good solvent, too.
My favorite beers are about 94% water.
And I am composed mostly of water.
It's good stuff.
1.6)
Blackskimmmer:
second guess the instabilities?
tminus7:
Rayleigh-Taylor instabilities.
http://en.wikipedia.org/wiki/Rayleigh-Taylor_instability
The real reason the water falls out of the tube.
Blackskimmmer:
that article hardly made a lick'o' sense, but i like the idea that crab nebula is RT fingers. my 2nd favorite place in the universe.
well as i aint got no answers to my problem, i'll have to go out and get a tube and experiment myself.
i'll report on it.
why do you say these instablilties is why the water flows out of the tube? in the turbulent regime? or is it just what gets it initiating the flow?
tminus7:
It is what intiates the flow.
Remember the only reason we are talking about this problem at all is that the outside air pressure is pushing the water back into the closed pipe with more force than the water weight pusing out. This is the condition Of RT instability. A low density fluid, air, pushing on a high density fluid, water. The simulation picture in the wiki article, if you turn it upside down is, is exactly the OP's problem. This is for the pipe straight vertical.
One simple proof is the old playing card/ glass of water trick. Place a card over the open end of a glass of water. Hold it and invert the glass. Let go of the card and, magically, the water does not fall out! The card is a stiff solid and changes the conditions away from the RT condition. The card is not free to flow. But it shows the outside air pressure is great enough to hold the water (and card) in the glass. So gravity is insufficient to pull the water out of an inverted glass. You need RT to make it fall!
Blackskimmmer:
aha! you are assuming that the if the water leaves the tube at first without any air flowing all the way to the end first, that the water will have to leave a vacuum at the opposite end, and thus... i'm not sure i understand... ok i understand merely a bubble flowing up through the tube of water but it's flowing up because the water over it is flowing down it, bouyancy and all... i still don't understand how to make a free body diagram with the volume elements to show why things move...
argh.... physics is hard!
ok, at least with the card trick i see that if the water tries to bulge out the upsidown glass with the card, it's gotta leave a vacuum at the top.. so air pressure keeps the card horizontal..
if i replace the card with the surface of the water... (surface tension effects? argghhh).. same problem, so .. you got to get some instability hapening... wow what would a movie be of the shape of the surface of that water the first millisecond that you remove the card (without causing any eddies where it touches... yikes, how to do it clean?)
surface tension IS important. if you do the trick with a hollow glass stirir, the water doesnt come out at all! hmm... what's the cuttof diameter per given hight of column...
yikes! fluids!
2)
Zillionaire:
answer is: 0
Zillionaire:
i mean negative tan(dia/lenth)
Blackskimmmer:
curious suggestion. that's the angle of the triangle from the lip of the tube to the opposite edge.
hmmm... gonna have to try this.
InOldenDays:
Yeah, nice idea, Z.
Angular measure, though: "arctan" instead of "tan".
3)
TheRealTryanJ:
1 degree below hoizontal so it doesnt bulid vacum to prevent water from flowing.
Blackskimmmer:
that's the idea! but how do you know 3degrees isn't faster? tricky problem.
i'm gonna have to go try it later.
4)
Geoloseth:
the angle will have to change in relation to the amount of water left in the tube. In essence you tip it over and once it starts to drain you keep tipping it to the maximum angle before air gets trapped in the tube.
Blackskimmmer:
that's a second version of the question.
5)
Toober:
I'll guess. The glu-glug frequency is a function of viscosity. I'm also not convinced that the recoil due to glugging would be enough to overcome a velocity of the maximum downward angle.
BUT, assuming you want to minimize glugging. That means getting a complete layer of incoming air to the very back of the tube.
So, place the tube at zero degrees horizontal, and draw a line from the lower open lip back to the upper closed lip. (you can figure it out from the dimensions you gave).I'm guessing that that is the minimum tipping angle for non-glugging.
6)
Blackskimmmer:
Ok, here is the report on my preliminary experiments:
well, i didn't get a tube yet, so i used two bottles:
I) louza bottle 1.5" wide mouth, 12" high, 3"wide bottom walls fairly streight
horizontal: 9sec
10sec
it starts off fast and then the last bits dribble out
30deg? about 2 sec, some glugging
45deg: 2sec? some glugging
2.5sec
vertical: 1.5sec
II)beer bottle: 3/4"opening, 4" of 1" neck, 10" tall, 2" at base
horizontal: 20sec, glugging, doesn't empty all the way slows to a dribble etc..
20deg? close to making the line from upper lip to rear bottom end horizontal: 11sec
11sec
45deg: 10sec fairly periodic glugging
9 sec
vertical: 8.5sec nonperiodic glugging? the glugging caused my hand to shake
8.5sec
7.5 sec
8.5sec
dynamic: 10sec
10sec
8 sec starting vertical and going more horizontal at end
10sec
9sec
dynamic maintaining NO glugging: 16sec
18sec
dynamic vertical then horiz then final vertical spill: 9sec
9sec
none of the measurements are precise. to the nearest second because how well could i time when i released the water with my palm? i used my computers clock with seconds. windows XP and IBM thinkpad.
http://sfbay.craigslist.org/forums/?ID=67868883
Blackskimmmer:
wow, i haven't done a physics exp in a while
alot of work!
analysis: while the glugging close to vertical is pretty bad, the speed of emptying between glugs and the speed of emptying at the end (less glugs) seems to more than make up for it.
would be interesting to time precisely the vertical emptying times maybe 100 times and see what kind of distribution i get.
would be interesting to analyse the periodicity of the gluging at various angles.
curious that dynamically changing the angle i couldn't get much better timing!
this is fun. it would be interesting to get a good long cylinder and a stand with a clamp and measure the angle (arcsin(height of rear end/len) more accurately. the longer the tube, the less imprecise my timings will be due to my impreciese "shutter" opening!
Toober:
To standardize:
When I had done similar experiments with students, we used PVC pipe closed-off with a PVC valve that you can cheaply purchase (>$8?) at Home Depot. The experiments we had done were pressure vs. height vs. velocity experiments, but only at 90-degrees vertical.
please consider this response: http://forums.newyork.craigslist.org/?act=Q&ID=67751574
Someday, I'd like to get back to Newtonian experiments.
Blackskimmmer:
yes, i hope to get around to finding some tubing, should be fun.
i suppose if i had glass tubing i could do things like time how long a bubble takes to rise to the top. i recall an exhibit on davinci and one of the things he messed with was the chaotic motion of bubbles...
Toober:
He described bubbles, but only as a part of turbulence (as I recall from my readings).
Blackskimmmer:
this stuff, from:
http://www.esam.northwestern.edu/~miksis/
Computation of Moving Boundary Problems in Fluid Dynamics
Rising gas bubbles play an important role in many physical and biological processes, such as the dynamics of multiphase flows, cavitation processes, and the flow of bubbles in the bloodstream. The rise of gas bubbles and the observation of a path instability has been documented since the time of Leonardo Da Vinci, but questions related to the origin of this instability still exist. CatherineNorman thesis topic was concerned with the development of a level-set numerical method to study the dynamics of rising bubbles. She considered both bubbles rising under an inclined plane and bubble free rising. She considered both cases were there was a film of liquid between the bubble and the plane and classes where there was a three-phase contact line. Hecode allowed for adaptive meshing and she developed a full second-order method.
On the right is a numerical calculation using the level-set code of C. Normann. Here we see a three-dimensional gasbubble rising from rest. The bubble initially rising along the center-line and flattens in the direction it is moving. With increasing distance, a spiraling path instability occurs. Because the bubble is rising inside of a finite channel, the spiraling instability eventually becomes a zig-zag instability where the bubble move back and forth in a center-plane normal to two of the faces.
References
* C.Norman and M.J. Miksis, "Dynamics of a Gas Bubble in an Inclined Channel at Finite Reynolds Number", Phys. Fluids, 17(2), 022102, 2005.
* C.Norman and M.J. Miksis, "Gas Bubble with a Moving Contact Line Rising in an Inclined Channel at Finite Reynolds Number", Physica D, 209, 191-204, 2005.
* C.E. Norman, "A level-set numerical method to determine the dynamics of gas bubbles in inclined channels", Ph.D. Thesis, Northwestern University, June 2005.
another description with davinci quote:
http://ct-cr4.chem.uva.nl/single_bubble/nature.pdf
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