Posted: Thu Dec 10, 2009 6:07 am Post subject: Making of the Atomic Bomb
1. Bohr
a. Assumed that forces in nature are different from mechanical forces
b. Confronted the problem of mechanical instability of Rutherford’s model of the atom
c. Lodged quantum physics within the atom
d. (Before: classical theory predicted that the electron would radiate light as it changed direction, losing energy, and would spiral into the nucleus and crash). BOHR proposed “stationary states” in the atom. Created a model
e. looked at spectroscopy to support model of atom.
f. Saw a relationship between orbiting electrons and lines of spectral light. With each jump, each electron emits a photon of characteristic energy
g. Produced Rydberg’s constant.. a numerical agreement between experiment and theory
h. CHANGED PHYSICS: Mechanistic physics became authoritarian. Said that the universe and everything in it is rigidly governed by mechanistic cause and effect.
i. Said the changes of state within individual atoms are not predictable. The electron’s location between orbits can not be calculated/visualized
j. Each stationary state of the electron is complete and unique
k. Reminded scientists that physics is more about ‘asking questions of nature’ than a defined system of “authoritarian command”. The purpose is not to find what nature IS but what we can SAY about nature
l. Points out that idealized concepts we come from our daily experiences
m. Wanted to find a way that matter and light could exist as both a particle and as a wave
n. Said what we know isn’t particles and waves but the equipment of our experiments. Said we must accept different and matually exclusive results as equally valid (light as a particle and light as a wave)
2. Heisenberg
a. Had a distate for visualizing unmeasurabe events. Thought Bohr’s electron orbits were unrealistic.
b. Looked to numbers for stricter evidence. He found that he had “mathematical consistency and coherence”
c. Invented QUANTUM MECHANICS (experimental evidence).
d. Wanted to abandon models altogether and stick to MATHEMATICS
e. Thought that it is THEORY that decides what scientists observe
f. Thought nature allowed experimental situations only to occur within the framework of quantum mechanics
g. Thought there must be limits to how precisely events could be known
h. Uncertainty principle= the end of strict determinism in physics. Atomic events are blurred so it is not possible to gather complete info, so predictions of their future can only be statistical
3. Schroedinger
a. His mathematics were clearer and simplified calculations
b. Thought that standing matter waves resided in the interior of the atom (not particles)
c. Thought multiple waves of matter produced light by constructive interference
What is different about the discipline of science because of the contribution of each of these scientists.
so this reading made my head hurt...and instead of trying to sum it all up ill just quote some stuff to make it easier on my brain.
"Mechanistic physics had become authoritarian. It had outreached itself to claim universal application, to claim that the universe and everything in it is rigidly governed by mechanistic cause and effect" pg 127
I interpret this as another proof that searching for the answer of the universe is impossible. And i might be completely misinterpreting it, but it seems that this was something that really shook up physics and made people view the ultimate goal of discovery differently.
"The prism spectroscope, invented in 1859, advanced the science. It used a narrow slit set in front of a prism to limit the patches of light to similarly narrow lines; these could be directed onto a ruled scale (and later onto strips of photographic film) to measure their spacing and calculate their wavelengths."
So this is pretty self explanatory-this invention is the reason people can accurately measure wavelengths. pretty big deal, definitely made it easier for people to make further discoveries.
All of the theories regarding atoms, standing still, their electrons (ect), they were often built off of each other. Scientists used other scientists discoveries as stepping stones for their experiments (thought or otherwise), which helped later scientists discover some more. all the theories and discoveries changed the discipline of science because they opened up new questions that needed answering and more things that could now be answered, that before would not have been possible.
phrased horribly...if its unclear i can try to word it better...
Bohr drew the line between nature and mechanics. He said "one must assume that there are forces in nature of a kind completely different from the usual mechanical sort." He studied enough of Einstein and Planck to apply what they knew to Rutherford's atom and make it more mechanically stable. As the text says, "Planck had introduced quantum principles to save the laws of thermodynamics, Einstein had extended the quantum idea to light, Bohr now proposed to lodge quantum principles within the atom itself." Bohr also said that there are some parts of the atom that do not move so that the electrons can orbit without colliding. I would say though, that the biggest impact he made on science was what he did to physics, saying that cause and effect rules everything in the universe. A pretty big idea, and so it changed physics and science.
Bohr invited Heisenberg to come work with him. While Bohr worked with models, Heisenberg worked with numbers and mathematics, looking for similarities within the numbers. Soon he found that he had "mathematical consistency and coherence." He was using matrices, those squares of numbers from Algebra 2. From these Heisenberg and some other scientists created what he called "a coherent mathematical framework, one that promised to embrace all the multifarious aspects of atomic physics." Of course, this had a big effect on science.
Schrodinger had a theory about matter, saying that when it is at an atomic level it acts like it is made of waves, that matter is a wave rather than an electron. A lot of physicists liked his ideas, because it somewhat contradicted quantum theory, and Schrodinger had much more solid proof.
Yikes. One minute I was chuntering along happily through quantum theory; the next minute I was slumped over my desk snoring loudly. I’m not feeling too great (perhaps the epic snowball fight didn’t help) so I’m not convinced I’m gonna be in tomorrow.
Bohr was “happy to force a confrontation between the old physics and the new”. He asked for methodological reform as well as usurping the brutal “authoritarianism” of mechanistic physics, taking the field down a peg so unconventional thinkers could get their ideas considered.
Bohr built on Einstein who built on Plank, and also extended the work of Rydberg and Balmer. I’m not sure how common this kind of scientific “relay race” (with the finish line being…. Objective truth!) was in 1900, but it seems rather cooperative and sweet.
Bohr and Heisenberg joined in a similar “unique cooperation”. Heisenberg started his studies with a “distaste for visualizing unmeasurable events”, which seemed “fanciful” (I can definitely relate). He raised an interesting question of how we should think about the imperceptible (ie what we can’t picture, even with measurement or mathematic forms of “perception”.) He relied heavily on matrix algebra (such a throwback to class with Matt Goodman) after “rejecting models entirely and looking for regularities among numbers alone”. As Sasha mentioned, quantum mechanics were largely Heisenberg’s doing- he also brought up the uncertainty principle, and thought that theory affected observation. Basically, H recognized how muddy-unclear-confusing quantum mechanics and atomic events were, and believed that we needed a new framework of scientific consciousness for understanding them.
I’m exhausted. In short. Shroeuedinger’s “sympathies lay with the older classical physics”, and brought up some old/new ideas about photonics…. “multiple waves produced light by the process of constructive interference”. Standing matter waves, not particles, made up the atomic nucleus. Again, as Sasha said (sorry sasha), it seems like he preferred simplicity, clarity, and elegance in all of his calculations.
Final Bohr note that really interested me: Nur die Fulle fuhrt zur Klarheit: Nothing but fullness will lead to clarity. I think this has serious implications for Science as well as History (both capital-letter disciplines). How would the movement of microhistorians have reacted to this maxim? Is there an movement in science equivalent to microhisorians in history? Is it more fair to apply Bohr’s fullness/clarity motto to Science than History?
first of all let me just say that marilyn, you were absolutely RIGHT about all chaos breaking loose. i feel im going slightly mad. but i managed to grasp on to a few things. i will at least attempt to answer the main question of the evening, how these discoveries changed the discipline of science.
when einstein said that it was not the brightness of light that determined the energy of its electrons, but the COLOR of the light, or its frequency. it blows my mind because whenever i think of light and dark, i think of brightness. but in a way that also relates to color. light is white and dark is black? something like that.
bohr, like tasha AND sasha said, changed science because he said that science is now under the iron fist of mechanistic cause and effect. this has to relate back to one or more of our philosophers, probably Kant and Hegel. the only difference is that Kant and Hegel didnt use the word mechanistic.
this guy Balmer clearly changed the discipline of science when he answered the important question reguarding the lines of helium by creating a formula, and equation, to address how the lines got there in the first place. im quite certain theres much more to this than what i just said, but its late, im rather tired, and cannot hope to come up with an intelligent thought at this hour.
lastly, i will sum up the entire reading into a very general statement. this group of scientists collectively changed big S science becausethey introduced an entirely new kind of science, one that was based on accurate experimental evidence (Page 132). If that doesnt change the discipline of science, im really not sure what does.
let me just start off in saying that by the end of this reading, the image of all these guys in one hotel in Brussels was the most exciting thing ever. how did all these geniuses exist at the same time? thats a whole nother tangent on zeitgeists. so i think i should start with schrodinger, who is proven wrong to an extent by bohr in an interesting interaction between the two. schrodingers believes that if indeterminacy is true on a quantum level, it must exist macroscopically as well. that is to say if there is innate uncertainty in the pattern of an electron or rather the necessity of an electron, then this uncertainty is a fundamental principle of reality that must exist on a larger more observable scale. he creates a thought experiment to serve as this macroscopic corollary which people may be familiar with... schrodinger's cat. its quite simple and goes roughly as follows (i might be distorting some of the facts a little but hopefully you get the general idea):
a cat is in a fully enclosed box. inside the box their is a singular atom, which is in someway rigged up to a bottle of poison. now indeterminacy, which states that the precise outcome of an electrons movement cannot be determined, would have us believe that the atom both behaves in a way that sets this poison to explode or break therefore killing the cat, while at the same time, behave in a way that doesn't set the poison to break thusly allowing the cat to live. now by the virtue that we cannot see whether the cat is dead or alive, in the same way we cannot measure (as heisenberg would discover) the position of an electron, then the cat is both dead and alive which is impossible, which proves that indeterminism is false.
schrodinger wasn't just a hater, he offered a perfectly legitimate alternative concerning the principles of waves. it seemingly explained everything but turned out to be 'too good to be true' as heisenberg joked, and was proven wrong. Bohr pressed on to find a unity between particles and waves, but heisenberg (perhaps in part to schrodinger's physical representation) wanted to abandon all attempts to visualize reality at this scale, and wanted instead to work on a purely mathematical level. skip ahead and heisenberg decides based on partially einsteinian reasoning that our methods of measurement are merely to crude to asses the necessity of electron movement without becoming that necessity. that is to say we can't actually measure the location of an electron without changing its location. not only are we unable to do this now, but we will never be able to. "there are inherent limits to how precisely events can be known." this is a paradigm shift. it indeed changes science by essentially saying there there is a physically unbreakable wall standing in the way of progress. it can never be broken, at least not by means of experiment.
so for the time being they would have to rely on mere statistics and the empirical without ever getting to the necessity. this is saying that the knower and what he knows are NOT in complete accord... wow, quite the revelation. but they must be! at least thats what einstein said and he believed so until the day he died. this new paradox which started with the particle versus wave paradox had evolved into a quest for unified field theory. Bohr however questioned the very notion that if two principles derived from evidence, contradict each other, one can't be true. he thought they both can be true in a complimentary way, kind of more hegelian. complimentary, meaning that opposites make something whole. needless to say both of them were unsatisfied with the status quo. now years later we have super string theory thought to be what einstein had been looking for. but its purely non experimental and too complex in many ways. but this is the new face of the struggle, the struggle to synthesize the struggle to know.
Last edited by jmax on Thu Dec 10, 2009 8:56 am; edited 2 times in total
Okay, so I did not finish the reading. I will skim the rest before B-Block tomorrow. But this is what I got:
Bohr, like Planck and Einstein before him, tried to "give way to a quantum approach" (p. 123) as the text said it. He tried to focus on the atoms itself. He took the ideas of other scientists and tried to propose alternative methods to them or try to prove them based on both quantum physics and mathematics and by thought process. This is another way of changing the discipline of science because along with the observation and experimentation, you can use the mathematical approaches of Maxwell and the insanely complex thought processes of Einstein into one hypothesis. Consequently, you see his ideas of the atoms and molecules. The concept of atoms and elements led to a greater understanding of the elements. That's just what I got. I had difficulty tackling this particular reading. Hopefully, it'll become clear to me tomorrow when I skim it.
I am a bit overwhelmed by the reading and did not quite finish it, so I am just going to put some quotes down and attempt to analyze them, because I have not fully formulated my own idea on how they changed the discipline of science.
"One must assume that there are forces in nature of a kind completely different from the usual mechanical sort" - Bohr
The things that make the universe go are not all necessarily like clockwork as Newton said, although Einstein had sort of already came up with this...
"He proposed the the heretical possibility that light, which years of careful, scientific experiment had demonstrated to travel in waves, actually traveled in small individual packets ... "energy quanta" - Einstein
Once again debating whether or not light is a particle or wave, maybe changed the discipline by making it so that nothing is accepted just because it is "proven"...
"The Rutherford atom, from the point of view of Newtonian mechanics - as a miniature solar system - ought to be impossibly large or impossibly small"
"On the constitution of atoms and molecules" was seminally important to physics... it demonstrated that events that take place on the atomic scale are quantitized"
Allowed for more changes of thinking on the atomic level...
I am having a hard time coming up with how the big question of "What is light?" and its corresponding explorations/experiments changed the big "S" Science. I see how they changed different parts of little S science but not how they changed the entire Discipline.
same as everyone else. I am exhausted, the reading may well be responsible, and this post will be an exhausted one.
What is different about the discipline of Science because of the contribution of each of these scientists.
First off, this quote serves little s nicely: "Planck had introduced quantum principles to save the laws of thermodynamics; Einstein had extended the quantum idea to light; Bohr now proposed to lodge quantum principles within the atom itself" (pg. 123)
but we're TOTALLY NOT talking about little s. so anyway.
Here are the big S quotes I saw:
(I think Bohr is kind of rad. Do you guys)
"Bohr was happy to force this confrontation between the old physics and the new. He felt it would be fruitful for physics. Because original work is inherently rebellious, his paper was not only an examination of the physical world but also a political document. It proposed, in a sense, to being a reform movement in physics: to limit claims and clear up epistemological fallacies. Mechanistic physics had become authoritarian. It had outreached itself to claim universal application, to claim that the universe and everything in it is rigidly governed by cause and effect." (pg.122) BAMMM!
"...(PARAPHRASE) the task of physics is not to find out how nature is but what we can say about nature" (pg.129)
on pg. 134 it starts talking about MATH in SCIENCE, and the reliability of a theory depending on the reliability of the math in it...
"It is the theory that decides what we can observe" -einstein pg.136//
uncertainty principle
"The problem, Bohr said, was that quantum conditions ruled on the atomic scale but our instruments for measuring those conditions- our senses, ultimately- worked in classical ways." pg. 137
(^ is that a doubt of EMPIRICISM?!!?)
alright. I hope those quotes were helpful. No synthesizing is coming out of me tonight, sorry to say.
Tonight’s reading was anything but Bohring (…heh.)
This is going to sound dumb, but I’m SO mad at Bohr for not being Hegel, because I want him SO badly to be the Hegel of science since his specialty is taking two contradictory viewpoints and aiming towards a larger whole, and towards progress, and yet he’s NOT about synthesis. His main contribution to Science was the theory of complementarity—that we should “accept the different and mutually exclusive results as equally valid and stand them side by side to build up a composite picture of the atomic domain…Light as a particle and light as a wave, matter as a particle and matter as a wave, were mutually exclusive abstractions that complemented eachother They could not be merged or resolved; they had to stand side by side in their seeming paradox and contradiction; but accepting that uncomfortably non-Aristotelian condition meant physics could know more than it otherwise knew. (137)”.
GAHHHHH I HATE THAT BOHR IS LIKE OH NO WE CAN’T FIGURE MUCH OUT FO SHO, BUT HE’S STILL EXCITED ABOUT AND TRYING TO FIGURE THINGS OUT. AM I MISSING SOMETHING HERE?!?! I feel like he should be giving up on the fucking world instead of putting dissonant objects that are “equally valid” together, but not to create a new form to the death of the new form, to create a sort of non-chemically blended amalgamation??? Is it a “hey when we figure out how much we don’t know we’ll be one step closer to figuring out what we know” Is that that what’s going on?!
Sorry about that. Bohr bothers me for the reason I think he bothered a lot of people: he was all about the “what we don’t know” and why we can’t (or Kant) know it; he said kind of the opposite of what Newton/Kant said: “”The problem, Bohr said, was that quantum conditions ruled on the atomic scale but our instruments for measuring those conditions—our senses, ultimately—worked in classical ways. That inadequacy imposed necessary limitations on what we could know”. (137) Also that “The situation in physics, he said, “bears a deep-going analogy to the general difficulty in the formation of human idea, inherent in the distinction between subject and object…the I who thinks and the I who acts are different, mutually exclusive, but complementary abstsactions of the self” . Like Kant and Newton were such little optimists because they were like “well, we don’t understand now, but since there’s a connection between the knower and the known, since a priori exist and since they exist inborn in us, we can figure it out someday!!!” and then Bohr was like JUST KIDDING ACTUALLY.
At first, upon reading this I was totally confused as to why Einstein and Bohr disagreed since Einstein’s relativity thang and Bohr’s complementaritiy thing, I thought, served the same-ish purpose in terms of the discipline of Science: to tear it from its concrete absolute-truth roots and aim it towards the relative, to emphasize the individual ‘s validity in Truth, but it seems like Einstein said, “well, this is all relative but there’s still an a priori formula, there are still rules for how things work, especially on a tiny itty bitty level, like microhistory. We can know truth from there. and then bohr was like THAT'S ESPECIALLY NOT TRUE ON A LITTLE LEVEL BECAUSE NONE OF OUR EQUIPMENT CAN GIVE US A LEGIT UNDERSTANDING (see quote at top of 139).
at the same time it's not even just that Bohr out-reletivity-ized Einstein. what throws me off is that reletivism, i think, should go hand in hand with abract thought instead of physical realities. yet bohr ONLY dealt with physical evidence whereas Einstein was totally cerebral? I think/hope I misunderstood everything in the reading. In which case, the anger of this post will be embarrassing, but everything will make more sense.
Heisenburg reminded me of my neurotic cat Woody, who frequently runs away from his own reflection, and when we got him a new cat chair thing, he literally clung onto the old one for dear life. Maybe I was just really tired when I read Heisenburg.
Posted: Thu Dec 10, 2009 9:48 am Post subject: everyone seems sooo tir..snorggkgkkkkgkzzzz (sleepy noises)
I think the few sentences that did make it to the thinking part of brain from this reading were the ones about the philosophy behind Bohr's science. Also the philosophy behind Einstein's and Heisenburg's science but to a lesser degree. So I think I will try to talk about that and less about quantum mechanics and their views on it. So Bohr seemed to be all about the the non-absolutism view. He got on quantum mechanics through argument and not through theory, but through things proven. Not mathematics though that was Heisenburgs field. Bohr's philososphy said that all "original work is inherently rebellious." I think that Bohr's ideas were best worked around argument and best proven through argument and that's why he argued so freakin much. I think Bohr took a lot from his everyday life and tryed not to theorize beyond a certian point. Abstract theorizing had limitations for Bohr as did any experiment one could use to prove these theories. Experiments were the limitations which were placed around any theory that was first placed in the abstract. to him "physics concerns what we can say about nature." Bohr eventually found that conflict in quantum physics and "classic" physics (I am having a hard time differentiatign between the two) eventually yielded a complementarity that clarified them... I don't think I understand this last bit of his thinking so I'm just gonna stop for now.
Heisenburg followed similar paths to Bohr, but he based much of his work around a mathematical base to which he could prove anything he came up with. He looked for "mathematical consistency and coherence."
The only big thing I noticed in Schrodinger's thoughts was that electrons did not jump around from orbit to orbit as Bohr had said but that the matter on that level acted in a wave like fashion rather than a particle fashion. His theory didn't out to be very nice and simple, but apparently Bohr was able to just completely shut him down. (Overall Bohr sounds really freakin annoying).
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