Posted: Mon Sep 26, 2011 5:40 pm Post subject: Einstein!
I guess I am starting this thread.
• What was Einstein’s insight about light and what role did the Michaelson-Morley experiment play?
• Did this insight change the discipline of science? How?
Post any questions you have and any insights the reading gave you on the light project.
The Michaelson-Morley experiment of improving the Interferometer confirmed that there is no ether, or medium which light can travel through. Einstein then said that everything moves in relation to everything else-movement is relative to the individual. This made the ether idea unneeded. From there he was able to explain that time and space linked together in spacetime, and objects are effected in terms of both depending on what speed they are traveling at.
As for Einsteins contributions offering significant change to the discipline of science, I say hells yes. Reading this, I kept wondering why certain parts didn't seem to have anything to do with light, but they all came back to ideas initiated by the study of light. In the spectrum explained on page 119, the speed of light is in the center of our universe and it's physical laws and some other universe that has laws that mirror ours, and the speed of light marks a point that cannot be crossed. Also, on the last page (121) it says "a new way of describing the behaviour of particles of light, which itself led to the creation of quantum mechanics itself."
Now, I say that last line is a big deal only because I've heard the term 'quantum physics' and 'quantum mechanics' used, but I still don't really understand what they are, if anyone could give me a better idea that would be great.
I think that Einstein’s insight about light was his proof that nothing can match the speed of light. Obviously this completely changed the concept of light. I couldn’t really figure out how the Michelson-Morley experiment affected Einstein’s insight about light. I feel like I’m getting this wrong but it seems like they were saying that the previous idea that light had to travel through stuff to get to earth was wrong and that really there wasn’t anything there. I’m not sure if that’s right though.
Einstein's major contributions seemed to be that a) "all motion is relative" and that there is no basic framework of time/velocity, b) it's impossible to run alongside a beam of light at the same speed, and c) the E=mc2 equation that says mass and energy are connected/ space and time are united.
Michael/Morley experimented with measuring the length of the standard metre in Paris in terms of a wavelength of pure light, and as Knaide said also built an improved version of the interferometer experiment that tried to measure the motion of earth through ether.
I don't feel as though I have a strong grasp of any of these concepts, so I don't really have a response to your question just yet knaide...but it does seem that the study of light afffected the discipline of science simply because many/all of the great science minds after Newton and beyond addressed this question over and over again, building on each other's foundations as they progressed.
I used to think I understood the theory of relativity, and then light got tossed into the mix and fussed it all up.
So if the theory of relativity says that all motion is relative, it fits nicely with the class, because it suggest that there are an infinite number of truths, but only one for every specific reference point. You can find a singular truth, you just have to decide whose.
but then there was light
I could just be misunderstanding things here, but it didn't seem like light was really all that relative. so,
How relative is light?
How does that relate to ether?
tess, you just took the words right out of my mouth.
I was having an ok time understanding some of the theories we were talking about but then we threw light into the mix and my mind turned to Jello.
So before I can even begin to answer the questions can I (with the help of others) backtrack and talk about light and the theory of relativity? I don't want to understand them but I need help understanding them in the context of progressing/not progressing science. As of right now, im SO LOST
Sooo, just a few things that I don't fully understand...It says in the text that light quanta were given the name photons; are photons basically just particles of light?
Also, in the text, it says "If a beam of light moves in the same direction in which the Earth is moving, we out to be trying to overtake it, so that it moves slightly less rapidly relative to our measuring instruments. But a beam of light moving across the direction of the Earth's motion, at right angles, should be measured to have the full speed c determined by Maxwell's equations." (113) This seemed important, but I don't really get what this excerpt is talking about...if someone could offer some clarification on this, that would be wonderful.
Also on page 113, it says "A combination of Newtonian ideas about the relativity of motion and the idea of light as an electromagnetic wave transmitted through the ether led naturally to the conclusion that the speed of light relative to the Earth must be different at different times of the year." I've read this sentence a million times and it still seems to not be sinking in. Is this just talking about the fact that the sun shines for a shorter amount of time each day in the winter and the days are longer in the summer?
About the light project...I definitely feel that out of all the things I've read about in the text that have to do with light, the concept of a light year has changed the discipline of science the most and I personally find it to be the most fascinating thing we've read about light so far. Reading about light years has definitely shed some light (hehehe) on how I'm going to answer the project question.
Tess i bursted out laughing when you said "but then there was light"
so all motion is relative, okay, so really there's a choice of fast yo want ot go through life, as far as motion goes not time. which is very ironic because yo hear stories form people who re like these adventurers and do all of these things and they talk about how eventful and long there life was, then you hea from people in small towns always telling you to enjoy life while it's here cause it goes by fast. the reading reminds me of this.
i feel as though the scientists were saying that light is not really relative. for the reason that no matter how fast you go chasing a particle of light, there is always the light you see from other places and that is still going the speed of light. so light is the limit, it;s not relative, its a constant thing. time can be relative, because going faster and faster makes the speed of light have to go further or something so times goes slower. so it's time (caused by light but not the light itself) that is relative.
i suppose the study of light changed the idea of truth forever, with its relativity buisness ad stuff. and science is the search for truth so yeah i wuld say it changed the study of it. but it's less that it changed the rules for everyone in their feild of study, more that it added another feild of study that ties basically everything together philosophically. so it changed it by adding onto it. and it probably helped to explain a lot of questions in the other feilds of science, but it didn't completely alter them
ok, so i'm not gonna lie, this relativity stuff makes my head hurt. But what i think i got from the reading is that, Einstein believes that all motion is relative, and that while motion makes lengths shrink, it makes time intervals expand. Also that light is both a particle and a wave. The Michaelson-Morley experiment introduced the question of if the speed of light relative to the earth was dependent on the earth's motion.
And for changing the discipline of science? I would say mostly yes. I agree with what knaide said, about how there were parts so far off from light, but then it all came back to the subject. And it is true that light and the speed of light is the center of our lives. From the subject of light, we can go in so many directions, like magnetism, electricity, relativity, the list is really endless.
Einstein's insight about light was that all motion is relative and that anyone can be at rest and measure all relative motion to themselves. It seemed that all Einstein cared about was the fact that there was motion and as long as there is motion, his theory stands true. I think that the Michaelson-Morley experiment helps dictate Einsteins insight on light. Together they came up with an improved version of the interferometer and tried measuring the Earth through the ether. By figuring that out, it helped Einstein figure out that motion is relative.
I think Einstein's insight did change the discipline of science because it helped people understand beyond what their eyes can physically see and somewhat changed physicists' approach to physics.
Tess and Jessica I am so with you! I think my biggest question right now is the one Tess posed "how relative is light?" I like Douglas' idea that if light does in fact relate to relativity than it majorly changed the idea of truth. I think I'm going to keep looking for evidence for this. (hope i'm not going in the completely wrong direction)
And Jessica, I'm feeling kind of lost too. I think I'm getting too bogged down in trying to understand the logistics of everything. My gut reaction is to try to understand everything in the big picture instead of focusing on all scientific theories and experiments. How are other people going about it?
Posted: Mon Sep 26, 2011 8:17 pm Post subject: Einstein
LiliaGaufberg wrote:
It says in the text that light quanta were given the name photons; are photons basically just particles of light?
Perhaps I can shed some light on that...(sorry, couldn't help myself.) I think you're right about photons, but specifically, they're units of light. They are often described as particles, 'little packets of light energy', but this is somewhat misleading because they also behave as waves sometimes. They travel at the speed of light. These are all unchecked things I remember from Physics IIa, so they might not be entirely factual.
I think Rachel and Marilyn mentioned that some people believe that neutrinos could potentially exceed the speed of light. I read an article where scientists working at a particle accelerator may have actually done it. Personally I'm pretty skeptical, but it's pretty funny that this happened just yesterday. If somehow it was correct, this would be inconsistent with Einstein's theory of General Relativity; pretty serious stuff.
I think I'm getting too bogged down in trying to understand the logistics of everything. My gut reaction is to try to understand everything in the big picture instead of focusing on all scientific theories and experiments. How are other people going about it?
I'm focusing on fully understanding the works of each thinker that we're reading about, what their theories were, etc. I feel like once I zoom in on each thinker and really understand backwards and forwards what their individual accomplishments and ideas were, I'll be able to put the pieces together and create one big picture that will actually make sense. I hope this helps!
Just going of what Tess said about an "infinite number of truths", i think this idea radically changed how we perceive science. Up until now I had been defining science in my head as "the search for truths independent of man". However, Einstein proved that the Newtonian ideas of "a universal standard of rest" and "an absolute standard of time" (116) do not exist. Instead all motion is relative, and all observers have the right to "measure all motion relative to themselves" (116).
I sort of see this as the relationship between Kant and Hegel. Kant thought that we had a priori knowledge that could not be changed depending on who you are or what your experiences were. Hegel thought that the knower creates knowledge through consciousness, and that there is no truth outside of man, but rather that truths are only for individuals.
Scientists like Einstein were just catching up with this Hegelian idea. Also, many of the scientists we learned about in this passage did thought experiments (for instance, Einstein's inspiration for the theory of special relativity based off what would happen "if you were moving at the same speed as the [light] wave" (116)) but for the most part their ideas were supplemented and "proved" by mathematical equations (ex. Maxwell's or the Lorentz transformation equations) and often times were later proved by experiments, Newton style. I guess the study of light caused scientists to broaden what they will accept as reasonable evidence to thought experiments, and also made them emphasize the value of math.
Also a big idea that came up for me in this reading was symmetry, the idea that things don't necessarily have to be orderly but that there is still a certain degree of "symmetry", maybe we can explore that a little more?
I don't feel I can speak to anyone's questions about the actual theories and relativity of the physics written about in the reading.
The Morley-Michelson experiment accidentally helped prove that ether didn't exist. The rest of 115 also made the argument that ether was a pretty ridiculous explanation in the first place. This experiment and insight is important to science because without the disproving of ether with solid evidence, humanity might not have figured out that outer space is a vacuum, and that knowledge was necessary to space travel.
Or was it?
Isn't ether and the thought experiments of Faraday and Maxwell just attempts to understand the world around us, and doesn't ether serve that purpose? If we had thought outer space was composed of ether, would it have affected space travel and Astronomy at all?
Kate, I am trying to focus on the big picture and how these scientific theories affected the discipline of science, as well as how this changes my definition of science.
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