This is way more conceptual than I thought in today’s class
Michelson-Morley experiment negated the existence of either, with the insufficient evidence of ether's existence as his evidence.
Einstein suggested every constantly moving observer can be the standard of measurements, thus ‘all motion is relative.’ (111)
Yet the speed of light is always constant to observers in every situation???
Can light be the untimate frame of reference like what Newton wanted to find? (Only if it is possible to define the perspective of light?)
...and it is uneasy for me to visualize 'while motion makes lengths shrink, it makes time intervals expand' (112)
I do understand motion requires time to take place, hence longer time means more motion, but I think there's something more that I could not grasp. The ‘shrunk’ part is totally incomprehensible…
I do agree with that Einstin's insight and Michaelson-Morley experiment played significant role in science, but for me, that's it. For anyone who is highly visual-oriented like me, think about hiking. When you climb higher, you can see further, yet you are still on the same mountain. They brought up crucial dedications to the progression of science, but I cannot agree with that they changed the discipline of science. Hugh steps might change our points of view, but never can change the essence of the subject. Or maybe I'm missing something.
So I was pretty tempted to use me not understanding any of this as my excuse for using one of those two acceptable skipped posts. But I figured posting and trying to answer other people's questions and putting out my own would be better.
Like Tess said, I think that individually, each of these theories or equations or contraction make some sort of sense to me. But once light is thrown into the mix I get a bit too lost. And like Kate, I tried to just see the bigger picture and how this all relates to the project, but it's really hard.
I agree with Naya that even though I might not fully understand these concepts, the fact that so many different great scientists and thinkers put their time and minds into trying to answer 'what is light?'
On page 119, top right side, I guess I have a question about the idea that tachyons can move backwards in time. "As a tachyon loses energy, it goes faster both through space and (backwards) through time." I think that is an amazing idea that I think ties into the idea of "the three-dimensional world around us is essentially a shadow from four-dimensional spacetime" (p. 118). I don't know if those two ideas connect at all, but they stood out to me.... Am I wrong in thinking that they connect? COuld someone explain in words I understand why they are?
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. _________________ "We have two ears and one tongue so that we would listen more and talk less." - Diogenes of Sinope
Last edited by edalven on Tue Sep 27, 2011 7:30 pm; edited 1 time in total
"The insight which led him to the special theory was based on his sound physical intuition about what Maxwell's equations were really saying." (116) Einstein's insights about light lay in his ability to think theoretically, allowing him to consider the things possible within the universe that are harder for humans to perceive. "Einstein's great gift was his genius for physical insight into what a problem was really about. (p.116) Einstein demonstrated how the speed of light could be constant no matter where you stand on earth.
I do think this changed the discipline of science because it showed that everything is relative.
Like Knaide said, the Michelson-Morley experiment convinced Einstein that there was no ether or medium which light could travel through and that the speed of light was not dependent on it. It also showed him that the laws of physics were the same in reference frames moving with a constant velocity relative to each other. When Einstein developed his special theory of relativity "he was not influenced by the evidence from the Michelson-Morley experiment that the speed of light is always the same."(p.116)
The part about this reading that excited me the most was when the author stated that there is "nothing in the law of physics that forbids time travel." (p.120) I find the concept of time travel so intriguing! Perhaps this relates to light somehow? Or maybe I just want it to...
So I understand the Michaelson-Morley experiment talking about how there is no ether, and how Einstein says that movement is relative to an individual, but im not sure how they are connected or how one impacted the other...
And I would say that this insight did change science, but im not exactly sure how it did more than any other new scientific result... It shows that light can be a particle as well as a wave but im not sure what else... I was understanding in class today when Marilyn was telling us that somethings are just created or used to explain something, but they may not be truth. I got that, but now im just confused again.
I agree with everything most people have said about why Einstein's theory of relativity and concept of the speed of light changed science. I loved the quote Miranda used, but for a different reason than she did. "The insight which led him to the special theory was based on his sound physical intuition about what Maxwell's equations were really saying." (116) I think this is a great connection to our class discussion today, and how math is one of the only real truths out there. Einstein was much more conceptual, and definitely did some thought experiment stuff. I think it's important to not overlook what held Einstein to his own reality, and math was one of those things. I also have a question, but I'm not sure if there's an answer. What are the direct effects of Einstein's theories on how our lives function today? Not like technology wise, more how we go about our day and which truths we can accept.
I don't feel comfortable taking any risks answering anyones questions, out of fear I'll confuse everyone and myself even more. Hopefully tomorrow we can get some specific questions about all of Einsteins weird particles answered, because I think understanding those concepts will point us in a more clear direction.
I really had a difficult time with the reading tonight. I think all of physics and theories just really aren't connecting in my brain. But I'll take a shot in the dark of what I found from the reading and my thoughts on it all.
What I got from Einstein was that all motion is relative, and that E=MC2 is "the theory that unites space and time into a whole, spacetime." (pg 112 right side). I found the example about the pencil's shadow which was used to describe spacetime and the fourth dimension (extension?) extremely helpful.. "the changing length of the shadow is equivalent to the changing amount of length contraction the object undergoes..." That part of the example really helped me understand that concept that motion makes lengths shrink, and it makes time intervals expand. Moving on in the pencil's shadow example, the last line says "The three-dimensional world around us is essentially a shadow from four-dimensional spacetime." This I found really interesting and I would like to expand on this idea.
Lastly, I agree with what Knaide said about how even though light wasn't mentioned in every part of this passage, whatever was being discussed always lead back to the study and discoveries of light. It seemed like all of these important discoveries in science all revolved around that of light which means as far as I can see now, light and especially the developments made by Einstein in regards to light, changed the discipline of science.
His insight completely changed the discipline of science due to his theory of relativity. The theory united space and time into one (p. 117). Prior to this, as we've read, these have been entirely separate entities. Through many of Einstein's including his equation that said "that if a particle did exist that travel father than light, it would always travel faster than light (p. 119)." Unlike most physicists before his time, he had the ability to allow theory's exist even if they aren't true (I feel that I'm wrong, so feel free to question/or refute what I just stated). On the contrary, his equations told us that you can "never get a relative velocity greater than that of light by adding up two velocities that are less than c."
Maxwell's theory of electromagnetism were the building blocks to Einstein's studies. The Michaelson-Morley studies played no role in Einstein's findings.
As for projects, I think it's important to convey that light essential unites space and time, something that we as a class, and many past physicists believed to be separate.
Joined: 18 Feb 2011 Posts: 27 Location: United States of America
Posted: Mon Sep 26, 2011 9:53 pm Post subject:
I don’t really understant today’s reading, so what I am going it write about is more of what I think the reading is trying to say.
Michaelson-Morley experiment was an important step futhur in the discovery of light because the experiment showed that there was no existence of ether. The importance of the discovery would be the begining of the free form of science, and also the end of conventional thought.
Einstein then carried on the result of experiment to talk about the special theory of relativity. He talked about time and space should not be seperate. Spacetime should be considered a whole. Also, he talked about that everything was related to each other. The velocity we felt was related to the others’ speed.
I still believe that Einstein broke the discipline of Science because he approached Science from a totally different prospective- though experience. Even though later on, other scientists prove his theories to be correct, the process was different than originally disipline as well. Especially the idea of spacetime really stood out.
However, the reading kind of change my mind about Einstein’s greatness. Originally, I thought that he came up with the idea of time travel and relativity, but as I read more, all his thoughts were extended from other’s thought. I think the reason he is so important is because he took the next step in science and other scientists’ discoveries.
All times are GMT - 5 Hours Goto page Previous1, 2
Page 2 of 2
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
