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Author | Topic: Misconceptions in Relativity | |||||||||||||||||||||||
cavediver Member (Idle past 3665 days) Posts: 4129 From: UK Joined: |
Over at THE END OF EVOLUTION thread, Lucy the Ape claimed that I had stated that "mass increases with velocity", and that I was wrong. Well, if I had ever made such a vague statement, I would probably have to agree that it is wrong. But equally wrong would be the statement "mass does not increase with velocity". Both are "wrong" in their vagueness, and both can be correct given the right context.
This thread is to explore and banish the myriad of misconceptions that arise in Relativity (and related physics areas). We can look at the "paradoxes" of Special Relativity, revisit Percy's favourite topic of cosmological vs doppler red-shift, and delve into black holes, wormholes and time-travel... QM could do with a thread of its own, but there could well be some overlap. The idea is for brief responses that may lead, if interest dictates, to new threads on specific topics. I would prefer not to get bogged down in any one area in this thread. My time can be limited, so hopefully Son Goku can jump in and help, plus anyone else who thinks they can clarify a situation. But as it is a thread on banishing misconceptions, I will not be pulling any punches if replies start to exacerbate those misconceptions Lucy the Ape has introduced our first misconception, so I suggest we start there... Big Bang and Cosmology, please... Edited by cavediver, : No reason given.
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AdminNosy Administrator Posts: 4754 From: Vancouver, BC, Canada Joined: |
Thread moved here from the Proposed New Topics forum.
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shalamabobbi Member (Idle past 2870 days) Posts: 397 Joined: |
Hi CD,
Thanks for the educational threads. It seems that on a certain forum run by YECs that much is being made of the voyager anomaly. It appears that your arch nemesis Russell Humphreys has put the anomaly to good use to support his theory and book "Starlight and Time". Despite the fact that the anomaly is thought to be due to some aspect of the craft, such as radiation of thermal energy etc, and that another craft is planned to investigate this phenomenon, it seems some YECs are busy slapping themselves on the backs over this. My question is if another experiment verifies the anomaly what modifications to cosmological understanding will likely result from this knowledge? Would the 'tired light' explanation of red shift take over or would something else result? Thanks. Edited by shalamabobbi, : wrong word replaced with it's correct cousin.
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cavediver Member (Idle past 3665 days) Posts: 4129 From: UK Joined: |
Oh great - I log in from Heathrow Terminal 4, looking forward to something nice and simple, and I get this Russell Humphreys seems to have a bad case of Lying for Jesus(TM) or perhaps Deluded for Jesus(c). Explaining why however is rather a large topic, as is the whole Pioneer Anomaly, if we are to treat this exhaustively. Far more sensible is to just wait for better data, but that does leave the YECs room to jabber incoherently... I'll see how much time I have to put something together over my vacation this week.
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RAZD Member (Idle past 1426 days) Posts: 20714 From: the other end of the sidewalk Joined: |
Hey cavediver,
Explaining why however is rather a large topic, as is the whole Pioneer Anomaly, if we are to treat this exhaustively. Far more sensible is to just wait for better data, ... So I take it there is no new information on these anomalies? Pioneer anomaly - Wikipedia
quote: As I recall, approximately the same acceleration would explain the rotation of galaxies without dark matter, but I can't find confirmation of that here. Galaxy rotation curve - Wikipedia
quote: Would that be a fair summary of the current status? I don't want to stir up old issues here, just want to keep up to date. Enjoy. by our ability to understand Rebel American Zen Deist ... to learn ... to think ... to live ... to laugh ... to share. • • • Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click) • • •
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WaveDancer Member (Idle past 5426 days) Posts: 37 From: NSW Australia Joined: |
I have a question! Is time and space the fourth dimension when people talk about the 10,11 or 12 dimensions or is it only the fourth dimension in special relativity and is not considered the fourth dimension anywhere else?
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cavediver Member (Idle past 3665 days) Posts: 4129 From: UK Joined: |
Is time and space the fourth dimension when people talk about the 10,11 or 12 dimensions We're all familiar with the three dimensions of normal existence, e.g. x,y,z or height, width, depth. Relativity introduces time as the fourth dimension, but those of us who work with Relativity almost always put time first - so (t,x,y,z) is a point in space-time, and time is the first dimension. When we start working with extra dimensions in Kaluza-Klein theory, Supergravity, or most recently String Theory, we are adding extra space dimensions, so we have (t,x1,x2,x3,x4,x5,x6,x7,x8,x9) which is a point in 10d space-time. Rarely, we may add a second (or more) dimension(s) of time, but this is now adding another level of complexity, and opening a whole new can of worms...
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cavediver Member (Idle past 3665 days) Posts: 4129 From: UK Joined: |
Would that be a fair summary of the current status? Well, it's my current level of knowledge - there may be more I can find out once I am back from vacation.
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Son Goku Inactive Member |
The Pioneer Anomaly is probably not gravitational in origin. This is because we can test the semi-major axis of Neptune and Uranus extremely pricisely. If there was a gravitational origin to the anomaly then it would have an affect on the axis of the two planets.
More details here:http://arxiv.org/abs/gr-qc/0608127 I should mention that these tests are model independant, that is they don't assume any theory of gravity in particular in order to carry out the observations. This paper is from 2006, as of 2009 the Pioneer Anomaly is consider to be almost certainly not of gravitational origin. Edited by Son Goku, : Repeated phrasing removed.
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RAZD Member (Idle past 1426 days) Posts: 20714 From: the other end of the sidewalk Joined: |
Interesting. Any idea what the best candidate is at this point?
Thanks by our ability to understand Rebel American Zen Deist ... to learn ... to think ... to live ... to laugh ... to share. • • • Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click) • • •
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WaveDancer Member (Idle past 5426 days) Posts: 37 From: NSW Australia Joined: |
Thanks Cavediver.
So for your average Joe time would be considered the 4th dimension. Just another thing if you get a chance can you or somebody else knowledgeable on the subject watch this video and tell me whether or not it describes the 10 dimensions correctly or does it over simplify it? https://www.youtube.com/watch?v=XjsgoXvnStY
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cavediver Member (Idle past 3665 days) Posts: 4129 From: UK Joined: |
So for your average Joe time would be considered the 4th dimension. Yes. The video is almost complete nonsense, so please ignore it.
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rueh Member (Idle past 3682 days) Posts: 382 From: universal city tx Joined: |
Hello Cavediver,
I have a question for you. A friend and I were discussing the order of events of the BB. My question is. Would there have been light emmitted during the intial moment of the BB, or would light not have been present until after the cosmic dark ages had come to an end, with the formation of stars? Edited by rueh, : subject correction 'Qui non intelligit, aut taceat, aut discat' The mind is like a parachute. It only works when it is open.-FZ The industrial revolution, flipped a bitch on evolution.-NOFX
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cavediver Member (Idle past 3665 days) Posts: 4129 From: UK Joined: |
Hi, sorry for late response - been diving for a week
Would there have been light emmitted during the intial moment of the BB No, for the simple reason that there was no such thing as light at that point - photons did not exist. They are a result of electroweak symmetry breaking, which did not occur for around 10-12seconds after the big bang - ages in Big Bang terms After thjat, photons were around but "light" as we think of it - free passage of photons through space - did not occur until recombination, some 380,000 years after the BB.
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rueh Member (Idle past 3682 days) Posts: 382 From: universal city tx Joined: |
Thank you for the response. I have been trying to explain this to my friend. However I seem to lack the aptitude to convey, that even though there were photons they would not have produced light as we know it. The photons would have been interacting with charged particles in the universe and would not have been able to travel freely until the universe decoupled and took on a nuetral charge, there by allowing the photons to travel freely. Is this still on the right track so far?
'Qui non intelligit, aut taceat, aut discat' The mind is like a parachute. It only works when it is open.-FZ The industrial revolution, flipped a bitch on evolution.-NOFX
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