Welcome!
Hello Dauto, and welcome to Wikipedia! Thank you for your contributions. I hope you like the place and decide to stay. Here are a few good links for newcomers:
I hope you enjoy editing here and being a Wikipedian! Please sign your name on talk pages using four tildes (~~~~); this will automatically produce your name and the date. If you have any questions, check out Wikipedia:Where to ask a question or ask me on my talk page. Again, welcome! Fawcett5 18:07, 19 October 2005 (UTC)
You were right that there was a problem with a sign, but it's not a good idea to just delete a minus sign without a reason. I corrected the sign error by taking the integral over M in the correct direction. 75.45.210.119 ( talk) 18:32, 4 February 2009 (UTC)
You deserve a barnstar. Best wishes. Axl ¤ [Talk] 18:32, 2 March 2009 (UTC)
The E=mc² Barnstar | ||
To Dauto, for contributions to scientific articles. Axl ¤ [Talk] 18:32, 2 March 2009 (UTC) |
I asked a follow-up to one of your answers on the science desk regarding quantum mechanics and predetermination. Your responses there are usually very helpful and appreciated. Thanks misli h 00:04, 24 April 2009 (UTC)
You gave a truly patient and correct response to a convoluted question. Cuddlyable3 ( talk) 18:31, 12 June 2009 (UTC)
Hi Dauto. Thanks for the reference desk answer -- I needed you help in seeing how simple it was. I'm not trying to pick nits here, but when you wrote "I forgot to include the energy realeased from two electrons" I assume that it was the mass of the electrons themselves that you had forgotten to include, because I get you initial number of 0.0068500 from 1 - mα / (4 mp). I am also assuming that your second number, 0.0071224, had a typo and you meant 0.0071204. Thanks again. -- Thinking of England ( talk) 09:29, 23 August 2009 (UTC)
Hi Dauto,
thanks for SO(10) diagram -- just one last question. I get everything except the vertical column of arrows and numbers on the right hand side. How do they work?
Do you have a similar diagram for the Pati-Salam model?
-- Michael C. Price talk 14:51, 2 November 2009 (UTC)
Obviously I understand less than I thought. What is a "level"? It seems I need to understand that to get your Pati-Salam explanation.
Incidentally, my interest in Pati-Salam was piqued when I read that it doesn't predict proton decay. Since minimal SU(5) has been ruled out by the lack of proton decay, this seems to be a plus for Pati-Salam. Strangely, there seems very little in textbooks (and nothing on Scholarpedia) about Pati-Salam, which makes life frustrating. -- Michael C. Price talk 18:12, 2 November 2009 (UTC)
Obviously I understand less than I thought. What is a "level"?
It's really pretty simple. The top component of the weight diagram (The anti-neutrino for that specific diagram) is labeled as being level zero. Now go down the diagram (walking with your fingers if you will) following the links. Your first step will take you down to an up quark which is labeled as belonging to the level 1. Your second step take you down to another up quark (of a different color) which is labeled as belonging to the level 2. Work your way down to the bottom of the diagram which (for that diagram) will be level 10. It is just a way to help label the different components of the diagram to make it easier to refer to them. Dauto ( talk) 20:18, 2 November 2009 (UTC)
I'm having troubling downloading the Slansky paper (lack of cryllic skills). Do you have any links that give the langrangian for Salam-Pati? I couldn't find any on the physics archives that explained just the basic model, as opposed to some SUSY extension.-- Michael C. Price talk 14:52, 4 November 2009 (UTC)
Here's my rather unpolished attempt to summarise the ferrmion SU(4)c, SU(2)L and SU(2)R quantum numbers for Pati-Salam:
2I1 | 2I2 | 2I3 | |||
---|---|---|---|---|---|
L/R fermions | u1 | d1 | -1 | 0 | 1 |
u2 | d2 | 1 | -1 | 0 | |
u3 | d3 | 0 | 1 | 0 | |
e- | 0 | 0 | -1 | ||
2T3L/R | 1 | -1 | |||
2T3R/L | 0 | 0 |
Where
-- Michael C. Price talk 00:47, 7 November 2009 (UTC)
I have a few points to make.
Note how the SU(4) generators are out of order.
Of course the last two points are just a matter of convention, but they lead to a staircase-like structure for the eigenvalues which is easier to remember
2I3,1 | 2I3,2 | 2I3,3 | |||
---|---|---|---|---|---|
L/R fermions | u1 | d1 | 1 | 0 | 0 |
u2 | d2 | -1 | 1 | 0 | |
u3 | d3 | 0 | -1 | 1 | |
e- | 0 | 0 | -1 | ||
2T3L/R | 1 | -1 | |||
2T3R/L | 0 | 0 |
The expression for B-L has to be changed accordingly: Dauto ( talk) 05:31, 9 November 2009 (UTC)
I just noticed your nice diagrams on your home page and wanted to find out more about them, but it seems they aren't used in either Pati–Salam model or weight diagram. That's a shame! Why aren't they? — Sebastian 19:45, 8 March 2013 (UTC)
Hi Dauto,
Thanks for all the help with SO(10) etc. I'm trying to apply some of this to neutrinos at the moment.
I've seen it was stated on one of the neutrino talk pages that sterile neutrinos can oscillate with "normal" neutrinos. I'm not clear whether "sterile" just means "right-handed within the SO(10) model" or not. If sterile neutrinos are just right-handed neutrinos then it seems to me that they will have different weak hypercharge (0 for right-handed neutrinos, -1 for the left-handed neutrinos) and X charge. If so, wouldn't that prevent the right handed / sterile neutrinos from mixing or oscillating with the left handed neutrions?
-- Michael C. Price talk 12:05, 21 November 2009 (UTC)
Okay, let's see if I've followed that:
Is that right? -- Michael C. Price talk 21:12, 21 November 2009 (UTC)
You said “Yes” to my question posted on dated Nov 22, 2009 in the following link
http://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Archives/Science/2009_November_22
But I don't know why relativity pundits hesitate in saying “Yes” to my original question which is the reverse play of Einstein experiment in which two bolts of light strike the longitudinal sides of moving train.
Please ignore all if you dislike. 68.147.38.24 ( talk) 19:03, 1 December 2009 (UTC) khattak
Hi, Dauto. I noticed you reverted my removal of your comment and the ones that followed, at the end of User:Neptunerover's question regarding his no-maths solution to gravity. As I stated in the edit summary (and on the talk page), I think we should refrain from making such characterizations of our questioners. I have therefore moved the section in question to the talk page. Your opinion would be most welcome there. -- NorwegianBlue talk 21:46, 2 January 2010 (UTC)
Hi Dauto, I finally tracked down a copy of the original Pati-Salam paper, Lepton number as the fourth "color". I'm puzzled by a few things (actually a lot of things). They say that B-L is preserved (although they define L as -L, so they call it B+L), but at the end of the paper they also say that the proton decays into three neutrinos and a pion:
But this seems to violate B-L. Do they mean 2 anti-neutrinos and a neutrino, in addition to the pion? -- Michael C. Price talk 00:10, 14 February 2010 (UTC)
Hi Dauto,
do the new gauge bosons predicted by PS, aside from the W' and Z' bosons, all have B-L=4/3? And do they have an electric charge of 2/3?
-- Michael C. Price talk 01:54, 1 May 2010 (UTC)
The Reference Desk Barnstar | ||
For this particularly astute response, thank you! Calliopejen1 ( talk) 17:44, 20 January 2011 (UTC) |
Thank you for a clear and thorough answer to my question on half-life and decay constant. jftsang 23:25, 21 February 2011 (UTC)
1. The U-turn wasn't avoided at all, since the spaceship still reverses direction of motion and comes back to earth.
[@@@@ Thanks for commenting. Reverse is a poor description of what happens. The point of furthest travel isn't detectable to the ship, or clock. If you maintain that these "know" of a U-turn, then describe by what force or means @@@@]
2. The principle of equivalence doesn't work the way you think. The gravity on the planet is NOT equivalent to the acceleration of the spaceship and here is why.
[@@@@ The gravity on the planet is equivalent in this case since the earth-bound twin and clock stay at a constant elevation - no tidal effects. http://en.wikipedia.org/wiki/Equivalence_principle "The equivalence principle proper was introduced by Albert Einstein in 1907, when he observed that the acceleration of bodies towards the center of the Earth at a rate of 1g (g = 9.81 m/s2 being a standard reference of gravitational acceleration at the Earth's surface) is equivalent to the acceleration of an inertially moving body that would be observed on a rocket in free space being accelerated at a rate of 1g. Einstein stated it thus:" @@@@]
From the point of view of the observer on the planet he is at the bottom of the planet's gravity well while the ship is outside of the well - that is further up the gravitational potential, and the difference between their gravitational potentials is constant throughout the trip. The planet's gravity isn't very strong so this effect is almost negligible. From the point of view of the observer in the spaceship sometimes the other observer is further up the gravitational potential gradient and sometimes he is further down, depending on whether he is acceleration towards the planet or away from it. [@@@@ The spaceship is outside of the planet's gravity well. It has an artificial gravity of its own, such as being on, say, Mars. General Relativity's Strong Equivalence Principle says that the effects of either acceleration and gravity will be identical for our time dilation problem. @@@@]
He interprets his a acceleration as uniform gravitational field (Yes, that is different from the non-uniform gravitational field of the planet hence the fact that a gravitational field is equivalent to an accelerated reference frame only locally. This problem doesn't satisfy locality since the distance between the observers is at times quite large). [@@@@ General Relativity is invoked to satisfy locality: "In 1905 Albert Einstein's Special Theory of Relativity postulated that no material or energy can travel faster than the speed of light, and Einstein thereby sought to reformulate physical laws in a way which obeyed the principle of locality. He later succeeded in producing an alternative theory of gravitation, General Relativity, which obeys the principle of locality. http://en.wikipedia.org/wiki/Principle_of_locality @@@@]
Because of that the difference between their equivalent gravitational potential can be extremely large and that effect is NOT negligible. Trying to bring General relativity into that problem is unnecessary and makes the problem much harder to understand. [@@@@ I don't understand this statement. We're only talking about 1G forces. @@@@] @@@@[I'm experimenting with methods to make your reading of my comments easier - it all seems to jumble up sometimes]@@@@
Dauto (talk) 03:52, 26 February 2011 (UTC)
GQuickstad ( talk) 16:24, 26 February 2011 (UTC)
GQuickstad ( talk) 16:37, 7 March 2011 (UTC)
...when it comes to donating skin and fat cells. That sounds like a quicker way to lose weight anyway, so why not? Re: Your Ref Desk reply.-- 98.190.13.3 ( talk) 23:13, 31 March 2011 (UTC)
You asked why I think that some questions or articles would be (considered by some to be) politically incorrect. Looking around, not only on wikipedia, there clearly are people who act as if science, especially nuclear science and space exploration, would be somehow offensive.
Look at the comment on this User_talk:76.64.30.242 talk page. Do you think the question about how to catch or kill a housefly would have been removed for the same reasons given? 5BYv8cUJ ( talk) 10:46, 19 June 2011 (UTC)
HI,
This is with regard to the undoing of my additional information regarding the theory and experimental Data, about the effect of galactic spin On spacetime.
any particular reason? — Preceding unsigned comment added by Chimesmonster ( talk • contribs) 12:59, 21 July 2011 (UTC)
Yes, there were three main reasons.
Dauto ( talk) 16:58, 21 July 2011 (UTC)
Headbomb { talk / contribs / physics / books} 23:58, 28 July 2011 (UTC)
Dauto: What do you mean by study of quantities? Here is my favorite definition: Physics is whatever physicists do.
Saeed: Thanks. definition was improved to: "the science of quantities." more explaination was added to Talk:Physics
Dauto: The definition of physics is a ontological matter, not a scientific one. Complaining that a definition includes words such as matter and energy on the basis that those things are subjects of ontology makes no sense.
Dauto (
talk)
16:48, 29 July 2011 (UTC)
Saeed: A really wise feedback. answered here.
The Brilliant Idea Barnstar | |
I was analyzing different definitions of physics, Thanks for giving me the Idea to analyze the concepts usually used by those definitions. this can allow analyzing more definition in less paragraphs.
-- Saeed 20:30, 29 July 2011 (UTC) |
Dauto: Chemistry is a branch of physics, so the subject of chemistry IS part of the subject of physics. Dauto ( talk) 17:15, 29 July 2011 (UTC)
Saeed: Almost correct. Chemistry is a branch of physical Science, but not Physics. Physical science is a study. An action distinguished by it's method, not a field of information, distinguished by it's subject.
Dauto: No, not almost correct. Exactly correct, chemistry is indeed a branch of physics. Dauto ( talk) 20:38, 29 July 2011 (UTC)
Saeed: Ok, I'm working on formulating reason for my claim. To understand what you exactly mean by branch, would you pleas answer a few questions? I
--Saeed 23:57, 30 July 2011 (UTC)
Dauto:
Saeed:
Please answer carefully. because it indicates I have to support my claim. Thanks.
--Saeed 17:02, 31 July 2011 (UTC)
Dauto: It's not an easy task to pin point a definition for physics and that's why a like the definition that physics is whatever physicists do. Just take a look at the article econophysics. If you really must have a clear definition for physics, and I can't see why anybody would need one, but if you rally must have one, a simple definition is that physics studies matter and its properties. Chemistry studies atoms and their interactions paying particular attention to the bounding of atoms. That definition falls within the first one so clearly chemistry is a branch of physics. Similar claims could be made about Cosmology, astrophysics, Meteorology, Geology, but not biology, geography, psicology, and sociology. Dauto ( talk) 20:00, 31 July 2011 (UTC)
Saeed:
"It's not an easy task to pin point a definition for physics"
"Just take a look at the article econophysics"
"I can't see why anybody would need [a clear definition for physics]"
"a simple definition is that physics studies matter and its properties. Chemistry studies atoms and their interactions paying particular attention to the bounding of atoms. That definition falls within the first one so clearly chemistry is a branch of physics."
--Saeed 01:57, 1 August 2011 (UTC)
Wow! That is fascinating. I never thought of it before! So fundamentally it is the change in the geometry of spacetime caused by a given scenario that determines whether the given scenario will result in time dilation or not. I would like to learn more. Is there any book that I can read that can teach me how to do calculations to allow me to figure out whether there would be time dilation, and by how much, there is in any given scenario, be they black wholes, traveling twins, centrifuges or other scenarios involving forces/relative motion/other scenarios of GR/SR/Q. Thanks for teaching me. I feel enlightened. L33th4x0r ( talk) 13:30, 18 September 2011 (UTC)
Thanks for bringing me enlightenment. L33th4x0r ( talk) 13:30, 18 September 2011 (UTC) |
hi, so wrt the reference desk - is it fair then to say that the amount of thermodynamic entropy in an object is strictly equivalent to the amount of entropy you would have to send over the wire to a replicator that was capable of perfeclty creating it? Thanks. 178.48.114.143 ( talk) 20:51, 10 December 2012 (UTC)
Hi Dauto, hope you don't mind me buzzing you on your talk page just for a greeting. I noticed your conspicuous absence from the ref desk around early last year, and didn't realise you had returned. Your edit history shows you've been back a while, but I only just noticed you were here again. You have helped me once or twice, and I have learned a lot from your answers to other people's questions. We need people like you, so a belated welcome back! IBE ( talk) 19:01, 6 January 2013 (UTC)
Let me restate the question: ""Galaxies X and Y appear equally bright in the night sky. When a radio spectra of both galaxies are taken, the 21cm line of galaxy X is twice as wide as that of galaxy Y." So is 21cm line indicate how big the the galaxy is? How is that mean the hydrogen line? I know the bigger the universe would mean the faster it rotate. If I assume 21 cm line is the size of galaxy Y then I can get the correct answer but not sure if that's the right way to do it. Hope you can help me with this! 174.20.15.246 ( talk) 20:47, 6 January 2013 (UTC)
Welcome!
Hello Dauto, and welcome to Wikipedia! Thank you for your contributions. I hope you like the place and decide to stay. Here are a few good links for newcomers:
I hope you enjoy editing here and being a Wikipedian! Please sign your name on talk pages using four tildes (~~~~); this will automatically produce your name and the date. If you have any questions, check out Wikipedia:Where to ask a question or ask me on my talk page. Again, welcome! Fawcett5 18:07, 19 October 2005 (UTC)
You were right that there was a problem with a sign, but it's not a good idea to just delete a minus sign without a reason. I corrected the sign error by taking the integral over M in the correct direction. 75.45.210.119 ( talk) 18:32, 4 February 2009 (UTC)
You deserve a barnstar. Best wishes. Axl ¤ [Talk] 18:32, 2 March 2009 (UTC)
The E=mc² Barnstar | ||
To Dauto, for contributions to scientific articles. Axl ¤ [Talk] 18:32, 2 March 2009 (UTC) |
I asked a follow-up to one of your answers on the science desk regarding quantum mechanics and predetermination. Your responses there are usually very helpful and appreciated. Thanks misli h 00:04, 24 April 2009 (UTC)
You gave a truly patient and correct response to a convoluted question. Cuddlyable3 ( talk) 18:31, 12 June 2009 (UTC)
Hi Dauto. Thanks for the reference desk answer -- I needed you help in seeing how simple it was. I'm not trying to pick nits here, but when you wrote "I forgot to include the energy realeased from two electrons" I assume that it was the mass of the electrons themselves that you had forgotten to include, because I get you initial number of 0.0068500 from 1 - mα / (4 mp). I am also assuming that your second number, 0.0071224, had a typo and you meant 0.0071204. Thanks again. -- Thinking of England ( talk) 09:29, 23 August 2009 (UTC)
Hi Dauto,
thanks for SO(10) diagram -- just one last question. I get everything except the vertical column of arrows and numbers on the right hand side. How do they work?
Do you have a similar diagram for the Pati-Salam model?
-- Michael C. Price talk 14:51, 2 November 2009 (UTC)
Obviously I understand less than I thought. What is a "level"? It seems I need to understand that to get your Pati-Salam explanation.
Incidentally, my interest in Pati-Salam was piqued when I read that it doesn't predict proton decay. Since minimal SU(5) has been ruled out by the lack of proton decay, this seems to be a plus for Pati-Salam. Strangely, there seems very little in textbooks (and nothing on Scholarpedia) about Pati-Salam, which makes life frustrating. -- Michael C. Price talk 18:12, 2 November 2009 (UTC)
Obviously I understand less than I thought. What is a "level"?
It's really pretty simple. The top component of the weight diagram (The anti-neutrino for that specific diagram) is labeled as being level zero. Now go down the diagram (walking with your fingers if you will) following the links. Your first step will take you down to an up quark which is labeled as belonging to the level 1. Your second step take you down to another up quark (of a different color) which is labeled as belonging to the level 2. Work your way down to the bottom of the diagram which (for that diagram) will be level 10. It is just a way to help label the different components of the diagram to make it easier to refer to them. Dauto ( talk) 20:18, 2 November 2009 (UTC)
I'm having troubling downloading the Slansky paper (lack of cryllic skills). Do you have any links that give the langrangian for Salam-Pati? I couldn't find any on the physics archives that explained just the basic model, as opposed to some SUSY extension.-- Michael C. Price talk 14:52, 4 November 2009 (UTC)
Here's my rather unpolished attempt to summarise the ferrmion SU(4)c, SU(2)L and SU(2)R quantum numbers for Pati-Salam:
2I1 | 2I2 | 2I3 | |||
---|---|---|---|---|---|
L/R fermions | u1 | d1 | -1 | 0 | 1 |
u2 | d2 | 1 | -1 | 0 | |
u3 | d3 | 0 | 1 | 0 | |
e- | 0 | 0 | -1 | ||
2T3L/R | 1 | -1 | |||
2T3R/L | 0 | 0 |
Where
-- Michael C. Price talk 00:47, 7 November 2009 (UTC)
I have a few points to make.
Note how the SU(4) generators are out of order.
Of course the last two points are just a matter of convention, but they lead to a staircase-like structure for the eigenvalues which is easier to remember
2I3,1 | 2I3,2 | 2I3,3 | |||
---|---|---|---|---|---|
L/R fermions | u1 | d1 | 1 | 0 | 0 |
u2 | d2 | -1 | 1 | 0 | |
u3 | d3 | 0 | -1 | 1 | |
e- | 0 | 0 | -1 | ||
2T3L/R | 1 | -1 | |||
2T3R/L | 0 | 0 |
The expression for B-L has to be changed accordingly: Dauto ( talk) 05:31, 9 November 2009 (UTC)
I just noticed your nice diagrams on your home page and wanted to find out more about them, but it seems they aren't used in either Pati–Salam model or weight diagram. That's a shame! Why aren't they? — Sebastian 19:45, 8 March 2013 (UTC)
Hi Dauto,
Thanks for all the help with SO(10) etc. I'm trying to apply some of this to neutrinos at the moment.
I've seen it was stated on one of the neutrino talk pages that sterile neutrinos can oscillate with "normal" neutrinos. I'm not clear whether "sterile" just means "right-handed within the SO(10) model" or not. If sterile neutrinos are just right-handed neutrinos then it seems to me that they will have different weak hypercharge (0 for right-handed neutrinos, -1 for the left-handed neutrinos) and X charge. If so, wouldn't that prevent the right handed / sterile neutrinos from mixing or oscillating with the left handed neutrions?
-- Michael C. Price talk 12:05, 21 November 2009 (UTC)
Okay, let's see if I've followed that:
Is that right? -- Michael C. Price talk 21:12, 21 November 2009 (UTC)
You said “Yes” to my question posted on dated Nov 22, 2009 in the following link
http://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Archives/Science/2009_November_22
But I don't know why relativity pundits hesitate in saying “Yes” to my original question which is the reverse play of Einstein experiment in which two bolts of light strike the longitudinal sides of moving train.
Please ignore all if you dislike. 68.147.38.24 ( talk) 19:03, 1 December 2009 (UTC) khattak
Hi, Dauto. I noticed you reverted my removal of your comment and the ones that followed, at the end of User:Neptunerover's question regarding his no-maths solution to gravity. As I stated in the edit summary (and on the talk page), I think we should refrain from making such characterizations of our questioners. I have therefore moved the section in question to the talk page. Your opinion would be most welcome there. -- NorwegianBlue talk 21:46, 2 January 2010 (UTC)
Hi Dauto, I finally tracked down a copy of the original Pati-Salam paper, Lepton number as the fourth "color". I'm puzzled by a few things (actually a lot of things). They say that B-L is preserved (although they define L as -L, so they call it B+L), but at the end of the paper they also say that the proton decays into three neutrinos and a pion:
But this seems to violate B-L. Do they mean 2 anti-neutrinos and a neutrino, in addition to the pion? -- Michael C. Price talk 00:10, 14 February 2010 (UTC)
Hi Dauto,
do the new gauge bosons predicted by PS, aside from the W' and Z' bosons, all have B-L=4/3? And do they have an electric charge of 2/3?
-- Michael C. Price talk 01:54, 1 May 2010 (UTC)
The Reference Desk Barnstar | ||
For this particularly astute response, thank you! Calliopejen1 ( talk) 17:44, 20 January 2011 (UTC) |
Thank you for a clear and thorough answer to my question on half-life and decay constant. jftsang 23:25, 21 February 2011 (UTC)
1. The U-turn wasn't avoided at all, since the spaceship still reverses direction of motion and comes back to earth.
[@@@@ Thanks for commenting. Reverse is a poor description of what happens. The point of furthest travel isn't detectable to the ship, or clock. If you maintain that these "know" of a U-turn, then describe by what force or means @@@@]
2. The principle of equivalence doesn't work the way you think. The gravity on the planet is NOT equivalent to the acceleration of the spaceship and here is why.
[@@@@ The gravity on the planet is equivalent in this case since the earth-bound twin and clock stay at a constant elevation - no tidal effects. http://en.wikipedia.org/wiki/Equivalence_principle "The equivalence principle proper was introduced by Albert Einstein in 1907, when he observed that the acceleration of bodies towards the center of the Earth at a rate of 1g (g = 9.81 m/s2 being a standard reference of gravitational acceleration at the Earth's surface) is equivalent to the acceleration of an inertially moving body that would be observed on a rocket in free space being accelerated at a rate of 1g. Einstein stated it thus:" @@@@]
From the point of view of the observer on the planet he is at the bottom of the planet's gravity well while the ship is outside of the well - that is further up the gravitational potential, and the difference between their gravitational potentials is constant throughout the trip. The planet's gravity isn't very strong so this effect is almost negligible. From the point of view of the observer in the spaceship sometimes the other observer is further up the gravitational potential gradient and sometimes he is further down, depending on whether he is acceleration towards the planet or away from it. [@@@@ The spaceship is outside of the planet's gravity well. It has an artificial gravity of its own, such as being on, say, Mars. General Relativity's Strong Equivalence Principle says that the effects of either acceleration and gravity will be identical for our time dilation problem. @@@@]
He interprets his a acceleration as uniform gravitational field (Yes, that is different from the non-uniform gravitational field of the planet hence the fact that a gravitational field is equivalent to an accelerated reference frame only locally. This problem doesn't satisfy locality since the distance between the observers is at times quite large). [@@@@ General Relativity is invoked to satisfy locality: "In 1905 Albert Einstein's Special Theory of Relativity postulated that no material or energy can travel faster than the speed of light, and Einstein thereby sought to reformulate physical laws in a way which obeyed the principle of locality. He later succeeded in producing an alternative theory of gravitation, General Relativity, which obeys the principle of locality. http://en.wikipedia.org/wiki/Principle_of_locality @@@@]
Because of that the difference between their equivalent gravitational potential can be extremely large and that effect is NOT negligible. Trying to bring General relativity into that problem is unnecessary and makes the problem much harder to understand. [@@@@ I don't understand this statement. We're only talking about 1G forces. @@@@] @@@@[I'm experimenting with methods to make your reading of my comments easier - it all seems to jumble up sometimes]@@@@
Dauto (talk) 03:52, 26 February 2011 (UTC)
GQuickstad ( talk) 16:24, 26 February 2011 (UTC)
GQuickstad ( talk) 16:37, 7 March 2011 (UTC)
...when it comes to donating skin and fat cells. That sounds like a quicker way to lose weight anyway, so why not? Re: Your Ref Desk reply.-- 98.190.13.3 ( talk) 23:13, 31 March 2011 (UTC)
You asked why I think that some questions or articles would be (considered by some to be) politically incorrect. Looking around, not only on wikipedia, there clearly are people who act as if science, especially nuclear science and space exploration, would be somehow offensive.
Look at the comment on this User_talk:76.64.30.242 talk page. Do you think the question about how to catch or kill a housefly would have been removed for the same reasons given? 5BYv8cUJ ( talk) 10:46, 19 June 2011 (UTC)
HI,
This is with regard to the undoing of my additional information regarding the theory and experimental Data, about the effect of galactic spin On spacetime.
any particular reason? — Preceding unsigned comment added by Chimesmonster ( talk • contribs) 12:59, 21 July 2011 (UTC)
Yes, there were three main reasons.
Dauto ( talk) 16:58, 21 July 2011 (UTC)
Headbomb { talk / contribs / physics / books} 23:58, 28 July 2011 (UTC)
Dauto: What do you mean by study of quantities? Here is my favorite definition: Physics is whatever physicists do.
Saeed: Thanks. definition was improved to: "the science of quantities." more explaination was added to Talk:Physics
Dauto: The definition of physics is a ontological matter, not a scientific one. Complaining that a definition includes words such as matter and energy on the basis that those things are subjects of ontology makes no sense.
Dauto (
talk)
16:48, 29 July 2011 (UTC)
Saeed: A really wise feedback. answered here.
The Brilliant Idea Barnstar | |
I was analyzing different definitions of physics, Thanks for giving me the Idea to analyze the concepts usually used by those definitions. this can allow analyzing more definition in less paragraphs.
-- Saeed 20:30, 29 July 2011 (UTC) |
Dauto: Chemistry is a branch of physics, so the subject of chemistry IS part of the subject of physics. Dauto ( talk) 17:15, 29 July 2011 (UTC)
Saeed: Almost correct. Chemistry is a branch of physical Science, but not Physics. Physical science is a study. An action distinguished by it's method, not a field of information, distinguished by it's subject.
Dauto: No, not almost correct. Exactly correct, chemistry is indeed a branch of physics. Dauto ( talk) 20:38, 29 July 2011 (UTC)
Saeed: Ok, I'm working on formulating reason for my claim. To understand what you exactly mean by branch, would you pleas answer a few questions? I
--Saeed 23:57, 30 July 2011 (UTC)
Dauto:
Saeed:
Please answer carefully. because it indicates I have to support my claim. Thanks.
--Saeed 17:02, 31 July 2011 (UTC)
Dauto: It's not an easy task to pin point a definition for physics and that's why a like the definition that physics is whatever physicists do. Just take a look at the article econophysics. If you really must have a clear definition for physics, and I can't see why anybody would need one, but if you rally must have one, a simple definition is that physics studies matter and its properties. Chemistry studies atoms and their interactions paying particular attention to the bounding of atoms. That definition falls within the first one so clearly chemistry is a branch of physics. Similar claims could be made about Cosmology, astrophysics, Meteorology, Geology, but not biology, geography, psicology, and sociology. Dauto ( talk) 20:00, 31 July 2011 (UTC)
Saeed:
"It's not an easy task to pin point a definition for physics"
"Just take a look at the article econophysics"
"I can't see why anybody would need [a clear definition for physics]"
"a simple definition is that physics studies matter and its properties. Chemistry studies atoms and their interactions paying particular attention to the bounding of atoms. That definition falls within the first one so clearly chemistry is a branch of physics."
--Saeed 01:57, 1 August 2011 (UTC)
Wow! That is fascinating. I never thought of it before! So fundamentally it is the change in the geometry of spacetime caused by a given scenario that determines whether the given scenario will result in time dilation or not. I would like to learn more. Is there any book that I can read that can teach me how to do calculations to allow me to figure out whether there would be time dilation, and by how much, there is in any given scenario, be they black wholes, traveling twins, centrifuges or other scenarios involving forces/relative motion/other scenarios of GR/SR/Q. Thanks for teaching me. I feel enlightened. L33th4x0r ( talk) 13:30, 18 September 2011 (UTC)
Thanks for bringing me enlightenment. L33th4x0r ( talk) 13:30, 18 September 2011 (UTC) |
hi, so wrt the reference desk - is it fair then to say that the amount of thermodynamic entropy in an object is strictly equivalent to the amount of entropy you would have to send over the wire to a replicator that was capable of perfeclty creating it? Thanks. 178.48.114.143 ( talk) 20:51, 10 December 2012 (UTC)
Hi Dauto, hope you don't mind me buzzing you on your talk page just for a greeting. I noticed your conspicuous absence from the ref desk around early last year, and didn't realise you had returned. Your edit history shows you've been back a while, but I only just noticed you were here again. You have helped me once or twice, and I have learned a lot from your answers to other people's questions. We need people like you, so a belated welcome back! IBE ( talk) 19:01, 6 January 2013 (UTC)
Let me restate the question: ""Galaxies X and Y appear equally bright in the night sky. When a radio spectra of both galaxies are taken, the 21cm line of galaxy X is twice as wide as that of galaxy Y." So is 21cm line indicate how big the the galaxy is? How is that mean the hydrogen line? I know the bigger the universe would mean the faster it rotate. If I assume 21 cm line is the size of galaxy Y then I can get the correct answer but not sure if that's the right way to do it. Hope you can help me with this! 174.20.15.246 ( talk) 20:47, 6 January 2013 (UTC)