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Topics - Pmb

Pages: [1] 2 3 ... 5
1
Geek Speak / Double click doesn't work in my version of Windows 8.1
« on: 01/04/2014 06:37:55 »
For some strange reason when I try to double click on a word to select it, nothing happens. Does anybody here know how to fix this? I read somewhere that someone recommended running "Disk Utility" and "repair disk permissions" but I can't find this program in windows 8.1 . Can someone tell me where to get a compatible version? Thanks.

2
Geek Speak / Using a digital camera as a webcam
« on: 31/03/2014 21:51:06 »
I recently bought a Nikon D3300 digital DSLR camera. Does anybody know if and how it can be used as a web cam? I.e. I've connected it to my computer using the USB port and cable provided. However I can't seem to find how to use the camera as a webcam.

3
Geek Speak / What do you think of Windows 8.1?
« on: 30/03/2014 06:05:57 »
Has anyone tried Windows 8 or 8.1? It's horrible. Just as I finally get used to their old system they go and change everything around. The worst thing it has is forcing you to log in even when your computer is at home. The second worst part is that they took the "start"menu out. Then they took out Outlook Express.

Blech!!!

4
Geek Speak / Can you help me with my new smart TV?
« on: 24/03/2014 08:24:20 »
Howdy, folks.

I just bought myself a smart TV. The instructions on how to use it vary from horrifically bad to none existent. What I what to be able to do is to stream Network TV channels and programs to my TV. But I can't figure this out for the life of me. Does anybody here have any knowledge about this and/or smart TVs? Thanks.

Pete

5
Just Chat! / Hello again
« on: 19/03/2014 08:41:44 »
I decided to take a leave from this forum for awhile due to various personal reasons. However I missed the place so I thought I'd stop by for a while. Plus there's something wrong with me ISP for my website because it's dead and I can't get in touch with them. Weird!

So I thought I'd take this time to say howdy to all my friends here and to let you know that I'm okay. Drop me a line and I'll fill you in.

Best wishes,

Pete

6
Geek Speak / Questions on Windows 8.1
« on: 19/03/2014 08:37:39 »
Hi Folks,

I just got a new ax and am having problems getting into the swing of Windows 8.1. E.g. I can't understand the instructions from the help guide of how to make it so that I don't have to enter a password to login to my computer. There's no need for it since I live alone and there's no sensitive information on it. Thanks.

Pete

7
Physics, Astronomy & Cosmology / The Truth of Relativistic Mass
« on: 12/12/2013 03:11:37 »
I've come to learn that there's a great deal of misinformation floating around the Internet regarding what some people call relativistic mass in modern relativity and relativistic cosmology. The misinformation is that it's an outdated concept that nobody uses anymore. This thread gives solid proof that this claim is invlaid and that relativistic mass is alive and well in the wonderful world of Einstein's world of relativity.

If anyone wants to verify what I said as being true the all you need to do is follow the URLs given below so that they can see it for themselves. I have many recently published SR and GR texts on my book shelf which use the concept and so their claim is just plain wrong.
 
Let's start off with a perfect example. Alan Guth, a particle physicist/cosmologist at MIT. He's a perfect example of somone who uses relativistic mass (which he simply refers to as "mass"). He uses it in his lecture notes for his Early Universe course that he teaches at MIT. I placed a sample page online so that you can see it for yourself. It's at
 
http://home.comcast.net/~peter.m.brown/guth.jpg
 
There is a large percentage of modern relativity and relativistic cosmology textbooks out there right now which proves such a claim is bogus. There are simply no facts out in the physics world that is consistent with the claim that its outdated other than the mere claim that it's outdated. Particle physicist often make this mistake so if one tells you that the only mass that's used in relativity is rest mass, don't believe them because it's a false statement. Particle physicists simply aren't relativists. They're merely people who use relativity as a tool in their work. They don't study relativity as a field in itself. Such physicists rarely, if ever, use the concept of mass outside the area of application of particle physics. They simply don't know the limitations of the way they chose to define "mass." And the fact that those limits don’t occur in their work makes it irrelevant for them.

Counter examples are given in my article on the subject. I wrote an entire paper giving all the reasons why what I'm stating is true. There's just far too much to place in as single thread or post. The paper is called On the concept of relativistic mass and is located at http://arxiv.org/abs/0709.0687 for those with the skill set to understand it. For those who don't please just ask. A perfect counter example to the claim that nobody uses relativistic mass in "particle physics/accelerator physics" is given in a web page under CERN's website at

http://teachers.web.cern.ch/teachers/archiv/HST2002/Bubblech/mbitu/energymomentum_4vector.htm

Notice that this page is to teach so please read what CERN wants you to learn.
 
The claim that it hasn't been used for over 20 years is demonstratably false as anybody who wants to look in a book can learn for themselves. I've provided a list to such textbooks and a link to where you can read it online if it's available. Here's how this problem got re-started back in the late 80's with an article by Lev Okun. And yes. I did say re-started because contrary to  popular belief Lev Okun didn't originate this spiel about mass. Lev Okun made an attempt to ban the concept from all of physics but failed miserably. A lot of amateurs and non-relativists claim that its not used tool. Relativistic mass widely used in relativity and cosmology textbooks
 
There were two notable articles to counter Okun's tirade. They are

In defense of relativistic mass by T.R. Sandin, Am. J. Phys., 59(11), Nov. (1991)
 
b]Putting to Rest Mass Misconceptions[/b] by Wolfgang Rindler, Physics Today, May (1990)

The USENET Physics FAQ had it wrong for a while until I explained these facts to Don Koks, the physicist who maintains those FAQs.

See http://math.ucr.edu/home/baez/physics/Relativity/SR/mass.html
 
The following are books that use relativistic mass

Concepts of Mass in Contemporary Physics and Philosophy by Max Jammer,
Princeton University Press, (1999). 
Download Available: http://bookos-z1.org/book/872005/406a03

A first course in general relativity by Bernard F. Schutz, Cambridge University Press, (2009), from page 88
Download Available: http://bookos-z1.org/book/573635/b31618
Quote
 
Thus, n is a scalar. In the same way that 'rest mass' is a scalar, even though energy and 'inertial mass' are frame dependant … 

 
This demonstrates a clear example of the use of relativistic mass as another term for inertial mass. It also shows an example of the fact that some people mean relativistic masswhen they use the term mass unqualified.

Gravity from the ground up by Bernard F. Schutz, Cambridge University
Press
, (2003). See page 241 
Download Available: http://bookos-z1.org/book/507531/96158f 
Quote
 
Immediately we see a problem: "mass" has no unique meaning in relativity. 

 
Relativity: Special, General and Cosmological, Rindler,Oxford Univ., Press,
(2006).
Download Available at: http://bookos-z1.org/book/931043/b4e4bd   
Introducing Einstein's Relativity, Ray D'Inverno, Oxford Univ. Press,
(1992).
Download Available: http://bookos-z1.org/book/1024503/b16828
 
General Relativity: An Introduction for Physicists by M.P. Hobson, G. Efstathiou and A.N. Lasenby, Cambridge University Press, (2006) 
Download Available: http://bookos-z1.org/book/929425/315169

Relativity; An Introduction to Special and General Relativity by Hans Stephani, Cambridge University Press, (2004).
Download Available: http://bookos-z1.org/book/1249890/ad351e
 
Cosmological Physics by John A. Peacock, Cambridge University Press, (1999).
Download Available: http://bookos-z1.org/book/451793/b5bb91
 
Basic Relativity by Richard A. Mould, Springer, (1994). 
Einstein's General Theory of Relativity: With Modern Applications in Cosmology by Grøn, Øyvind (2013)
Download Available: http://bookos-z1.org/book/884554/09b625


8
Physics, Astronomy & Cosmology / How does gravity affect the speed of light?
« on: 07/12/2013 12:32:20 »
I ran into something that caught me by suprised the other day.

Please consider the derivation of the fact that light slows down in a gravitational field at http://home.comcast.net/~peter.m.brown/gr/c_in_gfield.htm

Eq. (6) defines the Schwarzschild metric. Understanding the derivation means understanding the meaning of the variables in that derivation. In another forum there was an uncomfortably large number of people who didn't understand the derivation. In the end I learned that they didn't understand the physical meaning of the variables. Right now I'm curious about the general understanding of this metric and the meaning of the variables.

If you don't mind me asking, those of you believe yourself knowledgeable of Schwarzschild spacetime geometry what is the meaning of the time parameter, i.e. where is the clock that reads that time located. If it could be at a multitude of places then please describe that multitude. Thank you all! :)

9
Physics, Astronomy & Cosmology / Are inertial forces real?
« on: 22/11/2013 08:03:51 »
This thread is not about what an inertial force is, what Einstein thought of it, what you think GR has to say on it etc.

The definition of inertial force is well known and never debated. I know the definition quite well in fact so let’s skip any discussion on definition, okay? For those who don’t know what it is then please see

http://home.comcast.net/~peter.m.brown/gr/inertial_force.htm

In that page I've described various viewpoints from some well-known physics textbooks on mechanics general relativity and cosmology.

Before any of you claim to know how it's viewed in the physics community please see the quotes at the end which expresses one side of the viewpoint.

My question for you is  - Do you believe that the gravitational force cannot be thought of as a "real" force and must therefore be called, at best, a pseudo force? Or to phrase it another way - How many of you believe that if a particle is accelerating under the action of a field for which the 4-acceleration on the particle is zero that any attempt to define a "force" on the particle must imply that it should be thought of/defined as a pseudo-force?

Thanks

10
Geek Speak / New Computer System
« on: 23/10/2013 00:01:29 »
Hi all,

Since I created my NPO's website my councilor from the Massachusetts Rehabilitation Commision (MassRehab) has been very happy with me. She loves what I'm doing with it. I realized that eventually I can use this (the actually website and not the forum) as a tool to derive work as a Physics and/or Math tutor and thus work for myself out of my home.

She told me to put together a business plan, which I did and she liked, which she'll show to her boss. She expects that he'll approve it. At that point I'll have to buy a new computer system since mine is too old to handle the new software and hardware that's out there.

I'd like some advice on what kind of computer (I prefer a tower) I should get in order to be the best math/physics tutor I can be.

What kinds of bells and whistles will I need? She told me to make out a wish list so I’m thinking lots of memory and a massive hard drive and a very fast chip. Other thoughts?

11
Physics, Astronomy & Cosmology / List of journal articles of interest
« on: 21/10/2013 15:02:36 »
I've compiled a list of journal articles which I've found of interest and have placed it online for all to read. It's at http://home.comcast.net/~peter.m.brown/ref/journal_article_list.htm

A large number of topics that we discuss here can be found in that list. Others are about things that people here haven't posted on and might enjoy reading about, e.g.

Radiation from an Accelerated Charge and the Principle of Equivalence by A. Kovetz and G.E. Tauber, Am. J. Phys., 37(4), Apr. (1969). The abstract reads
Quote
The connection between an accelerated charge and one at rest in a (weak) gravitational field is discussed in accordance with the principle of equivalence. For that purpose, the fields produced by a freely falling charge and a supported one (i.e., at rest in a gravitational field) are transformed to the rest-frame of the observer, who may be similarly supported or freely falling. A nonvanishing energy flux is found only if the charge is freely falling and the observer supported, or vice versa. This agrees with previously established results.
This article talks about whether a falling charged particle in a gravitational field should radiate energy! That's a cool question when you think about it. :)

There is more on this at http://home.comcast.net/~peter.m.brown/ref/falling_charge.htm

Classical Radiation from a Uniformly Accelerated Charge, Thomas Fulton, Fritz Rohrlich, Annals of Physics: 9, 499-517 (1960)

Radiation Damping in a Gravitational Field, Bryce S. DeWitt, Robert W. Brehme, Annals of Physics: 9, 220-259 (1960)

Principle of Equivalence, F. Rohrlich, Annals of Physics: 22, 169-191, (1963), page 173

Radiation from a Uniformly Accelerated Charge, David G. Boulware, Annals of Physics: 124, 169-188 (1980)

http://www.hep.princeton.edu/~mcdonald/accel/unruhrad.pdf


The journal list contains a link to the journal's website and in most cases has the abstract available. I have all of these articles so if anyone wishes to read one of them please let me know. I hope some of you find this list useful.

12
Physiology & Medicine / What causes generalized numbness and poor balance?
« on: 21/10/2013 02:45:07 »
A friend of mine tells me that he has generalized numbness (proabably involving a lot of neuropathy) which has affected their balance and sensation in the lower half of my body. Brigham and Women's hospital had no idea what was wrong and sent him home.

If you were him what would be your next step in finding out what the problem is? I.e. what kind of doctor would yo go to?

13
Geek Speak / How do I update my webforum software by FTP?
« on: 20/10/2013 05:43:57 »
I have a new website and forum. I need to update the version of the forum software but I need to use an FTP program to do that. I've never used one before so I need some help. I am using WinScp for my FTP program. I don't know how to use it and the help files don’t' seem that easy to use.

Can someone please help me use it to update my software? Preferably in PM or e-mail so as not to make too much information public knowledge.

14
Just Chat! / Banning members
« on: 20/10/2013 05:37:38 »
I’d like some input from the team of moderators here.

I created a forum recently and am in the process of making some decisions about how to run it. The software allows me to select certain members so that all of their posts go into a moderator queue.

The general rule of thumb to follow in my forum is - Play nice. Don’t cause trouble by provoking others. Respect other members (whether you think they deserve it or not).

This means no ad hominems. Never use phrases such as Oh, for crying out loud. Essentially never place something in a post that shouldn’t be printed in a science text. Scientists never use phrases like Oh, for crying out loud. in textbooks or journal articles to address their audience.

So with this I mind I’ve decided that when it becomes apparent that a particular user does not follow the rules then all of their posts will go into the moderator queue and will be edited for content. A PM will be sent to them stating what has been changed and why. For this reason I don’t see a need to ban members.

It might be a waste of time editing too many posts. I’m sure there are some people who simply will never get it and will play games with the moderators just to be mean. I really don’t want to ban anybody since far too many science forums do that, and for shameful reasons. E.g. in other forums it was the moderators who provoked me. For some reason they believed that moderator comments should be placed in open forum rather than in PM. This only has the effect of angering the member since the moderators have chosen to publicly chastise/humiliate them. It was shameful of them to do such a thing. For that reason no moderator of those forums will be allowed to join. However I don’t see any of them wanting to join since they won’t be allowed to insult and be rude to people.

So my question is – Who should be banned? What have members here in the past done to get them banned? No names please. I’m thinking that a member whose posts need editing by a moderator too often should be banned if they refuse to follow the golden rule and are given numerous warnings about being banned.

15
Physiology & Medicine / Definition of "Drug seeking behaviour"
« on: 18/10/2013 03:18:46 »
I'm looking for the precise definition of the term drug seeking behaviour. Does anyone know what it is and the source of the defintion? I know a variety of definitions but I have a need for it as defined by a respectable source (and not a journal article which carries a personal opinion with it).

I looked in the DSM-4 and while it uses the term twice it doesn't define it.

16
Just Chat! / Searching for a member
« on: 16/10/2013 13:41:14 »
Several times I've wanted to search for posts made only by a specific individual but have been able to determine how to do this. E.g. I haven't seen Aethelwulf post in a long time. It could be that he's left or banned and I don't know it. Perhaps he's simply posting in forums I don't frequent.

For example; How do I find his last post?

17
Just Chat! / To the moderators of this forum
« on: 16/10/2013 11:59:13 »
Dear Moderators,

I've been posting here for some time now and have seen how some of he moderators here do their work here and as a result have one thing to say to all of you - Well done! :) And I truly mean it.

Most moderation that I know of comes to the member in the form of a PM. This saves the member from public humiliation. I would like to compliment the moderators who use this method. You've proven that this method works very well. Bravo.

18
Just Chat! / consecutive posts
« on: 15/10/2013 21:25:19 »
I would like some input here. I've seen some posters here and in other forums create consecutive posts in a discussion. I imagine that these people have something they want to contribute so they reply to a thread and then post their response. Later on the same person has more to say so they repeat what they did and in doing so create yet another post. Some people will do this many many times in a row. I myself have tried to reason with those who like to post this way because I find it makes things difficult in the long run. However I never got a response which told me why they do that. All I've gotten was the statement that I should forget about me changing how they post and that's that.

My question is - Why do people do this and why do forum administrators and moderators allow this?

19
Just Chat! / Who are the moderators?
« on: 15/10/2013 19:34:55 »
Since there is no forum here for general forum feedback or questions I'm going to use this forum for that purpose assuming that's one of it's uses.

There are times when I need to ask a moderator or administrator a question. Since there is no list for moderators and I don't know who the administrator(s) are please explain how I'm supposed to contact them.

20
Geek Speak / What graphics software can generate 3D models and shapes?
« on: 13/10/2013 09:11:22 »
I'm looking for freeware software that will generate images of simple geometric 3d objects such as a sphere with specific latitude and longitide lines drawn on them. Can someone recommend some software that will do this which is free and can be downloaded online? I'm searching through download.com at the moment.

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