Pad For some reason I couldn't return your message. ?. Move what you want as you wish. I trust your analysis. I wanted to ask you to think about the sudden appearance of a new poster. ?. Especially after you tell me that a thread has been moved to pseudoscience. This is an opinion of mine. It would be helpful to have the moderators read the threads that are proposed for publishing. They could decide if the original subject matter was appropriate for the physics threads. This way an appropriate thread subject can be recommended for discussion. The cranks still get to post nonsense but don't get to establish irrelevant bullshit as the topic. This should reduce the threads that need to be moderated to pseudoscience. Thanks for being here. You start many good threads. You do much work trying to maintain a coherent discussion.
Posts 58 and 59 were quite informative. I was suggesting that if we ask for them to be reposted in one of the other spacetime cosmology threads....a shame to see them go where this thread has rightly ended up.
Good work Kittamaru imvho...... Two posts though, 58 and 59, were quite informative belonging to bruce. Just a suggestion, any chance of moving those two posts to the other spacetime thread? Just a thought....shame to see such good stuff go to waste.
This going to take me time. My math ability runs at the level of a simple spread sheet I constructed to run my business. My first problem is even in the first simple equation I dont even know what each letter represents. I need to work it up from there. Maybe its to late in life.
To brucep Thank you brucep for going to all the trouble to help me. I am stumped on the simplist of levels and the best I can identify as the problem is I dont know what the letters represent. Sadly that basic. I am reading like crazy but it is so hazy when your my age.
Join the club Xel....I'm basically in the same boat. I prefer to get down to the nitty gritty though, the real deal so to speak, about what's going on, the why's and the how's. Yes, I need "faith"of course to trust the experts and their maths, and my adversaries will always use that fact against me. Like you, I'm too bloody old the get right into the maths and equations. But I do know, and common sense tells me, that our mainstream physicists out at the coal face, are not out to have us on. Couple that with the "would be's if they could be's" and the near fact that no one will rewrite 20th/21st century cosmology from a forum.
Thank you paddoboy I thought I was the only one. I find it ironic that I would have called myself a numbers man because I not only kept spread sheets for my business but spread sheets on the numbers my competitors were doing. I probably could project their profit better than they could. Anything I did had a spread sheet. Using simple relationships ratios percentages so I could put in house price commission number of salesmen cost of adds. Plug in the numbers and I could see where the best opportunity for profit. It may tell you four mug salespeople are better than two high flyers. I could lots of what ifs. It was not until I started trying to understand relativity that it hit math just what a subject it is. Visited my first math site which had an index 35 pages with 25? lines per page each line referencing a branch of maths that probably many men devote their life to its exclusive study. I started to understand the magnitude the precision what math folk thought about.. But at least it dawned on me how grand it all was. But I was interested in understanding scientific method and that can be as big as you make it. Lucky this thread landed here I interprete that we speak free. Have a chat. I must say I find the little clashes interesting but then I have lead a sheltered life. I do think it would be good to somehow record bruep posts in a thread in the cosmology section.
Please Register or Log in to view the hidden image! I see what you mean......Please Register or Log in to view the hidden image! Big chance!
Wow. Having the experience you have with running spreadsheets might make this interesting for you. The book is Gravity from the ground up. An introductory guide to gravity and general relativity. By Professor Bernard Schutz. A major part of the books pedagogical approach is to reveal what the derived equations tell us about the physics using computer analysis. You don't have to derive the physics unless you're fully prepared to do so. The alternative is the natural paths are revealed through computer analysis. This is the books site where you can download the computer stuff to your computer. The opening page is an explanation of the books goals for the student. Pad could do this easy. You could do this easy. If it was something you have the interest and time to work on. Or not. http://www.gravityfromthegroundup.org BTW I was introduced to using geometric units for the equations. This way you transform from conventional units to units that are expressed as a length [distance]. Using those units the metric you asked about looks like this dTau^2 = dt^2 - dr^2 - r^2 dphi^2 for me this is much easier to look at. Most of the gravitational analysis uses these units. The Minkowski metric you asked about doesn't have an angular component so it will evaluate radial paths only. This is common for learning the basics. You would just set the dphi component for 0. dTau^2 = dt^2 - dr^2 really easy to look at and understand. For example you could set dTau to 0 and derive the local speed of light using the metric. 0 = dt^2 - dr^2 dr^2 = dt^2 Just take the root for both terms dr/dt = 1 light, c=1 Most the radial paths are really easy to evaluate. The only GR math that's requires mathematics introduced during graduate studies is for evaluating spacetime using the original frame independent [invariant] coordinates derived from the original field equations. Tensor analysis. This was just an attempt to show that it's easier to study gravitational physics than you an Pad might think. BTW the information on how to convert conventional to geometric units is in Chapter 2 Curving at Professor Taylor's download site that I linked for you. That was my introductory book. Schultz book is pretty darn good and a great introductory pedagogical tool. In my opinion.
Thank you brucep I really appreciate you taking the time to guide me. I will be going home soon. I mentioned I live like a hermit doing my astronomy stuff and a bit of art so learning about things of specific intetest have room to become obsessional. I want to keep pushing my brain as it hints at turning to mush. Thanks again.
A bit more. The final equation that Schmelzer derived for you, from the flat spacetime metric, is the equation for calculating the proper time coordinate for flat spacetime. This time coordinate is equivalent to the proper time coordinate at boundary. The tick rate = 1. To determine a difference in proper tick rates you need to know the proper tick rate in two different local proper frames of reference. The SR component of time dilation. dTau = (1 - v^2)^1/2 dt Gravitational time dilation dTau = (1 - 2M/r)^1/2 dt v^2_escape = 2M/r v^2 in the SR component is equivalent to v^2_escape for the coordinates 2M/r in the gravitational time dilation equation. 2M/r is the curvature component in the metric. So you might conclude that 1 represents flat spacetime and 2M/r represents the local curvature at 2M/r. So we derived the local speed of light from the Minkowski metric and we can derive the radial remote, frame dependent, coordinate speed of light from the Schwazschild metric. Setting theta and dphi at 0. dTau^2 = (1 - 2M/r) dt^2 - dr^2/(1 - 2M/r) - 0 - 0 Setting dTau^2 light = 0 0 = (1-2M/r) dt^2 - dr^2/(1-2M/r) dr^2/dt^2 = (1-2M/r)^2 The root dr/dt = 1 - 2M/r this is frame dependent. Regardless what Farsight and RJBeery claim. The derivation for the local speed of light is invariant c and the remote coordinate speed of light can vary.
Thanks for everything brucep. I think I have made progress in the last few days. Is it the discussion involving math or the thread being moved that has caused tg to disappear.
That's an interesting point: To be continued: Please Register or Log in to view the hidden image! Hot sweaty and sticky in old Sydney town today! Please Register or Log in to view the hidden image!
He could learn from this hopefully. Even though he may feel knocked down he can chose to run away or face up. I said I would support him if he needed it I cant see how but I would encourage him to continue his participation even though his feelings may be hurt. Recover and learn more. We have two ears one mouth use them in such proportion and always suspect your infallibility.
I would love to believe that also Xel. From my experience with him, he'll either disappear forever and come back under another handle [which I believe he already has] but he'll never learn. His is an agenda of the worst kind, driven by religion. We have had a couple like him before, one particular maths savvy individual called chinglu, who would publish pages of maths, supposedly invalidating SR/GR Please Register or Log in to view the hidden image! Our real online expert took him to task and showed up more holes in his maths than in a sieve [rpenner] The god is in a similar vane...both religiously driven. If he hasn't "run away" and he does return, it will not be to face the music. He'll return with some other "fabricated"aspect that he will claim invalidates some other accepted part of cosmology. I'm not being nasty, just speaking from past from experience, that is his only intention and mission on this forum. And really, I would love to be proved wrong....But I don't believe I will be.
Back after a brief hiatus.....no access to any kind of electronic gadgets for last 4-5 days, Yoga, nature etc.. Feeling quite rejuvenated and alive..
Kittamaru, You appear to be such a nice lady, your avatar tells me about your niceness...Why for God sake, you shifted this thread ?...It would have mature as a wonderful learning thread.... Some maths is already pumped in, you know in reality the area can only be described as enclosed between lines and arcs, and a point can traverse only on lines and arcs....so spacetime has no useful meaning as area, (fabric of spacetime, like our bed spreads), it got to do with lines and arcs. Infact it is pop science to talk about spacetime as bending, it is fine to talk about a mesh of lines or arcs as bending......Can you visulaize Gravity sans motion ? Can you describe maths of motion of an irregular spinning body from the areas perspective (we generally talk about point mass...center of mass etc). With this thread the real aspect of spacetime as the mesh of arcs and lines would have come by, I would have pursued how some of the flawed enthusiastic statements about spacetime are nothing but vulgurity in Physics.. This thread can be a good learning thread as compare to other nonsensical threads like 'Aliens are dead' flooding the science section.....Please reconsider, or at least be kind enough to let me know why the concept of arcs and lines (graphs) is no science for you...
