LaurieAG

While we're thinking about dark matter, I always find it interesting that our total calculated matter, dark matter + ordinary matter, equals our ordinary matter times [latex]2 \pi[/latex] within the error bars of our observations. Call it numerology if you like but I think it's an interesting property, especially on a universal scale, as no other constants are involved. https://en.wikipedia.org/wiki/Numerology#To_describe_questionable_concepts_based_on_possibly_coincidental_numerical_patterns — I. J. Good[16]

Cycloid arcs, while an old concept, provide some interesting insights into circles and [math]\pi[/math], especially when you consider that the area of a complete cycloid plot equals the surface area of a sphere. http://quadrivium.info/MathInt/Notes/Cycloid.pdf In a complete cycloid plot (length [math]2 {\pi} r[/math], height [math]2 r[/math], area [math]4 {\pi} r^2 [/math]) (1) the area above the cycloid curve is equal to the area of the circle that created the cycloid and (2) the area below the cycloid curve is equal to 3 times the area of the circle that created the cycloid.

[math] {\bar \lambda} = \frac {\lambda}{2 \pi} = \frac{\hbar}{m c}[/math]

Hi iNow, Centralised energy generation and distribution systems have the same massive losses during transmission. That's why rooftop/local solar is the best option as there is no transmission from generation to use.

While the solar panel areas shown on the graphics may be equivalent to current energy consumption there is no allowance made for the (massive) energy loss during its transmission to Germany, Europe or the rest of the world.

Just for comparison.

The integral is just the opposite of the derivative so the tutorials on this forum should give you a helping hand. http://www.scienceforums.net/topic/29473-introduction-to-calculus-differentiation/ http://www.scienceforums.net/topic/4108-calculus-i-lesson-1-a-background-to-differentation/ http://www.scienceforums.net/topic/4182-calculus-i-lesson-2-a-continuation-from-first-principles/

I prefer thought experiments that could be tested as opposed to ones that cannot, especially if the difference is minor.

The second question is because an observer right beside the track would suffer from whiplash if the experiment was observed in real time. Either that or they would require a close to 180 degrees view to capture all the different events as they occurred.

No randomc, I haven't. In the latter example I gave the industry was rife with bullying fraud and theft. I'll try to dig up a link to a Phd paper I came across a couple of years ago as it may contribute to this discussion. The thesis was about the generic technical differences between corrupt organisations (CO) and organisations of corrupt individuals (OCI) operating within non corrupt organisations. While the corruption in CO's grew from the top down OCI's tended to grow from the bottom up and management indifference and/or complacency were the key things that allowed them to flourish. The two organisations referred to in the thesis were an international sporting body and the US Catholic church and the contents of reports produced after official investigations into these organisations was used extensively in the thesis. I only found out later that the author had been an employee at a public organisation in another state for 20 years and that the results of an official corruption inquiry into this particular public organisation was the main driver for my states Public Interest Disclosure (PID) regime.

randomc, I found the following on Wikipedia with regards to passive aggressiveness that I can directly relate to non technical bosses managing technical professionals, especially in female dominated work environments. The strange thing is that I have also worked in both male and female dominated work groups, in similar technical capacities, and have never had any issues like this in male dominated groups, mainly because that type of behavior would be regarded as bullying, including in the ones I've worked in with female bosses. http://en.wikipedia.org/wiki/Passive-aggressive_behavior I can understand why you don't want to go into details so I'll supply you with a few examples from my own past experience, that you might be able to relate to. When I started in a projects team in a female dominated (90%) section of 50 people in a 3K+ employee organisation I had a female technical boss who had a good understanding of the technical issues at hand and we worked well together and had a good rapport due to mutual respect. That changed after a couple of months when a non technical female was rotated into my bosses position and my technical minded female boss was rotated elsewhere. Initially I would just give my new boss the same executive summary type information that I gave my previous boss and reserved the technical detail for the technical people I worked with. Unfortunately she questioned everything so each small paragraph or sentence became a detailed novella with many chapters, and very quickly she was in over her head, multiple times. If she had only trusted that the information I communicated to her in good faith was correct she would not have had the breakdown. After her breakdown she changed and showed assertive passive aggression that matched the bolded points from the Wki above. Shortly after at my first one on one meeting alone with her she said that she and the team did not want to receive any emails or speak to me with regards to the work I was doing in the team, even my designated backup. I just continued working with everybody else in the team in the same way I always did because they were technical people who didn't have a problem, but whenever I came near her she would put up the barriers and smother any attempt at communication. At my second (six months later) one on one meeting alone with her she told me that my contract would not be extended when it finished in 4 months time. I didn't think that what my boss told me was false (my contract was extended another 2 times for 1.25 years, 4 months later) so I never realised that she was bullying me until much later on. I honestly believed what she told me to the extent that 3 months later, I responded via email to the CEO's secretary with regards to a CEO request for an update on my project, with a final paragraph that I had been informed by my boss that my contract would not be renewed. I didn't realise that I was being bullied for about a year because I was so busy working. Over that year I attended 2 team meetings where my boss organised for another female employee to assist me and both times, 10 months apart, the other employee was allowed to take 4 weeks of annual leave when the time came along. I was exhausted due to not being able to take any holidays but glad because everything was rolling out smoothly without any help. This was just when she revealed her hidden hand. Bullying behavior by males or females only has one end randomc, it should not be allowed to survive in any responsible organisation. If you have problems that are anything remotely like the above, check if your organisation has some sort of Public Interest Disclosure (PID) system in place where bullying etc can be reported by employees and investigated internally without disclosure. In some countries, state or federal legislation can require organisations of certain sizes to have these types of systems in place. An organisation usually needs some sort of a PID if it has systems whose access is incumbent on employees signing confidentiality undertakings, with dob clauses, (due to state/federal Info Privacy and/or Info Sec legislation) if they become aware of unauthorised disclosures or modifications of system information by other employees or third parties. Please note that all of my comments above are related to non technical females 45+ working in technical roles. I regularly work with female inspectors/engineers doing QA on major infrastructure projects and have never been bullied in any way shape or form. I give her the QA test results and she decides whether the job continues or not based on those results so she may as well be the boss. One way that bullying can be detected is through unusual rosters singling out individual employees. From personal experience, and unfortunately after the event, I can say to watch out if 1/ you are given a 2 week roster with 2 days off at either end and work 10 days straight, then have 2 consecutive 2/ 2 week rosters without more than a single day off in a row where you finish late before your day off and start early straight after your day off. This gets really interesting if you rotate between 5 different shift start times: 2am, 5am, 7am, 11am and 2pm and roll out the final 5 consecutive days 3/ by starting the first shift at 2pm, the next at 11am, the next at 7am, the next at 5am and the final shift at 2am. I was positively jet lagged by the end so I didn't notice the roster pattern described above. The disturbing thing was that the boss who designed these rosters was a white haired 60 year old grandmother, in a female dominant industry, who knew exactly what she was doing.

If v = c, dx/dt = (c^2)/v = c so is it lightlike? Also, if the observer was far enough away so it could observe all 3 events without moving, what would be the minimum distance to that point.

I have just corrected the image above and swapped the apparent shift colors for paths A and C.

Everything so far has been based on Einstein's original thought experiment with a train frame, an embankment frame and an observer so what happens when we move the observer to different locations? If you extend the basic train experiment to use a circular track you can use SR based relativistic rolling wheel solutions that have a wheel, a road and an axle or carriage frame. The points in the wheel frame rotate around the circumference and the road sits stationary as the wheel rolls by. The axle frame is different from the wheel frame in that it doesn't rotate with the wheel but stays at the same location as the axle while the carriage frame is any other frame that is fixed with respect to the axle frame/location and its movement at any time. If the observer moved directly backwards to the center of the circular track it would be equidistant from both the front and the back of the train. If the track has sensors that are triggered by switches built into the front middle and rear of the train as it travels past and these ground switches turn on a light at the side of the track pointed directly at the observer when triggered then how would the pattern of lights appear at the observer? From this location would you see the first image with 2 lights and then a later image with 1 or would you see 1 then 2 then 3 lights? Or is there a point where it goes from one to the other depending on the distance away? Extending the train experiment further you can put the observer in an air ship tethered directly above the center of the circular track at a distance of 2 * Pi * R * c/v from the axle or center of rotation/mass. From this location you can capture all the photons emitted during one complete revolution of the train up to v = c knowing that the photons emitted from every light on the track would reach the observer at the same point in time if they had all been emitted at the same time regardless of their point of emission. This diagram below shows the light paths that would exist in real time between two rotating sources and an observer at various angles to the plane of rotation if the sources continued to rotate and emit for one complete rotation and the photons were not distorted or blocked along the way. Note C, 0 degrees, where the observer is in the same plane as the plane of rotation is a SR based relativistic rolling wheel solution (x and y only, z = 0) and A, 90 degrees, shows where the observer is perpendicular to the plane of rotation of the sources and observes minimal shift.

Hi I_Zeratul, Wikipedia has some good information and the 2 links below cover over half of your questions. http://en.wikipedia.org/wiki/GUID_Partition_Table http://en.wikipedia.org/wiki/Parallel_ATA

Thanks Janus and pantheory, It will be interesting to see what the new calculations say as I was told on another forum that there would be no change..

I came across the two articles below and wonder if anybody knows of any developments with regards to revised galaxy rotation curves and/or the total amount of dark matter? 'Lost in Space: Half of All Stars Are Rogues Between Galaxies' http://www.space.com/27682-rogue-stars-between-galaxies.html 'Milky Way has half the amount of dark matter as previously thought, new measurements reveal' http://www.sciencedaily.com/releases/2014/10/141009091600.htm

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How do things work out if the spaceship travels in a circle at a constant velocity?

Why bother about the latin when you can read the english translations. I have been reading "On the Shoulders of Giants", edited, with commentary by Stephen Hawking and it contains 'On the Revolutions of Heavenly Spheres' by Nicolaus Copernicus, 'Dialogues Concerning Two Sciences' by Galieo Galilei, 'Harmony of the World, book Five' by Johannes Kepler, 'Principia' by Isaac Newton and selections from Albert Einstein's papers on relativity. They all invested substantial effort in developing their ideas geometrically before finalising the maths. Incidentally, whenever I read Einstein's 1905 SR paper I get the distinct impression that he intended it to allow the true beauty of relativity to shine through a window onto the euclidean world. Unfortunately somebody put up the shutters.

(i) 20 x + 80 y + 20 x gives x = 40, y = 80, total = 120, x = 1/3 of total and y = 2/3 of total (ii) 20 x + (80 - 20) y + 20 x gives x = 40, y = 60, total = 100, x = 2/5 of total and y = 3/5 of total

More like somewhere around 60 +/- 1.5 degrees. http://en.wikipedia.org/wiki/Solar_System Orbit about Galactic Center Invariable-to-galactic plane inclination 60.19°8 (ecliptic) http://en.wikipedia.org/wiki/Invariable_plane http://en.wikipedia.org/wiki/Earth Inclination 7.155 deg to Sun's equator; 1.57869 deg[4] to invariable plane.

Apart from inclusion of a common reference frame to anchor the practical application of the theory. Does our system of dates have an 'absolute' frame of reference, or how about our time or latitude or longitude? Just because their start points are arbitrary doesn't mean that they are not a form of 'absolute' reference frame for most practical intents and purposes.

From a western perspective alone the ancient Greeks and Romans used the method prescribed and, just to mention a few examples, several Irish towns suffered a similar fate in the 17th century at the hands of puritans. In the 19th century the defenders of 'the Alamo' were on the receiving end of 'the treatment'. Just because it is regarded as a war crime now does not mean that it does not occur. Also (fortunately) there is little archaeological evidence in support of the events as given. BTW, I write 'god' as I am not particularly religious and do not wish to project any potential bias that could interfere with analysis of the issue at hand. While I can understand why breaking down the process to core motivations of key players might help I cannot fathom why anybody would consider 'commands from a god' as a valid defense for any current or ancient war atrocity.

Why would anybody think that cutting the grass (while also fertilizing the soil with blood and bone) would lead to anything but another bumper crop of grass that has to be cut?