Ghideon

Sorry, misunderstood opening post. I'm of little help here, for the little reading about programming I currently do I'm more into online tutorials or documentation.

(bold by me) Thanks, but three of the books on the list seems to be about other topics than programming, was that intended? Last edition Code Complete by Steve McConnell i know of was released in 2004, I consider it rather outdated by now.

If the link I provided does not work (it works for me) Google for 'The Map of Mathematics' Poster by Dominic Walkman. I'm not sure about posting the actual picture here on the forum due to copyrights. The link again: https://www.flickr.com/photos/95869671@N08/32264483720

I'll try not to interrupt your discussion, just a question: do you mean centre of mass of balls only, centre of mass of the balls + the box the balls bounce around in? Other?

Not sure I grasp the idea completely but maybe the "the map of mathematics" could act as a starting point or act as a rough guide? It is a one page drawing showing how many concepts such as pure mathematics, applied mathematics, number systems, topology and many other fits together: https://www.flickr.com/photos/95869671@N08/32264483720

I have passively followed this from the sidelines due to limited knowledge in the area but I've learned a few things*. Are you sure? There are now 10 pages of excellent examples and objections from several experts in the field, none of which seems to bring you closer to the desired understanding. I've browsed through the thread again, each time a critical argument is added the standard type of response is: What prevents you from understanding the objections related to your idea while at the same time you seem capable to understand several other complex concepts of physics**? What prevents required new tools from being added? I may have some ideas about (over-)simplified analogies as a complement to the expert explanations given so far but at this time I'm not sure if that is what you are looking for? *) @Mordred's "What curves is the principle of least action" certainly trigger some thoughts, I'll try to study that, check if my intuitive understanding of that single line matches the mainstream science. **) I lack your level insight into GR but I can still understand much of the discussion.

Does the time dilation for observers in relative motion in a flat Minkowski spacetime count as an example?

Thanks, variations of SEIR is in use here. There is also a full scale model of the population on individual level, microsim*, but AFAIK not yet adopted to the new situation. Your post helped me in the right direction for further reading. Neighbour countries here have adopted other policies and have a lower number of deaths now. A better protection of the elderly people and/or people seems to be one important factor where others seem to have been doing a better job than Sweden. The underlaying reasons for that will probably be analysed and debated for years. I think your question is interesting because "success" needs to be defined one way or another In the context of the thread, Success Stories must be possible to separate from Abysmal Failures to be able to improve policies. Otherwise it will be tricky to compare policies and improve. I do not know if success now in the early phase is a guarantee for success in the long run. *) https://books.google.se/ extract https://arxiv.org/pdf/0902.0901.pd

Several valid points regarding Sweden have been made in posts above. My experiences so far: -There is not enough data available to state anything conclusive regarding the current approach here in Sweden. It's too early. -Most decisions so far seem to be based on scientific evidence. -As far as I can tell there are good models, adjusted to local conditions but maybe not adjusted to Corona yet My guess* is that the lack of data makes it hard to run the models with a valid set of parameters, models have been proven to work in other situations may or may not produce good predictions. The models' predictions are open for various interpretations. Data in this early stage can support both a lockdown and an open strategy; there is an overlap. Both may be sound scientific interpretations, there are scientists (and others) on both sides in the discussion. I can't guess if this policy will have a good or bad outcome. But I can see the logic behind the attempt to balance for instance: -Base decisions on local conditions, not so much on what others have done. -Try to close down enough to allow for health care to cope and adjust. But do not close down more than that. -Try to make recommendations that people will choose to follow over an extended period of time, it is not a three weeks sprint run for a vaccin. There are lots of other observations to add but that would turn this into blog post. If there is interest in some specific aspect I'll try to answer or find sources. *) I do not have studied the numbers and methods enough claim any insight (yet).

No problem, welcome to the forum! I agree. And this is an interesting topic. Regarding the opening question, and in addition to Phi's link, here is some info on the history of plate tectonics theories. The articles also contains some references covering competing theories (for instance expanding earth) and reasons why scientists abandoned them. https://en.wikipedia.org/wiki/Timeline_of_the_development_of_tectonophysics_(before_1954) https://en.wikipedia.org/wiki/Timeline_of_the_development_of_tectonophysics_(after_1952) Note: the pages are marked as having some issues so some care may be needed when reading. But usually the references sections may point in the right direction.

Could you present a plausible mechanism allowing that to happen, and explain how it works? Without usage of those substances maybe the current scientific consensus regarding this topic would make more sense?

Today I learned that skills improved by participating here on scienceforums can, at least in some minor way, be helpful in the current virus situation. I joined a local initiative where students studying from home can ask about math and physics. Debating science here has made me more confident regarding mainstream science and how to respond with useful hints (instead of solutions) to homework questions.

That is a good point. Redistribution of large amounts of water is not impossible, but hard to do cheap or with limited resources. There are large projects to redistribute water across seasons (Hoover Dam for instance) so with appropriate political will, need and organisation it would be possible to do geographically as well.

I cannot claim to be an expert but there is some quick local numbers. Also note that the local conditions here seldom causes drought. In Sweden there is a yearly production of 900x10^9 l of drinking water produced* Fuel delivered for usage by vehicles is approx 12x10^9** That means that the drinking water volume is 75 times the volume of fuel. And note that this is drinking water only. To that one have to add the vast amounts of water needed for other purposes such as farms. One figure I found* is that the amount is approx 28 times the volume of drinking water. The above example means that if 1% of the water would require a relocation it would still be approx 20 times the volume of all fuel transported. So in addition to the problem of making a profit as stated above there is the issue of delivering enough volumes of water to make a practical difference. References. Sorry, some may not be available in english at this time: *)https://sydvatten.se/vattenforbrukning/ **)https://spbi.se/statistik/volymer/

It may be easier and more efficient if you also provide a picture? If each interested member have to interpret your description there is plenty of room for confusion?

Three different modes tested: [math]f(x):=0[/math] \(f(x):=0\) [latex]f(x):=0[/latex] Code for above is [math]f(x):=0[/math] \(f(x):=0\) [latex]f(x):=0[/latex] Screendump from browser Mathjax-config: inlineMath: [ ["\[math\]","\[\/math\]"], ["\\(","\\)"], ["\[latex\]","\[\/latex\]"] ],

Thanks, that's a better expression.

Can you explain what that means? If your definition is identical to Pi then it is some redundant definition. If you get another value in your definition of Pi then your definition is wrong; it is not Pi anymore. As I said in a post above: pi, defined as circumference/diameter of a circle, seems to have an non ending sequence of decimals when expressed in base-10: 3.1415... that does not mean that circles, pi or their definitions are approximations. If you need to write Pi as a number maybe you could have look at base-Pi numbers at wikipedia.org/Non-integer_representation#Base_π or the source at http://datagenetics.com/blog/december22015/index.html

1: PNG: 2: Plain text: f(x):=0 3: text between math brackets: [math]f(x):=0[/math] 4: Screenshot of line 3 above before pushing submit:

Hello! A quick hint: the question is for Jupiter's volume, is the unit of your suggested answer a volume?

Thanks for confirming. Probably a language issue then, I know and understand a few things about arcs, circles and trigonometry. But I have been unable to find anything about "Arc of definition" in math.

Question: By ”arc of definition” Do you mean ”an arc of the unit circle”?

Ok. Please post the result and the issue it solvets once you have made progress. In the meantime I’ll continue doing my work, using trigonometry, transforms, straight lines, curves and other mathematical concepts. From what I’ve learned so far there is no need for any new definition of arc or trigonometry. Sorry that you think your own question is a waste of time. (Or maybe translation messed up your comment?)

Can you clarify your question, maybe by providing a picture and/or formulas?

Why? AFAIK value of trigonometric functions are exactly defined. Ability to numerically express a value exactly, using a limited amount of decimals, is not an issue with the definitions. Analogy: pi, defined as circumreference/diameter of a circle, seems to have an non ending sequence of decimals when expressed in base-10: 3.1415... that does not mean that circles, pi or their definitions are approximations.