studiot

Is Mars any better? From what I can understand $50 million is a lot of money in oceanographic research $50 billion is a drop in the ocean of space research.

Care to elaborate ?

I have just been listening to a programme about burying carbon in the american Midwest or central China. Why not the bottom of the sea? This is, after all, where Nature buries it. We have the International Space Station, and projected missions to Mars, but ocean bottom stations are still only available in Hollywood Scifi movies. I have spent the last half century hearing about how much treasure is to be had at the bottom of the sea, yet we know proportionately more about the Solar system than the depths because we put proportionately more effort into space research than subsea research. Why is theis? Surely the payback would be greater for many centuries to come?

Obviously I'm not being clear. I'm proposing an automatic programmed into the site cutoff with no need for mod intervention. That's why I indicated I don't know if it's practicable here. And if they prefer to spend 150+ posts re-educating you? As I see it it is a question of degree or %. The total input to non scientific threads should be limited to a small percentage of the total in some way. This is, after all, primarily a scientific site. Everyone should be able to put their opinions on say suppression of women in certain societies. But once or twice is enough. But not to the detriment of the main purpose of this site.

Should be much less if the site can restrict this automatically.

I don't know if it's possible wthin the site's programming but if we simply limited the number of posts in some way? I have noticed that religious and some other contentious subjects rapidly grow to 50 to 200 posts, sucking all the resources, members time as well as policing time, away from real scientific subjects. In many technical disciplines you have a certain number of goes at the exams that's it. If we said say 5 posts per member in the religion and politics sections and if you can't make your point in those, tough? I speak as one has has not made many more than 5 posts in total since I've been here in those non scientific sections.

Fancy books and fancy formulae? Why do you think folks study numerical techniques? What are the uses of integration and differentiation? Here is an everyday simple example. The construction of a concrete ground slab for a new building involves digging out ground for the slab to a depth of 0.5, along with a ring beam under the entire perimeter of the 30m x 30m slab. The ringbeam is an extra 1.0m deep below the underside of the slab, 1.2m wide at the top and 0.5 m wide at the bottom in trapezoidal section. How much earth has to be removed and replaced with concrete. This is an exercise in numerical integration that involves two of the three principle uses of integration.

Rather than continuing this squabble here is something on topic to ponder. Consider the set of all humans who are alive (or dead if you prefer). Now at present all (known humans) are concentrated on one planet so the relativity of simultaneity is not an issue. But Consider a set of transientobjects such that they have substantial relative velocity. What is in the set depends upon the time at which you enumerate the set, if the set has physical reality (even as a non material thing) But this conflicts with relativity of simultaneity. Some observers will include some objects, but others will exclude them since the observe the objects to have run their course at the moment of counting. My head hurts.

16 volts and 1.2 amps implies 20 watts. For a small pair of computer speakers? This would be most unusual. So please ohdearme check the rating befopre we proceed further and confirm that the adapter isn't really 6 volts.

Lucid explanation, John. +1 But hydraulics is still a poor to defective analogy for electrics.

Sorry I can't help further with your cupric hydroxide reaction, but I believe your search may be enhanced if you use the term polyhydric alcohol.

Hint; when making your list check the difference between a particle and an elementary particle. So protons and neutrons are not elementary as they are made of smaller particles But electrons were elementary, last time I checked.

But does the member OP need a discussion of Ohm's Law? Doesn't he needs a new mains adapter and/or a new multimeter?

Hydraulic analogies soon run into trouble because the analogy is not exact in importartant detail. Surely it is best to avoid all hydraulic analogies and go staight for the horse's mouth. Isn't post 3 clear enough? Why cloud it with muddy water? Incidentally if you want to talk about inductive circuits, why introduce resistance as in post3? Ohdearme, please, please don't connect your multimeter to the mains adapter when set to the ohmeter setting. This is a good way to destroy your meter, even if the adapter is not working properly. Definitely don't connect it like that to any new adapter, even after switching the mains off as the residual power may still be enough to damage the meter. Also do not connect it in current mode to the adapter. Bang. #So that leaves us with voltage mode. Off load the adapter can be expected to produce a higher voltage than when working at rated current. If you adapter bears a 16V rating then it could be as high as 20V off load. (But see my note about your voltage at the end of this post) The voltage should fall to 16 on full load. (Speakers rarely present full load.) Talking of loads, let me dispel the all too common misconception, Your adapter rating says 16V 1.2 amps. The amps are determined by the load not by the adapter. The amps are determined by the load. A different load will draw a different current. So the adapter will allow the load to draw any current from 0 to 1.2 amps at 16 volts. This is true of all normal supplies of electricity (batteries, the mains, power supply adapters) Only special purpose supplies such as battery chargers work the other way round. BTW are you sure the supply says 16 volts not 6 volts? That is most unusual.

Not sure. Are they saving water in the pumping from one side to the other or is the left hand side now disused? There is an arrangement in Holland that looks similar on the canal between the Isselmeer and Muiderslot castle.

Cladking I undestand your point. I often respond to the logical conclusion of what people are saying rather than the statement itself. I believe this better highlights my objection while cutting to the chase. I didn't remember the diagram and since I consider "science" a subset of "philosophy" I was just covering all the bases. Rather proves my point. You didn't respond to either of my statements, just your guess as to what they might have been or might have meant. You put in a lot of typing here. At best it is only one extra click to quote, and a few extra seconds to write X is what you said, Y is the logical conclusion which leads me to respond.....Z Doing this would save a lot of confusion all round.

Rubbish. The total number reproducing sexually (mostly higher species) runs into the millions. The total number of asexually reproducing species (mostly lower species) runs into the billions. See the section on numbers of species towards the end of this article. https://en.wikipedia.org/wiki/Species

I am not sure what your level of math is, rusty, never liked it so never worked at it, had to do other things ? So here are some extracts from books that may be of interest. 1) Dennis Rosen "Mathematics Recovered for the Natural and Medical Sciences" Answers lots of questions like what is differentiation?, what is integration?, what are matrices?, what are fourier transforms in a simple what is hypothesis testing?, in a simple way. Mark Levi "The Mathematical Mechanic" Offers a refreshing connection between maths and the physical sciences; tries to prove mathematical results using phycal methods. Ferrar "Mathematics for Science" A particularly clear textbook from a professor at Oxford for students going from upper high school into university.

Perhaps an online start with these people. http://www.esm.psu.edu/courses/emch12/IntDyn/course-docs/Euler-tutorial/

So post some pure mathematics here and ask your question about it. Others seem to manage this simple? difficult? task and find happiness.

+1 for perception, knowledge of one's limits and even handedness. Since I am posting again I will take the opportunity to reinforce my claim that human thought processes encompass other avenues than language and further that such processes are commonplace. What does an engineer, architect, builder, surveyor, machinist any many other trades and disciplines viewing a set of engineering drawings think? She does not use language, she visualised a three dimensional object, form the non lingual information in front of her. In particular this thinking skill requires correlating the non lingual information from several drawings into a composite picture. Of course most drawing incorporate words and numbers and the viewer can name the parts, but this is subsidiary information. The shape can be understood without a single word appearing. But of course, that is what engineering drawings are for. Further one of the beauties of this system is that it is language independent. So a Chinese viewer can understand an English set of drawings and vice verse, even though they cannot read the words, because their language is different. So different that, as I understand it, Chinese does not actually work in words in the way English does.

That's something to be proud of. One of the past presidents wrote one of the most famous and deep thinking textbooks on Thermodynamics, a few years ago. Does the name Pippard mean anything to you?

Do you understand the difference between differentiation and integration? There is a huge and fundamental difference in the nature of the integral and derivative. Unless you are talking about symbolic manipulations available in certain mathematical programs such as MathCad and Mathematica; The integral of interest in numerical analysis is the definite integral, which is a pure number. The derivative is, as always, a function (hence its full title the derived function). The purpose of numerical differentiation is to solve differential equations by finding the value of the derivatives at specific points. The purpose of numerical integration is to output a result such as the area or work done as a single number. So in asking this question you need to be quite clear what you are seeking. Personally I don't do online courses, but I can recommend books.

David as an engineer, though you do not say what sort, you should be used to poles appearing in calculations in dynamic formulae. These occur in resonant systems, whether you are talking electrical or mechanical engineering. There are even elastic instabilities in non dynamic situations (eg buckling) that exhibit this behaviour.

Even if you compress air until it becomes a liquid, it is still less dense that water (heavier is not a good word to use). The density of liquid air is only 0.87 of the density of normal water. https://en.wikipedia.org/wiki/Liquid_air Air bottles are designed to be heavy enough to be slightly negatively bouyant when filled. The thick metal walls are for weight as well as strength.