studiot

Thank you all who responded. I do not think it is just a question of risk. A question of acceptable risk maybe , but not absolute risk. There was a case a few years a go where a badly designed rear wheel bearing caused some rear wheels to fall off above (i think it was) 35 mph. There were a few resultant deaths, although many rear wheels did not detach. No one considered even one single death an acceptable risk. It just should not have happened. The manufacturer called in all the affected cars for urgent modification. Tesla in this case could have designed the car to be inoperable without someone properly in the driver's seat. I think it is BMW that has such a system if all passengers are not wearing their seat belts.

What if an obviously incorrect 'theory' is repeated posed and simply wastes the time and efforts of others (perhaps many) and confuses those who are not so good at the subject ? For example those few who continuous challenge the accepted value of Pi with an easily demonstrable incorrect value.

We have had several threads and discussions about this topic this news qwould seem to indicate we are not yet there.

I am sorry for any comment that could have been taken as offensive. Thank you for not being offended by my coment. I assure you no offence was intended. There is one more type of systems , that is really a variant of an open system. Flow systems are often modelled by the use of a 'control volume' , where the mass flow in is exactly equal to the mass flow out. Such a system is called quasi-static since the composition within the control does not change by energy and momentum flow through the box. The boundary is more problematic. Take for instance conformal mapping of flows or fields. 2D maps have sources and sinks which draw on materials or field lines from another dimension perpendicular to the plane. 2D manifolds may have not boundary, yet be finite eg the surface of a sphere. 3D manifolds may be finite in 3D and unbounded, yet flows or fields can require activity in fourth dimension. So the logic of the question "where does the energy come from ?" remains unanswered. The issue of working in X dimensions and borrowing from another introduces many wierd effects in Maths, some which spill over into theoretical Physics. You may have heard of Gabriel's Horn. An infinite surface that bounds a finite volume. https://en.wikipedia.org/wiki/Gabriel's_Horn This is one reason why the Lebesgue integral and measure theory was introduced to extend ordinary Riemann integrals.

What a shame you have started with a reasonable observation that many do get wrong. I agree that it is very difficult to apply a pulling force to a material object without also applying a pushing force. But it is not impossible. This is because most pulling forces (tension) are internal forces. However the rest of you postings appear to me to become increasingly fantastical and outlandish. John Cuthber has asked a couple of exceedingly perceptive questions, to which I look forward to reading your answers. +1 I would add the following one to these What did you contain your tungsten sample in given that the melting point of tungsten is about 3500 degrees and the boiling point about 5500 degrees ? Further your version of what Science and the Scientific Method is about is woefully inadequate. Since we are using melting and boiling points as examples, Here is a random page from my Lange's Handbook of Chemistry, which contains thousands of such pages. How on earth do you suppose all this data got measured, verified, collated and presented ? Science is not all about hypotheses Between every two hypotheses lies amountain of dedicated scientific infill work, far less glamorous that say gravity or electromagnetism, but equally necessary and often unsung.

OK so you have described how you see it (your problem) so no apology needed. I don't know about you skills since although you say you are not a scientist you clearly have a reasonable measure of knowledge and understanding. Your phone is probably not the ideal recording device, however. You need a gadget or gadgets mechanically coupled to your floor or other parts of your apartmenet structure. Such a device is called a seismometer or an accelerometer for higher frequencies. https://www.google.co.uk/search?q=seismograph&sxsrf=ALeKk01_X_O2wDFnlkHwFbfzkOrsxMsN9A%3A1618773670675&source=hp&ei=poZ8YNTqJq6JlwSKvrywAw&iflsig=AINFCbYAAAAAYHyUttRlHmbsMbU_OlZSqZM_jiiz5lU1&oq=seismograph&gs_lcp=Cgdnd3Mtd2l6EAMyAggAMgIIADICCAAyAggAMgIIADICCAAyAggAMgIIADICCAAyAggAOgQIIxAnOgsILhCxAxDHARCjAjoICAAQsQMQgwE6BQgAELEDOgUILhCxAzoICC4QsQMQgwFQ2ApY-iBgtD1oAHAAeAGAAegKiAHaPZIBCzMtMS4wLjIuMy4zmAEAoAEBqgEHZ3dzLXdpeg&sclient=gws-wiz&ved=0ahUKEwjU1fDswYjwAhWuxIUKHQofDzYQ4dUDCAg&uact=5 Although these can be very expensive simpler ones can be bought cheaply or even made by an amateur. They are indeed made as projects in some schools. This would give you an indication if there is something there and a permanent record of it as well. Another possibility for a trial would be an old fashioned gramophone cartridge with its stylus resting on a hard surface fixed to the floor (eg a ceramic tile) and connected to a data logger. It all depends upon you skillset and purse.

I recognise (at least) three (thermodynamic) system types. Isolated : Neither matter (mass) nor energy may pass across the system boundary to or from the surroundings. Closed : Energy but not matter (mass) may pass across the system boundary to or from the surroundings. Open : Both energy and matter (mass) may pass across the system boundary to or from the surroundings. Some rather parsimonious authors only detail two of these and say closed when they really mean isolated. "in that case the point-mass is the universe." Yes indeed so that is the point. But such a universe is isolated so how do you determine its energy, whether kinetic or potential. ? It is also worth noting that both the First and Second Laws of Thermodynamics refer to processes acting across the system boundary. That, of course, presupposes there is a system boundary. And, of course, that there is available energy on the other side of it whatever that means in terms of the universe. So I am saying we have run smack into the perennial problem of trying to extend properties of a finite system to a (perhaps) infinite one.

Perhaps not quite what you are looking for but here are some Chemistry links for you to explore. Chemdraw https://www.google.co.uk/search?q=chemdraw&sxsrf=ALeKk01PO048lS-m5UVKifuDGYj-5mGmkg%3A1618674249763&source=hp&ei=SQJ7YOWyLPGjgwfRxpzQCw&iflsig=AINFCbYAAAAAYHsQWZSfkesJqZhYUdT2ydUYVTrAEQH_&oq=chemdraw&gs_lcp=Cgdnd3Mtd2l6EAMyBQgAELEDMgUIABCxAzICCAAyAggAOgQIIxAnOgUILhCRAjoICC4QkQIQkwI6CAguELEDEIMBOg4ILhCxAxCDARDHARCvAToLCAAQsQMQgwEQyQM6BQgAEJIDOgsILhCxAxDHARCjAlDkEFiyPGDcPmgBcAB4AIABvgqIAeAfkgEPMC4yLjMuMC4yLjAuMS4xmAEAoAEBqgEHZ3dzLXdpeg&sclient=gws-wiz&ved=0ahUKEwil-6W9z4XwAhXx0eAKHVEjB7oQ4dUDCAg&uact=5 Chemsketch https://www.google.co.uk/search?q=chemsketch&sxsrf=ALeKk01dtdCGvDqE6Dkx8i0m0VwV8nCC2Q%3A1618674259389&ei=UwJ7YImmF5PygQax2prQDQ&oq=chemsketch&gs_lcp=Cgdnd3Mtd2l6EAMyBAgAEEMyBAgAEEMyBAgAEEMyAggAOgcIABBHELADOgcIABCwAxBDOgQIIxAnOgcIABCxAxBDOgUIABCxA1DktwtYitELYOrSC2gBcAJ4AIABxASIAbgLkgEHOS4xLjUtMZgBAKABAaoBB2d3cy13aXrIAQrAAQE&sclient=gws-wiz&ved=0ahUKEwjJm_PBz4XwAhUTecAKHTGtBtoQ4dUDCA0&uact=5 Crystal structure animations (mineralogy) http://www.wiredchemist.com/mineralogy/instructional/crystal-structure University of Liverpool UOL offers some excellent animations in Chemistry and spectroscopy. https://www.google.co.uk/search?q=university+of+liverpool+molecules+animations&sxsrf=ALeKk00JfY6HhmqA0g2YeACTA6l2Ixn24w%3A1618674452382&ei=FAN7YP7qFtCfgQbhqY0Y&oq=university+of+liverpool+molecules+animations&gs_lcp=Cgdnd3Mtd2l6EAM6BwgAEEcQsAM6BwgAELADEEM6BAgjECc6BQgAEJECOgUIABCxAzoICAAQsQMQgwE6BQguELEDOggILhCxAxCTAjoCCAA6BwgAEIcCEBQ6CAguEMcBEK8BOgUILhCTAjoGCAAQFhAeOgcIIRAKEKABOgUIIRCgAToICCEQFhAdEB5QgIEQWKCwEWCishFoBHACeACAAa4FiAHSK5IBCzI0LjIyLjEuNS0xmAEAoAEBqgEHZ3dzLXdpesgBCsABAQ&sclient=gws-wiz&ved=0ahUKEwj-xPad0IXwAhXQT8AKHeFUAwMQ4dUDCA0&uact=5 Online ph calculators https://www.google.co.uk/search?q=online+ph+calculators&sxsrf=ALeKk02RZMtO06VYoRPoWqV5g7qgF4dgmg%3A1618675059887&source=hp&ei=cwV7YOL3M6-cjLsPltm0sAU&iflsig=AINFCbYAAAAAYHsTg8X6pLI1qXxSv0vE35PzD7VaDShf&oq=online+ph+calculators&gs_lcp=Cgdnd3Mtd2l6EAMyCggAEAgQDRAKEB46BAgjECc6BQgAEJECOgQIABBDOgUIABCxAzoCCAA6BAgAEAo6BggAEBYQHlDmAlj0JmCQXmgAcAB4AIABogeIAe5KkgELMi0yLjEuMy40LjaYAQCgAQGqAQdnd3Mtd2l6&sclient=gws-wiz&ved=0ahUKEwii_cu_0oXwAhUvDmMBHZYsDVYQ4dUDCAg&uact=5

I have no idea what you mean as a reply to my comments. [ ] head scratching icon with puzzled look on face [/]

Caught me a bit short here, but I used Labview a good few years ago. https://www.ni.com/en-gb/shop/labview.html?cid=Paid_Search-7013q0000020cz6AAA-Consideration-GoogleSearch_LabVIEW_LabVIEW&s_kwcid=AL!6304!3!449107487676!e!!g!!labview software&gclid=Cj0KCQjw6-SDBhCMARIsAGbI7UhYjOk-HTJWavP8DJsgGGHUSgrvuIhTuM16XeqosQwuJnCmHNBRluYaAr86EALw_wcB Are you looking for free or commercial software ? What about add ons to say MathCad, Mathematica, Wolfram Alfa etc ? I also used to use a delightful software called DesignView. AutoCad now has a pale imitation copy as an add on. Sorry this is a bit rushed. There used to be a Visio module for this as well. You could help by narrowing the field of interest. We already have a few threads on Chemistry molecule and reaction software. Hope this helps

I understand that some folks have a natural immunity, but I am not sure you can 'build up' an immunity to Lyme disease. It should be noted that the disease is not due to the ticks themselves, but to certain bacteria that some ticks harbour. So in most parts of the UK your risk of Lyme disease is low even if you get several ticks. The worst areas are South West Hampshite and South East Dorset - The New Forest area. Luckily (for me) they have not really spread out onto the Blackdowns. If you do get the symptoms it is important to get the antibiotic treatment as it can develop into something much worse. https://www.nhs.uk/conditions/lyme-disease/

"But instead of it being seen a fabric of space time, what if time is just attracted to gravity just like matter is? Does looking at time from the point of view that it’s attracted to gravity rather than being seen as a part of the fabric of space actually change anything? " You might like to rephrase your OP question. Time is not a substance you can get a cupful and transfer from one place to another. In our world, time and space are not the same (or there would be no point distinguishing) but are intimately connected. Motion is the most common connection, but not the only one. Because motion uses time in its definition you arrive at a circular argument if you try to define time in terms of motion. So arguments about "the velocity of light" are moot since you need both space and time already given to discuss that concept. It is conceivable to imagine a world without time, (ie space only) but it would be quite unlike ours, which comes equipped with both. You would have situations like The cat sat on the mat... The cat sat on the mat...... The cat sat on the mat......... The cat sat on the mat............ Pretty boring really.

Energy of what ? 'Energy' is not a substance. What is the 'energy' of a single point mass in an otherwise empty universe ? So the question arises "How do you treat the energy of the very first point mass to be 'created out of nothing' ?" Gravitational 'energy' is potential energy or the energy of configuration (of a system). Some of this is released to other forms as a system is reconfigured. This happens through the action of forces (if your view is Newtonian) or GR field equations (if your view is relativistic). Makes one feel like the first chicken contemplating the first egg.

So do you have something specific to discuss ? Remember that this part of the forum (like most of ScienceForums) is for science and technical stuff. There is also politcial section if you want to discuss political aspect. Note you are allowed a total of 5 posts in your first 24 hours to prevent members being bombarded with spam (It works quite well) After that you can post to your heart's content.

+1 Thanks for the response I was hoping someone would try it as I have never put anything on youtube before. It did say something about private and then something about waiting a day whilst it 'processed' when I asked to make it public. That dfay has now passed. But I really don't know what I am doing so welcome all the help I can get.

I have managed to upload a 14 second video to youtube. The person standing on the scale starts quietly at rest to give a still reading. Then raises their heels slowly up a couple of inches and slowly returns back down to rest. The repeats quickly. The scale reading can be seen to drop in both cases. https://www.youtube.com/watch?v=NCwgvQf05SU

But such corrections were made, even before modern astronomy. But don't forget that measurements were/are made using angles, not distances. And all references to positions are in relation to an observer located on Earth. The astronomical system that has been developed assumes astronomical bodies are located on a sphere or spheres which rotate about the Earths axis. In the case of multiple spheres these are thought to rotate at different speeds to acount for the differences between fast moving objects such as planets and slower ones such as stars. But in all cases the actual radii of these spheres, ie the distance to the objects is irrelevent to angular measure. A more important, but finer correction needs to be made to do with what is meant by the 'position' of the object of observable size (diameter). How to we identify the centre of such an object in an observation ? Bear in mind that for most of the history of astronomic observations, the only important observation was about what is known as 'transit' ie the highest point reached by the object in the sky. For any observer the local noon is the time of transit of the Sun. To find the correct. postion astronomers and surveyors use what is known as The Equation of Time. https://en.wikipedia.org/wiki/Equation_of_time

It is a safety issue. If you add concentrated acid to water, the reaction can be so violent that the mixture spits drops of concetrated acid about. This is because the acid heat of reaction heats the liquid in direct contact and can be enough to generate steam which propels the drops. This effect is even more pronounced if you try to do it the other way round ie add water to acid, which is why you should always add strong acid to water, a small amount at a time.

That is not recommended practice. Here is the CDC policy So the policy is to wait 90 days after recovery. The UK NHS mandates a shorter time

What level are we discussing this topic at ? I am suprised at this argument because I think complex numbers are above the level of this question. However I could ask what is the square root of infinity in the extended field of the reals or the square root of 5 in the integers.

scale is really the wrong word as is size, since they both refer to measurements in our normal 3 dimensions of space. consider the following sequence [math]\frac{1}{2} + \frac{1}{4} + \frac{1}{8} + \frac{1}{{16}} + \frac{1}{{32}} + \frac{1}{{64}}..........[/math] The sum to infinity of this is 1. That is using successively smaller and smaller intervals as marks on a coordinate axis allows you fit an entire infinite 'dimension' into a length of 1 unit of one of our normal space dimensions. You could say the 'scale' is different or shrunk etc but there is much more to it than this. The lesson to be learned from this is that we are dealing with ratios (of two numbers one from each system), not simple numbers on their own. I will return to the significance of this after my next comment. Now consider a standard trio of three dimensional axes, say x,y,z. This trio of axes can be right handed or left handed, but there is no movement in 3D space (ie any combination of rotations and translations) that can turn a left handed set x,y,z into a right handed set x,y,-z. But if we had a fourth space dimension like the other three we could do exactly that ie we could move our trio about in 4 dimensions and turn a left handed set into a right handed set. So there is something to gain from this if it were tue. Of course observations suggest that we cannot do this and thus suggest that there are only 3 space dimensions available. So what do we have to gain by introducing string 'dimensions' ? Well consider the following again in normal dimensions, just 2 D will do this time for the example. A ship is observed from 3 observing stations and their lines of sight plotted on a chart thus. In theory the intersection of any pair of lines of sight should give the exact position of the ship. So all three lines should meet at one single point. But it can be seen that in my sketch, as in reality, they do not meet like this but form a small triangle pqr, the centroid of which is taken as the actual position. Notice I said small triangle. With better optics we can determine our line of sight more accurately. But there comes a point where the dimensions of triangle pqr are less than a planck length and we cannot do better than this. We then have here a situation where we move from an exact position to a most likely position and probability of position. What is meant by saying that the 'strings' are smaller than the planck length is that we are in the same position as the observers of the ship. Yes we can propose mathematical structures within the string similar to series I showed earlier to give us desirable properties las we did with the extra fourth dimension for our trio of axes. But as with our series we are talking of ratios.

Yes you are nearly right, good catch. +1 -32 is also a square root of the OP wanted to ask, but didn't pose correctly. neonwarrior did however identify his/her problem of taking the square root of (-2)5 = -32 However within the real number system, negative numbers do not have even one single square root.

Alternatively if you want to use brackets to write the square root as the power 1/2 then you must use [math]{\left( {{{\left( { - 2} \right)}^{10}}} \right)^{\frac{1}{2}}} = {\left( {1024} \right)^{\frac{1}{2}}} = 32[/math] Again you must work from the inside out, working out the value of the innermost bracket before applying the out one.

Well dissociation is the noun, which can stand by itself. Dissociative is an adjective which needs something to describe eg 'a dissociative reaction' (although many authors talk of dissociation reactions). Dissociation is a process which you may wish to distinguish from the reaction as only part of the overall reaction which may involve dissociation and other processes. "associatively dissociation. " is totally incorrect as you are trying to qualify a noun with an adverb. I would in any case frown on the correct, but confusing, English associative dissociation. Does this help ?

This is improper use of brackets. and of the square root function. If you are going to say "the square root of" this is incomplete by itself. It must be the square root of something. That something is called 'the argument' The result of applying the function to the argument is called the result of the function. But it must be the whole of argument. So we often put the whole of the argument in brackets. In this case the something or argument we want to take the square root of is stated to be minus 2 to the power 10, So we put all of that in brackets [math]\left( {{{\left( { - 2} \right)}^{10}}} \right)[/math] and take the square root [math]\sqrt {\left( {{{\left( { - 2} \right)}^{10}}} \right)} [/math] Now the question is unambigous and you can work on it using the PEMDAS or BODMAS rules you should have been taught. Note that the rules about brackets are often not included in the PEMDAS statements. Brackets are evaluated from the inside out. You work out the innermost pair of brackets first, then the next and so on. So only Ghideon's second answer to your question is correct as you have posed it. Here is a more complicate SAT question. [math]\frac{{126 - {5^0}}}{{{5^3}}} - {\left( {\sqrt {\frac{{\frac{{32}}{4}*6 - 3\left( {2 - 3*\left( { - 1} \right)} \right) + 4 \div 2 - 116}}{{ - 2 + {5^2} - 32}}} } \right)^3} + \sqrt[3]{{ - 8}}*27 - 12{\left( {1 - 2} \right)^3}[/math] This is worked out for you in fine detail here https://steemit.com/mathematics/@hansenator/sat-math-problem-4-extreme-simplification