studiot

Before anyone can explain an effect they have to have a proper knowledge of what happens. All I can see is the machine trying to jump around on the bench whilst you try to hold it down with one hand. In order to do this you will be concentrating on that restraining hand. You are holding piece of what looks like kitchen roll loose in the other hand, but this is a poor demonstration. The paper should be independently supported by a laboratory arm or frame. Then we could distinguish between judder in your arm and any other effect.

Perhaps you would like to enlighten me as to what I am supposted to be seeing in the video that has to do with gravity. At the moment I am completely baffled.

Let me wish you far greater success in your gardening thread (and gardening) than I had in my recent one, which received no replies.. As regards preparing a somewhat neglected patch for cultivation, don't expect too much too quickly. Yes you should most definitely dig over the proposed cultivated area before winter. I don't know if you have hard winters since you are a white bear, but frost action kills off many pests and breaks up large clods. You mentioned ploughing. Yes rotovating can relieve much of the work of digging. You don't need to achieve what is called a fine tilth before winter, just large clods will do. Cut back vegetation from around your area, and keep it cut back. Existing vegetation will harbour a source of pests next year otherwise. It will take 2 or 3 years to clean the csoil under cultivation of weed seed, roots and pest spores and grubs. So for the first couple of years you can expect lots of attacks on your plants. Birds help with the cleaning. Next sping turn the soil over and break down the remianing clods to a finer consistency (tilth) It is often said that potatoes are a good cleaning crop because the continual turning over of the soil promotes cleaning. Something to also consider is the cost of horticultural produce in your shops. Grow stuff which is expensive to buy, because anything that is 'in season for you' will also be in season for local commercial growers so will be at its cheapest then. For instance I grow soft fruit, particularly soft fruit, (strawberries, raspberries, gooseberries, blueberries etc). These are financially worthwhile. But tomatoes for instance are at rock bottom prices when mine would be ready, if I grew them. Capsicums and courgettes are a profitable crop too.

Yes I think you have are asking a very good question, +1, but unfortunately also arguing from extremes thus clouding the issue. Essentially you are observing (I think) that the curvature in GR in a given volume depends upon the matter particles present in that volume(as well as to a lesser extent those more remote). Thus if a particle that exists in one spacetime frame but doesn't in another doesn't that imply that curvature and therefore relativistic effects eg gravity are frame dependant? Please confirm my reading of your question or offer the correct one.

Excellent observation about independent existance. +1

I don't know what text you are using and not all textbooks bring out the differences btween Sn1 and Sn2. This extract from Geissman is particularly clear.

A layer of dust on components is a thermally insulating layer. Components are designed to operate in free air, insulating them will raise their tempeature and shorten their service life, resulting in premature failure. The important thing to do when blowing out fans is to immobilise the fan (eg with a screwdriver). Compressed air or even a vacuum cleaner can case excessively high rotation speed and the resultant back EMF can damage other parts of the circuit. Acetone attacks/dissolves the varnish on many components, (hence its use as nail varnish remover). It is also used as a perspex solvent/glue.

Is that all you get for answering? Doesn't seem worth getting out of bed for.

Compressed air is better than a vacuum cleaner. Make sure ther is somewhere that doesn't matter for the dust bunnies to go outside or in a garage.

Yes indeed there is at least one other choice. One or both particles may give off radiation which extends to the othr particle. Since there are only two (interacting) particles in your frame there is no observer in that frame. So we must look to some other frame to observe the interaction and this immediately brings in Relativity of simultaneity.

I use an old version of MathType, which is a commercial program to generate the Math. This allows me to type the maths in directly and copy / paste for the code in the webpage. I see no reason to learn yet another language/convention but prefer to expect the machine to do the work for me. Two free online alternatives are Sciweavers and Codecogs http://www.sciweavers.org/free-online-latex-equation-editor https://www.codecogs.com/latex/eqneditor.php

This is a valid conjecture and there is a recent Cambridge University book devoted to it, edited by a Professor of Mathematics from London University. Many august (pun intended) scientists have contributed. On Space and Time Shan Majid Cambridge University Press The current term used is not fragmented but granular. However time is continuous, in that there is nothing between the segments and all the segments 'line up' and abut each other, if they exist. This is unlike Quantum (energy) levels.

I'll second that and add a +1 for encouragement.

I was afraid of this so yes I will draw a sketch, but not till tomorrow as it's half past midnight here. You don't really need the torsion wire to consider what I am saying, that was an attempt to link the differential geometry of the isuue to the phyiscal implementation. You can have the meter on the floor, on the table, in the next room, facing North, South, East or West, upside down or whatever. Each of these will involve unique x, y z coordinate. Yet none of those x, y and z values will give you the reading on the meter; You need a fourth value -the angular deflection to specify that and this is therefore independent of the x,y,z coordinates.

I didn't mention the uncertainty principle. Are you afraid to do the simple calcs? Here is a simpler example. My car is 17 foot long and my garage 12 foot long. Could I close the door if I drove the car inside the garage?

Why? You stated that the electromagnetic field "fills all of space" I don't agree and stated why not. The EM field due to the light from our Sun did not exist in our (or any other) part of space before the Sun was formed.

We have several members strugglings with various concepts of dimension at the moment and this seems to come round again and again. So here, (hopefully) is some clarification by analogy. Consider an old fashioned torsion suspension meter and pointer. When the wire supporting the pointer twists about its longitudinal axis the pointer sweeps over the scale, giving us a reading measurable in one or two dimensions on the flat scale., as an angular deflection or as a pair of x, y coordinates like a graph on the scale. In principle the wire is of zero thickness so the twisting itself is not measurable in terms of the axis of the wire. That is the twist takes place in a (phase) space entirely different from the dimensions we measure the meter reading in. We can translate or rotate the meter as a whole in any of the normal 3 D, but the twist must occur independantly of these as the reading will (should) be the same. So a full specification of dimensions to state the condition of the pointer would include all three standard x, y and z coordinantes plus the twist of the wire. String theory postulates additional 'dimensions' like this to accomodate property activity of fundamental particles. Sorry it's a bit rambling and I know some diagrams would help but please feel free to pick over my analogy.

What a funny question. I am referring to 'instantaneous action at a distance' (Newton not Maxwell) . No there is no EM field in Newton, which is why I underlined the bit about the action filling all of space - ie instantaneous. But most certainly there is no field until the light arrives, by both QFT and classical theory, otherwise we could have a reversal of cause and effect.

That was Newton's theory. Relativity says something different, since there is no field till the light arrives.

Several members are struggling with the meaning of the term 'dimension' at the moment. It really depends what you are looking for?

Yeah but argument (in the proper sense of the word) about what? The OP goes in for the scattergun approach to threads and never answers questions about what he asked. It may well be that String Junky is correct in that this one is linked to his thread on string theory, in which case the answer would be very different from the question what is a 10 dimensional continuum like.

See the last post here https://www.scienceforums.net/topic/29763-bannedsuspended-users/?page=24&tab=comments#comment-1065488

Which is partly why I asked for more information about what was actually meant in the OP.

Thank you for responding. Did you see my reply to your test in the sandbox? I will think about your comments overnight, but two things to go away with. 1) The OP specifically asked for a classical discussion so anything else would be off topic (eg discussion of orbitals and probability.) 2) As I understand X ray diffraction of crystals electron density is directly observable, and calculable. Electron density maps are very useful between nuclei (atoms) in molecules or crystals, but of very limited value within an individual atom. What units are you measuring electron density in? Perhaps we mean something entirely different? My definition refers to a number (of electrons or moles) per unit volume. As such it has three important characteristics. The number part is one of the basic 'dimensions' in dimensional analysis Because it is discrete it is automatically 'quantized', without the need to refer to QM.

Just for encouragement, read this short biography of Mary Ward, who asked for a microscope as an 18th birthday present from her billionaire (in today's terms) father, in 1845. https://en.wikipedia.org/wiki/Mary_Ward_(scientist)