studiot

I saw no mathematical knowledge in your extensive post. Would you please point it out to me.

Well it was and it wasn't. The Earth as a whole rotates from West to East The solid inner core rotates slightly (less than a second a day) faster than the outer layers (mantle and crust) of the Earth, but in the same direction. The liquid out core rotates slightly (by a similar amount) more slowly in the same direction. Beware this leads to the newspaper headlines that the core or outer core rotates in a different direction to that of the Earth. This is only true relative to the surface of the Earth and this 'backward' rotation or slip, takes moe than a full century to complete one revolution. So the lines of flux sensibly rotate with the Earth. So only those conductors achieving significant speed relative to the Earth (surface) will experience any induction by cutting the lines of flux of the Earth's magnetic field, and this will be due to their own speed, not that of the rotating flux lines. Further any induction will be small since the flux is small, as shown by the previous post unlees enormous speeds are achieved. Perhaps swansont can tell you more about satellites.

You need to practice reading what has already been said. And I didn't mention photons. All I can remember is that is was in the technical press up to a couple of decades ago, probably in the 1990s. It might have been in the developments in electronics section od the now defunct Electronics and Wireless World. The point is that any functioning electric circuit has associated electric fields. By making them physically small enough and with a suitable arrangement in space a 3D cage was created to contain individual electrons.

The Earth's field is quite weak in comparison to the fields in useful human devices. By comparison the Earth's field is 25 t0 65 microtesla at the surface.

My class notes from 50 years ago should help you.

Those who bring a closed mind to the discussion table can gain no benefit from the discussion and may even antogonise others, even if they are right. Twasn't me guv, honest.

But we use the phrase " the camera cannot see" to cover both situations (and many more besides) Which brings us back to context and complexity. Here is an example you might appreciate. I state 1 + 1 = 0 You contest this and we could argue back and fore because I did not supply the context " in Boolean algebra"

Your are welcome. I was assuming you would come back with more questions if you wanted to discuss the subject (or any other) further.

But you are the one who defined seeing as the capture of light by the retina. I was specific in my example that that capture happened correctly ie without defect. Yet the subject said "I see nothing". That is why I say it's complicated and requires context, which has to be supplied by the utterer.

You can easily turn this line of argument on its head First let us agree that the car is a toy car so that we can perform the experiment in a darkened room. a) Remove the torch. b) Paint the car with electroluminescen paint. c) Connect the car to a suitable electric source via a switch. In the darkened room can you see the car? d) Close the switch. What do you see? You say "I can see the car" You do not say "I can see the light from the car" However now look sideways at the car so you can't directly see it. You can see a glow from a light source. You now say "I can see the light from the car" because you can't actually see the car In regard to your premises 1) Agreed 2) You do not need to shine a light on light to see it.

Good questions geordief +1

Thank you StringJunky and OldChemE for extending my knowledge. +1 apiece. I seem to remember something about barbers from the past here are some references. https://www.google.co.uk/search?source=hp&ei=E1ZwWsT-DJS5gQa9w4XgDw&q=history+of+barber's+poles&oq=history+of+barber's+poles&gs_l=psy-ab.3..0i22i30k1l2.1758.8333.0.8526.25.23.0.2.2.0.165.2309.9j13.22.0....0...1c.1.64.psy-ab..1.24.2367...0j0i131k1j0i22i10i30k1.0.KWoQu0QL760

Goodmorning Firechicken18 and welcome to ScienceForums. Yes chemical kinetics can be confusing, especially when deciding what power of the concentration to use in a rate calculation. The method your questions use stem from classical thermodynamic considerations of free energy with the introduction of a variable called the extent of reaction or degree of advancement of the reaction. I will use the symbol # for this variable because it is available on the keyboard and yet leaves Roman letter free for the Chemistry. At any stage of the reaction the rate of the reaction is defined as the time rate of change of this variable. So [math]Rate = \frac{{d\left[ \# \right]}}{{dt}}[/math] The trick comes in relating this rate to the concentrations of the reactants and products. To be asked these questions you should have covered some sort of derivation of the following for a general reaction with reagents A and B and products C and D [math]aA + bB \to cC + dD[/math] [math]Rate = \frac{{d\left[ \# \right]}}{{dt}} = \frac{1}{c}\frac{{d\left[ C \right]}}{{dt}} = \frac{1}{d}\frac{{d\left[ D \right]}}{{dt}} = - \frac{1}{a}\frac{{d\left[ A \right]}}{{dt}} = - \frac{1}{b}\frac{{d\left[ B \right]}}{{dt}}[/math] Note that the rate is the positive of the rates of change of the products but the negative of the rates of change of the reactants (can you see why?) I suspect this will be sufficient for most of your requirements. So substituting into your question A18 [math]A = \left[ {S{O_3}} \right]\;;\;a = 1[/math] [math]B = \left[ / \right]\;;\;b = /[/math] [math]C = \left[ {{O_2}} \right]\;;\;c = \frac{1}{2}[/math] [math]D = \left[ {S{O_2}} \right]\;;\;d = 1[/math] yields [math]Rate = \frac{1}{{\frac{1}{2}}}\frac{{d\left[ {{O_2}} \right]}}{{dt}} = \frac{1}{1}\frac{{d\left[ {S{O_2}} \right]}}{{dt}} = - \frac{1}{1}\frac{{d\left[ {S{O_3}} \right]}}{{dt}}[/math] or [math]Rate = \frac{{2d\left[ {{O_2}} \right]}}{{dt}} = \frac{{d\left[ {S{O_2}} \right]}}{{dt}} = \frac{{ - d\left[ {S{O_3}} \right]}}{{dt}}[/math] Which means that answer C is the correct one. Can you now tackle the second one again?

I would like to announce that I have seen the light. Halleluja brothers and sisters I have become a Jesuit. (So light can be seen)

Well I don't seem to have any replies to this, nor has the thread returned to my screen. What is happening please?

And yet every time I drop my helium balloon it floats stubbornly upwards and I have to get a new one.

I see you want to quibble with definitions again, rather than consider the substance of the discussion. Are you familiar with Rod Stewart and his song My Mind's Eye?

Yes thank you, I have never not 'got it'. That is why I credited you with introducing the end user viewpoint (the brain) from the outset and did not immediately take issue with this view. In fact my first response was to assert that although you wish to simplify, Nature is that much more complicated and will thwart you. You must have accepted this at some point because you yourself said that the meaning of words crucial to the discussion depends upon the context. My problem with the simple statement that what you see is the model constructed by the brain is that this model is constructed not only from the visual information received by the eyes but also from other information known to the brain and personal directives and controls guiding the creation of the mental model. Some of this additional information is voluntary, some is involuntary. In contrast the image on the retina is as faithful a reproduction as the laws of Nature allow (although there are also issues with this that we have not discussed).

I am posting this here on behalf of the OP who has reached his post limit. Eugene please rest asured that this limit is only temporary and you will be a fully accredited member soon. This limit was because we have too many false posters, like so many forums these days. However your post is just the sort of Science issue this forum exists for. It is not clear if you are a student or a teacher? No there is no flaw, The English is just badly written. As I said it is intended that 3 of the 4 possibilities can be eliminated, and I have indicated which one I think that is and why your other choice is not a corrrect reason for the ability to pushing the plunger down. Water can change its shape, as can air. But water is incompressible, air is compressible. That is the distinguishing point. Oh and welcome to the ScienceForums.

One point about this question is that everyone seems to be treating the issue as a static one. I think I pointed out that things change. Even within Science there have been a similar split or divergence. Many of the original scientists were engineers (some still are) though no distinction was once made. Engineering began to split off to a discipline in its own right about 150 years ago. A further split began within engineering about 50 years ago with Engineering and Technology. The question of what belongs where is a dynamic one.

No. The electric fields act like electric fences forming a cage around the electron ( I checked and I did say electron but did not mention neutrons or protons being controlled in this way)

I think we should consider this question at the level it is obviously aimed at, especially since the OP is looking for homework help. This level is obviously pre Boyle's Law, where the pupils are just being introduced to the idea of states and properties of matter. The question should be considered in the light of what is taught at this level. That is what known facts should be employed to answer this question? I agree that the question is very carelessly worded or poorly translated from another language. Either way it starts with a real howler. It start "Ahmad filled the sylinder with some water as shown". and then shows a diagram with the cylinder not full of water. IMHO this is a really poor example to set. In Scinece we need greater precision of language than this. The cylinder is partially full. On to the choices. At this level pupils are introduced to the idea of three states of matter viz solid liquid and gas, where both gases and liquids are fluids. The distinguishing feature between liquids (water) and gas (air) is that a gas expands to fill its container and therefore takes the shape of its container. A liquid does not do this and so does not expand and has a free surface. Using these facts, known at that level enable the correct answer to be selected. But I again agree the whole question is poorly worded.

Air has weight is true, but this dos not affect the piston. Air occupies space is true, but again does not affect the piston. Air has a shape. so that is not true. Air is a gas so fills its container and takes its shape. So you are left with the fact that the air is compressible, which means that its volume can be altered, as the correct selection.

Thank you. But my subtext is that the OP question/assertion was "Science is a subfield of Philosophy". And I have outlined my objection. To use some set terminology Any subject that is in the intersection of Science and Philosophy will obviously be common to both provices. But there are subjects that are in the disjunction of the two. In generating my examples I have realised that the Scientific examples are very specific and limited, whereas those offered for Philosophy are much more general and wide ranging. This is an observation not a rigid distinction.

Well I certainly see ( )that you are using a particular context for the word see, and nothing wrong with that. But, as I have already noted, there other cells in your body capable of 'detecting' certain wavelengths of light via other chemical reations than the ones in your eyes. So context is vital.