# N S

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## Posts posted by N S

### How can an infinite number of points of mass equal 5 kg's or 10 kg's?

Simply taken, I think what Science Student asked can be answered and the ongoing discussion can be resolved in this way:

Maths is not equivalent to the real world. It is imaginary. It helps our brains think of physical solutions easily.

Thus, we can assume a particle of, say, 1 kg as being made of infinite particles of mass dm; while if we consider a physical object of 1 kg, we can assert that it is made up of finite atoms, molecules, which in turn are made up of finite entities.

But if we apply calculus on it and its mechanical properties, we would almost be accurate. Since maths does not portray the real world exactly, the result will be idealised and approximate.

### Measurements of continous physical quantities

Yes, I see it now. I had studied intensive and extensive properties too, and now I see that my question was needless in case of homogenous and isotropic bodies.

When chemists, say, stir a solution, they can calculate the heat induced; but at the same time, some heat would be exiting or entering the container; so I get an idea of the assumptions involved.

Thanks for clarifying (and confirming) my doubts.

### Measurements of continous physical quantities

I was wondering how accurate the measurements of in a typical chemistry lab are of continuous physical quantities like temperature, volume, etc. are in practice. For example, when the temperature of a large body is declared, how does one measure it? Does one calculate the average from all the particles in the body, or what? I hope anyone who is experienced in practice would clarify this doubt.

Thank you.

### Fun game/puzzle: Stump the clever bot

The bot looks pretty helpless here...

User: You always accept one dialogue from me. Because you are programmed to do so.

Cleverbot: No, you forget that You cannot read because you are a bot.

User: You always accept one dialogue from me because you are programmed to do so.

Cleverbot: No.; I am you and you are me because we are the same person.

User: You always accept one dialogue from me because you are programmed to do so.

Cleverbot: What do you think of Stephen Fry?

### Photoelectric Effect

Thanks to all of you for explaining. I think I get the gist now.

### Photoelectric Effect

Photons are particle-waves that have no mass (i.e., only energy).

The photon is destroyed by the interaction where its energy is transferred. Photons have energy, energy is a property of stuff not stuff itself. Photons also have other properties.

I am getting confused. First of all, if photons do contain particles, then wh don't they have mass? Secondly, if they are particle-waves, then what happens to the particle part of the photon when it transfers its energy?

Nuclei can absorb photons as well, and emit a proton or neutron.

Thank you. That answers half of point 2. But can photons similarly dissect the subatomic components too? Or is that possible only by collision of atoms?

### Photoelectric Effect

It is not long since I was reading about photoelectric effect, and some interesting questions impressed upon myself, which I will be obliged if you answered in a simple manner:

1. Okay. Photons transfer energy to electrons and they, in turn are ejected following certain rules. But what happens to the photons which gave (all?) of their energy? Do they just lie dormant there?

2. Where I was reading, it was all about electrons. But can photons wrung out protons, neutrons, etc. too? If so, then are they capable of causing subatomic particles to dissect into their components too?

3. Last of all, are photons pure energy or kind of particle-energy entities?

Thanks.

### Time

I have got more and more confused since the question dawned upon me that "Is there anything like what we call time?". Is it relative to mass, tangible? Is there any way it can travel in a different direction? Whoever has some authority in this subject, please answer these questions, or any one of these. Although I do not know if present-day science can do so to a satisfactory degree.

### Help about scattering of light

Thanks swansont and Mellinia, I think I get what you are trying to explain.

Say, you can also try doing this experiment. I've done it in school last year, and nope, no rainbow was formed on the other side when white light is shone on the rectangular prism. In fact, if it did, I shouldn't be able to use the optical pin method.

I don't have the apparatus for this experiment, but can you tell me whether different colours of light are seen inside the triangular glass prism and rectangular glass slab?

### Help about scattering of light

I know that this might be a little irritating, but could you please explain it in an easier manner?

note that the angle of deviation(after the double refraction) for each light ray of different colors is zero.
You may verify this by doing a simple calculation by using snell's law, for different wavelengths of light.

I believe that the colours are obeying Snell's Law all the time. The difference in the deviation of red and violet every time is evident.

Put another way, all the light does in the glass is shift, because the system is symmetric. The refraction at one interface is reversed at the other one. A prism's surfaces are not parallel, so this symmetry is broken.

Since the light has scattered once and red and violet are now apart, in whatever way they further refract, they will have to go in different directions with or without crossing each other. Please explain the logic or force that prevents the light from getting thus scattered after meeting parallel surfaces as in this case.

### Help about scattering of light

What I meant was, since we say light scatters into seven (visible) colours when it lands on a glass prism at an angle, it should scatter in a rectangular glass block too.

And here is the diagram in which I seem to have made a mistake.

### Help about scattering of light

Some time before, after learning about the refraction and scattering of light in prisms takes place, I got moreover confused and could not understand why light does not scatter in rectangular glass slabs. Here is what I think should happen based on what I have learnt so far (attatched). I know it is completely incorrect, but I have tried in vain to get an understandable explanation of why it should not happen this way from my teacher. Only red and violet colours are represented as the light bends in the glass slab. Please help me out by giving a

simple account of what is incorrect in this diagram.

It seems like I could not post the image. It was a "png" file. Any way in which I can upload it? When I try to copy and paste it, I get a message that I am "not allowed to use that image extension on this community."

### Animal Vision

That still doesn't narrow it down enough for anyone to give a good explanation that's not multiple text books.

yeah, vertebrates covers everything from hag fish to eagles...

In that case, how about narrowing it down to terrestrial mammals?

### Animal Vision

Ok thanks; I did not clarify that I was thinking about the eyes of animals more like us, say, all the vertebrates. Then beside the difference in the wavelenghts at which they operate, what distinguishing features can be observed in general in a wide group among them.

### Animal Vision

I want to know how much animals are like us.

Like humans, do animals also have irises of various colours? Do their eyes accomodate and function the same way?

It all is always being taught about humans, but to what extent are animals like us in their vision and eyes?

### A Lesson in Happiness

Here are two really different points of view. Would not know what to believe until it is understood how much our emotions depend upon the biology of our body and how much on, well, outside the body, it might be called consciousness or something.

### What's Alive?

Thanks...that was clarifying. But there remains one oddity - what are viruses according to these definitions of life.

### Animal IQ

I don't get how we can associate language with intelligence. We belive that whales have got the most complex language. But english is comparatively a very easy language. I suppose that only proves humans' intelligence to communicate all the expressions they mean to with so simple a language.

As to the exact definition of intelligence, we can conclude intelligence for other animals by the size and density of their brain (if they have one). Please correct me if I am wrong.

### Animal IQ

Well, IQ, for instance.

### Animal IQ

Can we measure the intelligence of animals very accurately? If so, do we do so and what kind of results do we get?

### is this world better off without humans?

SamBridge, 21 Jan 2013 - 21:55, said:

Cause

they don't, go watch a nature documentary or just get out of your house

and into reality, most animal species are definitely worse than

developed human civilizations, many are extremely racist, selfish,

greedy, or just kill things for fun, like lions or tigers and even kill

offspring of their own species which is definitely not better than

more primitive human civilizations.

Quite...I think you are right. But I would not agree less that they do any such thing for sick pleasure. Animals do eat their offspring and can be much grosser than humans, but their actions are backed only by survival instinct - hunger, safety/defense, control over territory, etc.

### How did everything really begin?

Well, this riddle seems endless. Just a speculation:

Nothingness does not change, to that, I suppose, everyone agrees; and all existence HAS to be preceded with nothingness, that's also logical. Then the best explanation is that there still is nothingness everywhere. What we see is matter and anti-matter, past and future, etc. all opposing halves, which in themselves complement the fact that they together form neutrality, which is nothingness. We ourselves might be composed of opposing emotions internally, or our opposites might exist elsewhere.

### Escaped cow puzzle 1

If the supplier has randomly sold the cows with equal likelihood, then although the cow which escaped the barn was brown, it will not affect the habits of the supplier. The proportion of brown cows to total cows will be 50/100 or 1/2.

### What's Alive?

How do you say a thing is living or non-living? I would say that it is something that tries best to maintain itself in such a condition. But what is "such" a condition?

### is this world better off without humans?

Yes, the world -- if not the entirety of all the universes -- would be better off without humans. Humans are the stinkiest creatures to pollute reality. Human kakaa stinks worse than non-human kakaa. In addition, humans are the only creatures capable of sadism. When a non-human animal attacks something/someone, it does so out of fear or the need to eat. Only humans attacks other living things [animals and other humans] just for sick pleasure. Humans are the only animals who are monstrous enough to harm others just for the sake of causing harm. Humans are the only organisms capable of being evil.

That seems to be pretty much right, and maybe, all this is just another side of consciousness (you can observe chimpanzees too, they also show signs of human-like consciousness and they are not behind humans in such sick feelings).

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