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Everything posted by Strange
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Dark matter and Shell Theorem by Isaac Newton
Strange replied to David Levy's topic in Astronomy and Cosmology
You have stated, correctly, that the density of dark matter is greatest around and within galaxies. The density of dark matter outside galaxies is therefore lower. This is well known. Therefore the total amount of dark matter is calculated using this information. Therefore there is no conflict with expectations. -
Dark matter and Shell Theorem by Isaac Newton
Strange replied to David Levy's topic in Astronomy and Cosmology
That is correct. (Also, simulations of the behaviour of dark matter confirm this.) Not if the expectations were based on there being a lower density outside the galaxy (which, as you say, was already known). -
No. For example, gravity is described using Newton's laws or general relativity. Neither of these can be derived from (or requires) quantum physics. I also don't see why this would be a paradox. Friction is a real thing (otherwise the world would be a very different place). There are materials with very low friction, and we might find something with zero friction. But that doesn't mean friction doesn't exist.
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All negative Clicks must be made Public !
Strange replied to Commander's topic in Suggestions, Comments and Support
Who should that assessor be? And will you demand they be replaced when they give your posts a poor ranking? Your system also invites comments on the member and their character, something which is discouraged (if not forbidden) by the current rules. -
Dark matter and Shell Theorem by Isaac Newton
Strange replied to David Levy's topic in Astronomy and Cosmology
Correct. Your understanding, maybe. The total amount of dark matter is calculated taking into account it's distribution (as is the total amount of non-dark matter). -
Are mathematical constants equivalent to Infinity?
Strange replied to Mr. Astrophysicist's topic in Applied Mathematics
Interesting. It is a good job I specified seeds, then! I was specifically thinking of lotus seeds. So after reading this I thought I should check and the first seed pod I looked at (on the web) had two rings of 8 and 13 seeds. But that turned out to be an exception, none of the others had more than 1 number from the Fibonacci series (and many had none). -
Not necessarily. It depends on relative motion, gravity, etc. Bothing to do with physics, then. These are completely different things. Which are you thinking about? Binary is just a way of representing numbers. If they are be measurable in binary, then they are measurable in decimal. How do you intend to measure these things? So you are just counting. There is one universe. Which is not the same as "describing the universe with a number" or saying "the universe is one". These are, as far as I can tell, meaningless strings of words. So are you just counting again? Yes, there is one of me. So what?
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Dark matter and Shell Theorem by Isaac Newton
Strange replied to David Levy's topic in Astronomy and Cosmology
The dark matter around the Milky Way galaxy moves with the Milky Way galaxy. The dark matter around the Andromeda galaxy moves with the Andromeda galaxy. Just like all the other matter that makes up the galaxy. -
You think it is disporportionate to be upset about 16,000 deaths, which might include people I know, who I haven't heard from since the disaster? I know you are in the "Aaarrghhh! Radiation!!" crowd but your attitude is pretty sick and offensive. And I will ignore this thread from now on. And yet your responses to the objective data consist of hysterical straw-man arguments. Maybe you should go into business selling your straw men as scarecrows.
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How does determinism stop people making measurements, talking to other people and passing on information?
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I found your description of the relationship between molecules and atoms and elements confusing. I think it is all correct (for the appropriate definition of "molecule") but requires some thought to make sense of. This is arguably a good thing, as having worked through it, the ideas may stick better. (I think Sensei's introduction of non-standard atomic structures is likely to add to the OP's confusion rather than reduce it. But it is interesting stuff.)
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WHY DID YOU DELETE MY THREAD???
Strange replied to A Muslim's topic in Suggestions, Comments and Support
And this is a forum for discussing (man-made) science. So your posts are irrelevant. -
WHY DID YOU DELETE MY THREAD???
Strange replied to A Muslim's topic in Suggestions, Comments and Support
Then it isn't science. -
It is kilo-calories. What is referred to by the general public as a calorie is actually a kilo-calorie. I have no idea why. Which makes the question completely pointless.
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WHY DID YOU DELETE MY THREAD???
Strange replied to A Muslim's topic in Suggestions, Comments and Support
What you believe is irrelevant. This is a science forum: all that counts is evidence. -
Not-a-theory. Or wild guess. All theories are considered provisional, liable to be falsified at any time. So neither right nor wrong, just the best we have at the meoment.
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I seems that when I said "close" I meant not very close... I wasn't aware of the toxic effects. More here: http://en.wikipedia.org/wiki/Heavy_water#Effect_on_biological_systems Sounds like a particularly nasty way to kill someone (if it is possible). I wonder if anyone has ever used it in a crime story. I guess it would be hard to detect unless you were looking for it specifically. It isn't surprising that the difference between hydrogen and deuterium would be more significant than other elements as it doubles the mass of the nucleus.
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Exactly. The chemical properties of an atom are defined by the electrons. Mainly by the outermost electrons. And, at the level you are at, just by the number of electrons in the outermost "shell". It is slightly more complicated than that and as you go deeper it just gets more complicated! But you can get a very long way with the simple model. Other physical properties, such as the mass, are determined by the nucleus (because protons and neutrons weight about 2,000 times as much as an electron). Isotopes are, as you say, atoms with a given number of protons (and electrons) but a different number of neutrons. The number of neutrons is usually close to the number of protons, for stability reasons (which are not fully understood). Isotopes can have different physical properties (mass, obviously) and be more or less radioactive. The extra mass of the nucleus can also have an effect on the outer electrons and make very small differences to the chemical properties. No, these fundamental interactions behave the same in all atoms. But the varying numbers of particles can change the resulting effects we see. For example, although the weak interaction is responsible for beta decay, whether or not that occurs depends on the numbers of protons and neutrons. And the electromagnetic forces are always the same, but we see a huge range of chemical reactivity.
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All negative Clicks must be made Public !
Strange replied to Commander's topic in Suggestions, Comments and Support
I am guessing that sort of behaviour was the result of some of the negative votes in the Canadian Aliens thread. Many of the posts appeared to be more like random non sequiturs than strawman arguments. -
This sounds like an attempt to describe one of the assumptions/postulates of relativity: "The laws by which the states of physical systems undergo change are not affected, whether these changes of state be referred to the one or the other of two systems of coordinates in uniform translatory motion. OR: The laws of physics are the same in all inertial frames of reference." (http://en.wikipedia.org/wiki/Postulates_of_special_relativity) The last part is wrong: "in the same/common space-time frame." There is no common frame of reference (if that is what you mean by "space-time frame"; if not, you will need to define it.) The reason for that is the second postulate of relativity: "As measured in any inertial frame of reference, light is always propagated in empty space with a definite velocity c that is independent of the state of motion of the emitting body. OR: The speed of light in free space has the same value c in all inertial frames of reference." As for your questions, my attempt at answers are below (I have ignored the ones I don't know anything about or don't understand). a, Can we count the Universe as one? As one what? A single thing? Maybe. But it is composed of many things so describing it as a single thing is not very helpful. b, Does space and time started once or are they always existed? c, If space and time has started once did they start together? No one knows. d, If space and time has started once does information related to their funcions is a consequence of the appearance of this physical entities or information have determine theirs functions. It may depend on what definition of information you are using, but I would assume it is a property of things that we can measure (like energy or temperature). g, How far that other Universe would have to be that our universes gravitational field has 0 effect on it? Gravity never drops to 0. But I don't really know what "another universe" means, so I don't know if there is an answer to this question. i, Can nothing physically exit? In our universe? No. (There are useful models of empty universes.) j, Can nothing physically existed? No one knows. (See question b) k, Does the Universe evolving? Yes, as described by the big bang model. q, Does metaphysical values built on the same physical laws as physical values built on? What are "metaphysical values"? How would they be measured? I assume "metaphysical" means they don't exist and have nothing to do with physics or reality. But perhaps you can explain what sort of thing you are talking about. r, If you would have to describe the universe with a natural number which one would that be? How can the entire universe be described with one number? You could describe the radius (of the observable universe). Or its mass. Or the number of stars. Or ... s, If you would have to describe yourself with a natural number which one would that be? t, If you would have to describe nothing with a number which one would that be? Equally meaningless. u, Does Einsteins E=mc2 stands in the first physical process? I'm not sure what you mean by "stand in the first physical process". It is thought to be universally true (although you have only shown half the equation). But what is the "first physical process"?
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All negative Clicks must be made Public !
Strange replied to Commander's topic in Suggestions, Comments and Support
Maybe a significant number of other people thought your reaction was unreasonable. If those new ideas are not based on evidence then deterring them is a Good Thing. -
Of course. And I have, as you like to remind people, been here long enough to know better. The article provides examples of bad (traditional) scientific writing and clearer equivalents. There are also links to useful resources to learn more.
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The relationship is one of cause and effect.