mezarashi

dimension means: distance, time, temperature, or some other fundamental concept as listed by the base SI units. When you calculate velocity for example you must make sure your answer is in units of: meters/second or distance/time. There is a physical quantity associated with it. Angles are different... they have no physical dimensions associated with them. That's why angles can be exponents and you can perform Sin, Cos, Tan on them. What's the meaning of Sin(30meters) or e^30meters. Angles describe ratios, and from the mathematics I have done, is based on the ratio of a circle's radius to its circumference. The concept is dependent on the more fundamental concept of distance, which is already defined in SI.

?_? And sorry, I just updated my last post.

Yes, radians and degrees are the names of the units given to angles. They nonetheless remain physically dimensionless. I think that he was referring to the SI base units which only consist of the very fundamental concepts in which everything else can be derived from.

Dark matter is in fact not "exotic". Dark matter is simply matter that does not emit or reflect any substantial amount of electromagnetic radiation, thus serving it undetectable by our equipment here on Earth. How would you detect our own planet Earth for example 10 million light years away if it weren't for the Earth reflecting the sun's light. Photons actually do "inflict a force" when they are absorbed. Have you seen solar sails? You can get light to essentially "push" stuff. While photons are massless, they have momentum p which is a function of their frequency. The idea that a photon is massless was not hypothetical, but I will leave the reason for the consequence to someone more knowledgeable >_>

I've seen this question before unfortunately, so I might spoil the fun. I'll kind of try put it in spoiler tags. Highlight below to read: This problem exploits our inability to discern the difference of the area along the hypotenuse. If you look closely enough to the area along the hypotenuse, you will see that there is indeed a difference. The top figure shows more coverage. Mathematically, you can see that the triangles are NOT congruent. This is the main cause of the discrepency. They deviate by so little that it is hard to see visually. The composed "triangle" has a tan of 5/13 blocks (0.3846), the red with 3/8 (0.375), and the green with 2/5 (0.4). The overall shape is in fact not a triangle but a 4 sided polygon. There is a small angle between where the red and green triangles just touch

An angle is in fact dimensionless. An angle is a ratio. For example the ratio of a circles radius to a segment on its circumference. Using sin and cos, the ratio of opp/hyp and adj/hyp respectively.

Don't take it too personally. You started this thread with an inquisitive attitude. Where did it change so suddently? You asked if there was a scientific relationship or something fundamental about the ratio. The answer and responses so far say no, or atleast nobody has expressed themselves if they believed yes.

Well, that requires a bit of an explanation on the propagation of light through matter. Generally, light doesn't even go through matter in the first place (opaque items), but we have a class of optically transparent or atleast translucent materials. The photons will strike the medium's atoms and excite the electron to a higher state, when the electron comes back down again, it releases a photon of the same frequences in the same direction as the original photon. This continues in a chain until light exits the medium or finally gets absorbed somewhere. So in fact when light propagates through a medium, you are continuously creating and destroying light. The "mechanism" for which this happens will determine the speed of light through the medium. There is also a matter of loss. That's why things don't seem as bright through glass. Your sunglasses for example will restrain the vibration of electrons and thus the ability of light to pass through. Polarized glass will restrict vibration of electrons in a certain direction thus polarizing the light waves.

I probably write to defend Phi a bit on this ban, although personally I don't believe in permanent punishment unless the user engaged in an act to physically harm the boards (i.e. flooding, denial of service attacks, spam). I've seen many of Johnny5's posts and some of them did bring up interesting topics to think about. I read the mentioned thread that was mainly an exchange between Johnny5 and mattgrime. It appears to me to be Johnny5 challenging mathematical conventions and being thwarted time and again for each and every one of his "intelligent proposals". There was nothing ground-breaking about what he said. Doing neat tricks to how you write numbers on paper and interpretting their meaning is great, but it in the end it doesn't prove anything useful... it's a matter of convention. Yes, the proposals were somewhat logical and civil, given that you ignore a great deal of mathematics and don't think through it thoroughly. But being proven wrong every time clearly shows otherwise. Now I don't want to generalize, but I've seen many users respond similar to what Johnny5 has done on that thread. I would say it's basically trying to be egoistical and in some way prove the experts wrong and show that they are right, rather than constructing any meaningful point. He consistently brings up new points when the old points are shown to be wrong. Reading such threads make me feel awkward. On another point, I don't wish to undermine the intellect and scientific/mathematical capabilities of the users on this forum as I know that many are capable indeed, but some users are just preconceptually stubborn. They have high ambitions like proving great theories wrong when they don't even understand the theory in the first place. If you want to prove something wrong, you should atleast first understand what it is you're trying to prove wrong. Although these ambitious threads get alot of attention and add some spice to the forums, they can easily get dragged and eventually redundant. I would prefer threads on interesting consequences of proven theories rather. If they truly had a ground-breaking theorem, they should be in the academic community talking to their university professors, rather than here where only a handful of experts in the field exist. Sometimes they come to me as a hoax, and when you they fail to give up after being denied time and again, it is simply time to go.

Well yeah, it would be "cool" the same way a child would feel excited about getting to go on his first roller coaster ride. After a while you would probably be sick of not having any kind of ground reference. Our physique was built for gravity, and so it's kind of "at home" to have it present. No, just sitting on a spinning body will not make you experience a Coriolis force. You would need to be moving in a direction perpendicular to the instantaneous velocity of the rotation to experience this Coriolis acceleration. The force that will push you outside is the invisible/virtual centrifugal force, not the Coriolis. About the air, I would suppose there would be a difference of air pressure along the plane of rotation of the space station as well, since the air would tend to pile up at the outer perimeter.

Sounds like a thermodynamics question. Assume that it is an ideal gas (if it isn't you have no equations, you need to look up tables like with water). Apply the ideal gas equation: P1V1 = n1RT1 Work from there. You know P1 = P2, R = R, etc.

The artificial gravity generated by space stations has alot of "flaws". I could imagine stepping on one and feeling completely unnatural. If it is large enough, it would initially feel like Earth, but when you start jumping around and spinning, you'll definitely feel different. Coriolis forces may also come into play. Any gyroscopic motion like spinning a coin for example will not work properly. If you launch something up into the air at just the right angle and speed, it may also just appear to float (until it hits a cieling or something and friction takes it back into course). I guess it's the least we can do however to make ourselves feel at home while in space

You are confusing the propagation of light with that of sound in air. Moving towards a light source will not make the light appear any faster. You may at most experience a doppler shift if you are moving fast enough. If you align two sensors collinearly to any of the three pulses, you will find that the light waves will pass the two sensors at an interval that is equal to (distance-between-sensors/c). Your assumption of "relative speed" of light is already wrong. That is not what Einstein assumed. Tom Mattson had already quoted what the postulates were. I would say that to disprove a theory, you either 1. show an observation in which disagrees with the prediction of the theory or 2. show somehow that the theory's original postulates are incorrect. What you are doing is attempting to derive relativity using different assumptions (I don't even know what your postulates are), and then claiming that your results are different from Einstein's.

No, to any observer, light will always travel at the speed of light in a vacuum. As far as I know, light is not known to speed up, but it can most definitely slow down when propagating through a medium as with any other wave. Upon a change of medium, the wave changes velocity. That's where you get refraction and this constant known as the index of refraction. Diamond has one of the highest indices, greater than 2, meaning that light travels through diamond at half the speed it does through a vacuum.

Wow, calling someone an "idiot" is sure not a constructive way to make a discussion. Your arguments are to the point where frankly I want to be preconceptual and dismiss them. It doesn't matter if you're starting a cult, it is the wanting a number to be special that does. Your current claim is based on the fact that this number "108" isn't mined, and the reason? Let me quote you:

Honestly I never knew you could get spherical wheels, but as this is a 2 dimensional problem of course, we can just assume that they are cylindrical.

I don't understand what you mean. If the container in which you are stirring the barium and ammonium freezes, doesn't that also constitute the solvent (liquid water) in which they are being mixed in freezing as well? In any case, you might want to search for other reactions as well. The barium seems be somewhat poisonous

Try searching for: endothermic reaction freeze If the reaction is endothermic enough, you should be able to freeze the container. Here's one right here with barium hydroxide and ammonium thiocyanate: http://chemlearn.chem.indiana.edu/demos/Endother.htm

It's always amazing to observe the night sky. Seems like we're always discovering some new process in our universe (although thank god its happening a couple million/billion light years away). Probably one of the reasons many of us take up astronomy as a hobby =D

I put some additional explanations, hope that helps. Feel free to post what you think. I think Severian has already posted an interesting conclusion? It may serve to say that that sometimes the physical systems we know in the real world cannot be modeled ideally.

It's peculiar that you do not have DirectDraw since you are using Windows XP. DirectDraw is one of the many components that come with Microsoft's DirectX. Start-> Run-> dxdiag Your DirectX information will be shown. You noticeably have a very old computer. What I would suppose is that your video card (VGA) does not support DirectX at all? I've never seen such a case, but it's a guess as WinBench 99 seems pretty outdated, it shouldnt rely on any of the newer versions. Usually video cards have problems running newer versions like DirectX 9.0b.

I was doing a little thought experiment myself and thought maybe I could use some help. The rod here is an ideally rigid rod, and the tracks are of course frictionless and fixed. How does this configuration suspend itself up while gravity is pulling on it and there are no vertical forces to counter it? P.S. excuse my horrible paint skills again Additional Explanation: The two large circles are fixed tracks. The rod in the middle has two wheel rollers attached to it. Each roller is in one of the tracks. Because the rod is rigid, it won't allow the wheels to be separated anymore than they are. The red lines are just force vectors showing the tendency for movement of the rod. Intuitively we know that such a configuration will be more or less static, but given the ideal conditions stated above, what is the analysis behind it.

It seems like you take much worry in your body. From what I've read, there should not be a relationship. The human body was designed to run, walk, stand... well if it wasn't you wouldn't have legs in the first place. I think this misconception goes along with: lifting weights while standing up makes you short. Tall or short, it's genetics and a matter of what you eat.

Yes, the velocity is at its maximum when the acceleration is zero. So you know that the maximum velocity occurs at t=5. A couple of other things after this. I'm assuming "distance travelled" really means what it means and not displacement from s=0. If that is the case. 1. Find the roots of the velocity equation and see if it the velecity reversed over the period t=0 to t=5. 2. If there are reversals, integrate the velocity in segments. Say from t=0 to t=3, then from t=3 to t=5. Take the absolute value of the answers and add them up (integrating velocity over time will give you distance). As for the second part of the question, initial velocity = 4.8, half of it is 2.4, so find the value for t and do the same test as stated above.

NavajoEverclear, I think you may be overly defensive and somehow not looking at it logically. Just because this has to do with the Sun and Earth does not make it any more special. Yes I agree with you that this is a great coincidence, the information was "mined" by someone else who discovered it. As swansont said, there is a larger set of numbers and figures that do not coincide with this. I can give you an special number right now: 911 -Terrorists bombed the twin towers on september 11th. -911 is the American emergency dial number -the twin towers look like two 1's, 11. -9+1+1 = 11 -After September 11th there are 111 days left to the end of the year -September 11th is the 254th day of the year: 2 + 5 + 4 = 11 -George W. Bush - 11 Letters And I could go on and on. There are plenty of other numbers that may mean "significant" things to many other people, and they continue to build upon it in making it special. There is however nothing scientifically fundamental about these numbers I am sorry to say