Perspective Definition and 221 Threads

It seems that there is overwhelming experimental evidence that at least some quasars must have significant intrinsic redshifts (as Arp has been suggesting for years). There is also some evidence from a gravitationally lensed quasar suggesting a significant intrinsic magnetic field. These...

One of the postulates of the Big Bang theory taken from GR says that the universe is not expanding into anything, but that it's the metric that's expanding. The idea of metric expansion says that two points in space remain at the same spots but the distance between them grows(while these two...

How would an imaginary microscopic being measure distance or more precisely measure its position in some spatial coordinate system?

Homework Statement Give a clear and concise mathematical definition for Big-O. ("f(n) is O(g(n)) if...") Homework Equations The Attempt at a Solution I'm in a discrete math class and overall I understand the concept of run-time analysis. For example, if a variable is declared...

A 4000 truck is parked on a 15 slope.

Hello. I'm a 15 year old student interested in theoretical physics. I took Calculus I in 7th grade at Hood College, Calculus II in eighth grade, and Calculus III in ninth, so math doesn't scare me. I've heard ideas that the new LHC might confirm a Higgs field, generate micro-black holes...

Dirac's theory of the electron predicted that there were identical particles of equal mass but of negative energy. He appealed to the Pauli exclusion principle and proposed that there was a negative energy 'sea' of electrons that was full up to -2mc^2 in order to answer critics that positive...

I am reading The Elegant Universe by Brian Greene. It is really wonderful, however, I am confused by a section about Feynman's view on the double slit expiriment. Greene writes: "Feynman proclaimed that each electron that makes it through to the phosphorescent screen actually goes through...

Anyone lived in a timber home (house made out of weatherboard)? What is it like?

If ghosts or anyother supernatural entity exists then it means TIME is absolute for it ,they are out of time ie, they remain jacked in the system(universe) w/o being physically jacked in , i never thought like this but its like MATRIX

Considering the current rate of technology advancement and the political situation around the world, I think that there is no way our civilization will make it to the year 2100. I have thought about this a lot and I just cannot imagine a scenario in which civilization is not totally destroyed...

This is an invited review paper by a worldclass authority, so it could be useful. http://arxiv.org/abs/0804.2258 Let there be Light: the Emergence of Structure out of the Dark Ages in the Early Universe Abraham Loeb (Harvard) 32 pages, 18 figures, an invited review for the UNESCO EOLSS...

I guess this is my last theme here with this nick and from this IP:) But I just love the answer that came to my mind (maybe it is posted somewhere here, but I could not find it). 1) Our reality: If the thing traveling would have the brain operating the same way as our brain (or any other...

Given the idea that a photon experiences only one 'time-slice' from its perspective, and exists as one elongated unit that stretches from the point of emission to the point of absorption, what implications does this have on ideas of cause and effect? I was thinking about the so-called...

Hi all. Let me first mention I am academically way out of my depth at the forum. What I wanted to find out was which equations I need to study to play with an idea I've had for a while now, related to what appears to be a recent popular movement into 'the unified field theory through...

I ask this question as a non-philosopher whose ignorance of this subject and its history is profound. In my ignorance I nevertheless suspect that change in philosophy has over the last few hundred years lagged behind the explosive increase in our knowledge of the natural world, its history...

Constructive criticism please: In 1975, Hillary Putnam published a paper entitled “The Meaning of ‘Meaning’”, in which he proposed an interesting “thought experiment” (see Putnam, H; “The Meaning of 'Meaning'” In Philosophical Papers, Vol. 2: Mind, Langauge and Reality. Cambridge University...

It is far better than TV, i may be the least educated member but that makes it better because i have more to interest me, getting a plebs thoughts through to a scientist may be frustrating but hey you guys do take the time and try, it is not better than sex but it is the next best thing.

From its perspective, can't it "see" itself as being at rest while everything else is moving at c? Then, from its perspective it's massless AND not moving, so it doesn't have mass OR momentum and thus has no energy at all. Also, doesn't time stop from the photon's perspective? If an object has...

Hi guys, Its been said that dec21,2012 is the end of mayan calendar and the end of world.Let us leave the predictions of some calendars and prophets.but,i heard some astronomical information about dec21,2012.they are 1. winter solstice 2. Sun's pole shift 3. Earth's wobble finishes on...

Hi All ! here is a quote from the movie Little Buddha(http://www.imdb.com/title/tt0107426/) "Buddha could see beyond universe.Buddha has seen ultimate reality of all things." Although the statement looks simple but it didnt make enough sense to me.It is also said that "we can see only...

I'm trying to understand how time will be observed to have stopped for the traveller from an observer on Earth when a traveller travels at light speed, makes a round trip and returns to earth. Would this thinking be correct? The traveller is traveling infinitely close to the speed of...

I was with a group of religous friends and they started talking about the "true meaning of prayer". I felt like changing the subject so I diverted the conversation to the question of free will. I said that since the brain controls what the body does and the brain is a physical entity which...

In http://xxx.lanl.gov/abs/0705.3542 strings are derived from an attempt to formulate a more fundamental view of quantum mechanics, based on Bohmian interpretation of quantum mechanics. Such a more fundamental view is motivated by some foundational problems of quantum field theory (QFT), such...

The New York Review of Books got Lee Smolin to do a 10-page review of a handful of recent Einstein books. It's definitely stereoscopic (3D). with a sense of the complex personality. nice to see the oversimplified popular images countered http://www.nybooks.com/articles/20279 Mark Trodden of...

David Gross gave the concluding talk at a recent string conference in Jerusalem and Tel Aviv http://video.tau.ac.il/Lectures/Exact_Sciences/Physics/stringfest// I am having difficulty getting the slides and video, which Peter Woit says are online. This talk by Gross (Nobelist, director of...

There is a good documentary which i saw called Loose Change which gives you another perspective of how the "accident" or "incident" happened at the world trade center. the documentary can be found on places such as Youtube or google video and i found it amazing. Most of you probably know it and...

Hey , i am in grade 11 not yet studied gamma function, and not sure if it will be in the program but i have studied it a bit on my own f(x) = gamma(x) x = 1 : y = 1 x = 2 : y = 1 x = 3 : y = 2 x = 4 : y = 6 x = 5 : y = 24 x = 6 : y = 120 and i found a pattern : 1 * 1 = 1 2 * 1 = 2 3 * 2 = 6...

Hi. I'm curious how the science folks here would see this 'rocket equation' I formulated: Energy (E) = the cube root of mass (m) multiplied by 5 times the speed of light (C). I'm not a mathematician, I'm more into art. It was borne out from my visualization of the universe (an ideal future)...

I am looking for information related to computer hardware trade... which covers from prespective of international business..like major key players,,import,,export...restrictions that sort of things... but till now all my efforts have been unsuccessful to find such infn. I will be really...

I think most students develop their mathematical background up to classical tensors before digging into the physics of general relativity. I think this approach is good, but once this "Introduction to General Relativity" is finished, then the student should refine his mathematical background...

I was just wondering if anyone could give me some insight into how a paratrooper fair ride works from a science/engineering view.

i came across am argument about does .999~=1 and someone used this webpage to show they are not equal http://www.math.fau.edu/Richman/HTML/999.htm this page seems somehow wrong to me but i haven't gone far enough in math to disprove it , i just started to learn calclus so when it involes...

I'd like to better define cause and effect in engineering terms so I thought what better place to start than finite element analysis (FEA)… ok, strange you may say. But here's the idea. In FEA, one might say that each element is acted upon by some kind of 'causal action' which affects the...

Hey all! New to the forums here, and I must say, I've been greatly enjoying all the reading. Just three quick questions to ask... If one were able to have the 'perspective' or viewpoint of light, then they would see time as non-existent correct? They could go anywhere whenever and time...

I do not necessarly see what this has to do with a confirmation of the big bank theory. On the surface I would view this as a confirmation of QMs. It simple says that ocassionally you have enough KE to flip a spin of from the basic ground state. Maybe the "intensity" of the radiation might...

Introduction: This being President's Day, the News Hour with Jim Leher aired as summarized: http://www.pbs.org/newshour/newshour_index.html It reminded me of ongoing discussion of balance of power between branches of government, comparison of presidents in our history, the role of the vice...

I'm trying to ask a simple question, which is probably a fatal mistake but... According to accepted Einsteinian relativity, say I'm traveling at the speed of light. I understand I can't get to that speed. Suppose I was born at that speed, I'm a photon, whatever. From my "photonic perspective"...

I'm reading this book called Parallel Worlds by Michio Kaku and in it he explains some complex theories and discoveries without including the math behind it (lucky for me, I probably wouldn't understand it yet anyway). I like it a lot but there are some things I don't fully grasp. He says that...

1. There are approximately two billion children (persons under 18) in the world. However, since Santa does not visit children of Muslim, Hindu, Jewish or Buddhist religions, this reduces the workload for Christmas night to 15% of the total, or 378 million (according to the Population...

This review by Piers Coleman is a Tour de Force article on why condensed matter physics is such an exciting field of study. This conference highlights all the "new" stuff from condensed matter that still baffles people, and why they are so crucial not just within that field, but beyond. This...

I am conscious being (cogito ergo sum). The things that observe build my reality. Only the things that I observe build my conscious reality. The effect of Pluto´s gravity might have an effect on me but not in my conscious reality. Because I do not conciously observe the effect. The things that I...

I was thinking about that question (what is energy) and I realized that I could easily understand what energy is and why it is conserved if I thought of it as the total force needed to get a mass to the position that it is in. For example: Kinetic energy - inorder to give a mass speed you...

You're a newly born ant. As you grow, you help the colony build its home and ensure the future of the next generation. You understand this is what you were born to do. The world is how you know it, and because of this, you desire nothing more or less of it. You and your colony have explored...

i am thinking it partioning sleep patterns, and as far as i can tell, i can get it down to 3 hours or so a day, though i don't want to take 6 naps or so a day as this will lead to decreased levels of seratonin,melanin etc. i beliave that if i take two 3 hour "naps" or rather partitioned sections...

Hi there everyone, I'm troubled with a certain problem. I'm trying to locate the circles of view in perspective using math rather than using a right angle tool to manually locate the circles of view. I've summarized my problem in the picture below...

I was reading my friend's livejournal and I read this though (some person) kept telling me to finish my drink until i ended up chugging the rest of my mickey of vodka (i know it wasn't smart, but i was already drunk so my judgement was a bit impaired...) i payed for it big time the next day...

The reason I decided to post my queries out here is simple:I believe that ideas of PF members,by and large,represent the ideas of the world. :smile: I've been learning indian classical music for about 12 years now...have lots of friends who're equally passionate about music.I guess...

Anyone ever wondered what law pespective follows? If there is one... I mean a relationship between apparent height and real height over a distance. I was going to try an experiement if I ever get round to it. I'll be disapointed if its just another inverse square law :biggrin:

Though you guys might find this interesting. It's something I've not seen before. Consider the ODE: \frac{dy}{dx}=f(x,y) and the attached plot below. The blue represents the surface for the function f(x,y) (some particular example for the plot) in the first quadrant. The vertical...