Curious Definition and 185 Threads

A bit of unfinished business: I discovered this report back in 2008 and was satisfied at the time that it was legitimate, so I posted it in the UFO Napster - not to be taken as suggestive of anything beyond high strangeness from a seemingly credible report...

I've seen this a thousand times and never understood WHY? Someone trying to kill someone drops a toaster/radio whatever into a bath and the bathee fries. Why The path of least resistance for the current would not be through the person, I would've thought that all that would happen would be...

Analysis math help please!? 1. Let E be a nonempty subset of R (real numbers) Prove that infE <= supE 2. Prove that if a > 0 then there exists n element N (natural) such that 1/n < a < n 3. A subset E of te real numbers R is an inductive set if i) 1 element E ii) If x element E...

Analysis math help please!? 1. Let E be a nonempty subset of R (real numbers) Prove that infE <= supE 2. Prove that if a > 0 then there exists n element N (natural) such that 1/n < a < n 3. A subset E of te real numbers R is an inductive set if i) 1 element E ii) If x element E...

The integral I am seeking to evaluate is int_{-\inf}^{+\inf) exp(-|w|/2) exp( i w [ln(|w|)/pi-x]) dw a definite integral which is a function of x... at x=0, it is nearly the same as the "sophomore dream" integral... I don't know why, but this function seems to have a singularity at...

Just curious how electric motors work, specifically DC motors. I have some questions i would like to understand better. do the windings of a motor determine the required voltage to power it? Can a 110 volt ac motor be powered by a 12 volt dc battery without an inverter? Can a 110 volt...

http://www.mathworks.co.uk/products/matlab/demos.html?file=/products/demos/shipping/matlab/inverter.html http://www.mathworks.co.uk/products/demos/shipping/matlab/inverter_01_thumbnail.png ^^^ Random matrix, 100x100...

Homework Statement A car starts from rest and accelerates uniformly at 3.0 m/s^2 a second car starts from rest 6 seconds later at the same point and accelerates uniformly at 5 m/s^2. How long does it take the second car to overtake the first car. Homework Equations d=vit+(1/2)at^2 I...

So I am curious how many PFers own firearms here. What kind of guns do you own? What do you have on your wishlist? How often do you go on a range or hunting and practice?

In Sir Arthur Conan Doyle's Sherlock Holmes story "Silver Blaze" we find: "Is there any other point to which you wish to draw my attention?" "To the curious incident of the dog in the nighttime." "The dog did nothing in th nighttime." "That was the curious incident," remarked Sherlock...

Ok so this may be an odd question but maybe there is someone here who can understand what I'm talking about. When you have a wave of water and the water hits a wall, the waves will ripple back and causes the motion of the waves to traverse. I was wondering if there is anything like this...

So I'm sure you guys have heard about this. I can believe that he won the election by fluke. But what's his deal personally? The answers he gives in interviews are obviously coached, and are also obviously lies. Why? Ok, maybe some opportunist decided to become his manager and is...

Homework Statement There might be an obvious answer to this problem, but if two ball for example fall from two different building, one from a tall building and the other from a short building. If the ball from the shorter building hit a barrier, then the ball which fell from the taller...

Good evening, I am in high school (well we would have called it secondary school but I'm assuming most of you are Americans) in Ireland, I will be a senior (Americanism again.. :p) next year (i.e. finishing in 2011) and I have a keen interest in science (particularly physics) and mathematics...

Homework Statement find ⌠cotx using integration by parts with using u= 1/sinx and dv= cosx Homework Equations cotx=cosx/sinx The Attempt at a Solution u= 1/sinx and dv= cosx dx du = -cotxcscx dx v= sinx ⌠udv = 1 + ⌠sinx cotx cscx sinx and cscx cancel out. ⌠cotx = 1 +...

These identities might be considered as true: \begin{array}{rcl} 1 - 1 + 1 - 1 + \cdots & = & \frac{1}{2} \\ 1 - 2 + 3 - 4 + \cdots & = & \frac{1}{4} \\ 1 - 4 + 9 - 16 + \cdots & = & 0 \\ 1 + 1 + 1 + 1 + \cdots & = & -\frac{1}{2} \\ 1 + 2 + 3 + 4 + \cdots & = & -\frac{1}{12} \\...

Whence "Charm"? The quarks have very quirky names! All of them have an origin: * (up, down) refer to isospin states. * strange refers to "strange decays" that were, well, strange! * (bottom, top) are derived from "beauty" and "truth" ("Beauty" still is used synonymously with "bottom")...

I know that light "slows down" when traveling through air (doesn't really slow down but travels further because it traverses 'around' the atoms) but does this effect appear when it travels through fields of radiation and or heavy magnetism? just curious... and I AM an idiot if you're...

Hi guys, first post, sorry if it's in the wrong place. Frequent visitor, you seem to help pretty comprehensively. I'm using mathematica to calculate a bell inequality, with a general noisy quantum state. However, when I evaluate it, I get a sequence with an a in the result.. which isn't a...

I have come to this forum to see if someone can explain the following in non-mathematical terms. I board a steam train in Yorkshire and travel to London. I understand that energy is in the coal, which is burned and transforms some of the energy into heat which raises the steam which drives...

Just curious, has anyone traveled to Icleand ?

This is an interesting type of number series I found. I have no idea if it's good for anything, but somehow it's captured my interest. the first example, the simplest is 0,1,1,0 the rules of operation are that you start at each position and take a pair of numbers. At the end, you wrap to...

A stream of water traveling horizontally at 30m/s is ejected from a pipe of cross-sectional area 40 cm squared and is directed against a vertical wall. Calculate the force exerted on the wall assuming that the water does not rebound. What is the power of the pump needed to give the ejected...

The westboro baptist church recently completed a tour of protests in New Jersey (where I live). For those of you who aren't familiar with the WBC, they are an infamous group with a hyper-calvinist view point consisting of Fred Phelps and members of his extended family. They are not a...

Homework Statement My question uses the following problem. I am confused as to why s=v(bar) * t works out the same as s=(v0-vfinal)/2 * t Enlighten me please! Problem: How long does it take to fall 1000ft with no drag? What is the final velocity? displacement: s=1000ft acceleration...

Ok, so I started Sprintec birth control pills a week ago, and the chances of getting pregnant while on it alone is 1% per year of use (a little less actually, but for the sake of simplicity, we’ll stick with 1%). I also have condoms, the Today sponge, and can also use the withdrawal method...

I'm here doing some god awful physiology lab report about to write a paragraph on mean arterial blood pressure and was thinking about the pumping mechanism and was tying to think if there was any such organism which has a continuous flow fluid transport system, and if so what's the biggest one...

My cat tries to trip me up, feigns insult (meow!) if I step too near, plops herself at the busiest intersection in the house (at night), and sits or claws on material I am reading. I can imagine her being a hazard to her senior former "owner." Otherwise, she is a great gata. [Would you...

I am studying in Grade XI and have started with physics. Its very different from physics in last grade. So here are my questions about few units my tution teacher challenged everyone about. Homework Statement i)What is the name of the unit [Kg][Meter][Second]^{-3} - We may write it as...

I recently came across this article on wikipedia : http://en.wikipedia.org/wiki/Faraday_paradox#Inapplicability_of_Faraday.27s_law" I don't understand why is it that Faraday's law is inapplicable here. But wouldn't there be a increase in magnetic flux, since the open surface will increase in...

I chose this subject title to get your attention. :biggrin: Anyway, I know how to solve it; it's obviously a matter of factoring and the difference of two squares: 50x^2 - 72 2(25x^2 - 36) 2(5x - 6) (5x + 6) However, when I try to solve it the normal way -- by factoring -- things go...

I heard it said that there is no such thing as speed its all relative to a point of reference and also that there is no such thing as anything moving faster than the speed of light. so would a burst of light going in separate directions relative to each other be separating faster than the...

As with all my movie reviews, this contains spoiler information. F. Scott Fitzgerald wrote a light, shallow, short story of this name. The movie is a dark, deep, three hour long story that only takes one thing from the original: Benjamin is born with an old body which grows young. I liked the...

Simple Yes or No Question but how would you prove? If gravity is a property of matter, when it gets converted to energy (for instance light) does energy also have the property of gravity? If so how could it be proven as a very large amount of energy would be required to equal a small amount...

I was just wondering, let's say you launch a ball, what angle would give you the longest time in the air? I know that 45 degrees will make it go the farthest but is that also for longest time in the air?

I am not a computer hacker, and have absolutely no idea how to do so. I was wondering just how mathematically mind-boggling that computer hacking is. Don't you have to make extremely complex and fast mental calculations and type in thousands of odd numbers at some kind of prompt? Do you have to...

(Sorry I cannot follow the question format because this question is related to a problem, but is not the problem itself.) I am talking about the linear density μ that appears in this equation: v = sqrt(T/μ) .. used usually for musical instruments, where μ = m/L Now, I am wondering which...

The first two are theoretical. Please excuse grammatical and spelling errors. If you had a spaceship at the edge of the universe, and this spaceship could travel faster than the universe is expanding, what would happened if you tried to travel outside its boarder? Would you crash into the...

Hi I'm a senior in college and have one more year left until I get my structural engineering degree. I am thinking of getting a physics minor. I've taken 'Physics for Engineers' which is basically physics up to SR. I've also taken the Mechanical Engineering set of classes which include...

Hello, I'm toying around with a Jacobian that has raised some interesting problems. It's a case of differentiating rates of some variable x, with respect to itself. First one I suspect the answer is zero, though perhaps my reasoning is a bit flawed. 1. \frac{d}{d\theta}(\dot{\theta})...

Okay. Don't worry about 'where' or things in the way, and anything of the sort. A car and a plane both going 100mph and the plane being 10miles up in the air. Which one gets the the selected latitude ( or longitude I forget which is up and down) first? Wouldn't the car get there first...

We have an infinite net of regular hexagons. Each side of hexagons has a resistance R. What is the resistance between two opposite vertexes of hexagon(s)?

Q # 1. the film crew CANDID CAMERA replaces person's briefcase with an identical one that contains a mounted and spinning flywheel. explain what happens when the person tries to carry the briefcase around the corner?

Hi all, I'm now very busy trying to findout how to block external RF at my apartment room. I'm on 23rd floor. A huge radio boardcasting tower (714KHz, 90MHz) is just 20 meters away running along with my building. It's higher than 25 floors. I know that many GROUNDED conductive surface can...

It's clear that f(x)=e^x has no solution for f(x)\le0. So can there be imaginary solutions for values not in the range of the exponential function? Just as an example, can this have imaginary solutions, and how would one go about solving it: e^x=-e?

Hi. If you were on a train going 700mph and you shot a gun out the back that fired at 700mph. Would the bullet drop straight to the ground relative to the earth?

What are the fundamental differences in the nature of the work done in a master's thesis and a doctorate thesis? I'm guessing there is less help provided by the advisor at the doctorate level and also that the "difficulty" level is higher at the doc level because the doctorate student has more...

Just because one cannot know both where an atom is and how fast it is moving, does that mean that it doesn’t have a specific place and speed at any moment?

im curious...what does it take for someone to be immortal? i was having this argument with a friend, but was never finished, and we never seem to be able to start again... anyone care for a duel?:-p

Wells' "Dictionary of Curious and Interesting Numbers" Does anyone have a copy of Wells' "Penguin Dictionary of Curious and Interesting Numbers" 1986 or 1987 edition? I'm curious about how they compare to the revised (1997) version I have. On a lark, I decided to put together a list of...