Mystery Definition and 897 Threads

In the cosmology forum I posted this statement: , to which a PF mentor kindly replied: I fully accept what he says, but would be interested if any of "the GR crowd" would like to comment further. What I am asking is: by what means does mass/energy shape the geometry of spacetime? Does...

Found this fossil on Manitoulin Island in Central Ontario - Canadian Shield area. I'd be interested in knowing what epoch they're from. I'm thinkin' it's tube worms? Graptolites? Or rebar.

Light cannot escape from a black hole; however, x-rays have been detected from black holes. How is this possible? is it because of the accretion disk? where does it come from? is that all there is to the answer? thanks

Today I'd like to draw the attention to the end of the last glacial period. Those who have looked at ice core graphs may recall that the Antarctic ice cores appeared to react first around 17,000 years ago and then with a relative mild change in isotope values (interpreted as temperature change)...

planet venus? i read sometime ago that the venus revolves in opposite direction around the sun as compared to other planets.please tell me is it true? if yes then WHY?

Or the ancient titanic, it sailed from Barfleur, anyone know anything about it? i will not give any more details so you do not go wasting your time googling, it is just that i need some details.

At a time when there was a hose pipe ban, a person down the village noticed water gushing up from her lawn, she called severn trent (the local water authority and they told her ( it is not our problem it is a natural spring) for 5 weeks this lady watched her lawn being washed down the drain...

im reading some of feynman's lecture notes, and i stumbled upon a statement which i do not understand... he says that we can use ANY three different colors to produce any other color. lets say we want to see the color X, and we use yellow blue and red (Y,B,R) then X = yY + bB + rR. where...

I was just reading about "Morgellons Disease". At first I thought this was a psychotic symptom. I've definitely heard of similar crawling sensations experienced by schizophrenia sufferers. But it sounds like there might actually be a strange dermatological condition that these people are...

I am new to number theory and i so far like it. I recently found this problem but there was no explanation of how they got it and i was wondering if any of you knew how they got it. It is this: 1/3+1/3^2+1/3^3... + 1/3^n=1/2(1-1/3^n) Then they used: 1/4+1/4^2+1/4^3... +...

carol's age in years, can be expressed by reversing the digits in her father's age, in years. the sum of the digits in each age is 10. the positive difference between carol's age in years, and her fater's age in years___36 a.> b.< c.= d.uncertain In my opinion, there are four pairs...

Pi is the most interesting number. I was thinking about the value for Pi that is accepted by the Scientific and Mathematic community, which starts off as 3.141592653... and so on to infinity. My question is, How did they get this value of Pi as the most approximate? Did they use extremely...

Ok, every time after i use my bed i make it, three times this week i have found money on it when i next go to use it, now i am the only one that lives here so i must be putting this money between 30 and 40p on the bed, but for the life of me i can not remember doing it, i must be leaving...

What is the real answer to the mystery? http://www.chicagotribune.com/news/nationworld/chi-0605010196may01,1,5656742.story?coll=chi-newsnationworld-hed&ctrack=1&cset=true

http://www.signonsandiego.com/news/northcounty/20060423-9999-1n23bigboom.html

Hi, all; An interesting question was posed this morning by the science correspondent on Canada AM. Apparently, it's also in New Scientist magazine. He claims that it's unsolved, and I figured there's no better place than PF to go when searching for engineering solutions. I'm putting it in GE...

I got this question on my physics test "What will happen if you blow over a piece of paper?" I answered that with enough blowing, the wind created would make the paper fly off. Apparently according to my teacher, the correct answer was that from Bernouilli's theorem, the air velocity above...

Does anyone know why there is 360 degrees in a circle? Why not 100 for simplicity sake?

will someone who has google Earth please go to 1 deg 55'24.90"N 157 deg 21'52.47"W at an altitude around 100 miles Do you see an underwater mountain the exact same size and shape as the island next to it? the two foot print shapes could be where god stood when he created the earth, but...

Supposing I started off with a particle, which I know exactly the state it is in, hence, it is in a pure state. And hence also, its entropy is zero. Now, suppose we throw the particle into the black hole and be sucked in, then, then the area of the black hole increases and hence, the entropy of...

This topic could well be in a section related to biology, but more people visit the GD area. So... http://physicsweb.org/articles/news/10/3/8/1

Okay, I need some help yet again. Our teacher is giving us no hints on the "mystery problem" on our test tomorrow. "A boat sends a sonar down to find a submarine underwater. The boat estimates the velocity of sound under the water to be 1500 m/s. Howeer, they are wrong about that velocity...

what is your reading speed?? And if by the way,it is high..what factors are responsible for that.. Have you ever seen anyone having a reading speed of 3000 or more than that...i don't know how that's possible,,doesn't it mean the person has enormous control over his mind..

Does anybody know anything about this guy, Jerry Noble, who wrote this theory at: [url edited out - Zz.] Chris

"Perfect" Tense? Why are Perfect tenses called "Perfect" tenses? Where did they get the "Perfect" from? I require a source, as well.

Ok my thread seems to have gone into a black hole. The existence of such a number would disprove Andrica's conjecture.

Electric Force! I am uncertain how to apply Coulomb's law, if this is even the right way to go about it, to this problem on Electric Force because I am not given two charges. The question is: On average, the electron and proton in a hydrogen atom are separated by a distance of 5.3x10^-11 m...

My Seed Theory? Please help... This is what I came up with on my own and I was wondering if there is already a thought process or theory on this. Singularities formed by black holes are the "seeds" for new universes. The matter needed for new universes is created from the matter...

Ok here is what the problem states in the book "A ladybug settled onto the tip of a clock's minute hand. The minute hand is 12ft long. How far does the ladybug travel from 3:00pm to 3:20pm?" I figured there are 30 degrees to every hour (divide 360 by 12). Then the 20 minutes would...

http://www.gi.alaska.edu/ScienceForum/ASF4/422.html

Cu(en)2 ?? I was wondering what the (en) stood for in [Cu(en)2(H2O)2]2+ I was surfing the web and noticed that it appeared in several articles. Thanks!

From a materials science perspective, what is the point to folded steel? How does the folding process affect the properties of the metal? The place I see this extensively is in Japanese swords, such as Katanas. They will say "hand folded X times" with X usually being anywhere from 150-750, with...

OK this kind of has to do with physics, but more of what happnes when you squash something i suppose. Anyways my dad told me this riddle and when i gave up he said he forgot the answer and it has been bugging me for a while. One thing traveling on a straight path must come to a stop before...

I just ran across this today: http://www.trottermath.net/recurops/kaprekar.html I find this pretty neat, so I just had to post it. take any four digit number w/o repreated digits, and re-order from greatest to least, then subtract it's mirror image number from it and repeat, you will...

It is my understanding that the DNA guys have concluded that all Homo sapiens originated as progeny of a single "Eve" in Central(?) Africa. Since I haven't heard anything about "Adam," I assume that the genetic tracers don't allow anything to be said about the male lineage. Be that as it may...

In 2D for example, warping it only makes sense in a 3D enviorment. In a 2D world, bending 2D would be meaningless. So in GR when we talk about bending 4D ST, is a fifth dimension needed to give ST something to "bend into"? If not, in what sense can we talk about warped ST? I suspect that...

I saw penguins swimming at an aquarium yesterday. They swam deep underwater and they had streams of bubbles escaping from a spot on their backs. My mom thinks that penguins have some sort of a blowhole, but I've never heard of this. What was that?:confused:

I asked why a bomb going off on one side of a mountain would seemingly affect gravity for people on the other side of the mountain about a year ago. Experienced in Nam with valley floors about 2 miles apart. That's a lot of rock and soil seperating those who experienced this from the explosion...

I just saw this show, I know it has been on in europe for a while but it just started here in the US. I was wondering what the equation they were using for the offers from the "banker", anyone figured it out yet? Goooooogle turned up very little.

(t*y'(t))' = t*Dirac(t-2), t>0 we know that y(t) = 1 lim t--> o+ solve for y(t) the solution says that by using f(t)*Dirac_a(t) = f(a) * Dirac_a(t) we get (t*y'(t))' = 2*Dirac(t-2) Dont see how they get that

I consider myself a pretty advanced user of Excel, but this one has me stumped. I don't deal with toolbars very often, so I am in uncharted territory. I have a group of macros. At one time, when I ran one of the macros, I realized I had a circular argument and it created an error. No biggie...

The question goes as follows: Why are clockwise and counterclockwise referred to as "senses" rather than directions? It should be obvious, right? But I just can't seem to figure out what they are talking about. I mean, senses are touch, taste, hearing, seeing, smelling. What does...

This question has been bothering me for time. How does a moving bicycle manage to stay upright? but when it slows down it tends to fall to a side. Can someone please explain?

hi does somebody knows why we hear a noise when tuning a radio? I mean when you turn the radio tuner to find a station. not for a typical station. during turning the knib. I know it's becouse of a electromagnetic wave. but I don't know that wave and its source. tnx.

In free electron theory, electron doesn't feel any potential due to ions r co-electronsm they r totally free..then why don't they fly off from the metal boundaries?

Thanks for any replies in advance. I am currently trying to discern the theory behind an air-lift. A very large group of people are currently debating exactly how an air-lift works. Imagine a pond with a pipe in it. An airstone is place at the bottom end of the pipe and air is pumped...

A few days ago a buddy of mine showed me a two year old article, telling that Israel have developed an optical CPU. I did check i further and it is true, but I can not understand how such a device can work.. Is there anyone who could explain it to me?

Hi, this is going to sound very stupid. Is Re[SIZE="1"]d the same as Re? Its just that in some equations, I have Re[SIZE="1"]d, and then in others Re. It might not sound like much of a problem, but I'd really appreciate if someone could clear things up for me. Thanks!

Why are Bicycle wheels the same size? Is it because it is easier to manufacture and maintain or does having same wheel sizes in the front and back offer added stability when compared to having a bigger wheel at the back (like the early models)?

You can just google it so I won't get in trouble for linking to it. Anyone ever looked at it? It looks like just optical illusion silliness to me but is there any possibility of some other sort of thing going on? Was just wodering if anyone ever did anything meaningful there in the way of...