Events Definition and 357 Threads

I've written a scifi short story for a contest on the theme of environmental disaster, and I want to check the plausibility of the chain of events that occurs in the story. 1. It opens with a spill of massive quantities of methyl and phenyl isocyanate into a bay area on a planet in the...

I'm guessing this requires some difficult and monotonous math so I figure if it has been done, it required expensive computing equipment. But, does anyone know of any info or have participated in a computer astrolabe program that has ran the numbers backwards as to the position of planets and...

Is time ever existent (infinite number of events in the past) or did it come into existence with the big bang (finite number of events in the past)?

I am having trouble with measuring coordinate time in different inertial reference frames. For example: Say a car is driving around a circular track (at constant v) and passes a stationary observer. I'll call this event A. Then the car makes another lap and passes the observer again (Event...

Homework Statement Homework Equations no equations needed b/c its a conceptual question.The Attempt at a Solution my attempts.. A) the earliest it can occur and can only be connected by speed of light there t2= 1200/3*108=4*10-6.. B) yes it can because event(E0) occurred 1micro sec before...

Homework Statement The two events A and B have probabilities 0.2 and 0.4. Also P (A n B)=0:08. (a)Are the two events A and B independent? Explain. (b) Find the probability that either A or B or both occur. (c) Find the probability that neither A nor B occurs. (d) Find the probability that...

I have a problem where it requires me to find when a laser should be fired at an asteroid to ensure that in the reference frame of the asteroid, the laser hits the back and front within 1 millisecond. I thought that I could define events in S' such that the front and back are hit at t' = 0, and...

A recent forum thread went into a long disussion of simultaneity. The term "ansible line" was used (later referred to as a "simultaneity line.") Einstein demonstrated with a thought experiment with regards to lightning and a moving train that events can be simultaneous in one time frame but...

I'm a bit lost on use of mutually exclusive and independent rule on this. I know probability of winning a game is a loose term, but... If I had a team's schedule of 12 games with probabilities listed of winning each game, would I add those probabilities, then divide sum by 12 for an average...

Hi, A friend of mine asked me something about relativistic physics. It's all hypothetical and I told him it's a paradox that cannot be achieved since you cannot go back in time. Here's his assumption: Let's say that you pass through a 'wormhole' to a planet near Alpha Centauri (26...

if two events are simultaneous in an inertial frame, then they would not be simultaneous in another inertial frame as long as they are separated in space.Equally the vice versa is valid.Does this not imply that it would be possible for one to see someone to be born and to be dead at the same time?

So, Bayes' Theorem states P(H|D) = P(D|H) X P(H) / [P(D|H) X P(H) + P(D|~H) x P(~H)], where ~ = negation If my hypothesis consists of two events - S and O - would this be P(S,O|D) = P(D|S,O) X P(S,O) / [P(D|S,O) X P(S,O) + P(D|~S,~O) x P(~S,~O)] or this P(S,O|D) = P(D|S,O) X...

Hi all, I've a problem. Let's say I have 18 independant events. The outcome of each event could be 0, 1 or 2, with a probability of 0.5, 0.333 & 0.167, respectively. I want to know the easiest way to calculate the probability of achieving all scores between 0 & 36. As there's more than a 0 or...

Hi, everyone: I was reviewing some intro material, and I ended up confused with the issue of independence with the following problem: We are given two teams, A,B, playing against each other. A wins with probability P(A)=0.6 , B wins with P(B)=0.4 (games are played until...

With the signing of the Health Care Bill, I thought it might be interesting to post a few similar moments in history. Please post only videos that have historic significance. https://www.youtube.com/watch?v=334IO43A__k https://www.youtube.com/watch?v=aVZijG4WSOw...

Homework Statement Consider two events ct_{1}\; =\; 3\; m,\; x_{1}\; =\; 2\; m,\; ct_{2}\; =\; 5\; m,\; x_{2}\; =\; 6m What is the time difference between the two events? Find a reference frame for which the time difference is the negative of the time difference in the original frame...

I would like to see a detailed comparative analysis of specific historical events from the 1600"s, 1700's, and 1800's over 25 year intervals. Does anyone know of such a study?

Homework Statement Let S be the sample space for rolling a single die. Let A={1,2,3,4}, B={2,3,4}, and C={3,4,5}. Which of the pairs (A,B), (A,C), and (B,C) is independent? Homework Equations P(A|B)=P(A) P(A|B)=P(A&B)/P(B) P(A&B)=P(A)*P(B) The Attempt at a Solution P(A)=2/3...

Homework Statement Two cards are drawn from a standard deck with replacement. A=first card is an ace. B=second card is an ace. Show that A and B are independent Homework Equations P(A and B)=P(A given B)/P(B) P(A given B)=P(A) The Attempt at a Solution P(A)=4/52 P(B) =4/52 P(A...

How many heads in a row would you expect to find if you toss a fair coin 8 times? I am thinking that the probability of 3 heads is 1/8 and since you have 8 tosses, that would give an E(x) of 1. So I am guessing that 3 is the number of heads one would expect to see in a fair coin...

You can call time an unfolding of events... but what if there were no events as in a pure emptyness without objects... or objects present yet never changing in any way? Then there could still be time because you might have a consciousness that was watching the nothingness. That mind might be...

There's been so much research on the iceberg armada events (Wikipedia Heinrich events) since the classic 1988 paper by Hermut Heinrich himself. There's a host of different data concerning the events, so why is still such a mystery? Here's an excellent introduction to the research carried out in...

The primary problems with mental causation are nicely summed up by Yablo (“Mental Causation” The Philosophical Review, Vol. 101, No. 2 (April 1992) ). http://www.jstor.org/pss/2185535 Yablo defines dualism as follows: In other words, the physical description of the color red as it appears...

http://cmsdoc.cern.ch/cms/performance/FirstBeam/pictures221109/CollisionEvent.png Garrett Lisi has mirrored the official site, in case of any problems with accessibility. http://sifter.org/~aglisi/albums/LHCfirstcollisions.png

A box contains one yellow, two red, and three green balls. Two balls are randomly chosen without replacement. Define the following events: A: \{ One of the balls is yellow \} B: \{ At least one ball is red \} C: \{ Both balls are green \} D: \{ Both balls are of the same color \} The...

Homework Statement Show that if A1, A2, ..., An are independent events then P(A1 U A2 U ... An) = 1 - [1-P(A1)][1-P(A2)]...[1-P(An)] Homework Equations If A and B are independent then the probability of their intersection is P(A)P(B). The same can also be said of AC and B. The...

Let A1,A2, . . . ,An be subsets of . Show that if A1,A2, . . . ,An are independent, then the same is true when any number of the sets Ai are replaced by their complements (Ai)c. (Hint: First do the case in which just one of the sets is replaced by its complement. Then argue by induction on...

Hello! I am new in Relativity theory and i met somewhere that they say that the spatial distance between two events in two different inertia frames of reference is not the same. Did anyone meet this before. So how can one show that inequality. I am thinking about the contraction of length when...

Homework Statement Let (A_n) be a sequence of independent events such that Pr(A_n)<1 for all n. Show that P[limsup A_n]=1 if and only if P(\cup_{n=1}^{+\infty} A_n)=1 Homework Equations The Attempt at a Solution Suppose P[\limsup A_n]=1. Define $B_k=\cup_{i=k}^{+\infty} A_i so...

Is there some term for what I'm about to describe? I don't know if it's a philosophical or probability discussion or what. Take sports leagues, for example. So am I to believe that every permutation of MLB team records occur in that many number of parallel universes? I mean, what are the...

Hi all, I am not a physicist. Some engineer friends of mine and I have a question about special relativity in two dimensions. To set it up, there are 2 lights floating in space parallel to the x-axis and a spaceship is traveling at .8c flying parallel to the y-axis towards the midpoint of...

I am having trouble clearly/completely understanding the main cause of a transfer of thermal energy into the environment as a result of a bond formation. In terms of a very simple, generic, exothermic reaction... What I know...I can picture the atoms coming together through electrical...

Strange Confluence of Events... Has anyone else had several things happen all at once or one right after the other that made you wonder how, if at all, they are related? Tonight while at work I received a call about a female resident who needed to speak with me because she was worried her ex...

I'm having trouble with one of the rules of probability P(A n B) = P(A)P(B) which holds if events A and B are independent The following problem illustrates my confusion. I've defined Events A and B below, are these events dependent? Per the solution in the book P(A \cap B) = P(A)P(B)...

Generalizing entanglement: Aren't all quantum "events" superluminal? If as it seems, the speed of the collapsing wave front of entangled particles occurs at a superluminal velocity, what is special about entangled particles? It follows that all quantum changes occur at superluminal rates, e.g...

I am not sure how to answer the following question, which I have posed to myself to better understand the method: "Suppose two six-sided dice are rolled together N times. What is the uncertainty in the number of times any given total appears on the dice?" For example, what is the...

Hi there, I am trying to figure out the 64 events occurring in the flipping of a die. Can someone help me with this? regards kautilya

[b]1. A fair coin is tossed n times, let E be the event that the first toss is a head and Fk be the event that there are a total of k heads. For which values of n, k are E and fk independent events? [b]3. I don't see how these events can possibly be independent (surely the first influences...

Allright call me a naturalist , for those of you interested I had a short encounter with mother nature the other day. Friday afternoon - I found a starling bird in my front lawn , it was being real still with its head pointed to the sky. It started to hop in the other direction as soon as it...

Hi, I'm hoping that someone can explain one problem I have with the many worlds theory. If the many worlds theory is true, then we are currently living in a universe which is the product of an infinite number of splits in the past. Thus, looking at our history, we should have numerous...

Can dogs/cats (or wild animals [elephants]) anticipate future events and plan accordingly? I am sure that they can remember events and know how to respond to a particular event (like see stranger => bark hear a name => if its calling name => respond to it winter is coming => migrate etc) but...

I was wondering, if you are told that for two events A and B, We Have P(A)=0.4 and $P(A\mid B) = 0.4$\\ Can you assume as P(A) = P(A\mid B) That these events are independent? regards Brendan

Last night I watched the fun, if not reliable, history channel piece on volcanic eruptions large enough to significantly reduce sunlight. I'm curious. What's a rough order of magnitude of sunlight reduction expected from the various size of events? Some quick googling gives me: Small...

I have read a question which has Two events A and B such that p(A) = r and p(B) = s with r,s >0 and r + s > 1 My querry is about r + s > 1 is this possible ? I thought that it had to be < or = to 1 regards Brendan

Hello all, I am working on this problem, have searched my textbook, this forum, etc and am still as lost. I suspect I need to (in some form) use the formula P(AB)/P(B) = P(A) as it is the integral formula of this section. Any suggestions or hints are greatly appreciated. A fair coin is...

how do i prove that A and (B intersection C) are mutually independent? first of all how do i even read that question, is it read: A union (B intersection C) ??

Ok folks, this is my first post to this forum and I’m afraid that I might be asking an embarrassingly simple question! I’m reading Einstein’s book on SR and GR and I’ve reached a discussion of simultaneity that involves an observer attempting to decide if lighting strikes that occur ahead and...

If anyone here cold scientifically explain the extremely unusual number of occurances of natural disasters, and virus outbreaks more than any other point in history, and not link it to the foreshadowing of some malevolent paranormal force or the book of revelations/apocalypse. I understand the...

The physics behind the scene on some type of UFO reports (events on clear day) is explained here. This is an important issue to aviation security, and if you agree with this explanation make some effort in spreading the word. -------------------------------------- Jet planes have HOT...

Homework Statement A box contains two white, two red, and two blue poker chips. Two chips are randomly chosen without replacement, and their colors are noted. Define the following events: A) Both chips are of the same color B)Both chips are red C)At least one chip is red or white Find...