Review Definition and 459 Threads

Hi to everyone, For a while (which is only a few weeks) I have been thinking about a solar power plant with additional features. Here is a brief outline. Take an arid area close to the sea (Sahara, Saudia Arabia, parts of Australia etc.) Focus sunlight via computer controlled mirrors to a...

My friend wants to know why I think Teslar watches are pseudo-science snake oil. There's lots of sales pitches on the web about them. Can anyone direct me to an objective review?

While perusing the 'Never Ending Book' Site, I came across this link to the Terry Gannon ArXiv paper 'Monstrous Moonshine: the first 25 years'. http://www.arxiv.org/PS_cache/math/pdf/0402/0402345.pdf Lieven le Bruyn refers to this as a survey paper [33 pages with 124 references]. It...

Hello all! I have to write a review paper of several current articles for my Gas Dynamics course. My research is in Welding and Automation, so I have very little experience in the area of aerodynamics. However, I have recently read a book on Lockheed Skunk Works and think that I would like to...

Sin contest question from 2003-- Can't figure this question... it's exam review! help the questions is: A kid is 5m from a fence that is 4 m high. He throws a ball @ 45 degrees from the horizontal which just grazes the fence. How far beyond the fence does the ball land? You may assume that the...

Alright, I have a Physics Final exam coming up and I'm worried about it. How do you guys go about studying for everything from a whole semester? Should I just review all of the equations and clear up what each one means? Should I practice all of the problems at least a few times? What should I...

Marco Genovese has put out a review that fairly well summarizes where things are at in tests of Bell's Theorem. He has done similar papers previously, and the references are quite comprehensive (there are 505, and they cover the spectrum). Research on Hidden Variable Theories: a review of...

Help! My comments are appearing backwards in a doc I'm reviewing. See attached. What I typed was: [ Hello Bob A1234 ] The comment reads: [ 1234Hello Bob A :Comment ] (see attached diagrams) It builds like this: [ |H:Comment ] [ |He:Comment ] [ |Hel:Comment ] [ |Hell:Comment ] [...

You`ll find the review - to be published in "American Scientist" magazine - by the discoverer of D-branes, Joe Polchinski, here: cosmicvariance.com/2006/12/07/guest-blogger-joe-polchinski-on-the-string-debates/

im stuck on one of the homework problems I am reviewing for a test. any help would be appreciated. I am not sure on how to set up the problem. a small 1.32 kg mass is connected to a cord of length 1.62 meters, and spun at a constant angular speed of 8.0 radians per second. if the cord is...

i need to show that when A is a subset of B and B is a subset of R (A B are non empty sets) then: infB<=infA<=supA<=SupB here's what i did: if infA is in A then infA is in B, and by defintion of inf, infB<=infA. if infA isn't in A then for every e>0 we choose, infA+e is in A and so infA is...

I am in a calculus based college level Physics I class. We're doing a lab on projectile motion. He is a stickler for grading the labs and just wanted to make sure everything is ok. My problem is that my conclusion seems awful short, but all that is asked calculate and measue the range and...

Hello everyone. He told us he could of course change the parameters which he will of the proofs we have been working on so I'm testing out some cases but I want to make sure I'm doing it right. Here is an example of a proof the boook had...

Hello everyone, another review question I'm lost on, He has the following question A binary relation on a set S is defined to be any subset of the Cartesian product S x S. (We will study binary rleations later in the course.) If S is a set of size 3, how many binary relations are there on the...

My linear algebra is getting pretty rusty. I need something that will jog my memory about various computational details. The only text I currently have is the Springer yellow book by Curtis. I'm leaning toward a Schaum's outline, either the straight "Linear Algebra" one or the "3000 Solved...

http://www.math.columbia.edu/~woit/wordpress/?p=469#comment-17298 D R Lunsford points out that Lee Smolin replied to the review of TTWP published in the 30 September issue of New Scientist http://www.newscientist.com/channel/fundamentals/mg19125711.500-review-ithe-trouble-with-physicsi.html...

Nature’s review is available thru various blogs (one called Gravity and one hosted by Lubos Motl) which i will quote: http://nige.wordpress.com/2006/10/09/16/ ===quote=== Nature 443, 491(5 October 2006). Published online 4 October 2006: The Nature review link no longer works. Never mind...

find the minimum distance between the origin and the surface z^2=[8-y^2-x^4*y^2]/2 so d=sqrt(x^2+y^2+z^2)^(1/2) where for z^2 I sub in that expression in x and y? so then I take the partials of d wrt to x and y and set those equal to 0, then I solved that system of equations and got x=+-1...

SpaceTiger's Note: Taken from https://www.physicsforums.com/showthread.php?t=130680" Sorry, this question is somewhat off-topic, but aren't the arxiv.org-papers peer-reviewed?

Anyone know of a good book that reviews all the concepts needed for DE from Calc and before?

Ok i got this problem... T(x,y,z,t)= -2xy^2+e^(-3z)cos(5x-.75t) taking the partial derivative with respect to x first, so i break the problem apart with the left and right sign of the addition side so i get... -2y^2 for the left side and then am stubling on the right side, I am think just...

Hi, I'm an amateur so please bear with my question. I'm reviewing Algebra, patienly answering every exercise in the my textbook. I enjoy answering the exercises but sometimes I get impatient especially when the questions look the same and are less of a challenge. I've read somewhere that in...

The Trouble with Physics---Woit's review Peter Woit has reviewed Lee Smolin's book The Trouble with Physics http://www.math.columbia.edu/~woit/wordpress/?p=451 Also the article in 12 August New Scientist about 1. emergence of matter in LQG 2. recovering ordinary gravity---evidence of LQG's...

to keep track of the response to Peter Woit's book here is a review by John Horgan, a well-known science writer, in the August 2006 issue of PROSPECT magazine. Horgan's review is titles "Stringing us along": ====quote==== Stringing us along The tide seems to be turning against string theory...

Hi, sorry if this is posted/answered all the time, but I need some book advice. Basically, I will be taking this course in the fall: And required prep knowledge for entering this course is: Now I've taken tons of Linear Algebra and Multivariable calculus, but I need brush up on...

The scientific methods as developed by several philologists like Carl Popper provide objective tools for developing new hypothesis and theories. That’s theory though but far from daily practice where subjective elements play a role, making science rather conservative. Apparently it’s very hard...

Hi, I have some reviw questions for the upcomming chemistry exam, the problem is I don't have the answers so can some one read throught my work and check if it is wright? Thanks. *** 1. An anaysis of a valitile liquid showed that it wsa composed of 14.4%C, 2.37% H and 83.49% Cl. If 4.25 g of...

http://www.timesonline.co.uk/article/0,,2102-2214707,00.html The Sunday Times review is by John Cornwell, an historian. ===sample=== ...But is string theory true? Peter Woit, a mathematician at Columbia University, has challenged the entire string-theory discipline by proclaiming that its topic...

Hi guys, Just wondering if anyone has any recommendations for review on basic Chemistry topics. I will be taking my first college chemistry class next semester and just want something to do over the summer to be prepared for the course. I did take a chemistry class in high school, but...

please can you have alook at the attached file

Every wonder what your boss is really trying to tell on his yearly performace review...

Here is a question that i have on a test review and neither the book or the teachers examples are any help. If 200mL of 0.800 molar HClO is added to 400mL of 0.200 molar Ba(OH)2 solution, the resulting solution will be ________M in Ba(ClO4)2. I know that the answer is 0.133M i know...

It is blaringly obvious I have forgotten most if not all I learned from DEs. Could anyone direct me to any good sites for review or suggest areas I should specifically review for physics?

So, here I am again. This is to only have a proof reviewed. Like I said before, I will do this from time to time, so I know I'm staying on track. Theorem - Cantor Theorem Let {C_1, C_2, ...} be a monotone decreasing countable family of non-void closed subsets of a T_1 space such that...

i have this question that i couldn't get but it's on this quiz i have tommorow. A 600-kg jet car accelerates from rest under the force of its jet engine. After traveling 1.00 km in 21.0s, the jet engine shuts off and the jet car eventually comes to a rest at 1.4 km further down the track...

It's been three semesters since I was last required to do a dimensional analysis problem, and I could use a little help here. Just know that the subscript notices come before the variables. In this case, [B]the final set of units must work out to be W/m^2[B]. The equations are: a)Q(sub)s=...

Hello. A long time ago there was a post here of all the resources that we can find online for physics. I tried to find it searching a little bit, with no luck. Anyway, if someone know about that post, let me know, What I'm interested in is in a good thermodynamics review (or summary (?))...

http://arxiv.org/abs/astro-ph/0601469 Comparative Planetology and the Search for Life Beyond the Solar System Charles A. Beichman, Malcolm Fridlund, Wesley A. Traub, Karl R. Stapelfeldt, Andreas Quirrenbach, Sara Seager To Appear in Protosars and Planets V "The study of planets beyond...

For higher math classes, its trivial to say that if y=x, then y'=1. Higher level textbooks also don't review a lot of the basics that are easy to forget. So if you have an equation that looks like y=x(t), then even if dy/dt might be some complicated looking function in t, dy/dx is still just...

I'm doing a review in calc I to prepare for calc II. I'm now applications of derivatives (optimization). Okay so when I have the function I need to optimize, I need to take the derivative and find the critical point of the first derivative. But sometimes there's more than one critical point. Is...

Can anyone recommend a good book for me to review general math such as fractions, decimals, percenttages, and division etc.. those are my weakest points in math, and I would like to strenghten them a bit.

You can read lots of these - http://skyandtelescope.com/news/article_1649_1.asp", for example - I thought it might be fun to take a different view! :smile: What were the most notable non-discoveries for 2005? What were the most outstanding failures? I'll go first. In the second...

I think I got these right but I wanted to check first before I took my test... The ones that don't have any answers are ones I need help with. Concept Review: 1. Which of the following is most likely to form a cation? Xe Cl Ca S 2. Which of the following is a chemical...

I would appericate it if someone here could look over my essay and post some comments. The things to look for are: Varied wording Grammer and spelling Good sentence structure Good paragraphs Verb tense Anything else that you find wrong with the paper. It's suppose to be...

Please Help...test Review Problem That Wasn't In Any Homework I Can Find! i don't understand how to figure this problem out, and i really need the help. A kite is flying Y feet about the ground at the end of a 100 ft. string. the string makes an angle of (theta) with the ground. 1. find the...

Old Book Review - "Classical Charged Particles" Hi folks I've picked up a rather old book. It was written back in 1965 by Fritz Rohrlich and is called "Classical Charged Particles". I found this book by a reference in Jackson's EM text. I have to say that this is a superb book! I don't think...

I need to prove that the limit of a constant sequence converges, using the definition of a limit. This is what I have: Let e > 0 be given. Then |sn - s| < e But sn = s for all sn, thus |s - s| < e |0| < e 0 < e Thus N can be any number? This proof is simple, but I am making it...

Let (sn) be a real sequence and s in R. Prove that lim sup (sn) < s implies sn < s for n large. My answer seems too easy. Is there anything missing? Given lim sup (sn) < s. By definition of lim sup, we know lim N->infinity sup {sn: n > N} < s Then for n > N, we must have sn < s...

Problem: Suppose 0 < sn < 2 and sn+1 = root (sn + 2) for n in N. Prove 0 < sn < sn+1 < 2 holds for all n in N. Does sn converge? If so, what is the limit. I am able to show that sn+1 < 2 by squaring the equation sn+1 = root (sn + 2) and making a substitution. How would I go about...

Another question: Prove that if a set E in R has a finite infimum and e > 0 is any positive number, then there is a point a in E such that inf E <= a < inf E + e. The first part, inf E <= a, is obvious from the definition of infimum. I am having trouble showing that a < inf E + e, even...