Search found 235 matches

by Birk
Thu Jun 26, 2014 4:46 pm UTC
Forum: Science
Topic: Speed of Propagation of a Magnetic Field.
Replies: 116
Views: 28929

Re: Speed of Propagation of a Magnetic Field.

Sure I could measure distances on the ground instead of rotating the whole apparatus around. But who would come out to my location, measure the distances and check the results. Einstein did just a thought experiment and some calculations (which were done by his wife); there is no proof as far as we...
by Birk
Sat Jun 21, 2014 6:16 am UTC
Forum: Science
Topic: Speed of Propagation of a Magnetic Field.
Replies: 116
Views: 28929

Re: Speed of Propagation of a Magnetic Field.

P1T1o We used a 50 megahertz dual trace computer interfaced Oscilloscope. The CB transceiver sends out a 27 Megahertz signal. So what is the problem with that. The wave patterns shown were actual printouts, not hand drawings. The control experiment showed that by moving the antenna a distance of 11...
by Birk
Fri May 16, 2014 4:58 pm UTC
Forum: Mathematics
Topic: Need second opinion. I think I disproved God.
Replies: 72
Views: 13177

Re: Need second opinion. I think I disproved God.

I refuse to believe God uses AOL.
by Birk
Fri May 16, 2014 2:47 pm UTC
Forum: Mathematics
Topic: Need second opinion. I think I disproved God.
Replies: 72
Views: 13177

Re: Need second opinion. I think I disproved God.

Dr-Evil wrote:Who gets to decide if my hypothetical God counts as a god? I used only the minimum-criteria: extremely powerful and existing.


My Gods are David Dunning and Justin Kruger. Their effect is extremely powerful as evidenced by this thread and they absolutely exist. You can totally just e-mail them.
by Birk
Fri Feb 22, 2013 3:49 am UTC
Forum: Mathematics
Topic: Want to study astronomy... bad at math
Replies: 117
Views: 31477

Re: Want to study astronomy... bad at math

Nice! Welcome back. Happy to hear everything is still moving along.
by Birk
Sun Sep 02, 2012 2:56 pm UTC
Forum: Fictional Science
Topic: Observing the Big Bang
Replies: 31
Views: 9694

Re: Observing the Big Bang

But was there a gravitational event equivalent to the neutrino decoupling of the CNB or the photon release of the CMB? Maybe: if the Theory Of Everything which claims that gravity was once unified with the other 3 forces is correct, then gravity probably decoupled at the end of the Planck era. Well...
by Birk
Sun Jul 22, 2012 11:37 pm UTC
Forum: Mathematics
Topic: Want to study astronomy... bad at math
Replies: 117
Views: 31477

Re: Want to study astronomy... bad at math

The concept of a constant is somewhat context dependent. In the example of y = mx + b the slope and y-intercept (m and b) are constants for a given line and the values of x and y are what change as you move along the line.
by Birk
Sun Jul 15, 2012 9:30 pm UTC
Forum: Mathematics
Topic: Want to study astronomy... bad at math
Replies: 117
Views: 31477

Re: Want to study astronomy... bad at math

Yeah, sign errors are very skilled at sneaking their way into computations. They will subside in time.

Also just to clarify, although im sure you know this. The order doesn't matter but it does have to be consistent. For instance

m = y2-y1 / x1-x2

is incorrect. This would introduce a sign error.
by Birk
Sun Jul 15, 2012 9:15 pm UTC
Forum: Mathematics
Topic: Want to study astronomy... bad at math
Replies: 117
Views: 31477

Re: Want to study astronomy... bad at math

The slope should be the same regardless of the order you put the points into the forumla. Think about it this way: You have two points on a line. They are (x1,y1) , (x2,y2). Now: m = (y2-y1)/(x2-x1) Multiply both sides of the equation by 1. On the left hand side we just write "1" but on th...
by Birk
Sat Jul 14, 2012 2:15 pm UTC
Forum: Science
Topic: first radiation constant as 3/8th?
Replies: 5
Views: 2109

Re: first radiation constant as 3/8th?

What if thread was lock?
by Birk
Thu Jul 12, 2012 11:41 pm UTC
Forum: Mathematics
Topic: Want to study astronomy... bad at math
Replies: 117
Views: 31477

Re: Want to study astronomy... bad at math

Sure, computer programming is a good example. Linear Algebra is used all the time in fields like image processing. The application to physics is not that esoteric either. Perhaps there is some confusion about what a vector is? A vector is an object which carries information about both direction and ...
by Birk
Thu Jul 12, 2012 11:26 pm UTC
Forum: Science
Topic: Extracting energy from a black hole with a laser.
Replies: 5
Views: 1743

Re: Extracting energy from a black hole with a laser.

You might be able to steal some energy from it's spin, by slowing that down. Not sure if you could do much with that energy though. Or if you could do it without using another large mass in the process. There are mechanisms that allow the extraction of spin energy, for instance the Blandford-Znajek...
by Birk
Thu Jul 12, 2012 7:32 pm UTC
Forum: Mathematics
Topic: Want to study astronomy... bad at math
Replies: 117
Views: 31477

Re: Want to study astronomy... bad at math

Right! So now here's some extra credit: Can you apply this to something physical or practical? Don't over think this. Just try to make a jump from abstraction to application.
by Birk
Sun Jul 08, 2012 5:55 pm UTC
Forum: Science
Topic: Question about mass and stars
Replies: 16
Views: 4171

Re: Question about mass and stars

Oh sure that's a great clarification. I was just trying to avoid getting into a lot of the details and I ended up with poor wording. Thanks!
by Birk
Sun Jul 08, 2012 5:15 pm UTC
Forum: Science
Topic: Question about mass and stars
Replies: 16
Views: 4171

Re: Question about mass and stars

Thanks, they do look pricey but an offiial textbook might be worth it, there is only so much you can get from pop science. Pop science books are wonderful for inspiring people to think about these things and thats important! But I think you should start to move on to proper texts if this is what yo...
by Birk
Sun Jul 08, 2012 4:17 am UTC
Forum: Mathematics
Topic: Want to study astronomy... bad at math
Replies: 117
Views: 31477

Re: Want to study astronomy... bad at math

I would actually say you could begin to learn the basics of trig alongside algebra. But really every concept you pick up in basic algebra I would consider key and important. I've seen plenty of kids struggle in Calculus II or III simply because they never developed a strong algebra/trig background.
by Birk
Sun Jul 08, 2012 3:46 am UTC
Forum: Science
Topic: Question about mass and stars
Replies: 16
Views: 4171

Re: Question about mass and stars

I really wish I knew of a nice 1st year undergrad astronomy text that isn't 100 bucks. I think it would help you a great deal. Usually we assign something like: http://www.amazon.com/Universe-Roger-Freedman/dp/142923153X/ref=sr_1_9?ie=UTF8&qid=1341718944&sr=8-9&keywords=the+universe for ...
by Birk
Sun Jul 08, 2012 3:38 am UTC
Forum: Mathematics
Topic: Want to study astronomy... bad at math
Replies: 117
Views: 31477

Re: Want to study astronomy... bad at math

Wait until you start getting into maths that have much more interesting applications in physics like calculus and differential equations. I think that's when things really begin to shine and it only gets better from there.
by Birk
Sun Jul 08, 2012 3:05 am UTC
Forum: Science
Topic: Question about mass and stars
Replies: 16
Views: 4171

Re: Question about mass and stars

The elements that are the result of fusion are heavier because they have a nucleus with more protons/neutrons. For instance, helium has two protons and two neutrons whereas hydrogen has just 1 proton. Therefore a helium atom is heavier than a hydrogen atom. However, a star like our sun fuses hydroge...
by Birk
Sun Jul 08, 2012 2:57 am UTC
Forum: Mathematics
Topic: Want to study astronomy... bad at math
Replies: 117
Views: 31477

Re: Want to study astronomy... bad at math

Yup! There is nothing better than learning things by screwing up. It makes you very aware of that mistake and you always keep an eye out for it until you erase it completely. Working through things yourself with the proper amount of handholding is a great way to reenforce concepts. I'm happy you see...
by Birk
Sat Jul 07, 2012 3:39 am UTC
Forum: Mathematics
Topic: Want to study astronomy... bad at math
Replies: 117
Views: 31477

Re: Want to study astronomy... bad at math

Anyway, I was bored at work so I started making up my own formulas, no laughing (unless it's with me :P ). I couldn't remember what the speed of light was, but I knew the average Earth-Sun distance was 93 million miles and it takes sunlight 8 minutes to get here. So if d is the distance and t is th...
by Birk
Fri Jul 06, 2012 3:25 am UTC
Forum: Mathematics
Topic: Can you have matricies inside of matricies?
Replies: 11
Views: 4419

Re: Can you have matricies inside of matricies?

Absolutely. Here's one example:

http://en.wikipedia.org/wiki/Block_matrix
by Birk
Thu Jul 05, 2012 9:48 pm UTC
Forum: Mathematics
Topic: Want to study astronomy... bad at math
Replies: 117
Views: 31477

Re: Want to study astronomy... bad at math

BryanRabbit wrote:Or maybe it's because I'm older


As someone who is also a returning astronomy student I can tell you that you should never doubt the power of maturity. Oh, also wanting to escape a job you hate isn't a bad motivator either. :D
by Birk
Wed Jul 04, 2012 7:36 pm UTC
Forum: Science
Topic: Higgs and Mass
Replies: 20
Views: 6442

Re: Higgs and Mass

Sorry if you already saw this but is this what you are asking about?

http://en.wikipedia.org/wiki/Higgs_mech ... r_fermions
by Birk
Wed Jul 04, 2012 7:36 am UTC
Forum: Mathematics
Topic: Want to study astronomy... bad at math
Replies: 117
Views: 31477

Re: Want to study astronomy... bad at math

Also if I can offer a word of encouragement: The quantum you are exposed to in popular science and the quantum you deal with in practice are vastly different. In popular books quantum is portrayed as this incredible mystery that no one really understand where everything is dominated by strange pheno...
by Birk
Tue Jul 03, 2012 6:27 pm UTC
Forum: Mathematics
Topic: Want to study astronomy... bad at math
Replies: 117
Views: 31477

Re: Want to study astronomy... bad at math

I think we should also mention the importance of quantum and statistical mechanics are essential as they form the basis of radiative transfer which is the study of the absorption, emission, scattering, etc. of light by physical processes. Since you almost always observing light of some form (radio, ...
by Birk
Mon Jul 02, 2012 4:19 am UTC
Forum: Mathematics
Topic: Want to study astronomy... bad at math
Replies: 117
Views: 31477

Re: Want to study astronomy... bad at math

- 58(x^9)(w^7)(x) / 23(x)(w^2)(w^6) = - 58(x^9) / 23w 24(x^4)(w^10)(x^6) / -91(x^7)(w^7)(w^9) = -24(x^3) / 91(w^6) I get what happened to the variables, but how come, in the first example the real numbers (correct my terminology please) stay as they are, but in the second the positives and negative...
by Birk
Sat Jun 30, 2012 3:21 am UTC
Forum: Mathematics
Topic: Want to study astronomy... bad at math
Replies: 117
Views: 31477

Re: Want to study astronomy... bad at math

Ah, great! I'm so glad you started asking questions. :D Best way to learn in my opinion. I would like to add that you should really try and take a lot away from your first question and dopefish's response. The ability to turn a physical scenario into equations (and going the other way of course) is ...
by Birk
Tue Jun 26, 2012 3:26 am UTC
Forum: Mathematics
Topic: Want to study astronomy... bad at math
Replies: 117
Views: 31477

Re: Want to study astronomy... bad at math

You should use this thread as your tutor. Post problems you're working on, the steps you're taking, and where you're getting confused. I'm sure there's plenty of people (myself included) who would be more than happy to help you through it.
by Birk
Mon Jun 04, 2012 1:59 am UTC
Forum: Science
Topic: I want to learn (the basics of) quantum! Help?
Replies: 6
Views: 3336

Re: I want to learn (the basics of) quantum! Help?

Unfortunately, those are still fairly expensive books. You might have a hard time finding a good modern book that covers QM at the level you want that isn't almost 100 dollars. Perhaps try Quantum Theory by Bohm. It is part of the Dover series and should be ~10 bucks. It was written in the 50s so it...
by Birk
Thu May 24, 2012 12:56 am UTC
Forum: School
Topic: Your Schedule
Replies: 655
Views: 164967

Re: Your Schedule

Senior Year Astronomy/Physics Double and Math Minor Galaxies - Dynamics, structure, formation, and all that good stuff. PDEs - Need 3 credits to finish my minor and I wanted one more class with this professor before I left. Senior Thesis Research - Not sure of an exact topic yet. Most likely to do w...
by Birk
Thu May 24, 2012 12:44 am UTC
Forum: Mathematics
Topic: After calculus
Replies: 20
Views: 4792

Re: After calculus

If you are thinking about going into physics it might not hurt to develop a working knowledge of tensors. Learn what they are, how to do basic calculations with them, how to write familiar computations using tensor notation, etc. etc. It only occurred to me because some people were talking about E&a...
by Birk
Sat Sep 10, 2011 7:04 pm UTC
Forum: Mathematics
Topic: Vectors and Index/Summation Notation Question.
Replies: 0
Views: 854

Vectors and Index/Summation Notation Question.

Hi, This is homework for a mathematical methods course however I have already worked out a solution and written up my answers so this thread is more an issue of curiosity than anything. The question is: Consider a crystal whose unit cell has basis vectors \vec{e_1},\vec{e_2},\vec{e_3} that are not n...
by Birk
Fri Sep 24, 2010 11:10 am UTC
Forum: Mathematics
Topic: Symbolic Issues With Matlab
Replies: 1
Views: 619

Symbolic Issues With Matlab

Hi all, I am currently working on a homework question dealing with using Matlab to solve ODEs symbolically. The problem is that the book we have to use was written for Matlab 7 when Maple was still in use. I think that MuPAD in Matlab 2009a is now giving me issues. The original differential equation...
by Birk
Tue Jul 20, 2010 8:14 pm UTC
Forum: Mathematics
Topic: Homework: Complex Analysis [An Ongoing Adventure]
Replies: 9
Views: 1799

Re: Homework: Complex Analysis [An Ongoing Adventure]

That make any sense? Yeah, for the most part. Given the quicker pace of the class I kinda have to move on for now and I will revisit these problems over the weekend. Thanks for taking the time to type all of that out. Sorry my original sketch was so incoherent I was trying to slip a quick edit into...
by Birk
Mon Jul 19, 2010 9:58 pm UTC
Forum: Mathematics
Topic: Homework: Complex Analysis [An Ongoing Adventure]
Replies: 9
Views: 1799

Re: Homework: Complex Analysis [An Ongoing Adventure]

Yes, I understand exactly why what I wrote was wrong. I think its because I originally had planned to just type out a rough sentence description or sketch of how I was thinking about things and then it came out as some mangled half-proof. In the future I'll try to be more clear in my intent. We had ...
by Birk
Fri Jul 16, 2010 3:28 am UTC
Forum: Mathematics
Topic: Homework: Complex Analysis [An Ongoing Adventure]
Replies: 9
Views: 1799

Re: Homework: Complex Analysis [An Ongoing Adventure]

Ah that makes sense. I need to be better about that.

Would that be considered sufficient or is it still merely a sketch of a proof?
by Birk
Fri Jul 16, 2010 2:07 am UTC
Forum: Mathematics
Topic: Homework: Complex Analysis [An Ongoing Adventure]
Replies: 9
Views: 1799

Re: Homework: Very Basic Complex Analysis

I'm sorry to have left this thread hanging. Thanks for the link to the half-angle formulas, they did the trick. One week in and this class has been an interesting crash course in basic proof writing. We are doing planar sets and I understand all of the definitions but sometimes I have trouble puttin...
by Birk
Wed Jul 14, 2010 1:00 am UTC
Forum: Mathematics
Topic: Homework: Complex Analysis [An Ongoing Adventure]
Replies: 9
Views: 1799

Homework: Complex Analysis [An Ongoing Adventure]

Hey gang, Need a little bump in the right direction with this problem. As stated in the book: Prove that if n is a positive integer, then \left|\frac{sin\left(\frac{n\theta}{2}\right)}{sin\left(\frac{\theta}{2}\right)} \right | \le n , \left \{ \theta \ne 0 \pm 2k\pi \right \} Hint: ...
by Birk
Sat Jul 03, 2010 12:35 pm UTC
Forum: Mathematics
Topic: Application of differentiation question.
Replies: 2
Views: 1102

Re: Application of differentiation question.

Take the formula for the volume of a cylinder as one equation, then take the given constraint as another equation and then you have all the information you need.

(i) [imath]V=\pi r^2h[/imath]
(ii) [imath]h + 2 \pi r = 120[/imath]

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