## Search found 154 matches

Wed Apr 23, 2008 9:12 pm UTC
Forum: Science
Topic: Direct observation of genetic evolution
Replies: 33
Views: 3818

### Direct observation of genetic evolution

http://news.nationalgeographic.com/news/2008/04/080421-lizard-evolution.html Finally, living proof that tosses hardline creationism out the window. Even for those who still believe in a creator, this simply exemplifies how dynamic and extraordinarily beautiful life really is. I find their hesitation...
Thu Apr 10, 2008 4:14 pm UTC
Forum: Coding
Topic: BigInt class
Replies: 14
Views: 2771

### Re: BigInt class

Here is one of my bitint libs: http://cpp.criticaldamage.com/index.php/Big_Integer_Library_for_ETG_crypto_channel The library is self-contained ISO C++ code, and the code size is extremely small. Should hold you over until you find something more memory efficient / robust / faster. Feel free to use ...
Thu Apr 10, 2008 1:35 am UTC
Forum: Science
Topic: General Relativity
Replies: 23
Views: 3225

### Re: General Relativity

Oh, by that standard, we don't have physics that we know solves your problem. Nobody has figured out how to make QM and General Relativity consistent with each other in every case. You can get them to produce predictions that match our precision of measurement in many cases, but the same is true of...
Wed Apr 09, 2008 9:53 pm UTC
Forum: Science
Topic: General Relativity
Replies: 23
Views: 3225

### Re: General Relativity

I still say that, while the 4-momentum is important in GR, it comes from SR, so it's not quite right to say that you'd be using "an equation from general relativity" to solve the problem. It's like saying that you're using "an idea from quantum mechanics" when you're doing somet...
Wed Apr 09, 2008 9:42 pm UTC
Forum: Science
Topic: General Relativity
Replies: 23
Views: 3225

### Re: General Relativity

Sure, the concept of the 4-momentum vector was introduced to clarify the meaning of Special Relativity, but it also plays an incredibly crucial role in General Relativity. The source of gravitation is a 4x4 matrix (2nd rank tensor), where the top row and leftmost column just happen to be this very s...
Thu Apr 03, 2008 7:40 pm UTC
Forum: Science
Topic: How can I make my room more humid?
Replies: 10
Views: 6183

### Re: How can I make my room more humid?

Fill a metal soup can with water... place it on or near the heating elements (ex: the air vents) in the room so that it evaporates quickly. My dad does this to start off his tomato plants in the late winter, and they grow surprisingly well. So... obviously it's doing something.
Mon Mar 31, 2008 11:33 pm UTC
Forum: Coding
Topic: 3D Graphics
Replies: 15
Views: 4316

### Re: 3D Graphics

If you want to start from scratch-ish, you should try your hand at writing a simple raytracer/rasterizer in GLSL (OpenGL) or HLSL (Direct3D). You still have to do all the camera-related projection work, etc. The only thing the API will really do for you is handle memory transfer from the CPU to GPU ...
Mon Mar 31, 2008 7:28 am UTC
Forum: Science
Topic: calculating orbit time and rotation time based on distance
Replies: 11
Views: 1765

### Re: calculating orbit time and rotation time based on distance

Look for the posts by taby in the following URLs. It shows how to calculate the initial velocity for either a circular or elliptical orbit. If you have further questions, please feel free to ask. I am just too lazy to repeat all of this here: http://www.gamedev.net/community/forums/topic.asp?topic_i...
Sun Mar 30, 2008 4:55 am UTC
Forum: Science
Topic: "Quant Software" - anyone worked on stock trading software?
Replies: 5
Views: 1426

### Re: "Quant Software" - anyone worked on stock trading software?

I was using Neural Networks in an attempt to create a solver for the Navier-Stokes equations. My work wasn't very successful, because it wasn't any faster than direct solutions like Stam's, and it was susceptible to instabilities. It was fun though, and I got to learn the basics of calculus in the p...
Sun Mar 30, 2008 2:27 am UTC
Forum: Science
Topic: "Quant Software" - anyone worked on stock trading software?
Replies: 5
Views: 1426

### Re: "Quant Software" - anyone worked on stock trading software?

I have experience with AI, but not applied to stocks (I try to avoid gambling unless absolutely necessary). Ray Kurzweil has a piece of software called FatKat that might interest you -- http://www.fatkat.com/ Have you looked into some of the more common AI algorithms, such as Neural Networks or Gene...
Fri Mar 28, 2008 2:54 pm UTC
Forum: Science
Topic: Question Re: Giant Hole Through the Earth
Replies: 87
Views: 24615

### Re: Physics 'challenge question' ceptnotrly

evilbeanfiend wrote:clearly she will travel with damped harmonic motion back and forth through the core until the drag from air resistance slows her enough to stop in the centre, she will be weightless here.

if you want non-physical answers this might not be the right forum

Stole the words right out of my mouth.
Fri Mar 28, 2008 2:48 pm UTC
Forum: Science
Topic: Science is broken and we need to fix it.
Replies: 28
Views: 3171

### Re: Science is broken and we need to fix it.

arxiv.org is "not actually that good"... In what way? Not good compared to nothing? It is not good to my idea of perfect world, of course. :) The fact that you've "just" looked at arxiv.org now infers that you are a 1st year student. Everyone knows about it, even crackpots like ...
Fri Mar 28, 2008 2:02 pm UTC
Forum: Science
Topic: Science is broken and we need to fix it.
Replies: 28
Views: 3171

### Re: Science is broken and we need to fix it.

@SpitValve I've just looked at arxiv.org and it's.. uhhh... not actually that good. And it is really quite a pain to use our university library. It is a very slow process. And I think I should be able to do my science where I want to do it, for example at home. arxiv.org is "not actually that ...
Fri Mar 28, 2008 12:51 pm UTC
Forum: Science
Topic: Science is broken and we need to fix it.
Replies: 28
Views: 3171

### Re: Science is broken and we need to fix it.

David Morgan-Mar (I know you know him) wrote in his blog http://dmmaus.livejournal.com/361283.html : The problem is, most of the stuff you find, you can only read the article titles and (sometimes) the abstracts. In order to read the actual research papers you need to either subscribe to some publi...
Wed Mar 26, 2008 4:11 pm UTC
Forum: Science
Topic: Must-own textbooks for physics reference library...?
Replies: 17
Views: 2229

### Re: Must-own textbooks for physics reference library...?

Schutz' book is a good intro to GR. Of course, Misner, Thorne, and Wheeler may be the standard "reference" book on GR. It's tough to learn from, though. Probably ridiculously expensive, too. That's all I got. Asad I have the Schutz and MTW books too. Great reads. Schutz definitely should ...
Wed Mar 26, 2008 4:06 pm UTC
Forum: Science
Topic: Question re: wavelngth
Replies: 37
Views: 3182

### Re: Question re: wavelngth

Is there a theoretical limit to how short the wavelength of electromagnetic radiation can be? As we're talking theoretical, assume unlimited power and technology. If there is a limit, what would it be? The emission of photons of various wavelengths by a blackbody is an inherently probabilistic proc...
Thu Mar 20, 2008 4:43 pm UTC
Forum: Coding
Topic: Sorting a 2D Array
Replies: 18
Views: 2423

### Re: Sorting a 2D Array

If your value range is known (ex: values are 0 to 499), is small (ex: not 0 to 4 billion), and is of integer type (ex: not floats) then you could use a "count sort" method. It's blazingly fast, but requires a lot of scratch memory. Realistically, it could blow quicksort out of the water be...
Thu Mar 20, 2008 4:27 pm UTC
Forum: Science
Topic: Intetesting thought experiment
Replies: 18
Views: 1947

### Re: Intetesting thought experiment

skeptical scientist wrote:Wait, what? We've discovered the graviton?

... meanie
Thu Mar 20, 2008 3:33 pm UTC
Forum: Science
Topic: Ripping apart black holes
Replies: 11
Views: 1731

### Re: Ripping apart black holes

It was mentioned by another person that if the larger black holes are spinning, then energy could be extracted from them by simply "soaking up" angular momentum from the gravitational field (ex: the dragging of inertial frames due to off-diagonal metric components). However, I don't know i...
Wed Mar 19, 2008 10:53 pm UTC
Forum: Science
Topic: Intetesting thought experiment
Replies: 18
Views: 1947

### Re: Intetesting thought experiment

Replace all instances of the word photon with graviton.
Wed Mar 19, 2008 9:52 pm UTC
Forum: Science
Topic: A question for Physics experts.
Replies: 23
Views: 3644

### Re: A question for Physics experts.

Unfortunately the accepted convention has become that mass is the same as rest mass, and relativistic mass isn't really mass. (My understanding is that even when Feynman wrote those lectures in the 60s, he was in the minority.) But you'll still have a clearer understanding of some aspects of relati...
Tue Mar 18, 2008 8:11 pm UTC
Forum: Science
Topic: Ripping apart black holes
Replies: 11
Views: 1731

### Re: Ripping apart black holes

I've gotten an answer regarding this from someone who holds a PhD in physics (I certainly do not): 'I don't think this could happen classically, but I would certainly expect it to happen via Hawking radiation.' So you are correct to assume that classically (ex: a true singularity), the transfer woul...
Mon Mar 17, 2008 9:19 pm UTC
Forum: Science
Topic: Ripping apart black holes
Replies: 11
Views: 1731

### Re: Ripping apart black holes

If the steepness of gradient in terms of gravitational time dilation generated by the two large black holes is found to be strong enough to overcome the attractive bonds inside the passing black hole, then it's out of luck. Hmmm... I don't think there are any "attractive bonds" inside a b...
Sat Mar 15, 2008 6:16 am UTC
Forum: Science
Topic: Ripping apart black holes
Replies: 11
Views: 1731

### Re: Ripping apart black holes

If the steepness of gradient in terms of gravitational time dilation generated by the two large black holes is found to be strong enough to overcome the attractive bonds inside the passing black hole, then it's out of luck. Tidal forces would shred it to bits. If lucky, only part of the passing blac...
Sat Mar 15, 2008 4:27 am UTC
Forum: Science
Topic: A question for Physics experts.
Replies: 23
Views: 3644

### Re: A question for Physics experts.

Anton unless there is something new in that thread I have not read (not got the time now) what they're talking about has nothing to do with relativistic mass and Lorentz Transformation. It has lots to do with relativistic mass and everything to do with gravitational attraction. A moving object appe...
Fri Mar 14, 2008 7:09 pm UTC
Forum: Science
Topic: A question for Physics experts.
Replies: 23
Views: 3644

### Re: A question for Physics experts.

Anton unless there is something new in that thread I have not read (not got the time now) what they're talking about has nothing to do with relativistic mass and Lorentz Transformation. It has lots to do with relativistic mass and everything to do with gravitational attraction. A moving object appe...
Fri Mar 14, 2008 1:55 pm UTC
Forum: Science
Topic: Dark Energy Fraud
Replies: 21
Views: 2366

### Re: Dark Energy Fraud

SpitValve wrote:

Actually, "fundament" is a word. It doesn't mean what he thinks it does though. He just told us that he's studying the buttocks of gyroscopes.

ROFLMAO.
Thu Mar 13, 2008 11:48 pm UTC
Forum: Science
Topic: The Most Sciencey-Sounding Word/Phrase You've Heard
Replies: 176
Views: 34725

### Re: The Most Sciencey-Sounding Word You've Heard

Transuranic Bolide Biomimetic Perhaps not the most sciencey, but they're definitely personal favorites. There's something about certain words, you know? Like "beverage," for instance; it just has a certain je ne se qua. Cheers, --joe. "Je ne sais quoi". ;) Re: The word 'beverage...
Thu Mar 13, 2008 11:24 pm UTC
Forum: Science
Topic: Dark Energy Fraud
Replies: 21
Views: 2366

### Re: Dark Energy Fraud

Ok here was the guys response. I am very sorry but I do not look too much into dark energy maybe you mean zero point energy which is the average energy of particles at absolute zero. Viscocity is the resistance to flowing though it might have something to do with the diffusion of momentum since the...
Thu Mar 13, 2008 7:57 pm UTC
Forum: Science
Topic: Dark Energy Fraud
Replies: 21
Views: 2366

### Re: Dark Energy Fraud

I really don't know what to say. For anyone who's studied fluid dynamics, it's intuitive that viscosity is equivalent to the diffusion of momentum. If you throw a ball into a pot of honey, the momentum is transferred from the ball to the honey in a practically isotropic manner (isotropic because the...
Thu Mar 13, 2008 3:59 pm UTC
Forum: Science
Topic: Dark Energy Fraud
Replies: 21
Views: 2366

### Re: Dark Energy Fraud

Super secret edit.
Wed Mar 12, 2008 7:50 pm UTC
Forum: Science
Topic: The case for upper case K for Kilo
Replies: 42
Views: 5994

### Re: The case for upper case K for Kilo

SpitValve wrote:
Token wrote:Personally, I write x10-3 kg.

That's what I'd use, except astronomers are keen on cgs for some silly reason. ooh, we're playing with giant objects, so let's use tiny units like centimetres and grams!

I thought I was the only one who thought this was a bit odd!
Wed Mar 12, 2008 7:46 pm UTC
Forum: Science
Topic: The Most Sciencey-Sounding Word/Phrase You've Heard
Replies: 176
Views: 34725

### Re: The Most Sciencey-Sounding Word You've Heard

Phenomenology

Usually spoken to the cadence of the Muppet Show song (mena mena... duh duh duh duh duh... mena mena... duh duh duh duh)
Wed Feb 27, 2008 5:31 pm UTC
Forum: Science
Topic: BEHOLD Phun (2d Physics sandbox)
Replies: 12
Views: 3972

### Re: BEHOLD Phun (2d Physics sandbox)

Gamedev.net has a screenshot of the day on their main page that displays all kinds of projects (mind you, not all are of the calibre of Phun).
Wed Feb 06, 2008 9:44 pm UTC
Forum: Coding
Topic: Pair Programming Survey
Replies: 16
Views: 2687

### Re: Pair Programming Survey

Considering that a LOT of the hard core coders that I know of have bad body odour, I'm going to stick to lone programming for now.
Wed Feb 06, 2008 5:15 am UTC
Forum: Coding
Topic: Batch/CMD vs VBScript (Formerly: Delay a script in Windows)
Replies: 10
Views: 4699

### Re: Delay the running of a script in windows

How about a basic build system? I've put together build systems for two of my company's products using CMD-script, so this is my main perspective in this area. There are scripts that do different build-related things, like getting code from source control, updating some version number files in sour...
Tue Feb 05, 2008 9:06 pm UTC
Forum: Coding
Topic: Batch/CMD vs VBScript (Formerly: Delay a script in Windows)
Replies: 10
Views: 4699

### Re: Delay the running of a script in windows

The WMI provider object is indeed required to run processes, but this is built into the operating system, so it's available out of the box. The key difference is that with WMI, you can also do things like start processes on remote computers using alternative credentials. The WMI provider also gives ...
Tue Feb 05, 2008 7:06 pm UTC
Forum: Coding
Topic: Batch/CMD vs VBScript (Formerly: Delay a script in Windows)
Replies: 10
Views: 4699

### Re: Delay the running of a script in windows

This may also work: http://www.computerhope.com/batch.htm#4 TYPE NUL | CHOICE.COM /N /CY /TY,5 >NUL Have you considered making the jump from batch to VBScript? The benefits are uncountable, including the ability to get the Time(). Plus, it's available with any Windows that has cscript.exe... I think...
Sun Feb 03, 2008 4:06 pm UTC
Forum: Science
Topic: Dark Matter? Or is it time slowing down?
Replies: 8
Views: 1644

### Re: Dark Matter? Or is it time slowing down?

Well, you also can't ignore the impact that dark matter has on cosmic evolution, even though it typically gets lumped in with baryonic matter. :P I completely agree. The big difference of course is that dark energy is repulsive, and dark matter is attractive. Also, Hannes Alfven was a big proponent...
Fri Feb 01, 2008 4:26 pm UTC
Forum: Computer Science
Topic: Combinations and Permutations
Replies: 9
Views: 3423

### Re: Combinations and Permutations

If you're using C++, permutations are built into the standard template library:
http://marknelson.us/2002/03/01/next-permutation/