## Search found 235 matches

Sun Apr 10, 2011 7:13 am UTC
Forum: Science
Topic: inertia and gravity
Replies: 9
Views: 2439

### Re: inertia and gravity

I think the concept you are thinking about is kind of similar to the concept in Brans-Dicke scalar-tensor gravitational theory. In essence, in their theory, the presence of matter actually modifies the gravitational constant, and thereby modifies the geodesics or inertial paths followed by objects d...
Fri Apr 16, 2010 4:21 am UTC
Forum: Forum Games
Topic: Count by adding all your posts (aim for one million!)
Replies: 33
Views: 4551

### Re: Count by adding all your posts (aim for one million!)

42375+233=42608
Fri Apr 16, 2010 4:17 am UTC
Forum: Forum Games
Topic: Can you produce [X] in less than 15 seconds?
Replies: 7725
Views: 761338

### Re: Can you produce [X] in less than 15 seconds?

nope, it'd probably take more than 15 seconds to get several of my neighbors to come outside...

A Texas Instruments calculator?
Fri Apr 16, 2010 3:59 am UTC
Forum: Science
Topic: Gyroscopes
Replies: 14
Views: 2671

### Re: Gyroscopes

Makes me want to have Gyroscopes. I want Gyroscopes. What's the physics about gyroscopes? Rot Inertia converted to upward force? Is that it? The real short form is that they have a lot of angular momentum. Because there needs to be a torque to change the angular momentum of a system, the gyroscope ...
Thu Apr 15, 2010 2:06 am UTC
Forum: Science
Topic: just came up with something quickly
Replies: 6
Views: 1494

### Re: just came up with something quickly

The wave-nature of particles has nothing to do with the path of propagation. In fact, in standard QM, there is no real "path". A real particle trajectory really only comes in from the de-Broglie-Bohm formulation (or other pilot wave formulations) of QM I believe... It's not like an electro...
Thu Apr 15, 2010 2:02 am UTC
Forum: Science
Topic: Assumptions that the Scientific Method makes?
Replies: 45
Views: 5619

### Re: Assumptions that the Scientific Method makes?

Your first assumption is actually testable, so its not an assumption. Noether's theorem says that energy and momentum are only conserved if the laws of physics are time and space invariant. It is only "testable" locally, as we cannot guarantee that the laws of physics apply for all region...
Wed Apr 14, 2010 9:41 pm UTC
Forum: Science
Topic: About the speed of light
Replies: 17
Views: 2011

### Re: About the speed of light

"Perfectly rigid" usually means that all points in the object move simultaneously and with the same velocity and is only an approximation that is useful to use in many circumstances because with a rigid body one only has to deal with 1 velocity and 1 position really. In the real world, &qu...
Wed Apr 14, 2010 9:11 pm UTC
Forum: Science
Topic: About the speed of light
Replies: 17
Views: 2011

### Re: About the speed of light

And it won't. The energy that moves the see-saw will propagate along the see-saw at the speed of light through that material. I don't think it would propagate at the speed of light...probably more like at the speed at which a transverse wave should travel down this sea-saw which is possibly the spe...
Sat Apr 10, 2010 5:03 am UTC
Forum: Science
Topic: Is it possible to coordinate the color of your poop?
Replies: 22
Views: 2925

### Re: Is it possible to coordinate the color of your poop?

"why the hell would you want rainbow colored poo?" Probably an attempt to live out this meme Huh, I've never heard of that meme before. Actually, I'm just trying to come up with ideas for my school's science fair. Some of them are even weirder than this one. Also, I want to see how the ju...
Sat Apr 10, 2010 4:32 am UTC
Forum: Mathematics
Topic: PhD Woooooooooo
Replies: 23
Views: 3817

### Re: PhD Woooooooooo

Did you also manage to incorporate: "phase 2: ???????"
Sat Apr 10, 2010 4:29 am UTC
Forum: Science
Topic: Are cancer cells edible?
Replies: 29
Views: 4873

### Re: Are cancer cells edible?

I think if you created a company that sold cancer meat...your company would fail...no matter whether cancer cells are edible or not.
Sun Feb 21, 2010 9:13 am UTC
Forum: Science
Topic: Pick a number between 1 and 100
Replies: 74
Views: 7583

### Re: Pick a number between 1 and 100

13

I found this number as the 10388th and 10389th digit of [imath]\pi[/imath]
Sun Feb 14, 2010 11:57 pm UTC
Forum: Science
Topic: Batman Grappling Gun
Replies: 41
Views: 5116

### Re: Batman Grappling Gun

Ok, seems fair enough. Just, when you're hanging 50-100 feet above the ground, perhaps you want something more than your one handed grip to keep you from falling to your death. (And, yes You can do more than 1 hand, but 1 handed is obviously so much cooler...)
Sun Feb 14, 2010 11:38 pm UTC
Forum: Science
Topic: Batman Grappling Gun
Replies: 41
Views: 5116

### Re: Batman Grappling Gun

Another point to consider is that...is the human grip, for a well trained man, strong enough to grip onto this device one handed while it pulled him up (like Batman does it most of the time)?
Fri Feb 12, 2010 6:12 am UTC
Forum: Science
Topic: Flux
Replies: 18
Views: 1416

### Re: Flux

Birk wrote:Instead of \bold just use \vec. Also use \cdot.

It doesn't seem to like bold.
$\Phi=\int_{S} \vec{E} \cdot d\vec{A}$

Alright thanks!

Hmm, it seems weird now cus when I'm not logged in, I can see the latex, but when I log in I can't...
Fri Feb 12, 2010 1:38 am UTC
Forum: Science
Topic: Flux
Replies: 18
Views: 1416

### Re: Flux

Is Latex not working or something? Or am I doing something wrong? >_>
Fri Feb 12, 2010 1:33 am UTC
Forum: Science
Topic: Flux
Replies: 18
Views: 1416

### Re: Flux

The flux:
$\Phi=\int_{S} \bold{E} \dot d\bold{A}$

If the professor meant that this integral is difficult to evaluate except under the most symmetric of cases (spheres, long cylinders, infinite planes, etc), he is correct. The concept itself, whether it's complicated or not, is debatable.
Thu Jul 23, 2009 10:34 am UTC
Forum: Science
Topic: Please help, physics geniuses (question about drag)
Replies: 3
Views: 833

### Re: Please help, physics geniuses (question about drag)

You, sir, name? has given a pretty good explanation. I'd just like to add that most of the time, we only consider drag to be proportional to the velocity, i.e. F drag =-bv for some constant b. Only in higher velocities will drag become proportional to v 2 or higher orders of v. In general, the probl...
Sat Jul 18, 2009 2:48 pm UTC
Forum: Science
Topic: Life expectancy of scientists
Replies: 32
Views: 5854

### Re: Life expectancy of scientists

How can we know if a death is statistically less painful? Like, ask people who are dieing on a scale of 1 to 10 how painful it is? o.O

Don't be a Mathematician...Galois died at 20 from being shot! D=
Wed May 27, 2009 12:40 am UTC
Forum: Coding
Topic: Fortran 77
Replies: 45
Views: 7968

### Re: Fortran 77

Hey guys, yea I'm still working on this, I've just been busy the last 2 weeks with midterms and the GMAT. I tried the ffixed-line-length-0 and it reduced the errors down to 1!!! This is the 1 last error still present after I use -ffixed-line-length-0 (I don't really get what this option does, can so...
Thu May 21, 2009 5:21 am UTC
Forum: Science
Topic: Have you ever wished a particular theory didn't work?
Replies: 59
Views: 5951

### Re: Have you ever wished a particular theory didn't work?

I don't think there is a way to "prove" a non-deterministic, or random universe, because you can always say there's a higher method that we don't know about that is in fact deterministic, but behaves random to us...or something like that.
Wed May 13, 2009 4:16 am UTC
Forum: Science
Topic: Universal Time is Wrong!
Replies: 41
Views: 4023

### Re: Universal Time is Wrong!

I think the OP was making fun of the name "universal time"... rather than suggesting we define a time relative to the Virgo supercluster.

o.O
Fri May 08, 2009 8:06 am UTC
Forum: Coding
Topic: Fortran 77
Replies: 45
Views: 7968

### Re: Fortran 77

yea, I've been trying to find g77, but when i do sudo apt-get install g77 it tells me that g77 is archaic or some such. It's been replaced by gfortran I think... I've been unable to find a place to download g77, everywhere that mentions it tells me to go to GCC to find it...o.O I tried deleting behi...
Fri May 08, 2009 4:16 am UTC
Forum: Coding
Topic: Fortran 77
Replies: 45
Views: 7968

### Re: Fortran 77

Ok, I will go check, but from what I gather, the column indicated is not actually the end of the line. It's like 4 or 5 characters before. (Actually 1 error is like 10 characters after the line ended...o.O) I'll go look and get back to this XD Edit: You know what? I found that the errors occured on ...
Fri May 08, 2009 3:49 am UTC
Forum: The Help Desk
Topic: My Machine architecture?
Replies: 7
Views: 796

### Re: My Machine architecture?

32 bit

EDIT: I gave up on installing this lol...too hard for me...

forget about it.
Fri May 08, 2009 3:43 am UTC
Forum: The Help Desk
Topic: My Machine architecture?
Replies: 7
Views: 796

### Re: My Machine architecture?

I have Intel core 2 duo, and currently using Ubuntu-9.04
Fri May 08, 2009 3:41 am UTC
Forum: Coding
Topic: Fortran 77
Replies: 45
Views: 7968

### Re: Fortran 77

*cries* I tried, but it gave me the same errors... Mars2.f:152.72: X = 4.1854E7*INERTIA*SQRT(OMEGA)*(1.+0.5*BETA)/(EMISS*SIGMA*T0** 1 Error: Expected exponent in expression at (1) Mars2.f:179.72: WRITE (3,FMT='(I6,8(2H &,I4),3H \\\\)') MJD,ITBRITE 1 Error: Unexpected element in format string at ...
Fri May 08, 2009 2:38 am UTC
Forum: The Help Desk
Topic: My Machine architecture?
Replies: 7
Views: 796

### My Machine architecture?

So, I'm trying to initialize a program (which opens and edits .fits files) and the installation tells me to: Edit your $HOME/.login to include lines based on the following: HEADAS=/path/to/your/installed/heasoft-6.6.2/<PLATFORM> export HEADAS alias heainit=".$HEADAS/headas-init.sh" From t...
Thu May 07, 2009 6:17 pm UTC
Forum: Coding
Topic: Fortran 77
Replies: 45
Views: 7968

### Re: Fortran 77

Where the errors are located (the 136.65 or whatever) that the compiler is giving me don't correspond to the continuation characters. They are often in way later columns like column 70 or column 50 something. In those columns are just usually symbols that are used all over the place that it didn't f...
Thu May 07, 2009 9:05 am UTC
Forum: Coding
Topic: Fortran 77
Replies: 45
Views: 7968

### Re: Fortran 77

It calculates the surface temperature of Mars at different days in the future. It's used to calibrate flux measurements of other planets and such.
Thu May 07, 2009 6:26 am UTC
Forum: Coding
Topic: Fortran 77
Replies: 45
Views: 7968

### Re: Fortran 77

So, I guess the question is "what's a printing character"? :P Man this is confusing, my prof thought it could have been a continuation line thing, so I tried moving one of the lines up, it just gives me an new error on the new line...there's like 500 continuation lines in the code, I don't...
Thu May 07, 2009 6:12 am UTC
Forum: Coding
Topic: Fortran 77
Replies: 45
Views: 7968

### Re: Fortran 77

Ok, I have a few more question. 1) For the continuation lines, what determines what number we use? I can't see a pattern in the numbers my professor used to denote continuation lines. 2) My professor's code has the continuation lines in column 9, not 6. He also starts code on column 9. What's this m...
Wed May 06, 2009 9:33 pm UTC
Forum: Coding
Topic: Fortran 77
Replies: 45
Views: 7968

### Re: Fortran 77

Hmm, well speed doesn't really matter to me, the code is only 1500 lines. I don't think it should take that long. I will look into this ifort thing if I can't get it to work otherwise. :D Thanks. I have a question though. Does anyone still use Fortran? Is me learning this language gonna be completel...
Tue May 05, 2009 10:05 pm UTC
Forum: Coding
Topic: Fortran 77
Replies: 45
Views: 7968

### Re: Fortran 77

Update: So, I visited my professor and he fixxed one error (that the "IMPLICIT NONE" statement was not tabbed), and told me that the compiler is not picking up the "continuation lines" or some such. What is this exactly? From what he said, I gathered that these are lines that sho...
Tue May 05, 2009 1:20 am UTC
Forum: Coding
Topic: Fortran 77
Replies: 45
Views: 7968

### Re: Fortran 77

Uh sure: IMPLICIT NONE  1 Error: Non-numeric character in statement label at (1) Mars.f:1.1: IMPLICIT NONE  1 Error: Unclassifiable statement at (1) Mars.f:136.72: X = 4.1854E7*INERTIA*SQRT(OMEGA)*(1.+0.5*BETA)/(EMISS*SIGMA*T0** 1 Error: Expected exponent in expression at (1) Mars.f:163.72: WRITE (3...
Tue May 05, 2009 12:15 am UTC
Forum: Coding
Topic: Fortran 77
Replies: 45
Views: 7968

### Re: Fortran 77

Ok, I tried using gfortran to compile it, and I got about 10 syntax error messages. I'm gonna talk to him about it...
Mon May 04, 2009 7:19 am UTC
Forum: Coding
Topic: Fortran 77
Replies: 45
Views: 7968

### Re: Fortran 77

Ok, how do I open a terminal? :oops: I'm such a noob at this. EDIT: I found it, hold on if i have any more questions. Hmmm now it just seems I need to get this code into a f77 file... My prof appended the code to the end of his research paper (in the source file, after the end document line) This mi...
Mon May 04, 2009 6:52 am UTC
Forum: Coding
Topic: Fortran 77
Replies: 45
Views: 7968

### Re: Fortran 77

Ok guys, so I'm using Ubuntu right now, but I did not find a fortran compiler in the applications search, no big surprise. Uhm...how would I get GCC up and running now? I downloaded...uh...GCC 4.4 Fortran. And I extracted it. And now i can see that it's just a bunch of source files (code files? w/e ...
Mon May 04, 2009 5:16 am UTC
Forum: Coding
Topic: Fortran 77
Replies: 45
Views: 7968

### Re: Fortran 77

Hmmm, well I got Ubuntu up and running...but I don't have any of my applications (obviously), and I have no idea where to go from there lol. I'll look into what you guys posted. What's MinGW? Edit: I looked up MinGW, and I downloaded and installed it...(including the fortran and C++ compiler) but it...
Mon May 04, 2009 1:02 am UTC
Forum: Coding
Topic: Fortran 77
Replies: 45
Views: 7968

### Re: Fortran 77

Ok, I'm getting ubuntu now...I hope this works? <_<

I think the compilers for windows cost money but I haven't really looked into it.

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