Recent content by wvguy8258

It is an array of numbers. I regret ever using the term pseudo-code to describe a multi-step algorithm. It has completely sidetracked things. I have looked. This is a GIS journal where this type of work relatively rare (describing the development of a new algorithm). I have not found...

"I am writing pseudo-code for a publication, and am asked to use rigorous math notation, which is new to me." Hi, thanks for the input. I am writing pseudo-code that uses numerical vectors. I was asked to represent these numerical vectors using formal mathematical notation. Computer programs...

Preface note: the R and Z in the {}s below should be double-struck, but I couldn't figure out how to do that here. I tried the usual shortcuts to no avail. I am writing pseudo-code for a publication, and am asked to use rigorous math notation, which is new to me. I am trying to express the...

Thanks. In my case though, since the object increases its volume (and so mass) in all dimensions equally and simultaneously (not like a simple lengthening of a rod), then the force of drag does increase as mass goes up (larger surface facing air). However, the increase in mass seems to very...

Dear all, I am thinking of a simple situation: A cube is falling under the force of gravity. It is not in a vacuum, and so air resistance has an influence. However, to simplify, the air is still and the cube does not rotate, the cube has no surface texture, and other fluid dynamics are...

If the graph of the velocity vs. time is an upside down pointy V, then the acceleration is undefined at the peak, correct? (infinitely many, differently angled lines can be drawn tangent to it) If so, I find that the most interesting thing.

Just a thought experiment.

Thank you. So, I'm not totally crazy ;) So, a position versus time graph (position is in one dimension) for the ball would be linear but with a peak at the wall's location. Therefore, if we take the 1st derivative of the function to find instantaneous velocity, this derivative is not...

This likely represents a physical impossibility or contradiction, but I'd like to know that or, if not, understand what is going on at a deeper level. Let's say we have a perfectly rigid and immovable wall. We have a perfectly rigid (doesn't compress) ball moving toward it at 10 m/s. The...

Hi, Can a few of you please review the approach I plan to take for obvious errors? I have 50 subjects and each have a measure taken on the same variable before and after treatment. So, this is standard paired t-test time, but what I am actually interested in is the variance of the treatment...

Thanks Naty1. So, let me ask the group this in another way. Let's say I am only speaking of 3D space, but I want it to curve like 4D spacetime. Can I curve 3D space without needing a 4th dimension? If so, is similar to how I might view a glass cube with coordinates lines etch on the inside...

I'm familiar with space and time together being 4 dimensions and that mass causes a curvature in this spacetime. When I consider a line that is curved, I can view the curvature because the line is drawn on a 2D surface (plane). So, it seems an additional dimension is required for a...

Thanks for the thoughtful post, Lsos. And it is enjoyable to discuss this. I'm glad I'm not the only one who sees the difficulty in this seemingly simple concept. In case I was unclear, I was speaking of the atoms in the jagged teeth. Even if the jagged teeth don't seem to move, for them...

Thanks. Still struggling with why one piece of sandpaper accelerating the molecules in another piece it slides past (which raises the temperature by increasing average velocity of molecules) is significantly different from a box hitting air molecules and accelerating them.

This all makes some sense and I appreciate you taking the time, but what in the following view is incorrect? A bit of texture on a sliding surface hits a bit of texture on an opposing, non-sliding surface much like something hitting air molecules. Whether the object struck can move or not...