Recent content by mesogen

So, I'm still curious if people use, as standard practice, the "error" in a fit as the "error" in a measurement when in my eyes the fitting error is just a measure of the goodness of fit and not necessarily the uncertainty in the measurement.

I think that goes back to the days when IGOR was primarily used for signals processing. It later expanded into a full blown data analysis program. From what I understand, commonly "weight" means 1/variance (1/σ2). But IGOR has an input in the fitting dialog that asks for the wave of weights...

I'm using IGOR. (Also using Labview. Actually trying to determine which is best for this.) The IGOR Manual It says: I think it just makes up some random noise in the data just based on the residuals. Ok, so with that said, and let's go ahead and say that I fed the weights into the...

I think there is a standard deviation in the coefficients (slope and intercept) because there is a scatter to the data and there may be several values of the slope, very close to each other, that minimize the residuals. But I'm just guessing here. I do have uncertainty in the data, but I...

Sorry if I'm in the wrong subforum. This is a rather simple and straightforward question, I hope. I'm doing a measurement that requires me to do a linear regression on data points to get a value of the slope. The slope is the value of the actual property that I am measuring. Assuming...

Not at all. That was very helpful. It makes me realize that there is nothing that straightforward about VR hopping, even though to me it seems like a relatively simple concept. I'm definitely not a solid state physicist, just a lowly chemist delving into solid state stuff. The thing is, all...

I hope someone out there can help me with this fairly simple but specific question about the Mott 3-D variable range hopping conduction model. Mott theory has the energy difference between hopping sites as: ΔE ≈ 1 / g0rD Where g0 density of states near the Fermi surface, D is the...

Is it simply because there is a roughly a 1/6 chance there will be a 6 rolled, so if you have enough dice in one place roughly 1/6 of them will turn out to be a 6? But it is possible that no 6s at all will turn up. And just as likely that all 6s will turn up. Both outcomes are just as likely...

That's kind of what I'm asking. How is this possible? Each individual event is totally random, like for real. But, when you put them in a big group, the rate is predictable. This makes no sense to me.

Yes, but I was hoping for a magical probing. :) I guess I'm like Einstein and the thought of a causeless event just doesn't sit right with me. I guess I didn't realize that tunneling was considered a random event. And, I guess I didn't think of nuclear decay as a tunneling phenomenon...

What does "random" mean wrt nuclear decay? From what I understand, the process of nuclear decay proceeds at a very predictable rate. Given a lump of say, U-235, half of all the nuclei in the lump will have decayed after 700 my. There is no way, though, to determine which nuclei in the lump...

http://www.eurekalert.org/pub_releases/2009-07/lu-pro070309.php Well, according to this article, at least. http://www.sciencemag.org/cgi/content/abstract/1174962 Just thought I'd share. Problem is, they didn't entirely describe high temp superconductivity. O well.

From the other thread that you linked to (where I also see that, yes, someone has estimated the ratio): So, if the particles of dark matter cannot collide at all, then can they superimpose will nilly? As in, dark matter particles can be in the same place at once, or a trillion of them can also...

But if there is 5x as much dark matter, it should maybe compete to some degree with regular matter. I wonder if anyone has estimated the ratio of matter to dark matter that would tend to find its way into a black hole.

Well, if there is a lot of dark matter hanging around in galaxies, wouldn't it tend to also hang around black holes, especially the supermassive ones at the centers? Any dark matter that veered near a black hole would most likely be attracted to it, no?