### How can I configure Visual Studio 2008, so that it uses multiple cores for compile?

I use Visual Studio 2008 on a bigger project. If some files get compiled, it compiles them one after the other. My computer has 8 cores, except one they are idle. How can I configure Visual Studio, that it makes use of the cores?

### How to choose a language for web map development?

I am building a web map application using:

• GeoServer
• OpenLayers
• Tomcat

I would like to build a web application, where the user can log in and have the map arranged according to their profile. As I am already using tomcat, I would like to stick with java.

However, I have found that python is more suitable to web programming, so is jython an alternative?

This thread provided some light, but is not complete.

Are there any examples? I have thought of using JSF and implementing wms service from geoserver. Any ideas and suggestions to get started. I am ready to learn new technologies.

Features:

2. User Should be able to only view maps that their role/user permits.
3. The application should only make use of the technology listed above, if possible.

### Proving that the free energy is extensive

If I have two system of an Ideal gas $A$ and $B$ each of these system has a partition function:

$Z_{A,B} = \left ( \frac{V_{A,B}}{\lambda_T} \right )^{N_{A,B}}$

Where:

$\lambda_T = \left ( \frac{m}{2\pi\beta \hbar } \right )^{\frac{1}{2}}$

The free energy is:

$F_{A,B} = -kT \ln \left ( Z_{A,B} \right ) = -kT N_{A,B}\ln \left (\frac{V_{A,B}}{\lambda_T}\right)$

For the free energy to be extensive the following must be true:

$F_{A} + F_B = F_{A+B} \Rightarrow Z_A \cdot Z_B = Z_{A+B}$

However:

$Z_A \cdot Z_B = \left (\frac{V_A}{\lambda_T} \right )^{N_A} \left ( \frac{V_B}{\lambda_T} \right)^{N_B}$

and:

$Z_{A+B} = \left ( \frac{V_{A+B}}{\lambda_T} \right )^{N_A + N_B}$

So, for $Z_A + Z_B = Z_{A+B}$ to be true $V_A^{N_A} V_{B}^{N_B} = \left(V_A + V_B \right)^{N_A + N_B}$ must be true as well but this isn't true for any system.

Since we cannot create energy by mixing two containers of Argon in the same pressure and temperature, something in my understanding is wrong. Where is my fault?

### Injecting UUIDs into ROM during production

I'm brand new to electronics and was wondering if someone could explain to me how individual MCU/MPU-powered electronics units can be assigned unique identities on the factory line.

For instance, lets say a particular device is being built. This device has an MCU/MPU (still don't fully understand their difference) that has a CPU, ROM to hold a binary/RTOS and RAM for running that binary at runtime. A control program is flashed to the ROM at some point during production.

Say this device has the need to be given a UUID that can be read from memory when the control program starts up. Obviously, each device needs a different (unique) ID. And so I would imagine that the MCU would undergo two different phases during its production build: an initial flashing of the control program to ROM, followed by a second flashing that "appends" (without overwriting, that is) a device-specific UUID to a specific address in ROM. The control program would then be hardcoded to look for the value (UUID) stored at this address at startup.

Am I on track here, or is there a more efficient/different/standard way of accomplishing such a task? And I guess I would generalize it beyond a UUID and ask the same question of any situation where all units share a binary (the control program) but then also have their own unique information that must be present in ROM at startup.

### If guessing a display name, what kind of confirmation is needed?

In an iPhone app of mine, the user needs a display name, that appears for other users.

I found out that I can guess a user's display name. In the mockup below I have guessed that it should be "Sanna". This is possibly the first name of the user. But it can also be totally wrong, and in that case the user will probably want to change it.

The idea is only to avoid unnecessary setup steps. If the name guess is mostly right, then why ask every user for it? But the guess might be embarrassingly wrong in a few cases. I tried to find a more accurate way, but so far I am simply using the Device Name to extract the Display Name. Here is an SO question about it. Basically, if the Device Name is "Sanna's iPhone", it will extract "Sanna".

I do not want to force the user to pick a contact, log in to facebook or such things, just to get a name. I just want to have a name real quickly, and continue with the game.

Below I mocked four different ways to handle this:

1. Enter from scratch - not using the guessed name at all. This is how most apps I encountered do it.
2. Suggest - Use the guessed name as prefilled text in a text box.
3. Preset - Let the user see the name that is set, and be offered to change it before proceeding.
4. Don't ask - use the name directly. You can change it later anyway.

EDIT: At this moment, I am using #4. Most users (95%) never mention it, which I think means it is working as intended. But I have received complaints about bad guesses, from users not liking the name I picked for them. They seem to be annoyed that they have to change it, even though that task is as easy as it would be confirming it in advance. So perhaps it is just seeing the bad guess that is annoying. If using a confirmation, like #2 or #3, perhaps the bad guess would be equally annoying. /EDIT

Is it a good idea to use a guess for a display name, or will it confuse the user? And if using a guess, then what kind of confirmation is needed?

### How to separate factors by dependent variables (arguments)?

How can I separate factors in an expression by their dependent variables? For example:

expr = b * c[2] * a[x] * 2 * x^2 * g[x,y] * z[r] * D[q[x], {x, 4}];


I need function that will separate the factors independent and dependent on a specified variable, like so:

f[expr, x]

{2b*c[2]*z[r], a[x]*(x^2)*g[x,y]*D[q[x], {x,4}]}

f[expr, y]

{2b*c[2]*z[r]*a[x]*(x^2)*D[q[x], {x,4}], g[x,y]}


Can this be done?

As sub-question, I tried this approach, and I am puzzled as to why it didn't work. It separates the x-independent factor into several factors, and I can't understand why my code would do that.

g = a[x]^2 + 2 c1 a[x] b[x] + c1^2 b[x]^2 + 2 c2 a[x] c[x] + 2 c1 c2 b[x] c[x] + c2^2 c[x]^2 + a[x] b[x] c[x] ;
terms = Replace[#, HoldPattern[Plus[w___]] :> w] & /@ {g};
pairs = terms /. HoldPattern[q1___ r__ q2___ /; FreeQ[{r}, x]] :> {r, q1*q2}


$$\left\{a(x)^2,\{2,\text{c1},a(x) b(x)\},\left\{\text{c1}^2,b(x)^2\right\},\{2,\text{c2},a(x) c(x)\},\{2,\text{c1},\text{c2},b(x) c(x)\},a(x) b(x) c(x),\left\{\text{c2}^2,c(x)^2\right\}\right\}$$

What'd I do wrong?

### Deleteing photos from device but still have them in the backup (default Google+)

I've been looking all over for a proper explanation of how to delete photos from the device (nexus 5) to reclaim some space, while being sure that the pictures are still in the Google+ backup. Unfortunatley i have not found one, other than "wild claims" it works somehow, while other say it does not. Plus deleting photos via the Pictures app actually warns you (now?) that it will delete the backed up copies too. Do i have to delete them in the Gallery app?

I did delete some photos recently, and i was quite sure they ware still backed up (still showed up on the Google+ website) but looking now i see they are in the trash in the device.

Is there really no way to be able to know for sure if the pictures are backed up savely while i can delete them from the device?

Alternatively i'm also open for alternative solutions to this problem, or i just go back to the "good old copy and paste when plugging the phone".

### Historical background of wave function collapse

I wonder what were the main experiments that led people to develop the concept of wave function collapse? (I think I am correct in including the Born Rule within the general umbrella of the collapse paradigm.) Are there any instances where cases once thought to be examples of collapse have since been explained as the normal time-evolution of the wave function?

EDIT: I'm going to have to make an objection to Ron Maimon's very excellent answer about particle tracks as evidence of collapse. I've been waiting for someone to suggest what I personally have always considered the prototype of the wave function collapse, namely the appearance of flecks of silver on a photographic plate when exposed to the light of a distant star. This has the essential elements of collapse in a way that ordinary photographic exposures do not. The mere appearance of dots on a photographic plate does not signal the collapse of anything: it is readily explainable as a consequence of the rate of silver-bromide reduction being proportional to light intensity. It is only when the intensity becomes so very low that the time taken to accumulate enough energy for a single conversion becomes unreasonable that we must consider the explanation of wave function collapse.

The tracks in the cloud chamber do not demonstrate this phenomenon since the energy needed for the creation of the tracks is already available in the supersaturated gas. It is not necessary for the incoming particle to supply energy for the creation of the track, so there is no need to collapse its wave function. The straightness of the tracks is explained by Mott as an ordinary consequence of time-evolution of the wave function. There is no experimental proof that a single "particle" cannot be responsible for multiple tracks in the cloud chamber, because the tracks are not tagged according to which particle created them.

### Bug in Dev Console/Execute Anonymous?

I am trying to do some research, and coming across a stumbling block. Execute Anonymous seems to sometimes hit a statement that breaks all further debugs.

system.debug('Statements do appear'); // shows up
try
{
system.debug(Timezone.getTimeZone('America/New_York')); // never shows up
throw new DmlException();
}
catch (Exception pokemon)
{
system.debug(pokemon); // never shows up
}


However, if I change the DmlException above to LimitException, it does throw, so I know the execution is not halted. What's going on?

Logging Levels:

Even if I change my LoggingLevel on the above debug statements to ERROR, the behavior remains unchanged. But if I change the ApexCode level to FINEST, it works. Why?

### What are the conditions for decoherence to be irreversible?

Spin echo experiments have been able to reverse the motions of all the molecules in a gas in statistical mechanics in the manner of Loschmidt. The Fermi-Ulam-Pasta model has solutions with a single mode dispersing, only to recohere after quite some time has elapsed. Can the same thing happen for decoherence? What are the conditions fyor decoherence to be irreversible?