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Can brain cells move? By movement I mean long distance migration (preferably within the brain only). |
In our computer systems lecture we were introduced to the MIPS processor. It was (re)developed over the course of the term and has in fact been quite easy to understand. It uses a RISC design, that is its elementary commands are regularly encoded and there are only few of them in order to keep the wires simple.
It was mentioned that CISC follows a different philosophy. I looked briefly at the x86 instruction set and was shocked. I can not image how anyone would want to build a processor that uses so complex a command set!
So I figure there have to be good arguments why large portions of the processor market use CISC architectures. What are they? |
View tabular file such as CSV from command line, having horizontal and vertical scrolling would be great. |
Slater type orbitals (STO) are considered to be more accurate than gaussian type orbitals (GTO) for atomic and molecular QM calculations because - among other reasons - they decay with $e^{-\alpha r}$ as $r \to \infty$. But GTOs are more popular because they are easier to calculate with. GTOs decay with $e^{-\alpha r^2}$, so its adequate to sometimes add diffuse functions to the GTO basis set to compensate for gaussian decay behaviour.
Also, exact hydrogen wavefunctions decay exponentially, so the motivation for STOs.
I understand that the only boundary requirement for solving the Schrödinger equation for atoms and molecules in free space is that the wavefunction goes zero as $r \to \infty$, but there are no a priori requirements for the way it decays as it does so.
My question is: do we have theoretical (ab initio) and/or experimental reasons to believe that all atomic and molecular wavefunctions decay like $e^{-\alpha r}$ as $r \to \infty$. |
Explain what "git reset" does. I come from a SVN background and Git is a whole new paradigm. I got mercurial easily, but Git is much more technical.
I think ```git reset``` is close to ```hg revert```, but it seems there are differences. Please include detailed explanations about:
* the options ```--hard```, ```--soft``` and ```--merge```;
* the strange notation you use with ```HEAD``` such as ```HEAD^``` and ```HEAD~1```;
* concrete use cases and work flows;
* consequences on the working copy, the ```HEAD``` and your global stress level. |
I am looking to use Java to get the MD5 checksum of a file.
How is it done? |
What are the primary objections Democrats have to a border wall? |
I'm converting a video to GIF file with ```ffmpeg```:
```ffmpeg \
-i input.flv \
-ss 00:00:00.000 \
-pix_fmt rgb24 \
-r 10 \
-s 320x240 \
-t 00:00:10.000 \
output.gif
```
It works great, but output gif file has a very low quality.
Any ideas how can I improve quality of converted gif? |
Tor can only handle TCP connections, but DNS is a UDP protocol. How does Tor route DNS requests over its TCP based network? Why can the same approach not be used to route all UDP traffic over Tor? |
Why does this throw ```NullPointerException```
```public static void main(String[] args) throws Exception {
Boolean b = true ? returnsNull() : false; // NPE on this line.
System.out.println(b);
}
public static Boolean returnsNull() {
return null;
}
```
while this doesn't
```public static void main(String[] args) throws Exception {
Boolean b = true ? null : false;
System.out.println(b); // null
}
```
?
The solution is by the way to replace ```false``` by ```Boolean.FALSE``` to avoid ```null``` being unboxed to ```boolean``` --which isn't possible. But that isn't the question. The question is why? Are there any references in JLS which confirms this behaviour, especially of the 2nd case? |
How do DOS games like DOOM benefit from a PCI graphics card? |
I need to be able to open a document using its default application in Windows and Mac OS. Basically, I want to do the same thing that happens when you double-click on the document icon in Explorer or Finder. What is the best way to do this in Python? |
Why does PRC devalue its currency on purpose, but Turkey is worried about the devaluation of its currency? |
Is it worth patenting an algorithm if I don't have the money to defend against infringements? |
"I have a ```String[]``` with values like so:
```public static final String[] VALUES = new String[] {""AB"",""BC"",""CD"",""AE""};
```
Given ```String s```, is there a good way of testing whether ```VALUES``` contains ```s```?" How do I determine whether an array contains a particular value in Java? |
Does Java casting introduce overhead? Or the compiler just resolves everything and there is no cost at run time?
Is this a general things, or there are different cases? |
How can I copy a string (e.g "hello") to the System Clipboard in C#, so next time I press CTRL+V I'll get "hello"? |
I want to put a draft watermark using the below script but the problem is that the watermark don't come over the images and I want it to come over it.
```\usepackage{draftwatermark}
\SetWatermarkText{DRAFT}
\SetWatermarkScale{1}
``` |
Understanding the Rails Authenticity Token |
Why is FIFA against adding instant replay to the game? |
If we should encrypt the message rather than the method of transfer, why do we care about wifi security? Is this just security theatre? |
Applying filter in scipy.signal: Use lfilter or filtfilt? |
What do different people in the department expect from a postdoc?
By different people I mean the advisor, graduate students and PhD students.
I know it mainly depends on the job description but there are few basic things that a postdoc must be expected to do. How aggressive (proactive) must one be? This question is important since a postdoc cannot just wait for the adviser to give him/her inputs. Rather the postdoc must take the project(s) as another PhD research of his own but be completely accountable to the adviser in terms of what he/she is doing and how is he/she doing that.
The above are my thoughts. My question is divided into the following sub-parts:
* What would you as a professor expect from your postdoc?
* What preparation one must do to rise to the expected level?
* Is the preparation merely restricted to having sound academic record and experience? |
Can someone explain to me what the ```contentInset``` property in a ```UIScrollView``` instance is used for? And maybe provide an example? |
How is arc defined in TikZ? |
How to connect mysql workbench to running mysql inside docker? |
Can meat spoil outside the fridge if it's baked into bread as a filling? |
I'm wondering how the XML Schema specification handles these cases:
```
```
No maxOccurs given -> Is this the cardinality [1..1]?
```
```
I suppose this is simply invalid?
```
```
Is this the cardinality [0..2] or [1..2]?
Is there an "official" definition on how the XML Schema spec handles these cases? |
Were there any flying dinosaurs? |
Say, a table ```car``` has one-to-one relationship to tables ```electric_car```, ```gas_car```, and ```hybrid_car```. If a ```car``` is ```electric_car```, it can no longer appear in ```gas_car``` or a ```hybrid_car```, etc.
Is it a bad practice to have several mutually exclusive one-to-one relationships in database design? |
I see a low use of Mathematica in Kaggle competitions. Why would one use the Wolfram Language versus R, Python, or Julia for machine learning? Besides prettier plots and the Manipulate function, do we have something that is useful for ML that other languages are lacking? |
I'm using wp_nav_menu and am trying to create custom output for the sub-level drop downs. I came across the "items_wrap" argument but there's really not much information as to what it is, how it works, and what kind of things can be done with it.
What exactly is "%1$s" and "%2$s"? (Can anyone explain it in layman's terms?) |
I've noticed that people on YouTube and even on TV would sometimes say things like "I used to take lots of coke a few years ago" or "I used to smoke weed daily until this and that" or "Yea, I smoke weed every once in a while," or "I used to pirate games a lot when I was a bit younger" or "I used pirated Windows and Photoshop until I got a job," etc., etc..
Basically they are confessing to a crime, on public record, couldn't anyone come after them? They've already confessed - technically all that would have to be done is a trial.
How do people publicly admit to criminal activity and not typically get arrested? |
Did two dissenting Supreme Court justices agree that Trump was "absolutely immune" to the Manhattan DA's subpoena? |
Just curious, given how heavily from Tolkien D&D drew, and the fact that games like Wizardry used Hobbits, is there a good design reason why Gygax and company used Halflings (a term that also appears in Tolkien) vice Hobbits as the term for our little friends? |
My USB drive used to be originally 8GB when I bought it.
I'm trying to reformatted in Windows 7 by right clicking on the drive and selecting ```Format...```. But the capacity only shows 250MB.
Is there something I can do to get the original size back? Maybe it got partitioned in a weird way?
The flash drive is a SanDisk Cruzer Micro 8GB. |
I am a Tor developer. I understand that the .onion address is a public key of sorts, but not much more than that (I can vaguely guess, though). When nobody knows the IP of the .onion address, how do requests reach it? Are they bounced between nodes in the P2P network till someone decrypts it with the corresponding private key? |
I have been offered a PhD position by an inexperienced professor in a great institution in Europe. Despite the fact that the institution is very strong in my area, since the position was offered by this particular professor, I would have to commit myself to working with him for my thesis. This professor is young, and relatively inexperienced, but I enjoy the things he works on, and we seem to get along well.
My question is, would having an inexperienced advisor hurt my growth as a scientist, or my career in general? Will I have the time during my PhD to also work on the side with other, more renowned professors in the department, or is one usually focused in a single research project? |
Is there a phrase that means "too important" and "attracting too much attention"? |
This guy claims that Olympic powerlifters working in the 1-6 rep range can increase strength without increasing muscle size.
> Trained Olympic lifters, for example, were shown over a two-year period to have significant strength increases with barely noticeable increases in muscle mass (Hakkinen et al, 1988). I had a similar experience when I used AST's Max-OT principals. My strength went up like crazy, but I gained very little size. Obviously, traditional strength training with low volume and low sets (1-6 reps, 3 or less sets) is not the best approach. Strength training does cause hypertrophy (Hakkinen et al, 1985), but it won't cause maximum hypertrophy.
What is the scientific explanation for this? Is the inverse true? That is, can a buff guy (with lots of prominent muscle) actually be weak? |
What are the major concerns about planting trees to create carbon offsets? |
I am wondering how to generate uniformly distributed points on the surface of the 3-d unit sphere? Also after generating those points, what is the best way to visualize and check whether they are truly uniform on the surface $x^2+y^2+z^2=1$? |
In Shutter Island, at the end of the movie Teddy had a chat with Chuck, in that scene Teddy told to Chuck as,
Which would be worse: To live as a monster, or to die as a good man?
What's the implicit meaning of this dialogue? Who's the monster as Teddy mentioned?
And, who's a good man? |
To set the minimal distance between flexbox items I'm using ```margin: 0 5px``` on ```.item``` and ```margin: 0 -5px``` on container. For me it seems like a hack, but I can't find any better way to do this.
```#box {
display: flex;
width: 100px;
margin: 0 -5px;
}
.item {
background: gray;
width: 50px;
height: 50px;
margin: 0 5px;
}```
```
```
|
Is there a Git for data? The key improvement I'd want is to Diff/Merge more intelligently. e.g. in CSV rather than line vs line comparison, it would do cell vs cell.
And ordering is usually not significant, e.g. rows in a CSV, whereas Git does care and presents the user with 'conflicts'. |
I have been puzzling over where to put the submit button, on the left or the right. In researching, I noticed that many sites put buttons on the bottom right in dialogue boxes, and on the bottom left in forms.
It makes sense: in a dialogue box it seems to denote finality, being in the endpoint of the window for left–right readers; in a form, the bottom right could be in a different position relative to the rest of the form if the window is resized.
It seems to be a convention, but should the OK/Cancel buttons be aligned right or centered?
Should the OK/Cancel buttons be aligned right or centered? |
Is it at all possible to update object's properties with ```setState```?
Something like:
```this.state = {
jasper: { name: 'jasper', age: 28 },
}
```
I have tried:
```this.setState({jasper.name: 'someOtherName'});
```
and this:
```this.setState({jasper: {name: 'someothername'}})
```
The first results in a syntax error and the second just does nothing. Any ideas? |
What is the difference between Non-Player Characters (NPCs) and bots in video games? |
Is there anything like ```static class``` in java? What is the meaning of such a class. Do all the methods of the static class need to be ```static``` too? Is it required the other way round, that if a class contains all the static methods, shall the class be static too? What are static classes good for? |
The Episode IV-VI movies never mention the Emperor's name. In Episodes I-III, we can guess that Darth Sidious will be the emperor, but what about Chancellor Palpatine? If the audience didn't know that he was Sidious, the impact of the reveal would be far different than if they did.
But I did. In all the novels and comics that came out after "Return of the Jedi", the Emperor's name was stated plainly: Palpatine.
So when I saw the prologue movies, for the life of me I couldn't figure out: was I supposed to know that Palpatine was the villain?
Maybe the filmmakers figured that most of the moviegoing public never got into the Expanded Universe. But they had to know that the hardcore fans would know. Or maybe when you watched the movie, even if you hadn't heard of Palpatine, it was supposed to be obvious?
What was the intent? |
So, students in Gryffindor are supposed to represent bravery. How does Neville represent bravery, to the point in being accepted into the house. I've always thought of his strongest traits being things like loyalty, willingness to work hard, etc, and these things would tend to put him in Hufflepuff. |
This claim was made popular by being said in the movie The Social Network. It exactly says:
> Did you know there are more people with genius IQs living in China than there are people of any kind living in the United States?
|
I am trying to get my program to print out ```"banana"``` from the dictionary. What would be the simplest way to do this?
This is my dictionary:
```prices = {
"banana" : 4,
"apple" : 2,
"orange" : 1.5,
"pear" : 3
}
``` |
Different coffee packets advertise different amounts of 'Robusta' and 'Arabica'? What do these terms refer to, and how does it affect the taste of the coffee? |
So whenever we want to shoot our flash before taking a photo. we have to charge it first.
What is the point of the charging our flashes? Aren't their power directly supplied by the battery of our camera?
Please answer for the built in flash on the 2000D and the traditional hot shoe Xenon flashes.
Perhaps these hot shoe xenon flashes have their own batteries charged by the slow hot shoe port. Who knows? |
What are some strategies to maintain morale and productivity after massive layoffs? I am not in a managerial role, just a lead role, and am asking for myself and my fellow employees. |
Could you please clearly explain what is the difference between correlation and convolution that is done by a filter on an image?
I mean in terms of signal processing definition I know that convolution describes the output of an LTI system, that is if an LTI system produces an output due to convolution with an input system then the output signal can be described as the result of convolution of the input signal and the impulse response of the LTI system. As for the correlation, it describes the similarities between to signals. But how does convolution and correlation effect on a image and how different are they in terms of effects?
Thanks |
24601 has developed into being an iconic part of both the Les Miserables book and musical. Was that number special to him, or was it simply a random number he chose (I doubt it)? |
Why does Michael Crichton use US Customary measurements in hard sci-fi? |
How can horns, most of which have only three buttons, play all their notes? |
I am a big fan of worldbuilding. A common sight in science fiction is that aliens pretend to be human (For example in Third Rock from the Sun). Obviously if the aliens are advanced enough to disguise themselves as another species, there are much easier, simpler and less expensive methods to destroy humanity, so why else would an advanced alien civilization waste time, energy and resources to disguise themselves as humans? What possible scientific, cultural or commercial use could such an expensive procedure have? |
I've taken a look at the list of surveys taken on scala-lang.org and noticed a curious question: "Can you name all the uses of “_”?". Can you? If yes, please do so here. Explanatory examples are appreciated. |
My university usually asks that we book a flight via a travel agent, but the prices he gives me are about $50 higher than the prices I can get by online booking in the flight company's website. Why would a company want me to book a flight via a travel agent if it is more expensive? |
Layman's explanation of encryption backdoors |
I have a page where a scroll bar containing table rows with divs in them is dynamically generated from the database. Each table row acts like a link, sort of like you'd see on a YouTube playlist next to the video player.
When a user visits the page, the option they are on is supposed to go to the top of the scrolling div. This functionality is working. The issue is that it goes just a tad too far. Like the option they are on is about 10px too high. So, the page is visited, the url is used to identify which option was selected and then scrolls that option to the top of the scrolling div. Note: This is not the scroll bar for the window, it is a div with a scrollbar.
I am using this code to make it move the selected option to the top of the div:
```var pathArray = window.location.pathname.split( '/' );
var el = document.getElementById(pathArray[5]);
el.scrollIntoView(true);
```
It moves it to the top of the div but about 10 pixels too far up.
how to fix that? |
Suppose I have the geographic coordinates of "Saratoga, California, USA" as
```Latitude: 37°15.8298′ N
Longitude: 122° 1.3806′ W
```
I know from here that in the case of latitude ```1° ≈ 69 miles``` and that longitude varies:
```1° longitude = cosine (latitude) * length of degree (miles) at Equator.
```
How many miles is 1° longitude at ```longitude: 122°1.3806′ W```? |
I have read numerous times that some Norse warriors, upon death, would go in Fólkvangr, while some others would go to Valhalla. How was it decided which warrior would go to which place? Why did the need to have many "paradises" (whatever you many call it) exist?
Citing Wikipedia:
> In Norse mythology, Fólkvangr (Old Norse "field of the host" or "people-field" or "army-field") is a meadow or field ruled over by the goddess Freyja where half of those that die in combat go upon death, while the other half go to the god Odin in Valhalla. |
I noticed that there is a binary executable ```/bin/echo``` on my Ubuntu MATE 17.04 system.
I thought, that's odd, because
```$ type echo
echo is a shell builtin```
Cursory testing suggests that ```/bin/echo``` does the same sort of thing as the Bash builtin ```echo```:
```$ /bin/echo foo
foo
$ /bin/echo $USER
zanna
```
So, why is there another version of ```echo``` separate from the Bash program, and why or when would I want to use it? |
what's the difference between JavaScript objects, classes and functions? |
In most introductory algorithm classes, notations like $O$ (Big O) and $\Theta$ are introduced, and a student would typically learn to use one of these to find the time complexity.
However, there are other notations, such as $o$, $\Omega$ and $\omega$. Are there any specific scenarios where one notation would be preferable to another? |
Why is Gaia operating around Earth orbit? Why not send it to Neptune's orbit? |
I have a string representing a unix timestamp (i.e. "1284101485") in Python, and I'd like to convert it to a readable date. When I use ```time.strftime```, I get a ```TypeError```:
```>>>import time
>>>print time.strftime("%B %d %Y", "1284101485")
Traceback (most recent call last):
File "", line 1, in
TypeError: argument must be 9-item sequence, not str
``` |
In Django, the convention is to put all of your static files (i.e css, js) specific to your app into a folder called static. So the structure would look like this:
```mysite/
manage.py
mysite/ --> (settings.py, etc)
myapp/ --> (models.py, views.py, etc)
static/
```
In ```mysite/settings.py``` I have:
```STATIC_ROOT = 'staticfiles'
```
So when I run the command:
```python manage.py collectstatic
```
It creates a folder called ```staticfiles``` at the root level (so same directory as ```myapp/```)
What's the point of this? Isn't it just creating a copy of all my static files? |
I am used to thinking of finite-differences as a special case of finite-elements, on a very constrained grid. What are criteria to choose between finite-differences and finite-elements |
How important is multithreading in the current software industry? |
Is it true that the price of diamonds is based on a monopoly? And who actually runs/owns this supposed monopoly? Is this likely to affect diamond prices if I am interested in purchasing? |
Normal filesystem images can be easily mounted:
```mount system.img /mnt
```
Examined, and modified. But when I try this with a Raspberry Pi system image (e.g. raspbian), I get:
```mount: unknown filesystem type '(null)'
```
And no matter what I try with ```-t```, it won't work. How can I mount this image? |
How does immersion passively help with learning a language? |
I have a script, that does not exit when I want it to.
An example script with the same error is:
```#!/bin/bash
function bla() {
return 1
}
bla || ( echo '1' ; exit 1 )
echo '2'
```
I would assume to see the output:
```:~$ ./test.sh
1
:~$
```
But I actually see:
```:~$ ./test.sh
1
2
:~$
```
Does the ```()``` command chaining somehow create a scope? What is ```exit``` exiting out of, if not the script? |
Adding a new swap file. How to edit fstab to enable swap after reboot? |
How do I add a validation to make sure the date string being passed to the method is in the ffg. format:
```'YYYY-MM-DD'
```
if it's not, method should raise some sort of error |
When to use UICollectionView instead of UITableView? |
On my branch I had some files in .gitignore
On a different branch those files are not.
I want to merge the different branch into mine, and I don't care if those files are no longer ignored or not.
Unfortunately I get this:
The following untracked working tree files would be overwritten by merge
How would I modify my pull command to overwrite those files, without me having to find, move or delete those files myself? |
Since long time ago I have been thinking in two problems that I have not been able to solve. It seems that one of them was recently solved. I have been thinking a lot about the motivation and its consequences. Mostly because people used to motivate one of them with some very interesting implications. My conclusion however, is that there is a mistake in the motivation of the problem, and that, while being a really interesting result, it does not make any sense in the setting in which is formulated. As my opinion is not relevant compared to one of the experts in the area, I do not say anything.
My question is if you can provide me some examples of conjectures that were believed to be interesting in the mathematical community because of a specific reason, but that once having the proof, people realized that the reason to motivate the problem was not truly related to its solution. Or in other words, the solution of the problem gives no clues about the original motivation. |
How do GPS receivers communicate with satellites? |
Why is iceberg lettuce bad for rabbits? |
How do I open the JavaScript console in different browsers? |
I have Ubuntu 10 as the guest OS on a Windows 7 machine. I have been trying to setup shares through VirtualBox, but nothing is working. First, I create the share in VirtualBox and point it to a Windows folder. Then I try to mount the drive in Linux, but I keep getting
```/sbin/mount.vboxsf: mounting failed with the error: Protocol error
```
I have read so many solutions to this, but none seem to work. I have tried:
* Using the mount.vboxsf syntax
* Reinstalling VBox additions
* Rebooting
* Enabling and trying as root account
I made a share called "Test" in VBox Shared folders. Then I made a directory in ubuntu named "test2". Then I tried to execute this command:
```sudo mount -t vboxsf Test /mnt/test2
```
Any other ideas? |
What does %~dp0 mean, and how does it work?
I'd also like to know if it is a documented feature, or something prone to be deprecated. |
Should a tester feel bad about finding too many defects/bugs in the product? |
Millions of colors in the visible spectrum can be generated by mixing red, green and blue - the RGB color system. Is there a basic set of smells that, when mixed, can yield all, or nearly all detectable smells ? |
Do you bleed to death after your penis is cut off? |
In Swift, is there a clever way of using the higher order methods on Array to return the 5 first objects?
The obj-c way of doing it was saving an index, and for-loop through the array incrementing index until it was 5 and returning the new array. Is there a way to do this with ```filter```, ```map``` or ```reduce```? |
What's the simplest way to get an environment variable from a docker container that has not been declared in the Dockerfile?
For instance, an environment variable that has been set through some ```docker exec container /bin/bash``` session?
I can do ```docker exec container env | grep ENV_VAR```, but I would prefer something that just returns the value.
I've tried using ```docker exec container echo "$ENV_VAR"```, but the substitution seems to happen outside of the container, so I don't get the env var from the container, but rather the env var from my own computer.
Thanks. |
I am confused about the use cases for both ```InputStream``` and ```OutputStream```.
Please include a snippet of code to go along with your explanation. |
What is the difference between:
```npm install [package_name]
```
and:
```npm install [package_name] --save
```
and:
```npm install [package_name] --save-dev
```
What does this mean? And what is really the effect of ```--save``` and ```-dev``` keywords? |
pod install -bash: pod: command not found |
I read in the Essential C# 3.0 and .NET 3.5 book that:
GetHashCode()’s returns over the life of a particular object should be
constant (the same value), even if the object’s data changes. In many
cases, you should cache the method return to enforce this.
Is this a valid guideline?
I have tried a couple built-in types in .NET and they didn't behave like this. |
Especially in blitz or bullet games, it is possible that a player makes an illegal move, for example castles through check.
* If the opponent does notice the illegal move, then as far as I know the first player is obliged to make a legal move with the same piece, if one exists. What if there are no legal moves?
* What if the opponent, being in time pressure, doesn't notice the illegal move and makes a move. What happens after they realize that? Does the person who made the illegal move forfeit? Or is the whole game cancelled?
Are there any standard rules for these kinds of situations? |
How to set button click effect in Android? |
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