I'm designing a space ship for a comic I'm writing. I was just finishing up the first sketch when I thought whether such a design would actually be possible. Hence my question:  A spaceship is located in deep space. A propulsion system (let's make it a rocket) is attached to the side, and thus not in one line with the ship's center. Would this spaceship travel in a straight line, or rotate?
Assume there is a rigid body in deep space with mass $m$ and moment of inertia $I$. A force that varies with time, $F(t)$, is applied to the body off-center at a distance $r$ from its center of mass. How do I calculate the instantaneous acceleration, rotational acceleration, and trajectory of this object, assuming it starts from rest?
How do a tile with diagonal lines in Photoshop? How does one draw a tile with diagonal lines that can seamlessly tiled with Photoshop? How do I delete all my mail from my Gmail account? So, I've finally obtained the Werewolf form. After returning out of the form, fully naked...  I seem to be stuck in third person view! How can I fix this? Scrolling or pressing F does not work.  I want to get back in first person view...    Mouse wheel allows to zoom in/out but not get me into the first person view but rather behind and slightly to the right of the character. The command animcam locks me at a certain distance, doing it again brings me back into the mode that I'm stuck in third person view. Hitting F after this doesn't work. tfc doesn't help me either, although that command is nice to take screenshots... What bends fabric of space-time? I know that mass can bend fabric of space-time, which causes gravity by making an object curve around a planet or star but is there anything else that can bend it?  Other energy sources, forces anything? Drop bar to flat bar conversion Gearing             14-Speed Shimano A070 STI Crankset            Prowheel Ounce 42/52T Double Chainring Alloy Crankset Shifters            Shimano A070 STI Front Derailleur    Shimano Claris Rear Derailleur     Shimano A070 Brakes              Tektro Dual-Pivot Caliper Brakes Brake Levers        Shimano A070 STI  Above is what I currently have. I am looking to convert from drop bar to flat bar to use the bike as a casual fitness and commuter bike. All I know is that some parts are road bike specific and may need replacing if I want the conversion done. I hear that the front derailleur, shifters/brake levers (obviously since it currently has STI) and the bar it self. Is there anything else that needs to be changed? I would like someone who has more knowledge in bikes than me to possibly tell me what parts from the above mentioned list needs to be changed. I am not looking to do any upgrades. Just looking for cheap budget parts since it will just be a leisure bike.  Thank you all  Sincerely  Tom. Explanation of method for showing that $\frac{0}{0}$ is undefined When performing machine learning, the performance of the machine learning method is dependent on the original function $f$ that we are trying to learn (let's forget for a moment the non-deterministic error and focus on the properties of $f$).  I have a conceptual question. What would make a function easy to learn? For instance, a linear function can be easily learnt by linear methods such as linear regression and SVM. But in the general case, what would make a function easier to learn for decision trees or a neural network?   I believe feature engineering helps us move to a feature space in which the function we want to approximate is easier to represent. But what properties exactly are we trying to achieve for this function? Write Python stdout to file immediately When trying to write the stdout from a Python script to a text file (python script.py &gt; log), the text file is created when the command is started, but the actual content isn't written until the Python script finishes. For example:  script.py:  import time for i in range(10):     print('bla')     time.sleep(5)   prints to stdout every 5 seconds when called with python script.py, but when I call python script.py &gt; log, the size of the log file stays zero until the script finishes. Is it possible to directly write to the log file, such that you can follow the progress of the script (e.g. using tail)?   EDIT It turns out that python -u script.py does the trick, I didn't know about the buffering of stdout. Why does the mirror modifier sometimes give me an overlapping mesh? Is it correct? It's the message I see right before the metro/subway train shows up.  Shouldn't it be "train is approaching" or "train approaches"? The dimension of the Hilbert space is determined by the number of independent basis vectors. There is a infinite discrete energy eigenbasis $\{|n\rangle\}$ in the problem of particle in a box which can be used to expand a general state $|\psi\rangle$ as: $$|\psi\rangle=\sum\limits_{n=0}^{\infty} C_n |n\rangle$$ Here, the basis implies that the Hilbert space has countably infinite number of basis vectors. But one could well expand $|\psi\rangle$ in any other basis as well, say the continuous position basis. Then that superposition, $$|\psi\rangle=\int dx \psi(x)|x\rangle$$ is also possible. But this basis $\{|x\rangle\}$ is continuous and uncountably infinite. Such sets cannot be equal because they have different cardinality. Then my questions is how many independent basis vectors are really there in this Hilbert space? How to make a series of rectangles follow a pen path I am trying to get a series of shapes (rectangles) to follow a path (sine wave) that I made with the pen tool, but I have no clue how to do that or if it is possible.   I have tried warping a rectangle into the sine wave path, but it takes many different warped rectangles and it isn't smooth.  I thought  might work for rectangles, but it only works for text. SF novel about one-way scientific expedition to inhabited planet, where telepathic aliens "talk" sort of ++like this++ and ~*~this~*~ I'm looking for a novel I read in the mid-to-late 1990s. It was a science fiction novel about an expedition of scientists sent at sub-light-speed (maybe in cryo-sleep?) to investigate a star system. Once there they set up a permanent scientific outpost.  There was at least one inhabited planet in the system, with a sentient species that communicated telepathically. The aliens' speech was represented with various symbols instead of quotation marks, with each named character having (I think) its own characteristic set of symbols, as in the title of the question. The scientists are eventually able to communicate with these (generally friendly) aliens.  The thing I remember most clearly is the end of the book. This was a one-way trip for the scientists, so gradually they all die off from various causes. When the next-to-last member of the crew dies of old age, the survivor is looking for an epigraph for her funeral, and (ironically, considering my current plight) can't find it in his search of the electronic library. He finally discovers it under "humor" because it's by Mark Twain: "Wherever she was, there was Eden." (This quote, of course, I found immediately in  and many other sources; it's from Eve's Diary.)  Other pieces of information I'm less sure of:   I don't think the planet was hospitable to humans; it may have been something like a gas giant, with the aliens "swimming" through the gas. I think the scientists stayed in an orbital space station, though they may have made expeditions to the planet in vehicles or protective suits. There may have been a "twin" planet, or a moon in an eccentric orbit, that caused periodic "flares" of some sort on the aliens' planet. There might have been some conflict between the crew early on, maybe because there was a non-scientific (military) commander, or perhaps just because people have conflict. I think the author was of sort of middling fame; respected and known by SF enthusiasts, but not a superstar like Asimov or Clarke. Almost certainly male, and probably with a professional science background. I think the science was fairly authentic, although the first-contact bit was obviously highly speculative. Let $S$ be a finite collection of real numbers (not necessarily distinct). If any element of $S$ is removed then the remaining real numbers can be divided into two collections with same size and same sum ; then is it true that all elements of $S$ are equal ?  (I know the result is true if the &quot;reals&quot; are replaced by &quot;integers&quot;.) Why is $\Gamma\left(\frac{1}{2}\right)=\sqrt{\pi}$? How to split one string into multiple strings separated by at least one space in bash shell? Which is the correct gerund clause? 'People's killing animals', or 'People killing animals ... '? How do I count the number of occurrences of a char in a String? I have the string   a.b.c.d   I want to count the occurrences of '.' in an idiomatic way, preferably a one-liner.  (Previously I had expressed this constraint as "without a loop", in case you're wondering why everyone's trying to answer without using a loop). Finding all software packages in Debian that provide a particular alternative The Debian distribution has the . From the Wiki:     The Debian alternatives system creates a way for several programs that   fulfill the same or similar functions to be listed as alternative   implementations that are installed simultaneously but with one   particular implementation designated as the default. For example many   systems have several text editors installed at the same time. The vi   program is a classic example of an editor that has many   implementations such as nvi, elvis, vim, etc. but which one should be   designated as the default?   In general, there are multiple packages in Debian that provide a particular alternative. How does one obtain a complete list of all such packages that exist in the Debian repositories? Let us use the vi alternative as an example.  NOTE: Doing such a query against the list of installed packages is easy, but that is not what this question asks. In general what is the approach to switch the desktop environment or window manager on Ubuntu? The main difference between stock Ubuntu, Kubuntu and Lubuntu is supposedly the use of Unity vs. KDE vs. LXDE.  However, in order to try various desktop environments and window managers I don't want to have to reinstall the respective flavor from scratch just to get a particular desktop environments or window manager. There probably is an easier method than that.  The question: How can I easily test different desktop environments and respective compatible window managers (say KDE, LXDE, Unity, GNOME, XFCE and StumpWM)?