Is there a natural sounding text-to-speech package?
Natural Sounding Text to Speech?
What is the physical significance of dot & cross product of vectors? Why is division not defined for vectors? I get the physical significance of vector addition &amp; subtraction. But I don't understand what do dot &amp; cross products mean?   More specifically,    Why is it that dot product of vectors $\vec{A}$ and $\vec{B}$ is defined as $AB\cos\theta$? Why is it that cross product of vectors $\vec{A}$ and $\vec{B}$ is defined as $AB\sin\theta$, times a unit vector determined from the right-hand rule?   To me, both these formulae seem to be arbitrarily defined (although, I know that it definitely wouldn't be the case).   If the cross product could be defined arbitrarily, why can't we define division of vectors? What's wrong with that? Why can't vectors be divided? Did all Headmasters get a portrait in Hogwarts? Wifi Automatically Turning ON after iOS 11 Update What if the Earth stops in its orbit and instead falls straight towards the Sun? The Earth orbits around the Sun because it has angular momentum. If we stopped the Earth in orbit and then let it fall straight towards the Sun, how long would it take to reach the Sun in seconds?  Details and assumptions  The mass of the sun is 2*10^30 Kg. The mass of the earth is 6*10^24 Kg. The earth is 149,600,000 Km from the Sun. You may treat the Earth and Sun as point masses. I'm trying to determine which battery to use for my application. I'll be using a class 1 or class 2 Bluetooth (not low energy) module, which requires about ~50/60mA of RX/TX current. In addition, there is a microcontroller and some low power analog IC's. I require a continuous stream of data from the device for 1-10 minutes.  Are coin cells completely out of the question? I'm talking about CR2450 Lithium-ions. I don't really mind if they don't last long, but will they work? Because in my application, size is key, and battery life is a trade off that I'm willing to make. I get Chrome notifications from several websites and they work when I don't even have any tabs open for those sites.  But sometimes I get these Chrome notifications when I am not at my desk or looking at my laptop.  As some of these notifications are useful to me, I would like to be able to access any that I have missed.  Is there a way to view the notification history? I am trying to render this scene above [Snap-shot 1]. But when i am trying to render the scene, its showing me the result [Snap-shot 2]. Whats wrong with my blender [2.72] Show that $3p^2=q^2$ implies $3|p$ and $3|q$ Who created the veil in the death chamber, and why? Was the veil created by someone or was it always there in HP? What is its purpose? If one can't communicate with the dead through the veil, then what/how do unspeakables learn from the the veil? (except investigating how does it flutter,I suppose,,,,) Rear fender angle For a 20" rear wheel with a this kind of fender, what would be the best angle to install it to minimize the spray on one's butt/legs? How do I serialize a C# anonymous type to a JSON string? I'm attempting to use the following code to serialize an anonymous type to JSON:  var serializer = new DataContractJsonSerializer(thing.GetType()); var ms = new MemoryStream(); serializer.WriteObject(ms, thing); var json = Encoding.Default.GetString(ms.ToArray());    However, I get the following exception when this is executed:     Type   '&lt;>f__AnonymousType1`3[System.Int32,System.Int32,System.Object[]]'   cannot be serialized. Consider marking   it with the DataContractAttribute   attribute, and marking all of its   members you want serialized with the   DataMemberAttribute attribute.  See   the Microsoft .NET Framework   documentation for other supported   types.   I can't apply attributes to an anonymous type (as far as I know).  Is there another way to do this serialization or am I missing something? Organic yet accurate modeling with the golden spiral Foreword  First off, let me say that I am profoundly amazed at the orderliness in nature. If you haven't heard about the Fibonacci sequence (0, 1, 1, 2, 3, 5, 8, 13, ...), you should check it out.  This mathematical concept of the Fibonacci numbers can be shaped into a set of squares, where the lengths of the sides of the squares follow the Fibonacci sequence:     This is sometimes called a golden ratio. It can be formed into a (golden) spiral. (a.k.a. logarithmic spiral):      Application  I am looking for ways on how to utilize this concept in Blender. Primarily in organic modeling. The golden spiral is found all throughout nature. From flower seed heads, sea shells, and ram horns to hurricanes and spiral galaxies.  My question is: how can I model based off of one or multiple golden spirals? Specifically, I'm interested in modeling a sunflower head like the one in the following image. I'm mostly interested in the point of origin of the individual seeds (not worried about the shape). Does Blender have any features related to this? $\lim_{x \rightarrow \infty} \lim_{n \rightarrow \infty} f_{n}(x) = \lim_{n \rightarrow \infty}\lim_{x \rightarrow \infty}f_{n}(x) $ in case of uniform convergence of $f_{n}(x)$ to $f(x)$  I used this while I was given that $f_{n}(x)$ converges to $f(x)$ uniformly. Is this correct and I was also thinking to prove this! I'm a beginner at photography and own a Canon 20D with two lens; a 50mm prime and a 17mm-85mm zoom.  I've purchases all my filters at 67mm to fit my zoom lens and use a  to use them with my prime lens.  I'm looking at buying a . My question is, will the same principal work? Can I buy a 67mm wide angle lens and use it on my 52mm prime without any trouble.  One of the reasons for the purchase of a wide angle is my cropped sensor makes the 50mm prime rather close - I'm hoping the wide angle will make it easier to capture more.  Many thanks for any help in advance. Pete Last activity name still missing from migrated question According to this post  this should be fixed. But it happened again.  See Image below (link to )  There was also another migrated question () in the list where the name was missing, but it was edited on meta. Not getting email alerts on answers on Stack Overflow Not getting email alerts on answers on my questions on stackoverflow.com   Used to get it earlier (>1 month back), but not getting alerts in recent times Email field in profile is filled  In prefs, "I'd like email notifications of activity on questions I've asked" is ticked.   What is missing?  Is it possible that signing up on another Stack Exchange community (say, Server Fault), on which by default, "I'd like email notifications of activity on questions I've asked" is unchecked affects same preference on stackoverflow.com? If so, it is a bug. Can an Animagus take the form of any animal? Similar to my old question about  are there any limits to the animal forms an Animagus can be?     We know that the animal form can be much smaller than human (cat, rat, beetle) so I don't think size is a factor.   I'm not aware of any Animagus who transforms into a magical creature (e.g. unicorn or phoenix) so maybe those aren't possible.   Ultimately, what I'd like to know is whether there could be a T-Rex Animagus... (prompted by ) So I found this on the Wolfram website today:     So I was wondering about how one might be able to (if possible) solve those four problems by hand. Here are the problems, $\LaTeX$ed:    $ \lim_{x \to +\infty} \dfrac {\sqrt{x^3-x^2+3x}}{\sqrt{x^3}-\sqrt{x^2}+\sqrt{3x}} $ $ \displaystyle\sum_{k=1}^{\infty} \dfrac {(-1)^{k+1} k^2}{k^3+1} $  $ \dfrac {\mathrm{d}}{\mathrm{d}u} \left[ \dfrac {u^{n+1}}{(n+1)^2} \cdot \left[ (n+1) \ln u - 1 \right] \right] $  $ \displaystyle\int_0^{2\pi}\displaystyle\int_0^{\frac{\pi}{4}}\displaystyle\int_0^4 \left( \rho \cos \phi \right) \rho^2 \sin \phi \, \mathrm{d}\rho \mathrm{d}\phi \mathrm{d}\theta$     Ideas   The degree of the numerator is $\frac{3}{2}$. The degree of the denominator is $\frac{3}{2}$. The expression is of an indeterminate form, namely $\frac{\infty}{\infty}$, so we use l'Hoptial's Rule.  No ideas, really.  Derivatives are always pretty easy, although this one is a bit bashy. Basically bash Product and Chain Rules, etc.  Integration by Parts bash? The $\mathrm{d}\theta$ part is very trivial. I mean for the $\rho$ and $\phi$. How to split a very long equation (using AMSMATH package)? How do I monitor network usage on a Windows server?