Distinguishing monochromatic light from light of a mixture of wavelengths, both of same colour Red, green, and blue are the primary colors of light—they can be combined in different proportions to make all other colors. For example, red light and green light added together are seen as yellow light. This additive color system is used by light sources, such as televisions and computer monitors, to create a wide range of colors. When different proportions of red, green, and blue light enter your eye, your brain is able to interpret the different combinations as different colors.   My question is can the eye distinguish between light of the pure wavelength corresponding to yellow(monochromatically yellow) and a mixture of red and green light that also produces the sensation of yellow in our eyes?  The question is related to the question asked here:   But my specific question is whether the eye can distinguish between the mixture and a pure wavelength of purple.
Why can we distinguish different pitches in a chord but not different hues of light? In music, when two or more pitches are played together at the same time, they form a chord. If each pitch has a corresponding wave frequency (a pure, or fundamental, tone), the pitches played together make a , which is obtained by simple addition. This wave is no longer a pure sinusoidal wave.  For example, when you play a low note and a high note on a piano, the resulting sound has a wave that is the mathematical sum of the waves of each note. The same is true for light: when you shine a 500nm wavelength (green light) and a 700nm wavelength (red light) at the same spot on a white surface, the reflection will be a superposition waveform that is the sum of green and red.  My question is about our perception of these combinations. When we hear a chord on a piano, we’re able to discern the pitches that comprise that chord. We’re able to “pick out” that there are two (or three, etc) notes in the chord, and some of us who are musically inclined are even able to sing back each note, and even name it. It could be said that we’re able to decompose a Fourier Series of sound.  But it seems we cannot do this with light. When you shine green and red light together, the reflection appears to be yellow, a “pure hue” of 600nm, rather than an overlay of red and green. We can’t “pick out” the individual colors that were combined. Why is this?  Why can’t we see two hues of light in the same way we’re able to hear two pitches of sound? Is this a characteristic of human psychology? Animal physiology? Or is this due to a fundamental characteristic of electromagnetism?
Cannot inherit from multiple classes defining __slots__? I am asked to fill the genotypes in the spaces provided but looks like I am aving a little bit of trouble. can anyone help? thanks in advance! Applying for a Canadian ETA after previous visits without one no wifi in Ubuntu 15.04 I cannot see WiFi option in my Ubuntu 15.04. What should I do? Revert asap  lspci -nnk | grep 0280 -A2 output:-  03:00.0 Network controller [0280]: Qualcomm Atheros Device [168c:0042] (rev 30) Subsystem: Foxconn International, Inc. Device [105b:e09a]   rfkill list output:-  0: hci0: Bluetooth Soft blocked: no Hard blocked: no 1: acer-wireless: Wireless LAN Soft blocked: no Hard blocked: no      dmesg | grep ath [    9.545199] ath10k_pci 0000:03:00.0: pci irq msi-x interrupts 8 irq_mode 0 reset_mode 0 [   10.029684] ath10k_pci 0000:03:00.0: Direct firmware load for ath10k/cal-pci-0000:03:00.0.bin failed with error -2 [   10.029701] ath10k_pci 0000:03:00.0: Direct firmware load for ath10k/QCA9377/hw1.0/firmware-5.bin failed with error -2 [   10.029704] ath10k_pci 0000:03:00.0: could not fetch firmware file 'ath10k/QCA9377/hw1.0/firmware-5.bin': -2 [   10.029711] ath10k_pci 0000:03:00.0: Direct firmware load for ath10k/QCA9377/hw1.0/firmware-4.bin failed with error -2 [   10.029713] ath10k_pci 0000:03:00.0: could not fetch firmware file 'ath10k/QCA9377/hw1.0/firmware-4.bin': -2 [   10.029719] ath10k_pci 0000:03:00.0: Direct firmware load for ath10k/QCA9377/hw1.0/firmware-3.bin failed with error -2 [   10.029721] ath10k_pci 0000:03:00.0: could not fetch firmware file 'ath10k/QCA9377/hw1.0/firmware-3.bin': -2 [   10.029726] ath10k_pci 0000:03:00.0: Direct firmware load for ath10k/QCA9377/hw1.0/firmware-2.bin failed with error -2 [   10.029728] ath10k_pci 0000:03:00.0: could not fetch firmware file 'ath10k/QCA9377/hw1.0/firmware-2.bin': -2 [   10.029733] ath10k_pci 0000:03:00.0: Direct firmware load for ath10k/QCA9377/hw1.0/firmware.bin failed with error -2 [   10.029735] ath10k_pci 0000:03:00.0: could not fetch firmware (-2) [   10.029737] ath10k_pci 0000:03:00.0: could not fetch firmware files (-2) [   10.029739] ath10k_pci 0000:03:00.0: could not probe fw (-2) To find the total no. of six digit numbers that can be formed having property that every succeeding digit is greater than preceding digit. I have a question and got strucked on this.. To find the total no. of six digit numbers that can be formed having property that every succeeding digit is greater than preceding digit. Please guide me to solve this. Thanks in advance. Find Documents in MongoDB whose with an array field is a subset of a query array Why do rainbows have distinct colors? Database schema documentation for the public data dump and SEDE What is the accepted/most commonly used way to manipulate dynamic (with all dimensions not known until runtime) multi-dimensional arrays in C and/or C++.  I'm trying to find the cleanest way to accomplish what this Java code does:  public static void main(String[] args){  Scanner sc=new Scanner(System.in);  int rows=sc.nextInt();  int cols=sc.nextInt();  int[][] data=new int[rows][cols];  manipulate(data); }  public static void manipulate(int[][] data){    for(int i=0;i&lt;data.length;i++)    for(int j=0;j&lt;data[0].length.j++){          System.out.print(data[i][j]);           }     }   (reads from std_in just to clarify that dimensions aren't known until runtime).  Edit:I noticed that this question is pretty popular even though it's pretty old.  I don't actually agree with the top voted answer.   I think the best choice for C is to use a single-dimensional array as Guge said below "You can alloc rowscolssizeof(int) and access it by table[row*cols+col].".  There is a number of choices with C++, if you really like boost or stl then the answers below might be preferable, but the simplest and probably fastest choice is to use a single dimensional array as in C.  Another viable choice in C and C++ if you want the [][] syntax is lillq's answer down at the bottom is manually building the array with lots of malloc's. A group $G$ with $G'$ abelian and every abelian normal subgroup finite Let $G$ be a group such that  $G'$ abelian  and any abelian normal subgroup of $G$ is  finite. Show that $G$ is finite. complex polynomial satisfying inequality Some ships in Star Trek are referred to with definite articles. "The Enterprise", "The Defiant". Other ships are referred to without them. "Voyager", "Enterprise". Is there a pattern to or explanation for this behavior? Could anyone tell me what is up with so many archives, and how are they differ?  There's at least five that I can think of, .tar.tz, .tar.gz, .tar.bz2, .tar.lz, .tar.z  Which is best for what applications? It just seems silly to make so many variations of the same file but I'm sure there's a reason. Let $f:\mathbb{R}\longrightarrow \mathbb{R}$ a differentiable function such that $f'(x)=0$ for all $x\in\mathbb{Q}$ Let $f:\mathbb{R}\longrightarrow \mathbb{R}$ a differentiable function such that $f'(x)=0$ for all $x\in\mathbb{Q}.$ $f$ is a constant function? How do I find the angle between two vectors? I have 3 points on my screen:  a = a point which is (c.x, 0) makes a line pointing straight up b = a user input touch, can be anywhere on the screen c = a moving object         a _______.________ |      |       | |      |       |  |   b  |       | |  .   |       | |   \  |       | |    \ |       |  |     \|       | |      | c     | |______._______|   I have drawn some lines so that you can see the vectors.  I want to be able to get the angle between a and b. I have tried this, but it doesn't work, does anyone know what I'm doing wrong?:  //v1 moving object float boxX = this.mScene.getLastChild().getX();  float boxY = this.mScene.getLastChild().getY();  //v2 user touch float touchX = pSceneTouchEvent.getX(); float touchY = pSceneTouchEvent.getY();       //v3 top of screen float topX = boxX; final float topY = 0;  float dotProd = (touchX * topX) + (touchY * topY);  float sqrtBox = (touchX * touchX) + (touchY * touchY); float sqrtTouch = (topX * topX) + (topY * topY);  double totalSqrt = sqrtBox * sqrtTouch; double theta = Math.acos(dotProd / Math.sqrt(totalSqrt));   The answer I usually get is between 0 and 1. How do I fix this so that I get the angle in degrees? How to increase the width and height of the Rich Text area field in Visual force Page? I know this question has been asked earlier. but did not see proper responses so asking again.  &lt;apex:pageBlockSection title="Preview Pane" columns="1"&gt;     &lt;apex:inputTextarea richtext="true" id="EmailBody" label="EmailBody"            cols="1" ondblclick="false" disabled="false"           value="{!emailTemplateSelected.htmlValue}"/&gt; &lt;/apex:pageBlockSection&gt;   I have tried to set the column value for the pageblock section. As well as for the inputtextarea. Still the column width dose not span the entire page.    &lt;apex:inputTextarea richtext="true" id="EmailBody" label="EmailBody" cols="1"     ondblclick="false" disabled="false" value="{!emailTemplateSelected.htmlValue}"     style="height:200px;width:200px;"/&gt; Is commitment necessary to participate in beta (as of June 2015)? There's this proposal for a new S.E. site which is about to enter the beta phase. It reads  This proposal is in: Commitment A successful site needs people to commit to use it. This proposal is 100% complete. Committed users will be invited to the private beta soon.  I'd like to participate in the beta but I don't want to commit (due to a full name being required). Will I be unable to participate in the beta if I don't commit? Temperature and kinetic energy of molecules I was wondering if temperature is related to the average translational kinetic energy of the molecules then why does the average kinetic energy of say a moving object not affect the temperature? What is the mechanism regarding these vibrational motions that imparts temperature. Also do a gas and liquid at the same temperature possess the same kinetic energy? and a heavier molecule traveling at the same speed as a lighter molecule will have a greater temperature? How do I remove gapps from CyanogenMod I installed CyanogenMod 11 on my HTC One with CyanogenMod Installer. So I got also the google Apps (gapps) on my device. But I need a CM11 without gapps. I did then the following without success:   copy cm-11-20140308-SNAPSHOT-M4-m7.zip to /sdcard/ boot to recovery mode -> recovery -> ClockworkMod Recovery v6.0.4.6: "wipe data/factory reset" "install zip" choosing the zip-file "reboot system now"  So I got a new CM11 but with gapps still installed.  What should I do in addition to "wipe data/factory reset" to get rid of this apps? Can you maintain concentration on a spell from another plane?