Detection Definition and 324 Threads

It is promised that the quantum coherence will help to improve various measurements. Is it theoretically possible to improve detection of neutrinos with help of quantum coherence?

http://en.wikipedia.org/wiki/Coherent_state#Quantum_mechanical_definition From the link above: "Physically, this formula means that a coherent state is left unchanged by the detection (or annihilation) of a particle." My question is, why is detection of a particle equivalent to...

I am designing a laser targeting system on which various control methods will be implemented and compared. The system consists of a laser pointer mounted on a two axis gimbal. The laser shines on a 30 cm x 30 cm white screen, behind which is a digital camera. The camera sends all information...

Is there a simple method or inexpensive hand-held device available for Hydrogen gas detection?

I have heard that autocorrelation is used in pitch detection, but no proper or convincing explanation of how it is used. I had previously worked on echo removal using autocorrelation. But what puzzles me is that autocorrelation is done in time domain but how can this be used to detect...

Here are some recent papers on attempts to detect dark matter directly or indirectly: a solar system test with a possible positive result: http://arxiv.org/abs/1001.1697 direct detection, with seemingly contradictory results: http://arxiv.org/abs/1106.1066 via gamma-ray astronomy...

I have a vessel (~2 liters) that is filled with gases for combustion. It is made of some sort of steel and has various ports drilled out for diagnostic instruments. The vessel is spherical and is made from 2 hemispheres with flanges that are bolted together. An o-ring helps to seal the...

Hello. I used discrete electron multiplier (dynodes) for positive ions detection, and it works fine. Now I want to use it for electrons detection with no changes in mode of connecting power supply (-2 kV on 1st dynode, 0 V on last one) . In the past application I don't use the reflector...

I have created a very simple numerical simulation that models an object being thrown off a building at some angle, and when the object hits the ground, the simulation stops. Now I want to add in collision detection. How would I go about doing this? What would be the equations needed to compute...

what are fatigue cracks? what are the major sources of fatigue withing the fuselage? how can fatigue cracks be detected during inspection? how can the risk of fatigue cracks in the fuselage be reduced? why are they dangerous? what is their origin? I've tried to find answers for these...

One of my high school students recently demonstrated that the camera in an Android will detect the IR signal of a remote control, but the camera in an iPhone will not. (I understand that screening out IR is desirable in photography, and the distinction is arguably a matter of camera or filter...

Hey guys I'm looking for some good reading material on the following extrasolar planet detection techniques (not sure if there are any other...) Radial velocty Transit monitoring Microlensing Detection of IR thermal emission Direct Imaging. Basically I'd like to read about what these...

Hello Can anyone explain to me what measuring quadratures are in relation to homodyne detection? Thanks

Hello guys I was a confused by this part of the Wiki article on "Double-slit experiment": It seems like all the (popular physics) accounts I'm familiar with go out of their way to endorse exactly the point in question. Is the author of the wiki article trying to impress that "detection" is...

OK...I'm not sure how well I'll word this or if it's a coherent idea biologically but I'll throw it out there anyway... Regarding the evolution of senses - let's take the detection of sour tastes as an example. I know little neuroscience but I know that there's the involvement of H+ ions as the...

Refer to the delayed choice quantum eraser (DCQE) ...for example the kim paper http://en.wikipedia.org/wiki/Delayed_choice_quantum_eraser" i have a few questions, to understand this better, 1. Once the signal photon has been detected at D0, can the path of idler photon be...

(This a new thread as proposed by Borek post #2349) Neutrons and neutron "beams" are very hard to detect with portable instruments. The most common portable instruments are gas proportional counters using thermal neutron capture in BF3 (boron tri-fluoride) or He3 gas. Proportional counters...

Hi, How am I suppose to tell a computer what an undercut is? I myself am finding it hard to classify different features on a job as an undercut or not. Please help.

Is there any relatively not difficult way to detect if hydrogen peroxide (H2O2) is present in pure water? I can think of a few obvious ways for high concentrations but what about concentrations of around 0.001mol%? Is there a way of detecting concentrations that small or smaller?

RedZone, Second Life IP Address Detection Tool, Runs Afoul of New SL Policy, EU Data In an odd turn of events that is all too common online these days, an ingenious system created for Second Life land holders to reduce incidents of harassment and abuse by malicious griefers has itself turned...

http://www.scientiaweb.com/2011/02/28/smartphone-app-that-helps-doctor-detect-cancer/ Researchers at Massachusetts General Hospital in Boston have developed a system to detect cancer in a patient that will save them from many painfully long tests needed otherwise.

Let's say you have two pulses from the same source, one whose phase is slightly delayed relative to the other one. Now, I know that you can use an interferometer and a balanced detection-type scheme to measure the phase shift (in which case you can be shot-noise limited), but I'm wondering if...

1. I have a problem like this: I. As you see (in the attachment) each of the closed polygons (as in the attachment) is called a BAY II. The logic I need is: The user of my program will select a bay (with a mouse). And after selection he would want the program to draw some vertical (or...

Hi all. For a project I am doing, I need to find a motor with an encoder that we can use to detect the exact angular position of the shaft at any given point in time. I'd like to see if there is any motor out there with absolute feedback from the encoder - i.e., that I would be able to read...

Hello, this is my first topic. but i was thinking, Theoretically if you have a way to detect radiation from far distances, couldn't you detect the radiation from black holes?

Can anyone suggest to me a simple circuit constructed using digital gates for polarity detection? The circuit should be able to detect positive, negative as well as zero polarity. I need to check the polarity of a dc motor which is controlled by a bidirectional converter. The bidirectional...

Homework Statement You are to design a coating to enhance the detection efficiency of a silicon detector (n=3.42 at \lambda=351nm) (a) Is the coting a reflection or antireflection coating? (b) Should you use a higher or lower index material for the coating? Specify a material to use. (c)...

I hope this is in the right section of the forum. I figured astrophysics and cosmology could also be acceptable places to ask this. I was watching Lawrence Krauss's talk about everything from nothing, the one with the richard dawkins introduction. He talked about methods for trying to detect...

i m designing a MATLAB code for detection of heart murmurs... i applied segmentation using wavelet decomposition and reconstruction now i m doing peak detection can somebody help me how to do peak detection in matlab

Is there an experiment that uses photons or other particles to measure the effect of Earth's rotation on them? Thanks

(1) In the double slit experiment, if I fire individual electrons at the slits, is there a chance that an electron could interact with one of the atoms making up a slit in such a way as to alter the energy state of one of its shell electrons. i.e. I could imagine there is a probability of...

I want to know the ways newly created particles are detected during collisions such as in LHC or Fermilab, i.e either they check the EM force, electric charge being observed or other things...

Hi I am trying to develop a standing wave inside a rectangular cavity and detect it using a microphone.In one wall of the cavity ,I placed a loudspeaker and driving it at a frequency of 8.3 Khz. The chanel has a thickness for half wavelength standing wave. I am trying to detect the nodes...

Greetings, currently I'm working with cosmic rays (merely researching, not so much as working) and now I have a question regarding cosmic rays and cosmic rays detectors (specifically, Cherenkov detectors). How is the number of photons detected by the PMT's (photomultiplier tubes) related to...

Hey experts! I've designed an infrared detection circuit to drive a motor, but I need the circuit and my math checked. I tried 5Spice, but I can't get my head around it. Circuit image attached. Do you know about how far I would be able to detect someone crossing in front of the light? I need...

I'm trying to figure out the best way to find a collision between a moving circle and a stationary line segment. I have the x and y of the point, and the x, y, radius, x velocity, and y velocity of the circle. //Edit: I tried using the equation of a circle with the origin at the point (P)...

Hi, I'm trying to design a system which will be able to detect a hot object on a cold surface. The downside is the temperature difference is only 1 degree celcius and I'd like to use IR from a distance of about 10cm (further away preferred if possible). Does anyone with any experience of...

Hi, I'm not a physicist although I've studied it to first year degree level in the UK many many years ago. I was just reading an article today on the BBC about a new image that's been captured of the visible universe. The following quote got me thinking and I wondered if your expert knowledge...

Hi. I am using a 3 axis accelerometer for motion detection. I can easily determine the tilt using simple triginometry but cannot determine the movement in a particular direction. For example the sensor is at 45 degrees to the floor so the x,z coordinates are x = 0.5, z = 0.5. So if I keep the...

Hi I'm studying decay of atomic nucleus. Alpha and beta rays are essentially particles and their path are easily traced. But high frequency gamma rays easily penetrate metal foils, and I wonder that how gamma rays are practically detected and measured in lab experiments? Is photo-electric...

My understanding of how interferometers work is that they detect gravitational waves because they alter the distance between two mirrors as they pass through. They do this by using the wavelength of a laser beam passing through this space. However, shouldn't this always fail to detect anything...

my view. The current theory of the higgs field is based on the higgs boson. Now a boson, in theory has to conform to the rules of super-fluidity or a Bose-Einstein Cond. I can confer because of this, All higgs bosons, would be interlocked as a field acting as one particle. I can say that since...

So my mind tends to wander, but I was thinking... since active/passive sonar is used to detect objects underwater, couldn't thermal imaging be used as well (in conjunction)? Isn't there any reason why we couldn't combine the two sensors into cooperatively working together to detect submarines...

For this question I am considering a slit diffraction experiment set up as follows: {Monochromatic source} ------> {Single slit} ------> {Diffraction grating with N slits} ------> {Screen with small movable detector} The monochromatic light source emits photons one at a time. The principal...

I'm doing signal processing using MATLAB. But facing problem when doing Peak Detection. This is the signal that I used for the processing: This is what i wish to do: a) the horizontal line is the threshold point and b) the circle is the peak detection Can anyone help me...

As part of an engineering design project, I am using shock switches to measure accelerations of an object. As the name suggests they are just switches that turn on when a shock above a certain value is experienced. Does anyone know the details about how the switch contact is closed when it...

I am designing a system that must automatically detect if a person is inside their office. The trick here now is that there are people going in and out and i just want to detect the owner of the office. Tracking them is useless since the average office sizes are not big, 5m width maximum so my...

Hey everyone! I programmed a verlet physics engine that works great. I got to the collision detection and response and it's been frustrating to say the least. I've tried tons of different ways, but no cigar. The collisions themselves are between points and lines between points. These...

Hi, I've got a problem with collision detection of which I am struggling to find a solution. In the simplest case, I would have a sphere whose movement would be constrained inside a closed arbitrarily-shaped object. I have been looking into BSP trees which split the shape into chunks...

What is the state-of-the-art of detecting gravity waves. Are the instruments available now sufficiently sensitive to detect gravity waves? Have we identified 'low-hanging' sources from which gravity waves should have been detectable. Have we yet reached the point where doubts are arising as to...