What is Ray: Definition and 516 Discussions

Finland's Slot Machine Association or RAY (Finnish: Raha-automaattiyhdistys) was a government-supervised and -owned nonprofit gaming (gambling) association (statutory corporation) in Finland. On January 1, 2017 RAY merged with the government-supervised and -owned nonprofit betting agency Veikkaus and Fintoto. The new company that was founded as a result is also called "Veikkaus". RAY was a gambling monopoly whose proceedings went to domestic charity such as pensioner care and gambling addiction treatment. While RAY was best known for its slot machines, the company also dealt in online gambling and controlled the only official casino in Finland, Casino Helsinki.RAY's operations were governed by legislation and decrees. The operations of the other Finnish gaming organisations, Veikkaus and Fintoto, are also based on the Finnish Lotteries Act. The act was last amended in 2012.RAY's revenue came from slot machines, casino games, and casino and digital gaming. All the proceeds from RAY's gaming operations were used to support Finnish health and welfare, and these funding decisions were also based on legislation.The history of the Tuplapotti predecessor, the Potti game, dates back to 1986, and in the 1990s a newer version of it was developed that rose to much greater popularity than its predecessor. The game was developed by Veikkaus (by then known as RAY), and the game is still one of the favorite gambling games in Finland.

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  1. G

    Gamma ray irradiation and a shielded chamber question

    Hi I was reading an article about a gamma ray materials testing camera built into one of the research reactors that worked in my country a while ago. Now I have a few questions regarding some of the issues the article wasn't informing about. It says that they built a special enclosed and...
  2. esha

    The validity of ray optics in telescopes

    the largest telescope in the world has an aperture of 10 m. According to the fresnel distance this makes ray optics valid for it, for a wavelength of lightsay 500 nm, uptil a distance of 2 * 10^7 m. I have read that after the fresnel distance, diffraction tends to dominate. But telescopes tend...
  3. Allen_Wolf

    Single Ray of Light: Visible from All Angles?

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  4. Ventrella

    A Find a circle inside of and tangent to a larger circle

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  5. W

    B Cosmic Rays Charge: Expect Reissner-Nordstrom Black Holes?

    Cosmic rays are overwhelmingly positively charged. Hence, whatever is emitting them must be building up an enormous negative charge. So should we expect to see highly charged Reissner-Nordstrom black holes out there? Perhaps even near extremality?
  6. T

    I Really parabolic light ray in an accelerated elevator?

    In an elevator "vertically" accelerated at g in outer space, the equivalence principle says a "horizontal" light ray in the elevator looks like a parabola. I completely understand that the light ray is curved but don't understand why the deflected light ray is an exactly parabola. Almost all...
  7. F

    I Propagation of a light ray : Multiply or not by factor

    I am working on a project which consists in calculating numerically the trajectory of a light ray in the Friedmann-Lemaitre metric with the case "k = 0" (euclidean space) and zero cosmological constant. The light ray is emitted by a source galaxy at instant ##t_{0}=\dfrac{2}{3H_{0}}## (today)...
  8. Adam Rabe

    Percentage transmittance gamma ray through lead

    Homework Statement Homework Equations I = Io e^-ux The Attempt at a Solution 0.75 = 1 * e^-u1 using algebra... u =2.117 I = 1 * e^-2.117*3 I = 0.00175 Answer is apparently 42.2. Can someone tell me where i went wrong? Thanks for any help as always
  9. dholbach

    Can a cathode ray tube be made from a light bulb?

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  10. O

    Cathode ray tube, Voltage needed to move the beam impact spot

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  11. C

    Is the equivalent lens of two such that f_1+f_2<h divergent?

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  12. C

    Ray diagram diverging lens both object and image virtual

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  13. Spinnor

    Tracing a ray of light through a spiral phase plate

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  14. Daniel Petka

    B Energy of Gamma Ray Photon with Wavelength h

    What would be the energy (eV) of a gamma ray photon with the wavelength h (Planck's length)?
  15. P

    I Gamma ray cross sections from classical plane wave

    I am aware that in classical electrodynamics a metal exponentially attenuates TEM waves. I am wondering if this fact is sufficient to obtain estimates of the cross section of low energy gamma rays in metals. Obviously it would fail for higher energy gamma rays where Compton scattering and pair...
  16. R

    Energy of the photon emitted in a gamma ray decay

    Homework Statement An Fe nucleus (A=57) decays from an excited stated to the ground state by emitting a gamma ray. The energy of the photon is 14.4 KeV when the nucleus is held fixed. If the nucleus is free to recoil then the energy of the photon emitted will be? Homework Equations ## E =...
  17. Asamad

    Sun ray brightness quality after mirror reflection

    What is the Sun ray brightness quality after mirror reflection and what affects it? How to get the efficiency after reflection?
  18. P

    According to Maxwell, a gamma ray can be as energetic as a radio wave (given equal E amplitudes)?

    According to the old thery of light the energy carried by by a wave is proportional to the amplitude of the electric field not to the frequency as Planck proposed, so an eletromagnetic radiation in the gamma spectrum carry the same energy as a radio one if their amplitude is the same? They only...
  19. J

    Optical Tweezers in the Ray Optics Regime

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  20. T

    Approximating number of collisions in canal ray tube

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  21. F

    Chief Ray Angle and Field of View

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  22. P

    Ray gun from call of duty zombie?

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  23. M

    B Is the Gamma Ray Burst Diameter Wide Enough to Engulf Our Solar System?

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  24. Clara Chung

    How does a gamma ray get converted to visible light

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  25. M

    I Velocity 4-Vector for Light Ray

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  26. Clara Chung

    B What is the recommended method to reduce gamma ray exposure?

    A gamma ray source emits gamma ray to a photographic plate in a container. The book said the blacked region on the photographic plate wouldn't be affected if the gas pressure of the container was increased. However, I think that the gamma ray will ionise more air molecules and lose more energy...
  27. Cocoleia

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  28. Sebastiaan

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  29. C

    Why don't we have gamma ray microscopes?

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  30. CapnGranite

    Effects of a gamma ray burst on earth

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  31. O

    X ray crystallography - interpreting my graph

    Homework Statement I am currently part way through a laboratory experiment that utilises basic crystallography to ultimately calculate lattice constants and structure factors for NaCl (we receive formal training in the next academic year via full treatment of von Laue, Bragg diffraction etc). I...
  32. N

    Stargazing H.E.S.S. gamma ray telescope got an image of the moon

    https://en.m.wikipedia.org/wiki/File:Moon_egret.jpg Can we use better telescopes of this type (ground based gamma rays telescopes) to image the surface and subsurface of a planet with a lot of resolution?
  33. S

    I C60 Fullerene as a Freeze Ray?

    If a c60 fullerene was compressed below 70% of it's volume and accelerated at a target; reaching it before it decompresses, would it lower the temperature of the target on impact? If this was don't with a stream of fullerenes, could it be used like a freeze ray?
  34. Tareq Naushad

    When I lit a laser ray for 10 seconds from a distant planet

    I am on Alpha 4 light years away from earth. On 1st Jan, 2016 I lit a powerful laser light towards Earth for 10 seconds and then switched it off. My friend on Earth knows that he has to detect that light after 4 years on the night of 1st Jan, 2020 from a space station using a very powerful...
  35. SadPanda6022

    Bending of light concept help

    Homework Statement In this lab we used a half-circle container filled with water. Multiple angles are given to measure through the liquid in the container, calculating using snell's equation. However I don't understand why we do not have to calculate for the change in the angle from the plastic...
  36. EBPoncho

    PET/CT Gamma Ray Protection with Lead Apron

    I was informed I might get a better response by posting to this forum, so sorry for the double post. Hello all, I am currently attending a service course for a PET/CT system for my employer. We have been covering the physics behind the function of detectors and my instructor said something...
  37. A

    Cathode Coatings for Electron Emission: Investigating Materials and Techniques

    Homework Statement What 3 materials is the cathode coated with, from which the electron originate? Homework Equations None The Attempt at a Solution From what I managed to find, I think some may be nickel and barium but I'm not sure.
  38. Artlav

    Ray transformation of a 3d lens?

    Greetings. I'm working on a raytracer, and got stuck with trying to model a lens analytically. Given is a thin lens at position p with the axis n, radius r and a focal distance f, a ray hits it at position p1 going in the direction d. Which way would the ray be going on the other side of the...
  39. Chris Frisella

    EM Phenomenon: Magnetism from a Cathode Ray?

    I have recently studied about relativity being the reason for magnetism. The example given was about a magnetic field generated from current down a long wire. When two such wires with current in the same direction were parallel to each other there was an attractive force between them because...
  40. S

    Determining Gamma Ray energy from spectrum

    Homework Statement (Preface: I am not a physicist) The pulse height spectrum of a radioactive source known to emit high energy photons was measured using a small detector. Three distinct peaks were observed at heights of 7.38, 6.49 and 5.60 V, along with a continuous portion of the spectrum...
  41. Z

    For which incidence angle the ray won't come out of the prism's surface....

    Homework Statement A ray of light falls on the surface AC of a prism with a straight angle and with two sides equal. For which incidence angle the ray won't come out of the surface AB. The index of refraction for the prism is n=2. Homework Equations sina/sinb=n2/n1 The Attempt at a Solution...
  42. Eveflutter

    Help! Confused on Ray Diagram for Exam Question

    Fairly simple question I'd like someone to help with please. My teacher has me confused so I figured I'd turn to the forums for help. 1. Alright, so in an exam we had a ray diagram to draw. "Complete the ray diagram shown in Figure 6" they said (I sketched a replica * thumbs up*...
  43. prashant singh

    I Eratosthene's explanation of the sun's ray

    How can we say that when the sun is overhead then its ray will pass through the centre of the Earth , does it happens only at the one place on the earth. How they knew that synene is situated in the middle of north and south
  44. Developer_CM

    Gamma Ray Spectroscopy - 97 keV Peak for U238 Metal

    I recently acquired a 39 gram sample of U-238 metal. I ran a gamma spectrum on the sample and found a major peak around 97 keV. I couldn't find any documents that mentioned this peak for U-238, but it is very prominent. I ran a gamma ray spectrum on a 5 gram Uranium Oxide sample and it also...
  45. T

    Light ray deflected by the prism made of ruby

    i know snell's law is n1sin(theta)1 = n2sin(theta)2, and that sin(thetac) = (nair/n2)
  46. S

    Trace of cathode ray in changing magnetic field.

    I know that cathode rays follow a helical pattern if they enter a uniform magnetic field at an angle less than 90 degrees. This leaves me with two questions. 1. If the cathode ray described above, hit a phosphor coated screen, would it show only 1 spot or a circle? 2. If the magnetic field was...
  47. R

    B Cosmic Ray Muons: Finding Experimental Data for Special Relativity

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  48. Jonathan Scott

    A Gamma ray burst associated with LIGO GW event

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  49. prashant singh

    What Happens When You Connect a 10,000 V Supply to a Normal Tube Light?

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  50. Docscientist

    Understanding the Reflection of Light: Ray Optics and Concave Mirrors

    Why a ray of light passing through the centre of curvature of a concave mirror,gets reflected along the same path?
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