Radiation is a process in which energetic particles or energetic waves travel through a medium or space. The particles or waves radiate (i.e., travel outward in all directions) from a source.

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How do I calculate the Radiation length of a Molecule

I want to calculate the Radiation length in a Molecule with the Formula given on wikipedia. How do I calculate Z and A for a molecule to put it into the Formula?
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Light vs. X-ray interactions with Phosphor

Looking for some information on how light and xrays interact with phosphorous, or what might cause the following: Scenario A focus beam of light is directed at a phosphor plate at the same time as ...
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133 views

How to solve the Fukushima incident?

I am trying to find out if it is somehow possible to take all this nuclear material, put it in some type of gamma chamber or blast it with neutrons to change the uranium isotopes into something ...
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205 views

Does brightness of the light remains constant with the variation of the distance with respect to the source in vaccum?

I have this question going in my mind from many days, i.e why brightness of light emitted from any light source around us decreases with distance? The brightness of light from tube light, streetlight, ...
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51 views

Measurement of heat in electrons

Is there any method to measure the heat of an electron and if there is; then is it a constant or a variable.
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1k views

How can there be heat in a vacuum?

I keep reading in the Physics World focus issue on vacuum technology about scientists creating high temperatures in the vacuums etc. If heat is caused by thermal energy being radiated from particles ...
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201 views

How can we detect a black hole? [duplicate]

If black holes are phenomena of very high density (gravitational singularities) which don't emit radiation how can we detect them so far away from us where so much other radiation can hide the black ...
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458 views

What isotope has the shortest half life?

Question: What isotope has the shortest half life?
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263 views

What is the halving thickness of diferent materials against high energy gamma rays?

By high energy gamma rays I mean 10+ MeV to 100 MeV. Is there a way to calculate it ? Also, at these high energies, do heavier elements like Lead for example still have the advantage over lighter ones ...
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2k views

How to calculate incident solar energy on earth in a given day with a spectral filter

The daily solar radiation irradiation is often quoted as being between $3.2 \text{ kW hours}/\text{m}^2$ and $7 \text{kW hours}/\text{m}^2$ per day . If you filter out a range of wavelengths, how can ...
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335 views

Do and can phone signals come inside AC car which is glass-packed

Can phone signals penetrate glass, so can I expect phone signals to come if I am sitting inside a closed AC car. Thanks,
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55 views

Why do grey body radiators not heat up?

So I'm doing so work on the earth's climate system, and modelling it as a grey body radiators, and I've come across the phrase: "$62\%$ of the outgoing energy is lost to space and the other $32\%$ is ...
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194 views

Study of Black-body Radiation

Why did scientists study black body radiations from something as complicated as a hollow container rather than the radiation from something simple like a thin solid cylinder?
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124 views

Computing $\Delta m$ in $\beta^-$ decay

$\require{mhchem}$What is the energy $Q$ released when $\ce{^131_53I}$ decays and $\ce{^131_54 Xe}$ is formed? The atomic mass of $\ce{I}$ is $130.906118~u$ and the atomic mass of $\ce{Xe}$ is ...
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191 views

How to choose a $\alpha$, $\beta$, $\gamma$ measurement detector?

There are many different detectors for different radiation,such as NaI,HpGe,CsI for $\gamma$ detection,and ionization chamber,proportional counter,Geiger counter for $\alpha$, $\beta$ detection,but ...
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28 views

Alpha scattering, observations and conclusions

For Rutherford's alpha scattering experiment where he fired alpha particles at a thin sheet of metal to determine the size of the nucleus, please can someone give me the direct link between his ...
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167 views

1/r Counting Rate for Radiation Experiment

In an experiment performed in the lab, I want to justify that, when the width of the Geiger counter window is approximately the same size as the distance between the window and a mildly radioactive ...
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98 views

Does halving the intensity of a gamma ray mean absorbing half its energy?

Say a 1 MeV gamma ray is shielded by 1 cm (halving thickness) of lead. Now, what does "havling the intensity" mean ? Like will the new gamma ray exit with energy of 0.5 MeV ? and by that we can say ...
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191 views

What type of electromagnetic radiation strikes the Earth's surface the most?

If you can could you lists the types of light from the greatest amount to the least amount (Ex: Visible, Infrared, Violet).
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356 views

Alpha decay, why does it occur? [duplicate]

I was reading about alpha decay and why it happens. The strong force holds protons and neutrons together, but I don't get why does an atom emit helium nucleus when it has too many ...
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61 views

Does it happen at high energies (heavier leptons decay)?

A lepton is an elementary particle. The best known of all leptons is the electron which governs nearly all of chemistry as it is found in atoms and is directly tied to all chemical properties. The ...
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214 views

Is it true that an isolated fundamental particle does not decay?

Is it true that an isolated fundamental/elementary particle does not decay? It seems logical to me.
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478 views

How is tritium illumination possible without negative health effects?

Turns out there's tritium illumination - a tiny very strong plastic tube will be covered in phosphor and filled with tritium. Tritium will undergo beta decay and a flow of electrons will cause the ...
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371 views

How is a cathode ray tube different from beta minus radiation?

In beta minus the result is one neutron in the nucleus changing to a proton, plus an electron and an anti-neutrino being sent off. The antineutrino is indifferent to our health. So I guess what ...
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27 views

Increasing Earth's albedo

How much of a difference would it make if every roof, road and vehicle were painted white? This would certainly reduce the urban heat island effect but how much of a difference would it make to total ...
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57 views

Observation of light bending spacetime [duplicate]

Has radiation or energy bending spacetime ever been observed? If not, is it likely that it ever will, assuming current technology? Note: This is not a question of space bending light, but of light ...
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40 views

Calculate the effective linear attenuation coefficient of a megavoltage multi-energetic beam

Are you aware of a method or source for calculating the effective linear attenuation coefficient,$\mu_\text{eff}$, of a megavoltage multi-energetic beam ? For a mono-energetic beam one could use the ...
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29 views

In what forms do fire energy transfer in common situations

Yesterday I was standing by the campfire. I used to think that campfire heat carried to me only by air. It was heating my face too much, so I blocked it with my hand just like blocking the sun. Then ...
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188 views

is an electron gun dangerous?

Is an electron gun dangerous & what would be the repercussions to human tissue? If I were to do a DIY electron gun and put my hand in the beam would I regret it?
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56 views

How many radiotherapy sessions would it take to boil one cup of water? [closed]

Context: Gray (Gy) is a unit dose used in radiotherapy. It is defined as the absorbed energy of 1J per kilogram of matter. There is a wide misconception that ionizing radiation acts by heating ...
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47 views

$α$-decay and electron

I'm a Web developer and I'm working on a physic interactive Web page to represent how atoms interact. I'm reading information about α-decay and here is what I understand. Let's say we have a isotope ...
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36 views

Measuring radon level

In theory what are the techniques used to measure the levels of radon in air? On which principle/law do they rely?
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88 views

Radiation at plate of vacuum tube

Say you have a vacuum tube, such as the kind used in old amplifiers, wherein electrons are accelerated from the cathode to the anode through an electric field. Presuming, for the sake of argument, ...
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148 views

Mean stopping range of $\alpha$-particles in air

I did an experiment in university in which I determined how far $\alpha$-particles emmited from an $Am^{241}$ source penetrate into air. I want to compare my result to literature values but... I cant ...
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344 views

Inverse Square Law in Beta Radiation

Setup: A radioactive source is placed at alternating distances from a Geiger Counter. Counts per second for 10 different distances (each spaced 1 cm apart) were taken for preset times ranging from 200 ...
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150 views

What is Equilibrium Equivalent Concentration (EEC)?

Recently I am doing a research about radon measurement. During the process I met two concepts named Equilibrium Equivalent Concentration (EEC) and Potential Alpha Energy Concentration (PAEC), but ...
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211 views

Can there be energy with no force or energy with no power?

I think that both force (number of newtons) and power (p=ui(?)) implies that there is energy so we can't have force without energy and we can't have power without energy(?) But can there be energy ...
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234 views

effects of sunlight through a glass window?

Both my father and my grandfather where drivers, and over time ended up with a wrinklier left hand compared to the right hand, due to sunlight exposure over 40+ years while holding the steering wheel ...
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256 views

What is the relation between surface area and radiation, if any?

Basically I wonder what happens to emitted radiation by douubling a light e.g. twice the surface area of the sun will emit how much more radiation? 4 times more? Is there a formula?
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133 views

Radiative transfer equation solution

The solution of the radiative transfer equation for spherical ionized blob : \begin{equation} \frac{dI_{\nu}}{ds} = j_{\nu}-\alpha I_{\nu} \end{equation} and solution is (Ref: ...
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3k views

Why are umbrellas black?

Why are umbrellas specifically in black? Of course we do have colored ones, but black is the majority. Is there any scientific reason behind it?
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33 views

Is it possible to generate electric energy from the radiation of radioactive materials

I wonder if it is possible to generate electric energy from the radiation of radioactive materials like nuclear waste? If it is then wouldn't that also mean that it could be used as an energy source ...
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37 views

internal conversion and the electromagnetic force

I have read that the mechanism behind internal conversion, in which a nuclear transition leads to the ejection of an electron in one of the lower atomic orbitals, is related to the fact that the ...
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Why is relative biological effectiveness of photon and electron the same ?

I was wondering, why seemingly two distinct particles have the same RBE (relative biological effectiveness) ? Would the charge of electron not do more/less damage ? While on the subject, does anyone ...
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47 views

Could airport security devices detect differences between printed and written documents?

If airport security scanners of any kind (xray, thermal, whatever else they use) looked at two items: A printed paper textbook The same printed paper textbook into which we have inserted a regular ...
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45 views

Calculating a radioactive sample's mass from its activity [closed]

The question reads as such: "What is the mass of a 1.05 µCi carbon-14 source?" First I convert to decays/s: $R = 1.05 µCi=3.885 \times 10^4 decays/s$. The half-life for carbon-14 that we've been ...
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24 views

Rutherfords alpha scattering conclutions? [duplicate]

Please can some one give me rutherfords observations and his conclutions from each onbservation, I have looked in text books but they only give them sepratly with no direct link betweeen which ...
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19 views

How to compute radiated power from known instantaneous potential distribution

Friend of mine has a device that has an oscillating electric potential and he wants to know how much power it radiates. He can simulate the instantaneous electric potential using a software package, ...
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10 views

Dangerous levels of ozone from combined UVB lamps?

I have a reptil UVB lamp in my room, and a de-humidifier that uses a UV lamp to clean the air passing through it. Honestly since I got it working (the lamp was dead at first) my room is mold free. I ...
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43 views

Algorithm for distribution of radiation

Unstable atomic nuclei will spontaneously decompose to form nuclei with a higher stability. What is the algorithm for deciding what sort of it is? (alpha, beta, gamma, etc. Also, given that alpha and ...