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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Absorption coefficient from HITEMP or HITRAN [closed]

How to calculate the absorption coefficient (for radiation) from HITEMP or HITRAN databases? Or where can I find some tables or plots for the absorption coefficient?
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Would being underwater help survive a nuclear bomb?

If I jump in my pool, on the river near my house knowing that a nuclear bomb, or atomic or H-Bomb exploded around 10 km from my house, would I survive? The way I see it is that water will protect me ...
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58 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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97 views

Why do I get readings from my radiation meter with magnetized pieces?

What causes those radiation readings in my radiation meter (See the linked video)? Metal pieces were magnetized. Used radiation detector is RADEX RD1503. "Radiation" is not generated if the tube has ...
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1answer
91 views

Per unit of energy, what radiation is the most penetrating?

This question about nuclear reactor shielding got me wondering, what forms of radiation are the hardest to shield? I suppose Neutrinos will have to be excluded since they're the obvious winner. So ...
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277 views

Acceleration of electric charges and radiation

According to classical electromagnetic theory, accelerated charges should emit radiation and lose energy. The reason given in my book why atoms don't emit radiation (say, when the atom moves along a ...
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165 views

Is WiFi safe for humans? [closed]

I have wifi on at my home almost all the time. I learned that the frequency of visible light is around several hundreds of THz, while the frequency of wifi is only several GHz, which is only ...
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1answer
35 views

Explanation of binding energy in decays

Everyone knows that the mass of a system is less than the mass of its components, with the equation: $M = \sum_i m_i - BE(M) $ Now, if we consider a general decay, lets say $A \rightarrow \sum_i ...
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1answer
10k views

What common materials can effectively block infrared radiation?

I have a plastic container and want to make sure that infrared radiation (specifically, in the 750-850 nanometer range) cannot pass through it. Would wrapping it in aluminum foil do the trick? If not, ...
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2answers
99 views

How does gamma ray emission make an atom more stable? [duplicate]

One of the types of radioactive emissions is gamma emission. I understand how the other two types, alpha and beta, help to make the atom more stable. How exactly does gamma emission help to make the ...
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22 views

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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2answers
107 views

Why do $\beta$ particles not get attracted to the nucleus?

I currently have a very limited knowledge of how radiation works etc, but while sat in class the other day, one question occurred to me that even my teacher could not answer. We have been learning ...
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3answers
76 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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35 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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3answers
109 views

Tritium decay is spontaneous even if the binding energy of tritium is higher than the binding energy of 3He. Why?

Given this nuclear reaction: $^3_1\mathrm H\to {}^3_2\mathrm{He}+e^-+\bar{\nu}$ and knowing the binding energies: $BE(^3_1\mathrm H)=8.48 \,\mathrm{MeV}$ $BE(^3_2\mathrm{He})=7.72 \,\mathrm{MeV}$ ...
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1answer
72 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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1answer
82 views

Deriving Rabi rotation matrix

I want to understand where the matrix: $$ \left|\psi(t)\right> = \binom{a(t)}{b(t)} = \begin{bmatrix} cos(\Omega t/2)&-ie^{i\phi_L t}sin(\Omega t/2) \\ -ie^{-i\phi_L t}sin(\Omega t/2) & ...
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3answers
376 views

Any real life demonstrations of radioactive decay? [duplicate]

I'm skeptical about a lot of things in physics, but I have a great interest in it and I'm studying it in college next year. However I am very skeptical about some things. I find that for physics, it ...
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4answers
144 views

Can nuclear transmutation be observed in real time?

Ignoring the quantum zeno effect (if possible?), can we observe in real-time the transformation of one element to another? I'm talking about an amount visible to the naked eye where one could see ...
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1answer
184 views

When (Exactly) Does Bremsstrahlung Radiation Occur?

Regarding the Bremsstrahlung Radiation emitted when a charged particle curves inside a uniform magnetic field; Is there a way of calculating the angle through which the charged particle will precess ...
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3answers
467 views

How to detect Iodine 131?

$I_{131}\rightarrow \beta \text{ 333.8 KeV(7.27%)}\rightarrow \gamma\text{ 636.989 KeV(7.17%)}$ $I_{131}\rightarrow\beta\text{ 606.3KeV(89.9%)}\rightarrow\gamma\text{ 364.489KeV(81.7%)}$ (you can ...
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1answer
91 views

X-ray production rate [closed]

A 100 MeV proton beam of $10^{14}$ proton/s is perpendicularly incident on a rhodium foil 25 $\mu$m in thickness. Estimate the production rate of K and L x-rays(use the figure below). So far I ...
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4answers
376 views

Detecting radiation from tritium keychain

I am measuring radiation from 6 tritium glow keychains. Usual gamma detector does not detect anything (this is expected), but on beta detector with thin window I am getting about 5 counts per second. ...
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1answer
124 views

Physics and Skin Color: What differences do physicists observe between different skin colors?

I majored in social sciences, so I haven't taken a science class since 1999, so forgive me if I don't ask this right. What difference would skin color make from a physics perspective? Would there be ...
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2answers
48 views

How to measure the wavelengths of ultraviolet lines in the hydrogen spectrum?

how to measure the wavelengths of ultraviolet radiation isn't it invisible? it's possible to measure visible radiation but how to measure invisible radiation?
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2answers
76 views

Rutherford alpha scattering?

From Rutherfords alpha scattering, where alpha where fired at a thin peace of metal foil, he concluded that the nuclie was positivly charged. He made this conclution from the fact that alpha particles ...
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1answer
86 views

How did Lyman discover his series?

How did Lyman discover his series in hydrogen atom? How did he know that the final energy level is the first level and not the second or the third or etc.? Or how did the other scientists know which ...
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2answers
1k views

How is the Earth heated by a Full Moon?

While the moon is certainly not a good reflector of solar radiation, surely the radiation it reflects back heats the Earth (even if it is a terribly small amount). How would one go about calculating ...
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1answer
398 views

How does heat energy travel in space?

How does the heat energy from the Sun reach us on the Earth? Since the kinetic energy of an atom is the amount of heat energy and there is no matter in space, how does heat from the Sun reach us?
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1answer
172 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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3answers
956 views

Why is the black body radiation so important?

In the derivation of the black-body radiation formula the assumption is made that the system is an electromagnetic cavity, so that it can be considered in thermal equilibrium. Leaving aside the fact ...
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1answer
322 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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1answer
54 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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1answer
205 views

Calculating the number of quanta emitted as Cherenkov radiation in a wavelength interval dl?

This website gives an equation for it http://math.ucr.edu/home/baez/physics/Relativity/SpeedOfLight/cherenkov.html It appears as plaintext but this is what I believe it is parsed: $n = \dfrac{dl 2πα ...
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2answers
197 views

How can we detect cosmic background radiation?

From what I understand, CMB is the left over radiation from the Big Bang. As all matter, including the Earth, was made during the Big Bang and then as the universe expanded that matter/energy got ...
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1answer
105 views

Blackbody radiation and Spectral Lines [duplicate]

Blackbody radiation is thermal radiation from a hot object emitted over a continuous range of wavelengths. But why are spectral lines, lines (i.e., you only get certain wavelengths when an element is ...
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2answers
216 views

Does magnetic geometry determine the scaling of a Polywell fusor?

Does magnetic geometry determine the scaling of a Polywell fusor? Forgive imprecise terminology here - by "magnetic geometry" I mean the configuration of the magnets, the configuration that creates ...
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1answer
49 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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0answers
28 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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1answer
133 views

Energy balance for beta decay of cobalt-60

I am confused by a simple fact about the $\beta^{-}$ decay of ${}^{60}{\rm Co}$ nucleus. According to Wikipedia, the most likely decay branch is to an excited state of ${}^{60}{\rm Ni}$, see the ...
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1answer
50 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 ...
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2answers
126 views

Absorption of radiation due to temperature

I was wondering if the temperature of an object affects the amount of radiation it absorbs. For example, if I have a box that is hotter, will it absorb more energy as compared to the same cooler box? ...
2
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0answers
173 views

Effects of microwaves on optical properties of human eye [closed]

I have read a long series of paragraphs on wiki. Previously I thought that microwaves are not harmful to living beings but Wiki does not claim this explicitly. while doing an experiment in my college ...
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3answers
142 views

What is radiation(in simple words)? [closed]

I am a student who is interested in scientific facts. I want a simple definition for radiation. Neither too scientific, nor too simple.
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1answer
65 views

Characteristic x-ray in energy spectrum

Context: Monte Carlo simulation of a linear accelerator photon beam. The energy spectrum for photons as calculated from the phase space files found in here has a peak somewhere near ...
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2answers
44 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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1answer
52 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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1answer
3k views

Kinetic energy of alpha-particle in $^{212}$Po decay

Admittedly, Nuclear Physics is not my strength. I'm writing a simulation to model alpha-decay. So far, I have looked up the values of the kinetic energy of the alpha particles that are emitted in a ...
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3answers
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Is it possible to avoid the radiation that caused the American flag turned into white on the Moon? [closed]

While lunar images have proven that the American flags planted during the Apollo missions are still standing on the moon, lunar scientists have now said that they probably no longer hold the iconic ...