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 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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114 views

Optimal way to heat liquid from the sun?

I understand that one way to tell how much a liquid will be heated up by a remote heat source is by looking at its color. I assume clear and colorless heats up least, then white, other colors and last ...
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139 views

What's gonna happen if a nuclear bomb explodes nearby? [closed]

I live in the capital, 10 km from its center on the 9th floor, my windows facing the opposite direction will I still see a flash? Will I hear something? How loud will it be? How fast would I die? If I ...
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164 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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Why can Hiroshima be inhabited when Chernobyl cannot?

There was an atomic bomb dropped in Hiroshima, but today there are residents in Hiroshima. However, in Chernobyl, where there was a nuclear reactor meltdown, there are no residents living today (or ...
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671 views

When should angles be expressed in degrees vs. radians?

I am trying to calculate the albedo of a given latitude by following the methods of Brutsaert (1982), I have copied the formula below: 3.6 Shortwave and long-wave radiative fluxes Albedo ...
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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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80 views

What type of Radiation hits Europa

I was recently reading the Wikipedia Page for Europa as I am interested in terra-formation. In one of the sentences, it says that: The radiation level at the surface of Europa is equivalent to a ...
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857 views

Alpha particle and helium nucleus

The symbol for the alpha particle is α or $α^{2+}$, it can be written as $He^{2+}$. What I want to know is that, are they same? I mean alpha particle and helium nucleus are same or any subtle ...
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What is the difference between Radiation and Electromagnetic Radiation

Are the two equivalent or is Electromagnetic Radiation a subset of Radiation. I am further confused by the fact that electromagnetic radiation includes both ionizing and non ionizing types of ...
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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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371 views

Why are alpha particles such a prominent form of radiation and not other types of nucleon arrangement?

It is said in many textbooks that alpha decay involves emitting alpha particles, which are very stable. Indeed, the binding energy (~28.3 MeV) is higher than for $Z$-neighboring stable isotopes. But ...
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Effective amplitude in Neutrinoless double beta decay

Can someone give me the value of the effective amplitude($A$) of $\bar{\nu_\mu}\rightarrow\nu_\mu$ oscillation of Neutrinoless double beta decay? The expression is like this: ...
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189 views

$\beta^+$ decay

We've been discussing radioactive decay at school, and I grasped everything except for $\beta +$ decay. When I googled radioactive decay, I immediately found out they dumbed down radioactive decay for ...
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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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Is a beta decay possible with out the emission of an electron in the process?

Is a beta decay possible with out the emission of an electron in the process ? Beta decay involves the formation of a proton and an electron from a neutron.
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Modeling incoming solar radiation

I want to write a model for estimating incoming solar radiation for a specific latitude on earth but I am struggling to find an appropriate source which shows the required equations for doing so. ...
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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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809 views

Does an object's color change its rate of cooling?

The motivation for this question comes directly from this thread. The proposition is that the color of something changes how fast it cools (note: specifically the rate of cooling, not taking into ...
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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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Is it possible to record the 'blue air" effect when a core goes critical?

I've been studying about radiation, and I saw something called the Demon Core. Apparently, it was a core that was under experimentation by the government in Los Alamos to see the exact point at which ...
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75 views

Radiation Pressure [closed]

How much radiation pressure would be required from the sun for a carbon atom on the surface of the Earth to reach an acceleration of 1G? Can you show all the math required for the answer...thanks
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68 views

Nuclear transition notation

I have a question which asks me to determine what x is for the following nuclear transition $$^{29}Si(\alpha, n)X$$ But I don't have any idea what this notation implies. Another example: ...
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What was the first ionization radiation?

While trying to make somewhat of a timeline of the history of ionizatig radiation, i am wondering about the following questions: The first photoelectrical effect was found 1839 by Alexandre ...
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637 views

Determining energy of gamma-rays after alpha-decay of Am-241

So it turns into Np, and electrons just falling into 'free new' levels and emmiting, right? Give me a link where to read, please, if it's very easy to answer.
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The equal opposite reaction of radiation pressure

If the photons of a laser would produce a radiation pressure upon whatever it shown upon wouldn't it be accurate to say that the laser would be propelled in the opposite direction of its beam?
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Beta decay for Ar-38, K-38, Cl-38

I want to prove that $^{38}Ar$ is stable with respect to $\beta$ decay, that $^{38}Cl$ decays by $\beta^-$ and that $^{38}K$ decays by $\beta^+$. I know from Googling that this is true, and I also ...
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$\alpha$ decay to more than one nuclear state

I do not understand how $\alpha$ decay can be a probabilistic process such that there are multiple products from the decay. For example: $^{241}\mathrm{Cm}$ decays to the excited states of ...
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152 views

Radiation exposure to a child who was briefly in the presence of an adult who had received a 18FDG PET scan

I am a physician who thought she was good at math, but apparently am not as I cannot figure out this mathematical/physics question. (My background is obviously NOT nuclear medicine!) A family friend ...
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1k views

Would a laser with four possible energy levels be better than three?

I'm wondering about achieving population inversion for a laser. I learned that without an active medium, it's not possible to create a laser with only two energy levels, but it would be possible with ...
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104 views

Quantum yield and spontaneous decay

I'm trying to figure out how many atoms are decaying spontaneously in a span of 2 seconds. Let's say that the quantum yield is 0.45, and that the lifetime "τ" (tau) is 10 microseconds. Then I found ...
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220 views

Question on Radiance equation

The radiance equation is $$ L = \frac{d}{dA} \frac{2(\phi)}{dW cos(\theta)} (watt/srm^2) $$ where $\phi$ is the flux. I am thinking, should not be the cosine term on the numerator instead of the ...
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240 views

Specific electron energy gap values $E_{i+1}-E_i$ vs. photons with arbitrary energy $\hbar \omega$

The energy levels of electrons in an atom are quantized $E_i$. A photon of a specific momentum $\vec p$ and energy $$\omega=(E_{i+1}-E_i)/\hbar$$ hits an atom and gets absorbed. Okay now say the ...
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A hot object exposed to low temperature in a vacuum doesn't lose heat?

I heard somewhere that if the human body were exposed to outer space where the temperature is extremely low, the human won't actually feel cold because in a vacuum, the heat energy doesn't have ...
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Is it possible to speed up radioactive decay rates? [duplicate]

Possible Duplicate: Do some half-lives change over time? Would it be possible to considerably speed up the decay rate of an isotope? Considerably meaning more then a 1 or 2% increase in ...
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Surface UV exposure with cooler star

If the sun's surface was ~ 4000K (and earth closer to compensate), the UV component of the radiation would be less. However, UV makes ozone via photolysis of oxygen. Also, the stratosphere would ...
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257 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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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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Non reflecting boundaries in waveguides

Can someone please explain the Sommerfeld radiation condition and what is the alternative non-reflecting boundary conditions for waveguides of general geometries?
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How do electrons jump orbitals?

My question isn't how they receive the energy to jump, but why. When someone views an element's emission spectrum, we see a line spectrum which proves that they don't exist outside of their orbitals ...
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489 views

How to interpret Stefan-Boltzmann's law?

The Stefan-Boltzmann equation states $e=\sigma T^4$, but how do we interpret this? Is this completely wrong: A body of size $s^2$ generates the radiation/temperature $T^4$ for a given size and a ...
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Can you speed up radioactive decay of plutonium?

We all know the issue of deep geological repositories for fuel rods. Is there a currently feasible way to speed up the rod's decay to render them harmless in less than 10 years?
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Effect of Background Radiation on a Transmitted Signal

I'm coding a basic simulation of using error correcting codes to transmit data from a satellite back to earth. I'm not sure what to set the "noise level" to. Let's say a satellite orbiting Mars ...
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29 views

Half-Life Question [duplicate]

Possible Duplicate: How do we know that some radioactive materials have a half life of millions or even billions of years? I understand how to calculate decay, but it seems to me that the ...
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260 views

How to detect radiation on the metal (coin)?

I've got metal coin : http://www.worldpeacecoin.org/ Ruble/dollar, a coin of disarmament with certificate. But, I am very spleeny person, I fear of it's radiance level and I don't know if I can trust ...
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179 views

The Deflecting System in a Hot Cathode Ray Tube

In an HCR-Tube, the deflecting system used to deviate the electron beam is made of positively charged plates. How is this justified? If, due to some malfunction, the electron beam deflects from its ...
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69 views

Range of electromagnetic waves

I was reading this article. There is a statement "It is a well-known fact that the telecom towers mounted with antennas in the lower frequency bands can cover far greater areas than those using the ...
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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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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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Does the strong (nuclear) force ever contribute to decay?

Does the strong (nuclear) force ever contribute to decay ? Or is the weak nuclear force the only decaying force ?