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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Electric field radiation with moving charge and observation point

I've been working on Chapter 34 of the first volume of the Feynman Lectures on Physics http://www.feynmanlectures.caltech.edu/I_34.html#Ch34-S1. In Fig. 34–3 (reproduced above) Prof. Feynman shows ...
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48 views

What produces this 477 keV spectral line?

Question about a specific line on a gamma spectrum, here. Below is a background gamma spectrum observed by a Ge[li] detector. I've been able to identify all the lines with mostly certainty, apart ...
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Gadolinium poisoning vs Holmium Poisoning [on hold]

Question here on the poisoning used around neutron spallation sources (or reactors, or any neutron source). I use poisoning in the sense of absorbing neutrons to prevent their release into the outside ...
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24 views

Gamma spectrum: Question about cross sections

If I have a gamma spectrum and I suspect that I should have an isotope, Fe-59 for example, present in the environment, I will then look here: ...
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27 views

Atomic/nuclear physics question

I've got what's probably quite a basic question here but I can't get things clear in my head. If I have a cobalt isotope like Co-56, is it possible for this to undergo Neutron capture (becoming ...
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3answers
342 views

Fission of U-235 produces Cs-137 along with…?

Question about Nuclear fission in general, here. If I have the fission of U-235 and I know that one of the products is Cs-137, is there a way of figuring out the other product? Should there be ...
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Earth's magnetic field shields us… from what threat?

This is a nice artistic picture of the magnet field of the earth, shielding us from the solar wind. (source) Wherever you look, it is stated that without our shield, life would not be possible on ...
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143 views

Matter to energy conversion

Okay so I have a question, during a nuclear explosion or particle/antiparticle annihilation, matter is converted into energy. How do I determine if a from a explosion will come lets say a small ...
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27 views

Nuclear decay of V-48

I have a question on the "decay" of Vanadium-48. The reason it's in inverted commas is because I'm not sure whether decay is the right word. Basically what I'm trying to work out is whether it's ...
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46 views

How gamma rays are produced? [closed]

Radio active materials emit alpha beta and gamma rays. My question is, what causes (at subatomic level) an atom to produce such a powerful gamma rays and Suppose if I bring a fluorescent bulbs nearby ...
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Lens-Mirror systems and conservation of specific intensity

This came out of a discussion I started yesterday and a related discussion I found. I'll recap the problem quickly: Consider two blackbodies, with surface areas $A_1$ and $A_2$ and temperatures $T_1$ ...
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38 views

Definition of Sievert (Sv) unit - is it whole body mass?

I'm wondering about the definition of the Sievert (Sv) unit. It is J/Kg but is that Kg the mass of the whole body or just of the exposed body part? For instance, when a table says that an x-ray of a ...
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41 views

Light is EM radiation or field [duplicate]

What is Difference between EM Radiation and EM Field. Are They all are different quantities or interrelated with each other. Do they both follow inverse square law.Is light EM radiation or Field
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What is the strongest material transparent to alpha radiation?

Is there a material which is transparent to alpha radiation while being able to hold up under atmospheric pressure on one side and ultra high vacuum on the other? Put simply, what material is thin ...
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50 views

Why conductors don't scatter light?

Air molecules can be oscillated by E field and re-radiate EM waves in different directions. However, if light is shined to a conductor the E field oscillate the free charges but the effect is to ...
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2answers
37 views

How do we tell the CMB apart from other radiation?

Say I want to observe the CMB and the CMB only. I point my device (telescope in some frequency range) at the sky and start looking. How do I know it should be in the Microwave spectrum? How do I ...
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60 views

Explain Stefan-Boltzmann Law?

Can someone explain the Stefan-Boltzmann law in an easy-to-understand way?
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131 views

In the Iranian nuclear deal, how can IAEA detect nuclear activity after 24 days?

This is a question related to current events, but I want to ask about the physics, which are not explained in any news article that I can find. Ernest Moniz and John Kerry wrote an op-ed in the ...
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45 views

Current constraints on lightest neutrino mass?

This paper from 2005 claims that the mass of the lightest neutrino is unconstrained. (see p9) Oscillations are only able to constrain the differences in squares as far as I know, but perhaps ...
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45 views

Why does the cloud chamber trails differ in length?

Why does the cloud chamber trails differ in length? Also, why does the cloud chamber trails branch into Y-shape?
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22 views

Is it normal for radiation levels to be elevated near a medical imaging lab?

I work in a general-purpose, commercial office building where the first floor is dedicated to an x-ray / imaging lab for medical diagnostics. The public lobby of this building is routinely ...
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58 views

What force decays an oscillating charge?

Consider this scenario: We have a charge on a spring. As it oscillates, it loses energy to radiation. What force decays the oscillation? As far as I can see, the only forces in the scenario are ...
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2answers
271 views

Radioactive decay as pure radiation of neutrinos and antineutrinos?

Is it possible with radioactive decay as pure radiation of neutrinos and antineutrinos? From a theoretical point of view? I'm not asking for processes since I'm convinced there are no known processes ...
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36 views

Removing virtual surfaces in view factor calculations

I've managed to get myself into a quandary. I am looking at (radiation) view factors and I subdivided my system to make the math easier. Now I'm having a hard time figuring how to put the system back ...
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72 views

If temperature is dependent on mass, how did the early universe have a temperature?

I am near the end of the book The First Three Minutes by Steven Weinberg. I am reading it in order to get a better picture of the early universe in the Big Bang model. But one thing I am having ...
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27 views

Can natural gamma radiation be induced by cosmic rays?

When cosmic-ray particles like muons or neutrons impinge the ground, they get slowed down, thermalized and captured. This process is most effective when water/rain/moisture is present. Furthermore, ...
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64 views

Radiation from home heaters [closed]

My understanding of radiation is energy being emitted from a source. So much radiation would come out of a home gas or oil heater to become dangerous. I'm assuming infrared radiation.
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99 views

The logarithmic decay of WIFI

I have been told that Wi-Fi, LTE etc signal strength fall of as $$\propto \frac1{\log(r)}$$ where $r$ is the distance. I am wondering why this is. I better explain what I mean with this question. ...
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47 views

Kalb-Ramond action and topological string radiation

Let's have simple scalar $\Phi$ action involves spontaneously symmetry breaking in a form $$ \tag 1 S = \int d^{4}x\left( |\partial_{\mu}\psi|^{2} + \psi^{2}|\partial_{\mu}\theta |^{2} - ...
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69 views

What's the idea behind Wu's experiment?

Madame Wu discovered the parity violation in beta-decays. To do so, she took some Co-60 nuclei, which decay via beta-decay in Ni-60 with emission of electron, antineutrino and 2 gamma rays. She ...
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51 views

Why did scientists use a zinc-sulfide coated screen to detect the alpha, beta, and gamma radiation?

How does a zinc-sulfide coated screen work, and how does it manage to detect high-frequency radiation, electrons, and helium? Could it be possible that a delta ray managed to somehow slip past ...
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41 views

How to derive the Gamow factor in the simplest way?

I want to know how to derive the Gamow factor (how to solve the integral and which approximation I have to do) without the centrifugal correction. $$V(r) = V_N(r)+V_c(r). $$ The Gamow factor is ...
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96 views

Why is the energy spectrum of alpha decay discrete?

Are the other peaks with lower energy caused by the possibility that daughter nuclei have to be in excited states?as show in this link (count versus energy)
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4answers
116 views

Has cosmic microwave background kept a constant frequency?

Has the frequency of CMBR changed at all since the beginning of the universe? Has it always had a microwave frequency or has the frequency increased/decreased over time or is the change due to factors ...
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Can UV light make us invisible?

For an object to create different EM waves, it needs to increase the temperature, so what if we or some material could be so hot, that it would emit ultraviolet light, and thanks to that be invisible ...
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271 views

Why is the excited state of 116 Indium more stable than ground state?

Why is the excited state of 116 Indium more stable than ground state? Both undergo beta decay, but the ground state has a half-life of 14 seconds, while the excited state has a half-life of 54 ...
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50 views

Quantum mechanics prediction for Bremsstrahlung?

Does quantum mechanics predict the Bremsstrahlung Phenomena? I know it is predicted by classical mechanics through Maxwell's equations, but does QM predict this phenomena and how so?
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43 views

Black Body Radiation ELI5

If a black object and a shiny object were left in vacuum and bombarded with thermal radiation would the shiny object eventually reach the same temperature as the black object? The reason I ask is I ...
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Clarification on isotropic sources and fields

For an isotropic radiation field the net flux is zero, something I find quoted in a lot of notes and text on radiation. We often think of isolated stars as isotropic sources, but their net flux is ...
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2answers
92 views

Deflection Effects on a Spinning Solar Sail

Suppose I have a solar-sail-powered starship flying directly away from a star. The sail is flat and perpendicular to the direction of travel. Now, in order to make the trajectory more stable (we ...
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Is there a way to cause scintillation of air particles using an artificial source?

Is there an artificial source that can cause scintillation of air (nitrogen, oxygen, etc. )? What does it emit and what is the range?
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ionising atom(s) with gamma rays

if a gamma ray hits an electron and transfers energy, does it hit that electron (ionising the atom), transfer all its energy and stop or does it pass through multiple electrons, transferring a portion ...
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107 views

What Happens to electrons after Alpha Decay and Nuclear Fission?

Where do the electrons go? In alpha decay do 2 electrons follow the alpha particle and make stable Helium or does the larger daughter nucleus become an anion? Also what do the electrons do in the ...
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326 views

How hot would tritium water be?

I realize this is kind of a silly question, but if you have tritium water, with the tritium half life of 12.5 years, I expect it would be quite hot. (note, this is not a homework question, I'm just ...
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2answers
92 views

Can an element decay into an infinite loop?

I've been working on a problem and have been wondering is there any isotope of any element that beta decays under certain conditions but then under differing conditions the daughter nucleus electron ...
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229 views

Highest temperature possible to achieve using magnifying glass and sunlight [duplicate]

Temperature of the surface of the sun is about 5750K. Can you heat an object to more than 6000K using magnifying glass and sunlight? According to second law heat cannot be transferred from colder to ...
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If radiation didn't exist, would everything live longer? [closed]

I recently noticed that dying of old age is similar to a death by radiation - hair loss, weakened immune system etc. and I was wondering - Does background radiation limit our lifespan, or that of any ...
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40 views

Temperature effects on lead against radiation

I would like to know if bringing lead to near absolute zero temperatures would have any affects on how resistive it is against gamma radiation. It takes 40 centimeters of lead to reduce gamma ...
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57 views

What minimum energy is required to create tracks in a cloud chamber?

What is the minimum ionizing radiation required for that? I am currently living in Fukushima prefecture and I was wondering if let`s say a flower from my yard that emits 1 pSv will create visible ...
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How does radiation degrade mechanical parts and electronic devices?

I'm running out of places to look (lots of Googling, SE, [articles and books are too specific and never give a good overview]), and yet I am still unsure about how exactly radiation can degrade ...