All Questions
1,323 questions
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Relationship Between wind velocity and induced surface water current (general questions)
Consider the following scenario: There is a wind blowing right above lake surface. This wind will induce a surface current in the lake. I am quite new to this topic, so I would be interested to know ...
- 159
1
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1
answer
497
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What is the relevant phenomenon behind Undulatus/Radiatus cloud formations?
I am seeing many people claiming that cumulus clouds that sometimes form periodic wavy patterns (see images for "altocumulus undulatus" or "Radiatus" for instance) have no ...
- 279
0
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1
answer
248
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What is the influence of humidity on NDIR $\rm CO_2$ measurements?
The Question
I would like to use an NDIR $\rm CO_2$ sensor to measure $\rm CO_2$ in the 0.1-3% range. However, in the course of my experiments, humidity may vary from ambient (50-60%) up to nearly 100%...
- 101
2
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1
answer
88
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Why we typically see no deeper into an atmosphere for an optical depth of 1?
In An Introduction to Modern Astrophysics (p.243), Carroll and Ostlie say that for a optical depth $\tau = 1$ the intensity will decline by a faction of $e^{-1}$.
$I_\lambda = I_{\lambda,0}e^{-\tau}$
...
2
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0
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57
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Would ocean tides on the moon of a gas giant really be kilometers high?
I was reading an article on exomoon habitability constrained by illumination and tidal heating. The article imagines an Earth-like exomoon around Jupiter-like host planet. That got me thinking about ...
- 21
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1
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48
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Is this Volcanic or Impact winter management proposal right? [closed]
In case of a volcanic winter where a VEI 8 volcano releases large amounts of SO2 and H2S into the stratosphere making it react with OH and H2O to form sulfuric acid (H2SO4) wich would prohibit most of ...
- 19
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1
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472
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The Weight of Air A Human has to Bear
The average circumference of the human chest is $97$cm to $114 cm$. Let us, for the sake of simplicity, assume that this is a circle. The cross-sectional area of the human body then is $\approx 3 \...
- 183
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1
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84
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Are there laws of creation for biological life? [closed]
I am no scientist, but I do love science as well as the unknown. Are there laws of creation for biological life? Would it be safe to assume that our bodies are made up from things that came directly ...
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1
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40
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Explanation for an atmospheric optical phenomenon
Consider the atmospheric optical phenomenon appearing in this video. A screenshot at the appropriate time is shown below:
The video is footage from a drone flying just above a low-lying, thin layer ...
- 2,750
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2
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66
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Does air pressure change at the same rate on high elevation land as in the sky? [closed]
Is air pressure the same in a place like Denver, which is a mile (1.6 km) above sea level, as the same elevation above actual sea level? Same question for 2 miles high, as in any number of mountain ...
- 113
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1
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84
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Where do the electrons in a lightning bolt come from?
Where do the electrons in a lightning bolt come from?
There are problems with the explanations given up to at least two years ago.
The explanation that the electrons come from inside the thunder cloud ...
- 11
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1
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61
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Why does the dust in the sky make the light shine more or in other words it is visible from far away?
Why does the dust in the sky make the light shine more or in other words it is visible from far away?
This image shows how light is scattered in dust particles]1
6
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2
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580
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Book recommendations on climate science
I've had my eye on properly understanding climate, climate change and the wide array of phenomena related. But, as a physics grad student, I'd fancy more exact, math-based bibliography, that treats ...
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1
answer
44
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Derivation of particle distribution in a gravitational field
I'm trying to figure out where my logic is failing in the derivation of the concentation of particles with respect to the height in constant temperature and gravity ($n(h)$).
So we have the following ...
- 371
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0
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57
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Non-zero probability that detonating a nuclear bomb sets off atmospheric fission chain reaction [duplicate]
After watching Oppenheimer I am under the impression that there is always a non-zero probability that the detonation of an atomic/nuclear bomb will set off a chain reaction of fission in Earth’s ...
- 37
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1
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48
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Effect of Sun temperature on the thermosphere
Correct me if I’m wrong here.
The thermosphere is hot due to its absorption of moderately high energy UV radiation. (<200nm)
Cooler stars emit fewer high energy photons. So if the Earth orbited an ...
- 3,001
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57
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Does a planet's "equatorial bulge" induce any kind of motions or currents in the atmosphere?
Rotating planets, like the Earth, are not perfect spheres but are instead oblates. This affects both the crust and the atmosphere, creating a bulge in the equator 1.
I was wondering if there are ...
- 2,878
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2
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100
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Does air in the atmosphere get friction as a planet rotates?
Does air in the atmosphere suffer friction in some way due solely to the planet's rotation? I mean, if you took a rotating planet with an atmosphere (not being influenced or heated by its star, its ...
- 2,878
2
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1
answer
100
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How large would the earth have to be to retain hydrogen?
How high would the earth's escape velocity have to be to retain hydrogen or helium over geological timescales?
- 3,001
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1
answer
57
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Where does the centripetal come from, in a cyclone?
It needs a tremendous amount of impulse ($Force\times time$) to keep the large mass of air and water vapor spinning for several days. Where does the sustained force come from?
The centripetal force in ...
- 139
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1
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52
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Aggregating an atmospheric gas concentration profile
I have a list of CO2 gas concentrations in the atmosphere in g/g relative to dry air according to a pressure profile. I have the top and bottom pressures for each level.
The list corresponds to a 40 ...
- 11
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2
answers
126
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How does a vertical anemometer work?
We know that the vertical anemometer, just like the cup/vane anemometer, works by measuring how fast the cup/fan rotates because of the wind. But how could we possibly know that the fan rotation is ...
- 12.6k
15
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2
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2k
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The blue sky — is the simple Rayleigh explanation wrong?
Reading various answers here ([1], [2], [3]), Wikipedia, nasa.gov, and other places, the common explanation of our blue sky is Rayleigh Scattering due to gases and particles in the air, maybe with ...
- 259
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64
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Could rogue planets with cold nucleus have winds or water currents/waves due to the planet's rotation?
Are there any types of wind or waves caused and produced only and exclusively by a planet's rotation? Not influenced by the planet's rotation, but produced solely by it?
In the case of waves, are ...
- 2,878
5
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1
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222
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Why does a dump yard stink more in the night?
There was an open dump yard a few miles away from where I used to live for an internship. It was not noticeable during the daytime, but once the sun sets, the dump yard reminded us of its presence ...
- 12.6k
3
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0
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141
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What creates the orange hue when there is wildfire smoke?
I find a variety of opposing arguments on the internet:
That this is due to Rayleigh scattering, which "removes" the blue light from reaching our eyes. This is similar to how the sunset ...
- 131
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0
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25
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Why is the solar spectrum at the surface of the Earth strongest in the visible light range? [duplicate]
I watched a CrashCourse video saying that nuclear fusion of $\rm H$ to $\rm He$ in the sun radiates mostly gamma rays. Then why are the lights that come to Earth comprise mainly of IR & visible ...
- 191
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1
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37
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SETI: Are there holes in the EM spectrum that are quiet enough to communicate at decently large distances?
So this is a variant of this other question.
I know stars are big, they radiate a lotta energy, they have spectral lines. But how dense are these spectral lines and is there a noise floor at ...
- 1,733
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1
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140
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What is the physics behind the cooling of the atmosphere during a total solar eclipse?
Consider the Great American Eclipse (The total solar eclipse over America in 2017). Observed atmospheric temperature drops were in the range of 3 C to 8 C in a matter of minutes. Surface ...
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2
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93
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Visibility on an alien world [closed]
I asked this over on Worldbuilding, and I was told it'd be best to try here instead:
First, I should probably mention that I'm really bad at mathematics.
I'm working on a scientifically plausible ...
- 109
8
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2
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951
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Air pressure at ground level at the equator and the poles
At the equator at sea level you are about 17 miles higher up than at the poles ie 17 miles further from the center of the earth. Yet the air is not the same as it would be 17 miles up at a higher ...
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1
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1k
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Absorption Spectra of Atmospheric Gases
From this previous Stackexchange question:
Is a detailed absorption spectrum available for carbon dioxide from 300-1100nm?
and this paper:
https://www.osti.gov/servlets/purl/1613653
as well as this ...
- 113
1
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1
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493
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Why is the top of the mountain cooler than the surface? [duplicate]
Why is the top of the mountain cooler than the surface when the mountains are actually more closer to the sun and hence should be hotter?
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3
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348
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Do these common demonstrations of the atmospheric greenhouse effect actually work due to poorer $\rm CO_2$ thermal conductivity?
A common type of experiment to demonstrate the greenhouse effect is essentially to direct heat lamps at the bottom of two closed jars, one with regular air in it, and one with a higher concentration ...
- 1,277
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1
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299
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Why did the air not heat up in this experiment demonstrating the atmospheric greenhouse effect?
In the paper "Experimental Verification of the Greenhouse Effect", the authors (Hermann Harde, Michael Schnell (2022)) describe an experimental setup that they say demonstrates the ...
- 1,277
2
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5
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4k
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Why doesn't sun go all the way to the horizon during sunset?
This is a very silly question and I really don't know the answer to it but curious to know.
Everytime I see the pics of suset on beaches the sun appear to go all the way down to the surface of the ...
- 8,476
0
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2
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224
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Does the light from my flashlight travel into space? [duplicate]
Does the light from my flashlight travel into space?
1
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1
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38
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Should blue & white stars appear red and inflated while observed on the lower part of the night sky for the similar reason as the Sun during sunset?
Should blue and white stars appear red and inflated while observed on the lower part of the night sky for the fairly same reason as the sunlight during sunset? As these stars emit blue light ...
- 2,275
2
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1
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344
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Equations of idealized greenhouse model with $n$-layers?
I wanna work with this climate model, the idealized greenhouse model. The Wikipedia page explains it very well with an example using one layer of atmosphere. Then it mentions that you can add more ...
-1
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2
answers
187
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Examples of experiments replicating the idealized greenhouse model
I'm looking to find experiments that experimentally demonstrate the Idealized greenhouse model.
So far all the experiments I've come across do not quite demonstrate the model, but something else.
...
- 1,277
0
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1
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619
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Is there a way to calculate/estimate the orbital period of an exoplanet from only one transit detection?
I understand that multiple transit detections of an exoplanet are almost always used to derive its period, but is there a way to do it with only one transit detection? As in, with only one available ...
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0
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17
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Why do we not see Sun red in daytime? [duplicate]
I have had this question strike to me as when thinking about the reddish colour of sun during sunsets which is happening through rayleigh scattering , the highly energetic wavelength of colours are ...
- 646
2
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2
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220
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Different color between sunset and daytime
When we look at the sky, it's blue because blue light has shorter wavelength, so it scatters more energy; and at sunset we see a red sky because most of the blue color is scattered out. What I don’t ...
- 329
2
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1
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62
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Is this scientifically useful exoplanet transit data? [closed]
For a physics project, I am trying to derive properties of exoplanets through their transit light curve. I tried to get the data myself, on the known exoplanet Qatar-6b.
My Equipment:
8" Newt. ...
1
vote
0
answers
188
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Refractive index of air for different wavelangthes
When I tried to search about the refractive index of air, I found 1.00029. This is for which wavelength? How can I find refractive index of it for different wavelengthes like red light's wavelength ot ...
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1
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26
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How to decipher imaging method used in remote sensing images?
I am working on remote sensing for science olympiad (div c) and i am kind of lost on remote sensing image analysis. like how do i look at an image and know it was captured using infrared or microwave ...
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votes
2
answers
41
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$\rm CO_2$ emissions and ocean pH
I hear two seemingly contradictory statements:
$\rm CO_2$ emissions will cause the oceans to absorb more $\rm CO_2$ and therefore acidify.
$\rm CO_2$ emissions will heat the planet and therefore the ...
0
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0
answers
245
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Why is there a vacuum in the upside down glass and card demonstration?
In this Hila Science video on atmospheric pressure (https://www.youtube.com/watch?v=xJHJsA7bYGc&ab_channel=ScienceOnline) from 2:30-3:05, it shows the common demonstration of turning a glass of ...
- 1,090
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2
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60
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If a satellite is shut down, will it eventually reach the high temperatures of the exosphere?
If a satellite is shut down so that it neither generates additional heat from whatever internal energy source it might have, nor is able to dissipate heat by an active cooling system, will it ...
- 1,964
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2
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403
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Quantitatively, how much would radiation levels increase without the geomagnetic field?
Many, many popular science articles claim that if the Earth didn't have a magnetic field, then the much higher concentration of cosmic rays that reached the surface would cause health damage to humans....
- 49.4k