All Questions
1,323 questions
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'Physics behind the morphology of clouds' book recommendations?
Clouds are a wonderful and fascinating tracer of atmospheric motions, and I keep wondering if there's a textbook/popular science book out there that focuses on explaining the atmospheric dynamics/ ...
2
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1
answer
83
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Does a pop pop boat work with vacuum above the water?
(Given that there is an internal oxygen source then, of course.)
In other words:
Does the fluid pressure due to the boat's pipe(s) being underwater add to the water being pressed into the tube(s) in ...
- 228
0
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1
answer
42
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Does the Earth’s Geoelectric field affect its orbit around the Sun?
https://en.wikipedia.org/wiki/Atmospheric_electricity
https://www.sciencedirect.com/topics/earth-and-planetary-sciences/geoelectric-field
Is the interaction between the electric field of the Sun and ...
- 11
3
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1
answer
58
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Elevation for far away objects
I am trying to use a PTZ (pan, tilt, zoom) camera to point at far away objects that I have an exact bearing and distance of.
My main problem is getting the correct 'tilt' or elevation angle to point ...
- 31
1
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0
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18
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What factors and forces affect the velocity of volcanic emissions in the atmosphere?
Niche question for a niche subfield of Physics. While exploring the Sulfur Dioxide ($SO_2$) data from the Geostationary Environment Monitoring Spectrometer (GEMS), I noticed that during the moment ...
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27
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3
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3k
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Why are the northern lights so much less visible to the naked eye than to smartphone cameras?
The northern lights have been visible where I live recently, but I've found them to be practically impossible to see with the naked eye. Phone cameras, however, show them quite brilliantly. How is ...
- 1,289
2
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1
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41
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Why is $ n(r) = \frac{dN(r)}{dr} $ positive if the cumulative distribution $ N(r) $ is decreasing?
I’m currently studying the physical characterization of atmospheric aerosols, and I’ve encountered a conceptual problem regarding the particle size distribution.
I understand that $ n(r) \, dr $ ...
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3
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1
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102
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Derivation of the solar resource at Earth's surface
I am reading Jenny Nelson's The Physics of Solar Cells and am a bit confused with the derivation of the solar irradiance at the Earth's atmosphere she supplies. I'll outline it here, and I provide ...
- 1,271
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2
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50
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Atmospheric Physics to Quantum Phenomenon
Is there any possibility of application of Quantum mechanics to understand complex atmospheric phenomenon? Such as precise quantification in forecasting
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0
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14
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Determining the distance to an emission from "plume width" assuming a plume is gaussian
I am measuring pollutant concentrations, from a source downwind, using aircraft data. Occasionally, I observe an enhancement related to an upwind emission, and this enhancement lasts for some amount ...
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0
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24
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How can I calculate the heat transfers caused in Venus's atmosphere by a stellaser?
In Isaac Arthur's video Winter on Venus, he discusses using a stellaser to heat Venus’s atmosphere and remove its gases, but he doesn't go into much detail about the heat transfer involved in it.
The ...
- 101
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1
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73
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Sea level rising - what is the effect of humidity?
Cause of Sea Level Rises
According to the report in World Economic Forum, sea level rise is the result of two effects:
Ice melting.
Ocean water expanding because of the temperature increase.
They ...
- 103
0
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1
answer
88
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Why does Sun appear white at noon?
I have found several source citing the reason for the white apperance of sun is due to less scattering of light before sunlight reaches an observer on the Earth (as it is relatively closer to us at ...
- 11
2
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2
answers
208
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Why do airplanes sound louder when its cloudier?
I am from India, and now its monsoon season. Typically, during this time, the sky is filled with dark rain clouds. Me, along with several of my friends, have observed from childhood that the planes ...
- 12.6k
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3
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67
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When can we expect a black-body radiation?
During the pandemic last few years, the Infrared thermometer is widely used to measure the body temperature.
However, the fundamental question or the question in the first place is, why do we expect ...
- 2,165
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1
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66
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Feynman Lectures - 100V/m in the air
Feynman suggests that:
There is a vertical electric field E of 100 volts/m in the air.
This voltage is in part maintained through the action of thunderstorms. The highest part of our atmosphere has ...
- 755
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1
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60
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How do these nearly-periodic small clouds form?
I recently saw these clouds when flying:
I wonder what causes them to create these many small lumps -- intuitively, I would expect water vapor to form a more-or-less uniform mist with much vaguer ...
- 428
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0
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16
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What would the temperature of the tropics be if the atmosphere did not try to balance out heat the latitudinal surplus and deficit
The atmosphere acts to even out the heat imbalnce between the surplus at the tropics and the deficit at the poles. Assuming that the composition and density of the atmosphere stay the same, what ...
-4
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2
answers
135
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Surely $\rm CO_2$ reflects incoming solar infrared radiation?
Is the greenhouse effect not cancelled out by the $\rm CO_2$ in the atmosphere reflecting solar infrared radiation back into space? It seems logical to me that, if $\rm CO_2$ reflects infrared shifted ...
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3
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3k
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How does gravity overpower a vacuum?
While watching experiments with vacuum chambers, I had a thought.
If you put a sealed box at normal atmospheric pressure inside a vacuum chamber, pumped out the air and pierced the pressurized box I'd ...
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1
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0
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55
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What is the range of noon sun color temperature, when a light meter reports full expected sunlight (+/- epsilon)?
My question came from trying to find what uncertainty bounds, if any, I can assign to a color temperature sensor, without access to an artifact with a precisely calibrated output spectrum.
This leads ...
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2
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2
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171
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Why can't we see green color in the sky? [duplicate]
From sunrise to sunset we can see a variety of colors in the sky.
For example, during morning the most dominant color is blue whereas during sunset orange,red,yellow and there shades are more dominant....
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1
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93
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Can we use thermonuclear explosion to fight climate change? [closed]
Nuclear war can create nuclear winter, which is opposite to global warming. Can we detonate thermonuclear (because they don't create radiation) bombs somewhere to decrease global temperature?
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0
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24
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Blue color scattering [duplicate]
I'm trying to understand, in terms of cross sections, why is the sky blue? Intuitively, blue has a smaller wavelength than the rest of the colors so it can "see" the internal structure of ...
- 379
0
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0
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37
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Expanding the barotropic nondivergent potential vorticity equation: Which vector calculus property/identity to apply for dot product and del operator?
I am trying to expand the barotropic nondivergent potential vorticity (PV) equation [link]
$$\frac{\partial \zeta}{\partial t} = -\vec{V} \cdot \nabla(\zeta + f)$$
where $\zeta$ is the relative ...
0
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1
answer
60
views
The Darkening of the Sky During a Total Solar Eclipse
During a solar eclipse, the sky maintains a high brightness even when the Sun is, say, 95% eclipsed by the Moon. During the last ten seconds before totality is when most of the darkening of the sky ...
- 103
2
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1
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36
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Besides Beard and Chuang model, any prevalent models for the shape of raindrops?
In Beard and Chuang, 1987, the famous Beard and Chuang model that describes the rotational cross-sections of raindrops in their equilibrium state.
My question is:
Besides this model, any prevalent ...
- 121
2
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1
answer
70
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Why doesn't gravity causing the adiabatic lapse rate violate the laws of thermodynamics?
I'm looking to fully understand how the adiabatic lapse rate works and why it causing warmer air doesn't violate the laws of thermodynamics.
My understanding is as follows: consider a parcel of air ...
- 1,277
0
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1
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41
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Atmospheric pressure and gas pressure
Can somebody please explain this to me. How is it possible the cap didn't fall since there's air trapped inside the container? If not mistaken, the trapped air has a pressure same as the atmospheric ...
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2
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0
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38
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Which of the blocked radiation windows will (mostly) open if one where to observe from the surface of Mars, instead of the Earth?
Earth’s atmosphere is composed of about 78 percent nitrogen, 21 percent oxygen, 0.9 percent argon, and 0.1 percent other gases. Trace amounts of carbon dioxide, methane, water vapor, and neon are some ...
- 415
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58
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It is possible to estimate the height of an explosion by its looks?
There's various social media postings (e.g. on reddit or on Twitter) saying this is what an exoatmospheric intercept (by an Arrow) missile looks like (I took 4 frames from the video, in case you don't ...
1
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0
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25
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Any research or study that monitored the spectrum of the natural light during the entire day?
I am interested in understanding the light spectrum during sunrise, morning, midday, afternoon, golden hour, and blue hour.
Is there anyplace I can look at those?
0
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2
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77
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What regulates the size of our atmosphere?
Our atmosphere is only about 100km thick before the official start of space. That is a mere 1.57307% of the radius of Earth (6,357km). The difference between the gratitational force at sea level and ...
- 413
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48
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Hot dust contribution to whirlwinds forming
My father observed an event with a whirlwind and had an aha moment on its forming. What he saw was a weak wind blowing over a sun heated patch of dust, and when the dust rose up, all of suddenly a ...
- 111
5
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2
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307
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Helium in Uranus atmosphere
I read that in 1986 Voyager 2 measured the composition of Uranus' atmosphere, which turned out to be composed of $85 \%$ hydrogen and $15 \%$ helium.
It's not clear to me how this relevant amount of ...
- 566
3
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2
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548
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Is it possible, by monitoring the brightness of stars, to find a “copy of the Earth + Moon” near them?
More than a dozen Earth-like planets have been discovered around nearby stars based on observations of changes in the brightness of their sun as they pass across its disk (transit events). If an Earth-...
- 168
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0
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32
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Why shear stress vector must be parallel to flow in this example?
In the book by S. Pal Arya "Introduction to Micrometeorology" there is a chapter about Laminar Ekman Layers.
I refer to the following example:
Variables are:
U, V wind velocity in x, y ...
- 1,391
1
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1
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175
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Formula for air density given temperature, pressure, humidity
What is a good formula for air density (kg/m^3) given temperature (°C), pressure (hPa), and relative humidity?
I tried implementing the formulas from here as follows:
...
- 924
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2
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130
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When rain clouds are formed, does the entropy decrease?
Water droplets gathered and formed into cloud which gets heavier then does the entropy of the system decreases? If so why 2nd law of thermodynamics allowed it?
- 13.1k
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4
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5k
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Why doesn't the outer most atmosphere that touches spaces freeze?
Why doesn't the outer most gasses in the atmosphere freeze?
- 151
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0
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12
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Sunset and blue light scattering
During Sunset we see the lower part of the sky changing into red colour wich is of course due atmospheric thickness increased... The higher parts of the sky are still blue suggesting that as blue ...
- 2,275
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0
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16
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What would be the pressure, temperature and density gradients with altitude of atmosphere with ideal gas?
What would be the pressure, temperature and density gradients with altitude of atmosphere with ideal gas considerations? That is no convection or radiation.
Most of the answers I have seen are ...
- 171
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47
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What would happen to a person's body if they were struck with a meteorite?
Considering that this is a meteorite that has broken through the Earth's atmosphere, what would happen to one struck by a meteorite? Not a large one of any sort, but one around the size of a fist. How ...
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0
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18
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What is a simple way to estimate $σ_{RV}$ assuming photon noise in radial velocity measurements?
Hello there i have been trying to figure out what is wanted in the question "Simple way to estimate σ_RV assuming photon noise" for a presentation. But i can not seems to find much, but i ...
1
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1
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124
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Atmosphere of a hypothetical planet
A hypothetical planet is 2/3 the radius of earth but has 1g surface gravity. Given the planet has the same surface gravity as earth, the atmospheric pressure would be the same. This would also mean ...
3
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0
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69
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Why is sunset in mars blue?
This is the Martian sunset, as captured by the Spirit rover of NASA. Notice the colors are inverted, i.e. the direct rays blue and diffused rays red, which is exactly the opposite of what you would ...
- 12.6k
2
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2
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89
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Warming due to traditional heating vs heat pumps
I'm curious about the climate impact of different heating solutions, particularly regarding the comparison between traditional fossil fuel heating sources and heat pumps. Traditional fossil fuel ...
- 21
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90
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Has a heavier atmosphere and the relocation of oil around the Earth had a measurable effect on the rotation of the Earth?
I am wondering if the man-made carbon emissions put in the Earth's atmosphere over the past 100+ years, and also the relocation of oil around the Earth over this same time period, has had any ...
user300400
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1
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354
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Amaterasu particle's secondary particles travel faster than the speed of light?
From this article in The Guardian
When ultra-high-energy cosmic rays hit Earth’s atmosphere, they initiate a cascade of secondary particles and electromagnetic radiation in what is known as an ...
- 119
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0
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56
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If you are on the moon, would you be able to hear your hands clapping if you're not wearing your spacesuits?
As I understand it, sound needs a medium to travel and more often than not, the medium is the atmosphere, however sound can also travel through solid objects.
And even we can hear our own voice ...
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