# Tag Info

31

Electricity isn't a gas that expands out to shock anything in contact with it. Electricity is a flow from high voltage to low voltage. Touching a charged object is only dangerous if you become a current path--if it uses you to get somewhere. Even if the earth had a net charge, you aren't providing it anywhere to go, so you will not be shocked. It's somewhat ...

8

Firstly we are not the best conductors, so current might be having a relatively hard time getting through us. But I believe the real reason is that you also need a high potential difference in order to get current flowing through you. Like lightning which needs a huge potential difference between the clouds and earth (so big that most of times a neutral ...

6

I'll answer the concrete question, because it's one of those fun ones where the units are all wrong and the scales are just absurd. Does this also mean that if I release a million amperes of current into the earth, every living entity walking barefooted should immediately die? It depends on how long you do it and with how much power. And ...

4

It is actually very easy to consider this. We don't need any models. we are blessed with a sizable rock at exactly 1 AU from the Sun, a rock with no trace of any atmosphere at all: Moon (Source: Wikimedia Commons) Temperatures on the moon vary from 70K to 390K. Average temperatures, depending on location, vary from 130K at the poles to 220K at the ...

3

Technically this question is off topic and would belong in an astronomy SE, but the answers you probably are seeking are terrestrial or terran depending on whether it is a person or an object. Terran has been sorta scooped up by the Starcraft community though so terrestrial is used in almost all cases to my knowledge.

3

From the Outside Your intuition is right. Rayleigh Scattering would come into effect, making the insides red and the outsides more blue. If the sun is at your back, or if the angle of sun-air-you is a right angle, you will still see light coming off of the air. However, this reflected light may be faint enough in places that you get the color of the night ...

3

The Kola borehole seems impressively deep, but compared to the thickness of the crust it is but a scratch. There's nothing special about the rock at a depth of 12km (except that it's hot - 180ºC!). Setting off a nuclear blast at the bottom of the borehole would be little different to any underground nuclear test. The seismic waves might propagate a bit ...

3

Dark matter does not readily "accumulate". If(?) it exists then it interacts very weakly with normal matter and is primarily influenced by gravity. The Earth's gravity is far too small to make a local concentration of dark matter. The local dark matter would be moving in the Galactic potential at speeds similar to that of the Sun around the Galaxy ($\sim ... 3 There is a difference - but not exactly why you think. There are prevailing winds around the earth - these used to be called the "Trade Winds" because traders, knowing the direction of the wind, knew how best to navigate the globe. Basically, on the equator (in the tropics) they flow from east to west, and at higher latitudes they flow from west to east: ... 3 Let's define the direction of motion of the Solar system as the direction of motion relative to the cosmic microwave background i.e. the direction defined by the dipole anisotropy. Suppose the Solar system is moving in the plane of the ecliptic as shown in (a): In that case no particular part of the Earth is in the forefront of the velocity. Because the ... 3 The fact that the apparatus is using outer space as a heat sink or just using the atmosphere should not have any significant impact on radiative cooling properties. Is this reasoning correct? No, it is not. The cooling properties of the apparatus depend on the heat sink to which the heat is aimed, as the final result will be an equilibrium of ... 2 If i interpreted your question correctly and based on my knowledge (i don't know how good it is). This is because there is nothing to apply frictional force on the outer edge of the earth's atmosphere, whereas in case of bucket the water rubs against the boundaries of the bucket which slows down the outer part of the spinning water (dont look at it for long ... 1 To answer your question think of how we get light from the far away galaxies. It is the same problem as you posed, though inversing the path of the light. Each photon that we get from a galaxy, travelled for billions of years (depending how far is the galaxy). However, take in consideration that the further we look into the sky, we have knowledge about the ... 1 Some studies have suggested that the Earth may have had a second tiny moon, which later crashed into and merged with the bigger current Moon. This might explain the lopsided back and front faces of the Moon. The second moon may have orbited the Earth for between 10 million and 100 million years. This little moon was likely about 750 miles wide, which ... 1 I'm not entirely clear on what you mean exactly, but I have a feeling you are unclear on the idea of a rotational and irrotational vortex. Using your paint bucket analogy, there are two effects that create a rotational vortex. The spinning ball will drag fluid along with it. But because there is an outer wall to the bucket, viscosity requires that velocity ... 1 I think Terran is as good a word as any, as is Geo. Thinking of terms where Solar or Lunar are used. Solar Gravity, Lunar Gravity, Terran Gravity, or Earth's Gravity. Solar Magnetic Field, Lunar Magnetic Field (which, I'm not sure there is one), Earth's Magnetic Field or Geo-Magnetic Field is also used. Earth's, Geo or Terran are the best 3 options I ... 1 Simple black body radiation theory (adapted from http://www.atmos.washington.edu/2002Q4/211/notes_greenhouse.html): The earth receives a certain amount of heat per unit area from the sun - this amount is about 1370 W/m$^2$for parts of the earth facing the sun when there is no atmosphere. But the earth presents a "disk" with area$\pi R^2\$ to the sun, when ...

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