# Tag Info

6

Your question seems to be about human body heat rather than other human activities that contribute to global warming. Humans body heat doesn't actually add any energy to the whole-Earth system (see below) but for a moment, I will assume that it does. Instead of looking at the mean temperature of humans, it's easier to look at the amount of energy our ...

2

Matter above absolute zero will radiate (electromagnetic) energy no matter what. This is due to the motion of atoms (specifically charged subatomic particles) in the energized matter. Conduction between two bodies in thermal contact is only one means of transferring energy - it is different than radiation. The earth does not need to be in contact with ...

1

The Earth radiates heat as well as absorbing it from the Sun. At any given time, it does not radiate exactly as much heat as it absorbs, since the difference can be accounted for in changes in its internal energy (climate shifts etc.), as well as in sources of heat here on earth (geothermal and manmade energy).

4

The Earth receives approximately $6.8\text{mW/m}^2$ of reflected sunlight from the moon (see below for details of how I calculated that). However, the sunlight is also absorbed by the moon and this raise the surface temperature. So the moon also emits thermal radiation towards the Earth (assuming the highest day time temperature of 400K, see comments below ...

2

Assume the moon is at roughly the same distance from the Sun as the Earth and so receives the same amount of solar energy / area. Find the area of the moon facing the Earth (hint, it's roughly the area of the moon's disk). Multiply by the reflectivity of the moon (about 12%). But that power is reflected from the moon in all directions, so you need to ...

12

"Total energy of the Earth" is somewhat of an odd concept, but there's no reason we can't really entertain it. It brings up some genuinely difficult questions. The right way to approach this is to define the system correctly and then identify forms of energy content and flows. Things to "count" in the Earth's energy: Heat content Nuclear energy ...

6

The heat generated from the Earth's core is about 4x10^13 W while the Sun provides about 1.7x10^17W so although the Earth's core is slowly cooling this has very little effect on the Earth's temperature. The Earth is in equilibrium between the energy received from the sun and the energy it emits into space. If the amount received changes, then temperature of ...

2

I'd say depends on the definition of 'total energy' - see Alan's answer above. The total thermal energy is not in equilibrium, it is increasing: global warming, that is an imbalance of around 0.5 W/m^2, corresponding to a total imbalance of 2.5x10^14 watts (if I did the multiplication correctly...)

1

Interestingly I recall the same kind of account (I am 49) and was looking seeking and researching it in the last few weeks; see http://www.amnh.org/learn/ocean/Resource1 . It would seem that one infers that this has to be a fairly accurate picture: the origin of water on Earth though is still very uncertain but it seems that much water was here in the ...

1

Most certainly it does: the variation can be measured by a sensitive acceleration called a Gravimeter (see Wikipedia page with this name) and is the basis for gathering data important for minerals exploration. Bodies of mineral ore distort the Earth's gravity and thus can be found by measuring the variation of the local gravitation as a function of position. ...

3

The acceleration due to gravity changes not only on the surface of the Earth (depending on where you are) but also how high up you are (which varies by $\frac{1}{r^{2}}$, where $r$ is the distance from the center of the Earth to you). For more information on how it varies depending on location, maybe this will be of use? GOCE Delivers Best Gravity Map of ...

2

Yes, you'll gain extra hours, but you'll lose them on the way back, unless you keep going round. Let's assume you're in a plane flying along the equator, moving at 800 km/h (in the direction of the earth's travel) - a normal jetplane speed. The earth is rotating so that a point stationary on the equator moves at 1600 km/h. That means that, for every km you ...

3

The material in the Earth's outer core is both a liquid and an electric conductor. Fluid flow is driven by thermal convection currents. The source of heat driving the convection is the decay of radioactive elements that are also carried by the fluid flow. Fluid flow and electric currents are coupled through electromagnetic forces. The core is also likely of ...

-2

I guess those flips are caused by instabilities of the dynamics of the Earth's core.

1

Strictly speaking, Newtonian dynamics problems on the Earth's surface are done in an accelerated reference frame owing to the Earth's rotation. But often this acceleration is very small: at the equator (Earth radius $6.317\times10^6{\rm m}$) the centripetal acceleration of a body on the Earth's surface is \omega^2 R = \left(\frac{2\,\pi\,{\rm ...

1

There are tides in rocks and those tides affect volcanoes and volcanoes can affect climate. http://www.google.com/url?q=http://geography.about.com/od/physicalgeography/a/Land-Tides-Or-Earth-Tides.htm&sa=U&ei=9VB-UsPBDMfOiAf4wYHwBw&ved=0CBMQFjAE&usg=AFQjCNFKp3eO6wViMUgi-pPa9JLQ3NCM8Q

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