56 votes

Why is the pond in my backyard not frozen when it is -15 °C (5 °F) outside?

Water is a rather strange substance. With most substances, the solid phase is denser than is the liquid phase. This is not the case with water. Ice is less dense than liquid water. A side effect of ...
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53 votes
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Why is the pond in my backyard not frozen when it is -15 °C (5 °F) outside?

Water melts at 0 °C (32 °F) but freezing is a more complicated affair. It is safe to say water gains the ability to freeze at 0 °C, but it can get much cooler before it actually does so resulting in ...
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52 votes

Global warming - why doesn´t mankind collect heat (thermal energy) and turn it into electricity or send it to space?

This is due to thermodynamics, the three laws of which can be summarized as 1) You can't win; 2) You can't even break even; 3) You can't leave the game. The crucial point here is that heat engines don'...
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34 votes
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Do fossil fuels insulate the crust from the Earth's interior?

Quoting from John Russell's response to this article, "This is arrant nonsense!" Russell concludes with How did this paper get through the peer-review and editorial review processes? What ...
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30 votes
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Global warming - why doesn´t mankind collect heat (thermal energy) and turn it into electricity or send it to space?

Collecting thermal energy is really hard. As others have said, things like heat pumps exist for moving heat around, but the laws of thermodynamics (which are fairly fundemantal in physics) require ...
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22 votes

Why is the pond in my backyard not frozen when it is -15 °C (5 °F) outside?

Due to convection (the cold water sinks while the warm water rises), the entire pond needs to be brought to near-freezing temperatures before the surface can freeze. With only the top of the pond in ...
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15 votes

Why is the pond in my backyard not frozen when it is -15 °C (5 °F) outside?

The water in a pond is in contact with the ground and the ground is not even close to freezing even if the air temperature is 27° below freezing.
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15 votes
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Why does it rain more at night than during the day?

First off, your observation that Tamil Nadu gets more rainfall in the evening is partially backed by records. Sahany, Venugopal, and Nanjundiah, 2010 provide data on diurnal scale rainfall ...
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15 votes

Do fossil fuels insulate the crust from the Earth's interior?

What neither the authors nor the response by John Russell takes into account is that all underground oil and gas is stored inside tiny pores of rocks. An oil reservoir is not a big underground cave, ...
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14 votes

How does anthropogenic heating affect global warming?

Disclamer: I am not an atmospheric or climate scientist; corrections are welcome if I have anything wrong. Human heat production According to the IEA, world primary energy consumption in 2012 was ...
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14 votes

Sea Level Rise due to Climate Change

The first part of the association is that increasing levels of greenhouse gases in the atmosphere will cause rising temperatures on earth. Here is some information on why that is so, if you are ...
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12 votes
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How does Antarctica stay frozen?

It doesn't stay frozen. Ice evaporates (or sublimates is the correct term) under direct sunlight, but that's at a molecular level, it doesn't melt, it goes from solid to gas under sunlight and in the ...
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12 votes

How does anthropogenic heating affect global warming?

Basically, we can ignore the heat we release compared to the effect of the $\ce{CO2}$ we release. To be more specific: Heat we release has only a temporary effect because heat is radiating out to ...
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12 votes

Is global warming being moderated by latent heat of melting polar ice?

Latent heat is a factor, but is completely eclipsed by the rate of global warming. For example, since 1978 the April (maximum) Arctic sea ice has decreased in volume by about $11,000$ cubic km. The ...
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11 votes

Global warming - why doesn´t mankind collect heat (thermal energy) and turn it into electricity or send it to space?

Like passive radiative cooling? The new materials reflect a broad spectrum of light, in much the same way as mirrors or white paint do. In the crucial 8–13-µm part of the infrared spectrum, however,...
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10 votes

Why is the pond in my backyard not frozen when it is -15 °C (5 °F) outside?

This could be because the air cools and heats faster than water. Air has a lower Specific Heat than water. It may take some time for the water to freeze.
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10 votes
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First to Sail the Jet Stream Around the World

As your diagram shows, the jet stream actually has two circulating components: one is "around the earth" (which is why the transatlantic crossing is so much faster going East than going West), while ...
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7 votes

How does Antarctica stay frozen?

First of all, the Earth does not receive heat from the Sun, it receives visible light that is absorbed by the surface of the Earth and then heat is re-radiated back into the atmosphere. If the ...
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7 votes
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Why doesn't subducted earth crust melt?

...the submerging plate is always drawn as deep (seemingly tens of km) into molten rock... It's actually hundreds of kilometres, not tens of them. But let me correct a common misconception: The ...
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6 votes

How does Antarctica stay frozen?

userLTK has explained that not all of the ice in the Antarctic stays frozen all the time. But perhaps there's a more basic view needed : sunlight in temperate areas melts all of the ice quite quickly, ...
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6 votes
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Pressure of condensation of an air parcel

The lifting condensation level (LCL) is the level at which a rising particle reaches 100 % relative humidity by adiabatic cooling. Please have a look at Wikipedia: LCL and LFC (level of free ...
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6 votes

Why is the pond in my backyard not frozen when it is -15 °C (5 °F) outside?

No-one has mentioned fish yet. Do you have fish or other animals in your pond? Not only do they provide a small amount of warming, their movement will help prevent ice forming.
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6 votes

Why is the pond in my backyard not frozen when it is -15 °C (5 °F) outside?

The variable you need to consider to understand the problem is the pond's depth. I bet that in contrast to your pond, shallow puddles around did freeze. The water is denser at 4°C, so to freeze the ...
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  • 17.1k
6 votes

Sea Level Rise due to Climate Change

It's a harder direct relation to show that it appears. On the surface, warmer = less ice, file under "duh", but while it probably is that simple, showing a causal relation is a more difficult. The ...
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6 votes
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A balloon falling from space?

You cannot leave "temperature outside", as temperature is the key factor to know if the balloon would pop or not. Let's set up some assumptions about the problem so we can calculate something: The ...
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5 votes

Why is the pond in my backyard not frozen when it is -15 °C (5 °F) outside?

In addition to the accepted answer from Casey, it is likely that the sun is warming the pond over the course of a day more than it warms the thermometer used for the temperature readings you are ...
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  • 191
5 votes

Please help in understanding redox buffers

First let me start by saying that redox buffers are a made-up thing. All these QFM (actually FMQ) or NNO or other abbreviations don't exist in nature. They were developed as a way to "cheat" in ...
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5 votes
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Sensible and Latent Heat. how to separate them

First some definitions: Latent heat is the heat that leaves or enters a system during a process where the temperature of the system stays constant. Phase changes are prime examples where latent heat ...
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5 votes

Global warming - why doesn´t mankind collect heat (thermal energy) and turn it into electricity or send it to space?

As others have pointed out, if you use the energy, it turns right back into heat. Radiating it back to space is at least theoretically possible. But there is a problem with scale. The Earth ...
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