Podcast #128: We chat with Kent C Dodds about why he loves React and discuss what life was like in the dark days before Git. Listen now.
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This is an interesting question, but it lacks a key factor that is crucial to the answer: TIME. The point on Earth closest to the Sun varies through time, so the question can be asked about any moment in time, or over periods of time. Let's analyze the factors involved. At any given moment in time, the point on Earth's surface that is closest to the Sun is ...


35

Does human body temperature impact climate change? Directly? It's not even a blip. The Earth's population is 7.6 billion. With each person radiating about 80 watts (basal metabolism), that's about 600 gigawatts, or 760 gigawatts using a round figure of 100 watts. That sounds like a lot, but it's only a tiny fraction of the 18 terawatts consumed by humanity, ...


18

Yes, it's true (in the northern hemisphere). The small eccentricity of the Earth's orbit is not anywhere close to a key driver in the seasons. The key driver of the seasons is the Earth's obliquity. In the northern hemisphere, the axial tilt of Earth's rotation axis has the northern half of the Earth facing a bit toward the Sun in June/July/August and away ...


12

The answer is No, the Earth would not remain in any recognizable form without the Sun. There would still be a husk of a dead planet with a small amount of energy coming from the residual heat of the core which might be able to sustain chemosynthetic life in small colonies. However, this is a pretty minor amount of energy compared to what we usually ...


10

The Earth moves faster around the Sun when it is near its perihelion (the closest point of its orbit to the Sun). And it moves slower when it is further away (aphelion), just as Kepler realized quite a while ago when enunciating his Third Law of Planetary Motion. There are many ways to write a formula to calculate Earth's speed around the Sun. But for your ...


10

It is impossible to know. Solar flares can have more than 500,000 kilometers. So if we consider them part of the sun, the moment when the earth is closer to the sun can be very different from perihelion if a big flare happens, making much of what was discussed in other answers irrelevant.


9

Do you know what the weather will be in four hours time? You can probably make a very confident guess. How about this time tomorrow? You can probably make a reasonably confident guess. How about this time, in fourteen days exactly? Now, you're much less confident. That's because weather is a chaotic system, and it's very sensitive to boundary conditions. ...


8

The Earth is as it currently is and has been since most of the Phanerozoic (542 Ma), the Eon of life, because of some important (not exhaustive) characteristics presented here, being: its inclination (causes seasons) its mass (gravity) its rotation (regulate a temperate climate) its revolution trajectory around the sun (latitudinal seasonality) its internal ...


8

You are correct in thinking that oxygen comes from photosynthesis. In fact it is so much associated with photosynthesis, as opposed to any inorganic process, that the presence of oxygen in the atmospheric spectrum of other planets (solar or exoplanets) is reckoned to be one of the best indicators of life beyond Earth - not that such oxygen has been ...


8

You would have to cut somewhere along this circle: The only landmass here is New Zealand, eastern Australia, eastern PNG, western North America and some Pacific islands. I'm pretty sure you can tweak it a bit, but that's the basic idea. Notice that this actually shows less than a half because of the relatively low altitude. If you "zoom out" infinitely you'...


8

As alluded to in some of the comments, all of the CMIP5 models will have been run on supercomputers, and it takes a lot of effort to get one of them running on a new platform, even for a team who know both the model and platform well already. In addition to that, many of those models are closed-source and are not generally available to an individual ...


7

We are moving all of CESM to open source - in particular here is the latest version of the Community Terrestrial Systems Model (CTSM) https://github.com/ESCOMP/ctsm Formerly known as CLM, CTSM includes capability to run on linux or MacOS systems.


6

David's answer is correct, but I wanted to elaborate a bit further. The Earth's axis is tilted about $23.5^\circ$ from being perpendicular to the plane of its orbit (as David mentioned, 'obliquity' or 'axial tilt' is the name for this.) As a result of this tilt, at the solstices (the first day of winter or summer,) the sun is directly facing latitudes of ...


6

The media loves the butterfly effect, but they also love to mis-portray what it means. When Lorenz gave his talk "Predictability: Does the Flap of a Butterfly’s Wings in Brazil Set Off a Tornado in Texas?", that made the media pay attention to the emerging field of chaos theory. The media focused on the title of his talk. It sounds so cool! They didn't read ...


6

Sea level rise estimates use changes in relative mean sea level. The definition being: Relative sea level is the sea level related to the level of the continental crust. Relative sea level changes can thus be caused by absolute changes of the sea level and/or by absolute movements of the continental crust. In general, Mean Sea Level means the 'water ...


4

The linked article talks about irrigated agriculture so I'll focus on that, but things are generally the same for rain-fed agriculture, except you have less control on the water application and there is no loss in getting the rain to where it hits the ground (yes some rain evaporates as it falls but we measure rain at the ground). For irrigation water, ...


4

The water cycle isn't geology, but it's important to pedology, which is an earth science. Agricultural water can be converted (by photosynthesis) directly into simple carbohydrates that we eat; or converted into carbs and then used as structure or energy that keeps the organism alive and growing, but isn't the mass we finally eat; or used to build more ...


4

Popular science has a good write up on this. In short, everything on the surface is doomed in a year or two. Life in the Oceans would last several hundred thousand years. After that, it's probably just microorganisms living near vents at the bottom of the ocean. http://www.popsci.com/node/204957


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A body has to emit as much thermal energy as it absobs to remain in thermal equilibrium. The Earth has been doing the same since its formation, i.e, it absorbs solar shorwave radiation by its atmosphere, solid earth and water body, and releases it in the form of longwave radiation. The amount that is released has to be equal to the amount that is absorbed ...


4

I don't know who voted down your question. I'm guessing those who voted it down thought that prior to asking your question you could have searched on the internet to find out how the Sun and the solar system, including Earth formed. I've just found the following two links by doing just that. The following quote is from one of them and it explains the ...


4

The point on the surface of the Earth where the Sun is currently immediately overhead is called the Zenith Point. Its Latitude and Longitude correspond to the Declination and Greenwich Hour Angle of the Sun. These data points can be approximated to any degree of accuracy and timeframe by a Fourier series of n terms. Accuracy sufficient for sextant work ...


3

I suspect that the answers you seek lie as much in computer graphics and human perception as they do in physics or earth science - for example, colours on a cloudy day won't actually be significantly less saturated than on a sunny one - it's still white light to most intents and purposes - but we may perceive them that way due to the differences in contrast, ...


3

Here's a quick-and-dirty estimate. The gravitational self-energy of a uniform-density sphere is $$ U = \frac35 \frac{GM^2}R $$ Let's assume Theia had the same mass and density as Mars, and that Gaia contained the rest of the mass of the Earth-Moon system. The binding energies for the four bodies are then theia/mars 4.82e+30 joules gaia 1.90e+32 ...


3

It's a moot point, and probably varies somewhat according to the state of the tide. Visually, however, the 'pole of maximum ocean' is about half-way between two atolls in the south Pacific: Tautua, 9°00' S; 157°58' W, and Starbuck Island, 5°38' S; 155°53' W. (Not that I wish to give overpriced and over-rated coffee any undue publicity!). By ...


3

At the moment, the question is unanswerable, because nobody knows if the vents exist - or even if there is an ocean under Europa's icy exterior (although the idea is reasonably well-accepted). At the moment, they're hypothetical, and until a mission is sent to Europa to observe the depths of its oceans, we won't know much about them. Well, there actually is ...


3

Circumstellar habitable zone There are a few pages that explain the concept in detail, but the gist is that the circumstellar habitable zone is (my definition) The region around a star inside which a planet similar to Earth can have liquid water on it surface. However, with more detailed observations of Europa, with its possible underground ocean, and ...


3

When rain displaces pore gasses in the soil, bubbles of soil gas are released into the atmosphere. It's impossible to be precise about the composition because it is so variable from place to place. It varies according to soil type, organic content, degree of rotting, temperature, and the microbiological cross section (itself hugely variable). Most soil gas ...


3

You can take a look at the Predictive Ecosystem Analyzer (PEcAn) - it is a statistical framework and workflow system that supports parameterization and analysis of a number of land surface, crop, and ecosystem models. It supports a half-dozen models and support for another half-dozen or so is planned. The mission of the project is to "Develop and promote ...


2

It is the warmth of the atmosphere that you feel on your skin. The atmosphere is warmed from the surface of the Earth. Visible light from the sun hits the surface of the Earth and some of it is absorbed, causing the Earth's surface to warm, which is re-radiated as infrared light and is then blanketed by our atmosphere. Without the atmosphere, the ...


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