Hot answers tagged

57

Let's say your magical sphere has radius $r$ of 10km (so just poking up into the outer atmosphere) and is at a temperature $T$ of 1,250K (so glowing a nice warm yellow). The total radiative heat flux from the sphere is given by: $$ Q = \sigma T^{4}. 4\pi r^2 \approx 1.7 \times 10^{14} \mathrm{W} $$ Where $\sigma$ is the Steffan-Boltzman constant. A ...


41

Yes it is possible, if the planet has little axial tilt but an eccentric orbit. Then summer will be when it is closest to its sun, and winter will be when it is furthest away, which will be the same all over the planet — at the equator as well as in higher northern and southern latitudes.


35

For one thing, natural bushlands would get overgrown. Anyone who listens to world news knows that the south west of the US; California and Arizona especially, are prone to bushfires. So is most of the Australian outback where there is natural bushland areas. In Australia particularly, some species of tree are so integrated with the natural fire cycle that ...


34

How cold does it have to be to freeze the waterfall? Obviously, below freezing. The colder it is, the faster the water will freeze. Depending on the size of the river and the brightness of daytime sunshine, it might have to be a long way below freezing. This waterfall (Kinder downfall) froze during a period of slightly-below-freezing weather, after a ...


20

Ozone levels in the atmosphere would be reduced Lightning is the major producer of ozone and NOx in the atmosphere. No lightning means less ozone means more UV light gets through. Basically life on the planet would get much harder to survive. lightnings-role-in-ozone-formation


19

Altitude. The big island of Hawaii has just about every climate type. Discussed here: Could an island on Earth with these climate types exist? It is a combination of the giant central mountain intercepting rain clouds (and thus a dry side and a wet side) and the ability of higher altitude to simulate higher latitude. Higher is colder. Put your land in the ...


17

This is a picture of the town of Grand Banks, Newfoundland. The Guiness Book of World Records states it as being the foggiest place on Earth. Here, cold sea currents from the North meet up with the much warmer Gulf Stream from the south. This creates up to 206 foggy days per year, so well over half a year of fog in total. With a little stretch of the ...


15

How far below zero it needs to be is not the most important factor here The real important factors are the dimensions of your river, how slowly it freezes, how fast the water is moving, and how far your drop is. Waterfalls do not just suddenly freeze in place, instead the surface of the river freezes creating a surface for the liquid water underneath to ...


15

You can't, unfortunately. Without surface water you won't have a sustainable hydrologic cycle to keep life flourishing in the variety and density of a tropical jungle. Water will disappear into the crust beyond the reach of any root system (the Earth's crust is estimated to contain as much water as all the oceans, if not significantly more) in greater ...


15

Of course. Just make sure the axial tilt is zero. Basically, 99% of our weather changes are due to the angle of solar incidence, and only a small amount is due to the distance Earth is from the Sun (elliptical orbit). Earth's axial tilt is roughly 23.44 degrees. For a given latitude, a little trigonometry will show how the angle of solar incidence (draw ...


12

There is no hope. Emergency units which are trained and equipped to contain emergencies like this can cope with small scale incidents like a truck breaking open it's load of acid on the highway after a crash. An oil spillage from a tanker is already too big. Worldwide acid rains means extinction: we don't have means to protect nor to sustain ourselves which ...


12

Here's the problem: you have posited that there is free water, and plenty of it ('rainforest'). So, where is that water going? Either you have lots of lakes, or they get bigger and are "oceans." In either case, over time these water bodies will get salty just as they did, and do, on Earth. Next: do you want this planet to be habitable when humans ...


12

Yes Expanding on the other answers here, let's start with an overview of why there are seasons. I really like this description: We have seasons because the earth is tilted (wonky) as it makes its yearly journey around the sun. The Earth's axis is tilted at an angle of 23.5 degrees. This means that the Earth is always "pointing" to one side as it ...


11

It’s 3D rather than 2D. In atmospheric circulation cells there is wind moving in opposing directions, separated at different heights (often separated by heat layers, aka thermoclines). Winds also tend to circulate in jets, rather than spreading evenly across the planet. Other phenomena like differing heat absorption between land and sea leads to coastal ...


11

The mountain folk use an older calendar. The Julian calendar was introduced in the time of the Roman Empire and was adopted throughout the western world. In 1582 the Pope introduced a revised calendar called the Gregorian calendar, and over the ensuing centuries this calendar supplanted the older Julian calendar. Except where it didn't. The Berbers in ...


10

Why is the dome the best solution? Think about the original designers of the dome - why have it? An answer to this question may answer your question. The only reason to have a dome is to be on the surface of a planet, otherwise you might as well be underground in a large protected cavern. But why risk being on the surface of a planet? The only real reason ...


10

We don't know. There will be several factors which affect the climate in different ways. There is no empirical data on which will dominate. How many weapons and where? Arsenals are much smaller than they were at the height of the Cold War, and we can assume that Moscow, Washington, and places like Minot AFB are still getting overkill. Firestorms could blow ...


10

Make it long Chile is almost like that, except it is attached to a larger land mass and it has 3x the land area of UK. But since it spans a lot of latitudes, it naturally has polar climate at the south and deserts on its northmost areas, with some tropical pockets in between. It also has the world's second highest mountain range to the East, so it has a lot ...


9

There is no scenario in which the biosphere survives long. You have, at best, a few centuries. Say the fireball is as cool as possible while still being a fireball; 100 degrees celsius. All the oceans will continually drain towards the fireball and will boil on contact, as you said. This is bad news for your biosphere, because that's a huge amount of ...


9

Since nothing exactly like this exists on Mars, let's look at the best real-life example of what you're describing: A crater. On Mars Hellas Planitia is one of the oldest and largest craters on Mars. It was formed during the Late Heavy Bombardment, which started around 4.1 BYA. At more than 7 km deep, it's one of the deepest craters in the solar system. ...


9

As suggested in this answer on Aviation.SE If you're flying through a thunderstorm, lightning is the least of your concerns. Airplanes are struck by lightning all the time, and while it may mess with your electronics (navigation, radio, etc.), it very rarely causes any more damage than that. But to answer the second part of your question, there's no one ...


9

Model it after New Zealand Speaking from personal experience, you can go from glacial heights to fjords to tidal flats to forest to swamps (or at least mucky farmland) within the same day, sometimes even maintaining vision of the previous terrain. Closest thing to Neverland in Robin William's Hook I've seen. There are a number of geographical features that ...


8

A planet's tilt is not directly linked with tornado formation. More important factors include things like the overall energy of the storm and pressure dynamics. Due to the proximity to the sun and the abundance of water, this skewampus version of earth will still have weather. This includes tornadoes. (It will likely not be the current weather patterns, ...


8

Other answers are right at pointing at eccentricity as the most likely cause for global seasons. However, there is another possible cause: multiple stars. If the planet were orbiting a double star, the distance to each star might change as the stars orbit each other. If they have different mass and bright, the total amount of heat the planet gets may change ...


8

The Gulf Stream I don't know if you are British or have visited Britain but we already have much of what you are asking for. There are mountains in the Highlands of Scotland and Scottish days are shorter and, in general colder, than the South of England. Manchester is reputed to have constant rain - surely an exaggeration. We have plenty of forests - just ...


7

dome to have it's own self-regulating ecosystem Since the dome has its own self-regulation, there should be no impact of external climatic phenomena in general. However, effect of external climate can at times be aggravated in terms of extreme events like cyclones, floods, heatwaves etc, which can impact the efficacy of the self-regulation system your dome ...


7

What I'm looking for is a plausible estimate. Would one freeze to death during night time for example, or would a temperature drop to "a slight chill" be believable. Obvious answer: do you want people to freeze to death? Then fine: they freeze to death overnight. Personally, I'd rather not. The long nights are obviously problematic in this regard, ...


7

You are basically cooking your planet on a stove. This magic fireball is an infinite source of heat, so it will sit there continually pouring heat into the planet's system. Water near it will be heated into steam, but the coolness of the water will not cool the fireball at all. This will cause the overall temperature to rise and rise until everything on the ...


7

Interpreted literally, there cannot be a source point with wind coming out of it in "every" direction unless you invoke magic. For the same reason that there cannot be a source point somewhere in the ocean depth emitting water out of it in every direction. Where would all of this new water be coming from? Roughly speaking, every enclosed region must have an ...


7

On Earth, oceans exist because rainwater runoff collects into large pools called "oceans". Oceans are at the lowest point on earth, so the water has no where else to go, and it stays there until it evaporates. Ways to eliminate oceans: Bury the oceans. Earth's mantle contains at least as much water as all of Earth's oceans, dissolved in various minerals. ...


Only top voted, non community-wiki answers of a minimum length are eligible