Skip to main content
143 votes

A 40km diameter alien saucer is floating 2km above the ocean for a long time. What are the effects on the sea ecosytem below?

The ocean is a dynamic and very large place, so it's unlikely to have many large-scale effects unless humans overreact. I'll focus on the local, immediate effects of this saucer from a physical, ...
Dubukay's user avatar
  • 12.2k
86 votes

Is it a forgone conclusion that any exo-bacteria discovered on an alien, albeit Earth-like planet will be deadly to human life?

Exo-bacteria is more likely to be harmless than harmful There are a couple assumptions that you're making that really aren't the case. To start with, microorganisms that our immune systems have no ...
Rob Watts's user avatar
  • 19.9k
66 votes
Accepted

Wasp hives in a walking corpse. Why would wasps do this?

Because it's a viable ecological niche, of course. The wasps are an evolutionary development of the Ichneumonoid wasps https://en.wikipedia.org/wiki/Ichneumonoidea which lay their eggs in living ...
jamesqf's user avatar
  • 20.5k
51 votes
Accepted

Why would a creature both have carnivore teeth and side-facing eyes?

Your creature evolved within an ecosystem where it was both hunter and prey.They've exclusively hunted smaller prey but there was one or more other carnivores that hunted them as well. They've hunted ...
Gillgamesh's user avatar
  • 6,083
51 votes

Could a pine forest with year-round snowfall survive?

A few notes. You can have it snow all year, without snowing every day. The problem with snowing every day is the snow will just pile up, and gravity will compress it into an ice sheet. No matter how ...
Amadeus's user avatar
  • 34.7k
41 votes
Accepted

A pack of velociraptors in a modern ecosystem, that would be pretty horrible, right?

What are these dinosaur's competitors? According to Wikipedia, a velociraptor is up to 2m long and 15 kg. A Deinonychus is up to 3.5m long and 75kg. I'm going to assume that those masses are the ...
kingledion's user avatar
  • 85.4k
38 votes

A 40km diameter alien saucer is floating 2km above the ocean for a long time. What are the effects on the sea ecosytem below?

Why is it that in questions like this about something blocking light, everyone seems to forget that the Earth rotates? To simplify the geometry, we'll use the following assumptions: the saucer has a ...
Keith Morrison's user avatar
38 votes

99.9% of the flight-capable birds died at once. How screwed is the rest of the world?

Insects swarm, crops die, people starve, society collapses The death of all birds would be apocalyptic in short order. While John O's question covers a lot of aspects of birds' place in the ecosystem, ...
Daniel B's user avatar
  • 19.5k
36 votes
Accepted

What measures might an ancient civilization take to protect itself from extreme heat?

Two of my favorites for this scenario. Dig. Fresno is pretty close to what you describe. This guy Forestiere bought land sight unseen thinking he would grow fruit and nut trees but on getting there ...
Willk's user avatar
  • 305k
36 votes

How would you build a road system that respected nature?

Mass transit and alternatives to cars There are many countries that are focused on cars. As I'm from the Netherlands it's easy to think about grabbing a bike. Every person/group of persons on a bike ...
Trioxidane's user avatar
  • 37.1k
34 votes

Is it a forgone conclusion that any exo-bacteria discovered on an alien, albeit Earth-like planet will be deadly to human life?

I think the question is less, "Would we be able to survive alien bacteria?" and more, "Would alien bacteria be able to harm us?" Bacteria and viruses typically harm people because, to put it simply, ...
Azuaron's user avatar
  • 4,747
32 votes
Accepted

Can every animal eat most other animals?

From the plant's point of view the herbivore is a predator. The only thing that matters as far as that goes is that more plants grow than the herbivores can eat, otherwise they will run out of food ...
AndreiROM's user avatar
  • 34.7k
31 votes
Accepted

If a creature's best food source was 4,000 feet above it, and only rarely fell from that height, how would it evolve to eat that food?

Have you ever come across giant isopods? (image credit NOAA via wikipedia) Some of these can live in the bathyal zone, as deep as 7000ft. Its cold and dark down there, so no sunlight. They'll hunt ...
Starfish Prime's user avatar
29 votes

Which plant species would be most likely to recover after a decade of no light?

which species of flora and fauna are most likely to be capable of recovering? Though some seeds can still be vital after more than 10 years (see Pink Sweetener's answer), animal's seeds won't ...
L.Dutch's user avatar
  • 289k
28 votes

What's a reasonable environmental disaster that could be caused by a probe from Earth entering Europa's ocean?

The Europans are terrified of what the probe means. The probe does not do anything more than it was supposed to do. But it is recognizably an artifact of an advanced alien culture. That means aliens ...
Willk's user avatar
  • 305k
27 votes

Is it a forgone conclusion that any exo-bacteria discovered on an alien, albeit Earth-like planet will be deadly to human life?

Earthly germs have a hard time infecting anything. They have specific tricks to get past the defenses of specific types of cells in specific species. Most bacteria is harmless as it is quickly ...
JDługosz's user avatar
  • 69.5k
26 votes

How would you build a road system that respected nature?

Frame challenge. Your complaint is about suburbs not roads. Suburbs are horribly unsustainable, they are the least desirable type of living in terms of environmental impact. Suburbs can't even support ...
John's user avatar
  • 81.4k
25 votes

How would you build a road system that respected nature?

Just the other day I was reading an history atlas about the city where I live. The chapter I was reading mentioned that the works for the first paved road from the town to the local administrative ...
L.Dutch's user avatar
  • 289k
24 votes

How to wrap the Moon in plastic to make her a giant, supported by the atmospheric pressure, greenhouse

Actually, there are multiple reasons it can't be done as you hoped Trying to make a single air-supported structure to cover the entire moon is a rather insane idea. For safety and other reasons, ...
Gary Walker's user avatar
  • 22.4k
24 votes

How can kaiju exist in nature and not significantly alter civilization?

They do destroy settlements. From time to time. But then, settlements are also destroyed by barbarian invaders, famine, plague, volcano eruptions, flood, and forest fires. From time to time. The ...
o.m.'s user avatar
  • 116k
23 votes

How can plants reliably intentionally poison those that eat their fruit?

It wouldn't be the first plant to live off of corpses, but usually they find the corpses instead of making them. Here are a few ideas for biological strategies. In addition to animals avoiding it, ...
Robert Rapplean's user avatar
22 votes
Accepted

How to wrap the Moon in plastic to make her a giant, supported by the atmospheric pressure, greenhouse

I saw several answers here close to what I wanted to say, but none of them quite do. So: Plastic Wrap Not Needed If you supply the Moon with an atmosphere, that atmosphere will not be instantly ...
Jim2B's user avatar
  • 28.7k
22 votes

Which plant species would be most likely to recover after a decade of no light?

Many plants produce seeds which would remain viable after 10 years. A few years ago, a group of students managed to produce a crop from 800 year old squash seeds. Online, you will find charts ...
Pink Sweetener's user avatar
22 votes

Why would a creature both have carnivore teeth and side-facing eyes?

I think the best way to make this work would to make the animal a scavenger. Carnivorous teeth are best to tear and slice decomposing meat, and the side facing eyes would be used to scan for danger as ...
Sol's user avatar
  • 221
21 votes

How would a free floating ecosystem on an ocean world function?

On the moon titan, beyond the initial ice layer, there is an entire ocean layer. If you continue further down you hit ice VI (which is always ice, just with a denser crystalline structure). This ...
Neil's user avatar
  • 4,290
20 votes

Life on a planet with never-ending rain

What would life be like on a planet where it rains constantly, assuming conditions similar to Earth? The Netherlands and the UK manage it pretty well, they just complain a lot about the weather. ...
L.Dutch's user avatar
  • 289k
19 votes
Accepted

Make a tiny island robust to ecologic collapse

What you need is a fast type of ecology something where the plants and animals grow and cycle quickly. To aid this add lots of energy so a tropical or subtropical island with plenty of rainfall would ...
Slarty's user avatar
  • 37.6k
19 votes

Where do forge-worms live outside of forges?

They are surface-adapted bugs originally of cthonic origin These critters are the descendants of organisms that live in molten lava. The dwarves were friendly to the originals, who kept returning ...
Christopher Hostage's user avatar
19 votes

Where do forge-worms live outside of forges?

Forest fires Forge-worms metamorphose through a complex life cycle. Only the adult stage requires extreme temperatures. Adult forge-worms emerge from their pupae in the inferno of a forest fire. They ...
causative's user avatar
  • 7,302

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