45
votes
How to kill trees?
I know this is a slightly short answer, but it applies to most European trees (not all I admit) at least: if you hammer a copper stake into the tree low down, close to the roots, it will poison the ...
- 8,502
40
votes
Is it possible to live without killing?
It is inconcievable that any evolved non-autotrophic life form could exist without preying upon and killing other life forms for their sustenance, whether they be sessile or motile (that we call ...
- 63.3k
38
votes
Accepted
How to explain human life expectancy increase?
Cure for cancer, Alzheimer's and heart disease
These three are the big natural killers.
Cheap, clean, ubiquitous and plentiful energy sources
Air pollution is the biggest non-natural killer. The ...
- 43.9k
31
votes
How would fantasy dwarves exist, realistically?
Dwarves might not need to dig tunnels and caves, but instead rely on natural ones that they modify, like the Migovec and Postojna cave systems in Slovenia, which are 42 km and 24 km long, respectively,...
- 16.4k
26
votes
Is it possible to live without killing?
There Is A Simple (Sci-Fi) Solution
We can easily join the Federation, though not as we are now. But all we have to do is develop mind-uploading technology and live as machines on a sterile world. (...
- 11k
24
votes
The cruel life-cycle of biscuits (cookies)
Ultimately, the answer comes down to breeding. No, not thát kind of breeding! I mean the kind that results in
Making More Biscuits!
You see, the entire life span of any biscuit species is long and ...
- 40.8k
23
votes
Is there enough fresh water in the world to eradicate the drinking water crisis?
Depends upon what you mean by solving the water crisis and how much it costs, but yes
Let's assume that teleportation is truly cheap. The question then becomes is there enough available fresh water ...
- 22.5k
22
votes
How to kill trees?
To kill it keep it off the ground and dry, in the case of cut timber if you keep the logs off the ground, under shelter, any roots that they might otherwise grow will encounter air rather than soil or ...
- 46.4k
21
votes
Accepted
Can there be life on a planet with water, but without atmosphere?
There's really no such thing as a planet or moon with no atmosphere. But as it so happens, the object in our solar system most often pointed out to possibly harbour life is Jupiter's moon Europa, ...
- 2,098
21
votes
Would carbon-based lifeforms be able to eat silicon-based lifeforms?
We are not able to digest silicon based materials. See for example rice hulls:
Rice hulls are the coatings of seeds, or grains, of rice. The husk protects the seed during the growing season, since ...
- 292k
20
votes
Is there enough fresh water in the world to eradicate the drinking water crisis?
This misses the problem.
The problem is not a shortage of fresh water. The problem is a shortage of purification and delivery. Because you don't normally drink water straight from a well or river....
- 25.3k
19
votes
Would carbon-based lifeforms be able to eat silicon-based lifeforms?
The majority of the nutrients we need (proteins, carbohydrates, fats) are carbon-based, and silicon-based life is presumed to have incompatible analogs instead (with silanes replacing alkane groups).
...
- 4,789
18
votes
Would you shoot out DNA onto baby planets if you planned to visit it someday?
Bearing in mind that the only reason DNA exists is through Amino Acids and a nitrogen-rich atmosphere that allowed it to exist; I'd say the answer to your question is:
Not Likely
Firstly, as Green ...
- 1,523
18
votes
Accepted
If only the sun's light went out, how long would it take for all living things to die out?
How fast will the Earth cool down?
This is going to be the dominant factor. If it takes too long to cool down, then maybe all the plants will die without sunlight and creatures will starve to death. ...
- 85.6k
18
votes
Accepted
What amount of forrest-fire in square km or metric tons, would be necesary to bring oxygen levels below 19.5% that humans require to stay alive?
Let's start with considering the entire mass of the atmosphere:
The total mean mass of the atmosphere is $5.1480 \cdot 10^{18} kg$.
We know that Oxygen accounts for 21% in volume, and considering ...
- 292k
18
votes
Accepted
On a planet with larger gravity, would aquatic creatures be larger or smaller?
The size of marine animals on Earth isn't really restricted by gravity... it is more about food supply and metabolism. The ultimate limit in size is probably quite complex, and a factor of various ...
- 78.3k
18
votes
Accepted
Could there be an alien life form (a complex animal) that lives hundreds of thousands of years, or even millions of years?
A problem with such a life form: how would it come into existence? Evolution requires production of new generations with varying characteristics and selection of those characteristics by environmental ...
- 5,635
17
votes
How to kill trees?
It doesn't seem that much of a problem to me.
Even growing roots within a day isn't going to make it very hard to just cut the wood to what you need and use it. The wood would need to cannibalize ...
- 45.5k
17
votes
Accepted
Could bacteria survive on a star?
Some simple molecules can exist in stars - but not the right ones.
Contrary to popular belief, many different types of molecules can exist in stellar atmospheres, especially cool stars like red ...
- 102k
17
votes
Habitable Planet with Highly Eliptical Orbit
I think that because of how orbital mechanis work, a planet with an aphelion inside the habitable zone and a perihelion too close to the sun would be better for life. A planet spends a lot more time ...
- 17.1k
17
votes
Accepted
Is an almost entirely water-based planet stable enough to stay as a planet for long enough for complex life to form?
Probably such a body would not host life, no matter how long you wait.
One can read everywhere that water is the basis for life, however a water only planet would be a terrible place for life to start,...
- 292k
17
votes
Would My Planet’s Blue Sun Kill Earth-Life?
Let's invite an expert's opinion
Dr William Stiles of Aberystwyth University wrote the following (emphasis is mine):
Light is an essential component of plant development and is a key driver of plant ...
- 127k
17
votes
Could there be an alien life form (a complex animal) that lives hundreds of thousands of years, or even millions of years?
It's a plant
The entity you are looking for will in some way be akin to trees on earth. Redwoods and oaks are known to be able to get older than 200 years, and with the right circumstances, such an ...
- 16.8k
17
votes
Is a desert planet with a small habitable area possible?
How about a very deep rift valley?
The surface could have a thin atmosphere, and continuous illumination from a cloudless sky. It would be hot and dry in the day and freezing at night, and the air ...
- 10.9k
16
votes
Accepted
Would you shoot out DNA onto baby planets if you planned to visit it someday?
I'm going to throw my hat in the ring with an answer different than the others. Simply, yes... there are some reasons. I think the reality-check tag makes this a tougher argument, but you also ...
- 890
16
votes
Biological siege weapons: Part 1 - Are living things capable of breaking down the gates of a medieval gatehouse?
Depends on the gatehouse design, but the answer ranges from "absolutely, like butter" to "It might, if you're able to push the animal beyond it's normal limits."
Another answer ...
- 3,076
16
votes
Is a desert planet with a small habitable area possible?
Nile River
Have you seen a satellite photo of the Nile River? It is basically a small stretch of very green "forest", surrounded by very harsh deserts.
Your world could be very old, with ...
- 1,340
15
votes
Biological siege weapons: Part 1 - Are living things capable of breaking down the gates of a medieval gatehouse?
Use a Tree
Tree roots are designed to push thier way through solid Earth as they grow. This includes breaking apart and displacing solid concrete and brick work as many property owners have had to ...
- 97.7k
15
votes
Could there be an alien life form (a complex animal) that lives hundreds of thousands of years, or even millions of years?
In theory there is no reason why a very long life span should not be possible from a chemical perspective. It should be possible to create an entity that has sufficient repair mechanisms to repair any ...
- 37.9k
14
votes
Accepted
Smallest possible habitable planet? (also taking density into account)
The answer to this question is actually quite complicated or rather it depends very much upon the parameters that you plug into the equations. I'll tell you the values that I used to get my answer ...
- 28.8k
Only top scored, non community-wiki answers of a minimum length are eligible