Posts by celtschk
After an age of highly developed technology, including many different satellites in various Earth orbits, humanity loses the technology needed to control those satellites. After many centuries, how...
While the other posts did already explain the issues with the cube-formed Earth, I just want to give a feeling of the dimensions we are speaking of. Imagine that the centre of the cube's faces are...
I've got this idea of a rogue planet that is moving that fast through the intergalactic void that the cosmic microwave radiation, thanks to the Doppler effect, actually provides enough heat that it...
The first question is: What is instantaneous speed measured against (that is, what is the “ground” relative to which the speed is measured)? Remember that there is no such thing as absolute speed. ...
Since manipulation of the brain is prohibited and illegal modifications are assumed to be reliably caught, the obvious way to check someone's identity with biometry would be by checking their brain...
Gravity You seem to assume that the Moon's mass is mostly concentrated in its core. While I didn't find detailed data on the Moon's density distribution, this Wikipedia page tells that the density...
Machines are not in a hurry, impatience is one of those inferior human traits the machines want to eliminate. Therefore it is not necessary to have humans give up their life; it's sufficient to jus...
Growing from a very small size to an extremely large size is no problem, as dinosaurs show (and remember, ultimately even the largest dinosaur started as a single cell; the size of the egg is basic...
According to this answer to another question an Alcubierre drive would need to have a channel setup far in advance. So with such a technology, you'd need to have a network on established lanes just...
All the answers so far dealt with the ship creating gravity itself. But there's another possibility: The ship might have some sort of gravity shields (to allow to pass close nearby heavy objects li...
OK, so we have two sun-like stars (I'll just write "suns" from now on) at $100\,\rm AU$ distance, and a (probably earth-like) planet at $1\,\rm AU$ distance from one of the suns. I'll call the sun ...
It would mean a more complicated modulation of the tides. On earth, we have a superposition of two cycles: An exactly 12 hour cycle of the sun, and a cycle deviating from that by the moon. The moon...
I think a reasonable assumption is that you don't want to accumulate entropy from the Dyson sphere. That is, the entropy you get from the star must not be lower than the entropy you send to outer s...
When reading "faster than light" one normally thinks of it as faster than the limit speed of relativity, which is the same as the speed of light in relativity, as the photon is massless and therefo...
(Ab)Use Religion to control the people A properly maintained religion can get people to do almost everything, and can guide their behaviour. People have killed others in the name of their religion...
Human language evolved for the interaction between humans. That may sound like a trivial fact, but it isn't: If there had not been social interaction between humans, humans would not have evolved l...
How would the civilization discover electricity? That one is easy: There are animals in the sea that use electricity, like the electric eel. The underwater civilization would certainly be curious ...
I'm making the following simplifying assumptions: No time travel, time dilation or other temporal effects through use of those technologies (basically, the travelling works as if there were an un...
tl;dr: No, it is not possible to have the force proportional to the product of the square roots of the charges. In an alternate universe there is a force known as the emotion force although the...
Well, the first obvious difference would be that the square-cube law would basically be replaced by a cube-tesseract* law. Since 4/3 is closer to 1 than 3/2, this means that there could be greater ...
The hair could contain a combination of chemical substances that changes colour after a given time. If the time needed for that process is long enough to allow the hair to significantly grow, but s...
Assume someone detonates a Hiroshima-sized nuclear bomb in space. Since in space there's no air, the bomb will behave differently than on Earth. In particular, there will not be an air pressure wav...
A recurring theme is how an artificial intelligence that was built with completely reasonable and positive goals instead does great harm to the world. However I'm now thinking about the reverse: A...
Let's do a bit of math. According to Wikipedia, the mass of the moon is $7.3\cdot10^{22}\,\rm kg$ and its average orbital speed is $1.0\,\rm km/s$. That means its kinetic energy is $3.7\cdot 10^{2...
It is definitely possible. Like for example the earth at the time of the dinosaurs. Quote (from relatively far down on the page): As the world entered the Cretaceous Period, Antarctica was very...
