57
votes
Can a gunsafe survive a nuclear blast level attack?
As specified, this question is trivial - you're saying that a thermonuclear weapon is going off within nine yards of the safe.
Though there's variation, a relatively typical thermonuclear weapon in ...
- 26.1k
36
votes
Can a gunsafe survive a nuclear blast level attack?
Steel may not remain solid within meters of a nuclear explosion
The safe is not “extremely strong” at all. The model is likely Liberty Safe Co.'s Freedom 30. According to the specs, the save is ...
- 486
35
votes
Antiballast for flying ship
Volume-based Adjustable Buoyancy
The key here is to not use so many stones that your ships float up. Instead, use as many stones as is needed to make your ship effectively weightless. If 1kg of ...
- 6,085
31
votes
What is the best ways of cleaning/bathing inside an astronaut suit?
Rotate troops often enough and it's a non-issue.
In a system of earthworks, the fire-trench where the action happens is only the outermost layer of a complex tiered system of trenches, bunkers, and ...
- 35.2k
29
votes
Accepted
What would a spacefaring race use as fuel for their matter-to-energy reactors?
Mine tailings:
In your scenario, you can destroy matter. But even waste materials for your civilization out in space are made of the things you find valuable. In space, people are interested in places ...
- 62.6k
27
votes
Antiballast for flying ship
Harvest extra ballast water from clouds.
The Graf Zeppelin did this in real life during the 1930s. A set of gutters on the side of the vessel collected the water. The airship brushed against the edge ...
- 27.9k
22
votes
Does this alternate Universe with easier-to-understand physics behave the same as ours?
Technobabble is Technobabble
No, this model of the universe as a cellular automaton cannot be reconciled with the basic behavior of our real-life universe.
Let's take a simple example, exploring a ...
- 80.2k
19
votes
What would a spacefaring race use as fuel for their matter-to-energy reactors?
Solar Wind
Converting Mass to Energy creates such a crazy amount of energy that you barely need any mass. One kilogram of matter has ~ 25,000 Gigawatt-hours of energy. Since a normal US house uses 10,...
- 9,789
18
votes
How could humans repeatedly lose their latest memories
Backup Restoration
In a far future world, people make backups (periodically, perhaps daily in a hazardous environment) to protect their memories and identity in the case of their body being killed (...
- 44.4k
17
votes
How could humans repeatedly lose their latest memories
This effect is a common one for people who have had clinically safe doses of opioid drugs like oxytocin and fentanyl.
It is really quite remarkable to see it play out in real life with people who have ...
- 11.3k
17
votes
Accepted
Would two people standing on opposite sides of a flat world be able to see the same constellations?
Depends on how close to the edge they are
Overlapping fields of view of two observers on opposite sides of a disk world. The field where both observers can see an object is purplish sector; note that ...
- 80.2k
16
votes
Would two people standing on opposite sides of a flat world be able to see the same constellations?
The part of the surface going from their feet to the edge will shield vision of part of the sky, so their field of vision will only partially overlap, as you can see in the below schematic.
The ...
- 262k
16
votes
Suppose an array of mirrors 50 km above the surface reflect light straight down. How long before the sun rise are they illuminated?
From a height of 50 km, the horizon is at about 800 km. At 45 degrees latitude, 800 km is about 10 degrees of longitude. The solar time 10 degrees of longitude away is about 40 minutes ahead or behind ...
- 80.2k
15
votes
Are Mass Effect "style" guns possible?
The answer is "no," but just how it fails depends on the details.
If the projectile is a "shaving", a curved sheet of material, rather than axisymmetric, then it's going to be ...
- 22.2k
14
votes
Antiballast for flying ship
The stones are expensive, so you dont add so many that the ship becomes weightless.
You essentially build a Heavier-Than-Air airship. It will naturally float down if nothing is done, but by the use of ...
- 43.1k
14
votes
Accepted
Would compound-like eyes that gave a "pixelated" image be possible/practical
. . . meaning only light reflected from a narrow angle from the front of the ommatidia would get to the second half where all the photoreceptor cells lie.
An obvious difficulty is that this kind of ...
- 22.2k
13
votes
What would a spacefaring race use as fuel for their matter-to-energy reactors?
First it might be a good idea to ballpark how much matter you would need. From Newtonian physics it takes about $62$ megajoules of energy to get a kilogram completely off planet earth, so 2 kilos ...
- 2,013
13
votes
Accepted
Is it possible to build a transmitter small enough to fit inside of a .45 caliber bullet?
Yes, it surely is.
The radio proximity fuze as used in the Second World War functioned after being fired from (in the example image at the link) a 40 mm Bofors gun, despite requiring an onboard ...
- 44.4k
13
votes
A person in the air being struck by lightning
A lightning discharges through the path of minimum resistance.
In a process not well understood, a bidirectional channel of ionized air, called a "leader", is initiated between oppositely-...
- 262k
13
votes
Does this alternate Universe with easier-to-understand physics behave the same as ours?
Fundamentally no.
Our model of physics is the simplest one we can pull off that explains as many of our our observations and experiments as we can.
If a simpler model that would predict the results of ...
- 13.9k
12
votes
Can Mars disintegrate entirely in this scenario?
One part of the question says:
Before the fly-over, Mars's rotation can be accelerated to up to 1 Martian day per hour if that helps Mars to disintegrate.
Would that help Mars break up into pieces?
...
- 27.7k
12
votes
How could humans repeatedly lose their latest memories
You can use the following facts from neuroscience:
Perhaps the most famous patient in neuroscience is Henry Molaison (patient HM) who had his hippocampi and surrounding regions surgically removed in ...
- 121
12
votes
Would compound-like eyes that gave a "pixelated" image be possible/practical
The image might be pixelated, but vision will not be.
Our brains do a huge amount of processing of the "raw data" that comes from our eyes, and presumably, your organisms will do the same. ...
- 2,657
11
votes
How could humans repeatedly lose their latest memories
Anterograde amnesia
This is a form of memory loss that prevents an individual from forming new memories of things that occur after the specific event that caused the amnesia. Importantly, memories ...
- 13.1k
10
votes
Industrial scale Tritium production from Helium3?
So, especially in the outer solar system, where refining Helium3 from the atmospheres of gas and ice giants is rather trivial
If you first assume that extracting and exporting stuff from the ...
- 67.3k
10
votes
What would a spacefaring race use as fuel for their matter-to-energy reactors?
Waste.
Landfill sites are expensive to set-up properly. The sites can eventually have housing built on them, but not without extensive plumbing to allow methane and noxious gasses to escape safely. ...
- 23.7k
10
votes
A person in the air being struck by lightning
Being hit: Plausible. Surviving it: Plausible?
You might be interested in the story of Zhongpin He, who was sucked into a storm while paragliding and later found dead. Lots of things could have killed ...
- 6,182
10
votes
Does this alternate Universe with easier-to-understand physics behave the same as ours?
Frame challenge: Make late-19th century physics accurate
Toward the end of the 19th century, there were several prominent physicists who thought we had figured out pretty much everything fundamental ...
- 574
9
votes
How would a sky with extreme kessler syndome look like?
Permanent skyglow
If Kessler syndrome does occur, most satellites in orbit would be properly shattered, which means that few, if any, would be seen with naked eye. Significant proportion of the mass ...
- 42.1k
Only top scored, non community-wiki answers of a minimum length are eligible