So, probably a dumb question from me, but why are we "all entitled to at least basic courtesy"? What is the "basic courtesy" that everyone has agreed to follow?
> this has nothing to do with open source or software; it's just common sense when dealing with people
Common sense is very different than entitlement. Back to the open source software point of view, your entitlement is described by the license. Basic courtesy, or even the opportunity to interact with anyone, is not included as a part of any open source license I remember. It isn't even a consideration for most [0].
> As a designer of a billion-sold device, your job is to make sure that the expected number of people harmed by your device is substantially less than one
Source? People take risk in their day to day life and should expect to take risk. Why would they expect their microwave to be completely free of risk?
I think there are two key imperatives that lead to company "psychopathy".
The first imperative is a company must survive past its employees. A company is an explicit legal structure designed to survive past the initial people in the company. A company is _not_ the employees, it is what survives past the employees' employment.
The second imperative is the diffusion of responsibility. A company becomes the responsible party for actions taken, not individual employees. This is part of the reason we allow companies to survive past employees, because their obligations survive as well.
This leads to individual employees taking actions for the company against their own moral code for the good of the company.
See also The Corporation (2003 film) and Meditations On Moloch (2014)[0].
I wanted to learn about wavelet transforms. I also wanted to use Rust in a non-trivial capacity. Since jpeg2000 uses discrete wavelet transforms[1] and doesn't have a Rust implementation it caught my interest.
I think other have already corrected you, but radiative cooling is probably the least common on the ground and the only viable option in space.
I can help explain why. On earth, we are surrounded by stuff. Radiative cooling relies on thermal radiation leaving an object. Crucially, it also requires the object to absorb less thermal radiation than it emits. On earth we are surrounded by stuff, including air, that emits thermal radiation. There is a window of wavelengths, called the atmospheric window[0], that will allow parts of the thermal radiation out into space, rather than returned back. Imagine shining a flashlight on tinted glass, the light will get through depending on the color. If the light gets through, it has escaped. If not, the light is returned and heats up your surroundings again.
Also on earth the other methods (conduction, convection, and phase changes) are more effective. The earth can be used as a very big heat sink. On a spaceship or satellite, you don't have the extra mass to store the energy, so radiative is the only option.
Passive cooling refers to "passive radiative cooling"[0]. This is a well established technique, but I have doubts on how well it will scale with the heat generated by computation.
Radiative cooling works by exploiting the fact that hot objects emit electromagnetic radiation (glow), and hot means everything above absolute zero. The glow carries away energy which cools down the object. One complication is that each glowy object is also going to be absorbing glow from other objects. While the sun, earth, and moon all emit large amounts of glow (again, heat radiation), empty space is around 2.7 Kelvin, which is very cold and has little glow. So the radiative coolers typically need to have line of sight to empty space, which allows them to emit more energy than they absorb.
This is exactly right, and an important fact is that there is a limited bandwidth for heat radiation. So essentially they need to create a giant lightbulb...
> Additionally, deep space is cold, which is accurate in that the "effective" ambient temperature is around -270°C, corresponding to the temperature of the cosmic microwave background.
There's a lot of bad information in their document too. This -270C temperature is ambient space, i.e. deep space. You may experience this when you're in the shadow of Earth or on the dark side of the moon but you're going to switch that negative sign to a positive when you're facing the sun... Which is clearly something they want to do considering that they are talking about solar power. Which means they have to deal with HEATING as well! I don't see any information about this in the document.
> he mass of radiation shielding scales linearly with the container surface area, whereas the compute per container scales with the volume
This is also a weird statement designed to be deceptive. Your radiation shielding is a shell enclosing some volume.
> Therefore the mass of shielding needed per compute unit decreases linearly with container size.
They clearly do not understand the mass volume relationship here. Density (ρ) is mass (m) divided by volume (V).
m = ρV.
Let's simplify and assume we're using a sphere since this is the most efficient, giving V = 4/3r^3. Your shield is going to be approximately constant density since you need to shield from all directions (can optimize by using other things in your system).
m ∝ ρr^3
I'm not sure what here is decreasing nor what is a linear relationship. To adjust this to a shell you just need to consider the thickness so you can do Δr = r_outer - r_inner and that doesn't take away the cubic relationship.
FWIW, i think their description for the radiation shielding is fine. Your analysis is off. If we assume the spherical case, the mass of the shielding is proportional to surface area, not the volume[0]. You might be confusing general radiation shielding and thermal shielding. Thermal shielding is easier because you can point things towards the sun, earth, and moon.
I am more concerned about heat dissipation, which should scale with surface area, but heat generation scales with compute volume.
[0]:
shell thickness, t
compute radius, r
shell volume is (r+t)^3 - r^3 = 3 r^2 t + 3 r t^2 + t^3 = O(r^2)
shielding/compute is O(r^2)/O(r^3) = O(1/r), ie their linear decrease
You may not have intended it as a "flex", but you are teaching your children to be snooty. If they have "never" eaten a school lunch, they have judged the lunches based on appearance rather than substance/flavor. I wonder how you have judged the school lunches to be lesser than MREs, perhaps you tried the lunches before your children.
> this has nothing to do with open source or software; it's just common sense when dealing with people
Common sense is very different than entitlement. Back to the open source software point of view, your entitlement is described by the license. Basic courtesy, or even the opportunity to interact with anyone, is not included as a part of any open source license I remember. It isn't even a consideration for most [0].
[0] https://en.wikipedia.org/wiki/Comparison_of_free_and_open-so...
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