I don’t understand where this is coming from. Isn’t Meta offering to EU users exactly the choice you are describing? (Even though in the case of the subscription we can’t really be sure they also don’t still use your data.)
The problem is that is also against the rules. GDPR bans using private data as a form of payment. You can give your data away freely but it can't be requested as a form of payment. In this case Meta is asking you to either pay with your money or your data. One is OK, the other isn't.
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
Massive radiators. The ISS has radiators that have a dissipation capacity of about 3m^2/kW. If we use that number, we'd need a 3000m^2 radiator per megawatt, which is the scale they're talking about. This could theoretically be brought down, but not even by an order of magnitude.
I wonder how much cooling the solar panels alone would need, when operating at that scale.
You cool the fluid by flowing it through the radiator. The radiator emits heat radiation into space and cools down the fluid. As long as the fluid is hotter than the equilibrium temperature of the radiator (determined by radiator, space and sun radiation), it will emit more energy than it receives and cool down the fluid.
Followup question, wouldn't nearly any cooling solution that works in space also work on the ground? Radiative cooling is the most basic/common cooling solution on the ground, the main challenge is just figuring out how to to move heat from the component to the radiator, which I don't think is solved by simply putting it in space?
> Radiative cooling is the most basic/common cooling solution on the ground
Thats tricky. I know the heat exchange components are called radiators but most of the heat they give off is by convection not radiation. (At least here on the ground.) I heard 80%-20% rule of thumb.
But you are right in the broad strokes. Cooling is not easier in space. Mostly because you have no convective heat transfer.
Oh right, that makes sense. So the argument is that comparing a 50C GPU+radiator in a 20C room vs a 50C GPU+radiator in 0K space, the one in space will dissipate more heat via radiation than the one on the ground? As you say, I'd expect that air cooling is much better than EM radiation, but I guess there is some basis for claiming the possibility that cooling in space is somehow better than on the ground, however unlikely.
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.
Is radiative cooling the most common on Earth? I don't think so. Most terrestial "radiators" actually work with convection, ie moving relatively cold air across hot metal fins, which doesn't work in space.
The N-body _reality_ _might_ be deterministic. The N-body simulation using digital computers will technically still introduce errors because of the time steps even if you had perfect knowledge of initial conditions.
The errors are deterministic. Determinism has nothing to do with the existence of errors, it's about uncertainty. They're different things. A system that is deterministic will produce the same results every time given the same initial conditions. If there are numerical errors, they will be identical for each run. A non-deterministic system will give you different results every time given the same initial conditions, with some variance. You can still have numerical errors in such a system.
Ironically, reality probably isn't deterministic. It definitely isn't at small scales (e.g. radioactive decay). If it's non-deterministic at a macro scale, the effect is small enough that we don't see it.
That’s the point, reality isn’t deterministic,so you can’t really use deterministic math to describe it. That’s just an approximation, regardless of errors in the simulation. That’s also why you run Montecarlo simulations, not to even out simulation errors, but to compute as many probable outcomes as possible and then have a probability distribution that represents your best bet at guessing the non deterministic reality that you are trying to predict. If you “run” reality twice your not gonna get the same result
What kind of capitalism-apologist hot take on parents/families caring for the well-being of their children/members is this? Surely the world is not frequent with Tom-like Oxford-educated actors feeling bad about how good they have it. If some people arrived to the conclusion that they don't have to work because their parents provide for them, then I would argue their parents have failed them in other ways, but not because of what they provided.
Should we decide on a different social contracts where people return things when they die? Sure. But start with the wealthiest please.
(Very) wealthy families already face stiff inheritance and/or estate taxes at both Federal and State levels. Important note, most middle class and all lower class families and individuals will never face inheritance/estate taxes.
Minor note, on the federal level and most states, the “estate” is taxed, not the inheritance which has some subtle differences and loopholes. Also, very very wealthy families can pass much of their wealth through family office funds, blind trusts and company share transfers while living, that are taxed differently.
Between the very high caps before an estate tax is used and the loopholes, extremely few dollars are taxed this way.
Indeed! Estate taxes are subtly different from inheritance taxes.
My dad and I got a crash course introduction when my mom passed; he inherited everything being the survivor so it was all very simple with next to no paperwork, but all the debtors (banks) my mom owed money to when she passed graciously explained to us that any such debts were the responsibility of my mom's estate and not us.
In practical terms the difference meant little, debts are supposed to be repaid and we were happy to clean up her financial affairs as estate executors, but it's a good fact to know now rather than later.
I understand your point and thank you for raising it. The article mainly discussed the UK where a similar steep 40% estate inheritance tax exists for values above a certain threshold. There is also the 7 year rule that completely avoids inheritance tax. Elsewhere in Europe the situation is not as "progressive" and it's more frequent to face inheritance taxes. At the same time, it feels like there are many loopholes around these for the truly wealthy.
Though, the perspective of the article reads like it's accusative of upper middle class families (and not higher).
> However, while banks shouldn’t charge for receiving SEPA payments, unfortunately there is a very small number that may still do so.
I can also confirm for example that (despite the UK still being in SEPA), wire transfers of Euro from Unicredit in Italy are getting extra charges when sent to a british IBAN (Unicredit is charging the sending side).
It was never free or instant. It only works from 9-15 on workdays and not on weekends. Also if there are holidays in eu also doesn't work for domestic transfers. Easter is fun whe it stops for 4 days even though country has only 3 state holidays during those times. Costs from 25-40 cents per domestic transaction or 7-17 euro per over border one. Depending on the bank.
It takes around an hour or some days over border for transfer to go through.
Maybe you think of sepa instant which is supported by some banks. Very new. Mostly used for people to people transfers. Some shops are starting to support it. It is actually instantaneous anc works weekends. It seems to be mostly free.
In addition, SEPA was never free. So OP is also wrong there.
The regulation only stipulates "equality of charges", that the bank's fees for a payment into another SEPA country/bank must be the same as into the same bank or within the same country [0]. I.e. no payment fee discrimination across SEPA: if my Czech bank X charges me Y for a local EUR payment into X, it must also charge me Y for the same EUR payment into Italy, for example.
Would any bank actually charge their customers Y>0 like that? Yes they would. For example the Bank of Cyprus (in Cyprus, which is in both EU & SEPA) will charge you 6 EUR for a SEPA payment of 1200 EUR if the sender is a physical person, and 10 EUR if legal person [1]. And 4 EUR for smaller EUR amounts. Far from "free".
One thing I always accidentally click is the animation-expanding Google results when I return back to the search results after visiting one of the result pages, while trying to quickly visit the next result’s page.
