I share your enthusiasm about heat pumps, but I wonder what the efficiency of using waste heat is. Couldn't it be competitive with heat pumps? As it's a waste product, isn't it reasonable to also expect it to be more than 100% efficient?
As a rule of thumb (obviously it varies) you spend about 1% pumping water round a heat network. So your CoP is around 99 if you consider heat truly free. It's actually higher as pump energy largely is converted to friction/heat.
You can’t extract energy from heat by itself. Only from a heat delta.
Think of heat like flowing water or charge. Only an altitude or voltage delta creates the flow needed to harvest energy.
You get no useful energy from heat you are already trying to shed because you have no delta to work with. (The entire problem exists because there is no surrounding environment with high heat capacity and lower heat.)
Yes, because there is a heat delta. A heat difference.
Using higher heat to raise lower heat is just the most simple case.
But purpose isn't relevant to this constraint, it is a physics constraint. Regardless of purpose, you can't extract useful energy from heat without a heat difference to work with. (And without a heat difference, even "heating" with heat doesn't do anything.)
Yes you can, that is exactly what heat pumps do. As long as the total entropy increases it is not in violation of the laws of thermodynamics.
But I don't really see how that is relevant to the question of using waste energy to heat homes. We don't have ideal Carnot machines so there's always energy wasted, which most of the time is still good enough for residential heating.
The conversation was about harnessing energy, from heat, in orbit.
Heat pumps take energy to move energy. But you can't power the heat pump from the heat it is already pushing against the heat gradient.
Waste heat can be used, if there is a difference in heat to work across, but not if there isn't. A datacenter in Antarctica could recover energy from waste heat, against the freezing outdoor temperatures.
In orbital systems, the problem is getting rid of heat, so there isn't some cold place to use to create a heat gradient and harvest energy. Space is cold, but particles are so diffuse they have little heat energy capacity, so essentially a heat insulator, and not useful to create a gradient. Thus the use of radiators.
I wonder whether people who disagree about this are talking at crossed purposes. I think there's politics in a narrower sense (concerning partisanship and state intervention) and politics in a wider sense (concerning power relations and decision making). To depoliticise things in the former sense (by depolarising and deregulating) isn't to depoliticise them at all in the latter sense. In society, arguably everything is economic, legal, psychological, etc. Presumably, what people mean when they say "everything is political" is that politics in the wider sense is both important and on this list.
I see. I disagree with them if they think everything really is political propaganda, but I think in a sense everything is political (in the wider sense) in its causes and consequences, so perhaps it might as well be propaganda, even if those involved don't think of it that way.
To return to your previous comment that "everything is political" is a tedious worldview, maybe there's a possible compromise. We could accept the idea that "non-political" everyday things have a (small) political significance, while never (or rarely) engaging with that political significance in any specific instance.
> To return to your previous comment that "everything is political" is a tedious worldview
It is tedious specifically because of the "in the wider sense" you put in parens
It is an overly broad definition of political to the point of uselessness and absurdity
Edit; for example, consider the case of a child throwing a ball for their dog.
The child is not political. The dog is not political. Yes, you can say that there's politics in letting people own pets like dogs. There are politics in having a public space where children are allowed to play fetch with their dogs. There are politics involved in the parents deciding to have children in the first place, or where they choose to live and work.
> It is an overly broad definition of political to the point of uselessness and absurdity
I don't think it's useless or absurd, just not usually applicable. After all, each action has a specific political significance.
> It's also just tedious
Fair enough, but couldn't we say the same about many other things? For example, Brownian motion might not usually warrant our attention, but it's there for when we decide it is of interest.
It's worrying. Assuming there's a risk of such fraud going undetected and harming a paying guest, I think a punishment more serious than a warning could easily be justified. Even if it isn't reasonable to prosecute, banning the host would help. Users of other online services are sometimes banned without warning or explanation, so the deference to Airbnb hosts is jarring.
As terrible as proprietary app 2fa is, it still beats the tar out of SMS or email 2fa, security-wise. I don't get why my bank, who used to be pretty cutting edge, never implemented TOTP or passkeys...
> For example, if I love Obscure Artist A, and 90% of my songs are Obscure Artist A, then Obscure Artist A should get 90% of my $15 or whatever subscription fee (minus Spotify's cut). But instead, Spotify says "Obscure Artist A only had .000001% of total plays, so they only get .000001% of total revenue" - it ends up being a better payout for the big names but a worse deal for all the smaller artists.
Why would the former pay obscure artists more? Are non-paying users more likely to listen to mainstream artists? Or do fans of obscure artists just play fewer songs each? Is ad revenue shared in the same proportions, but just lower per user? Is revenue really shared on the basis of plays, rather then playing time? If so, and if obscure artists make longer songs, does that contribute to their lack of revenue?
I don't want the obscure artists to get more ― or less, for that matter. I want the artists I listen to to get my money, obscure or not. That's a simple transaction and has worked forever. If I buy a CD from artist X, I know I won't be supporting artist Y with my money, just X. If I then want to listen to Y, I can support them as well. But in any case Z won't be getting any of my money because they make noises I don't consider music.
Money is fungible. Where “your” money went means nothing, just what the final payout the artist got at the end of the month.
It doesn’t seem obvious that smaller artists have audiences who stream music less than listeners to Taylor swift. Because that’s the only way the current system might rip people off.
> If I buy a CD from artist X, I know I won't be supporting artist Y with my money, just X.
That's not entirely true, since by buying X's CD you're also giving money to the label/publisher of that CD, who may be allocating that money to Y if Y is also one of their artists. However, overall I agree that the buy-a-CD model makes it more clear where your money is going.
It seems like if anything the current model would end up paying obscure artists more? (If you assume that people who listen to obscure music tend to listen to more music overall, which would be my guess.)
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