Eino Kenttä

Glenn Herbert wrote:Worry about horizontal movement of hot air is a red herring. As long as there is a good push or pull of draft from a vertical element in the system, a certain amount of horizontal movement is easy to reliably maintain. These factors have been experimentally established; early trials often pushed too close to the limits for reliability, and there are always amateurs who think they are going to do something different and better who end up smoking themselves out, and those who don't understand that certain elements of a system have to be done just so in order to work. I think publicity from those people has done great harm to the RMH movement.

A good draft can be established in ordinary conditions with only a 150-200F stack temperature. A rocket mass heater combustion core is specially designed to burn essentially all combustible gases so that there is no creosote at all, and thus no need to keep a chimney very hot. A hot fire in a wood stove is good, but does not approach the performance of a J-tube or batch box core built according to published specs.

The situation of vertical chimney and horizontal ducting feels like an equivalent to a siphon... If you just look at one part of the system, taken out of context, it seems in defiance of the laws of nature ("water flowing upwards/hot gases flowing horizontally? Ridiculous!") but if you factor in the other part of the system, that pulls the water/hot gas through the first part, it all makes sense. Just a random thought.

To answer the original questions: Yes, we're interested in building a rmh, and what's holding us back is just a slight (and hopefully temporary) lack of house...

Ac Baker wrote:Good evening.  Although I only did observational astrophysics, and how it helps constrain cosmology, I do have an observational cosmologist to hand.

Our first note is, we are observing from within the system when it comes to the Universe.

So that's fundamentally different from when we observe a black hole, as in that case we're outside the system, and the event horizon.

With the Universe, there is no "outside" from which to observe it.  By definition, the Universe contains everything within itself.

I hope you feel better soon: no rush to reply!

Hello Ac, and thanks for the reply!

As far as I can tell, we can't really observe the "inside" of a black hole from the outside, all we see (or would see if we actually spotted one close enough to observe it directly) is the event horizon. My understanding is that the regions outside the observable universe are an almost exact equivalent of the inside of a black hole. Both are separated from the observer by an event horizon, and so everything that goes on in these regions is completely unobservable. The only difference I can see is the curvature of the event horizon going different ways (the cosmological event horizon is essentially "inside out" compared to that of a black hole) and the somewhat related fact that in the cosmological case, what gives rise to the horizon is expansion due to dark energy, rather than gravity.

I gather that both types of event horizon are theorized to behave the same way regarding Hawking radiation (although there aren't any direct observations of either to back this up) which makes sense, since Hawking radiation is related to the Unruh effect. An observer just outside the event horizon of a black hole has to accelerate in order to avoid passing through the horizon, and due to the Unruh effect will then see a "glow" in space that appears empty and dark to a non-accelerated observer. Likewise, if you had two observers standing half the diameter of the observable universe apart, they would need to accelerate toward one another in order to not be separated by their respective cosmological horizons, and the same phenomenon would occur. I'll confess that I don't understand the details of how the Unruh effect and Hawking radiation are related to one another (like I said, I don't have a lot of maths, and this stuff is beyond me) but from what I've read, it's like that.

(Also, I feel more or less okay at the moment, but this virus is extremely back-and-forth. I feel fine, then I do something that's apparently just a bit too much physical effort, and I'm back to feeling lousy. It's frustrating. Thinking about this stuff is just fun, but maybe the clarity of my explanations suffers a bit. Anyway, thank you for helping to distract me from feeling bad!)

Nancy Reading wrote:I'm sure that is well explained, but beyond my feeble brain at present (I'll have to read it a few times).
I've sent a query into the ether and we'll see if we get a responce.

Understandable. I probably didn't explain as clearly as I could have, either (my head is full of flu at the moment), and again, maybe it's just a huge load of rubbish. But thank you so much for passing it on!

That would be wonderful. Thank you!

Briefly, the idea is a cyclic cosmology model based on a Big Rip-like scenario, that is, the acceleration of the expansion of the universe is fast enough to push the cosmological event horizon ever closer to the observer. From what I've understood, this scenario hasn't been ruled out, and some things I've read suggest there's some data pointing in that direction.

Now, if I've understood this correctly, the cosmological event horizon is believed to be similar to the event horizon around a black hole. Crucially, it's thought to have its own equivalent of Hawking radiation. The radiation temperature of the Hawking radiation is inversely proportional to the mass of the black hole, i.e. a very small black hole radiates at a very high temperature and quickly evaporates. Since the radius of the event horizon depends on the mass of the black hole, and the surface area of the event horizon depends on the radius, it follows that the smaller the apparent surface area of the event horizon, the higher the radiation temperature.

If the same is true for the cosmological event horizon, and if we assume that it gets closer to the observer with time, the radiation temperature, which is at present extremely low, should increase over time. There should be a point, when the observable universe (and thus the surface area of the event horizon) is sufficiently small, where the radiation temperature gets high enough to emit massive particles. Increasing numbers of massive particles emitted into a shrinking volume of space means increasing density. Eventually, the gravitational influence of this mass would be sufficient to slow the expansion, the cosmological event horizon would recede to a vastly greater distance, and its radiation temperature would drop nearly to zero.

This model would seem to avoid the singularity and the issues associated with it, since the expansion is continuously ongoing, albeit at a variable rate. It's widely accepted that the expansion was much more rapid very early in the history of the universe (cosmic inflation), which follows naturally from this model. It would also solve the horizon problem, just as cosmic inflation does, since the initial temperature in the early universe would be determined by the point where enough massive particles were emitted to slow the expansion, which would presumably be the same everywhere.

There are some more implications I've thought of, and probably a lot that I missed, but this might be enough to outline the idea. I'd be very grateful if someone knowledgeable in the field would take a look at it and let me know what they think. (It's very likely to be nonsense, but then I'd still like to know where I went wrong.)

So, I tend to think about a lot of stuff. Some of which I'm not qualified to even think about thinking about. One of the things I keep coming back to is theoretical physics. I don't know a lot of maths, which does tend to hinder any deeper understanding, but I like reading and thinking about it nonetheless. It's like a puzzle the size of the universe.

There's an idea in physical cosmology that I've been thinking about for a while now. It works in my head, the puzzle piece seems to fit with all the adjacent pieces that I'm aware of, but... I'm still not qualified to tell whether it's anything except utter nonsense. Neither is anyone I know. I've tried emailing a couple of different physicists, but never got a reply. I suppose either they shook their heads in tired disbelief and erased the mail, or it ran afoul of their spam filters.

I'd still like to ask someone about it, though, so I'm posting this here on the off chance that one of you might know a physicist in the right branch of the field, who might be willing to take the time to tell a complete layman what's wrong with his idea. Any clue to finding such an individual would be much appreciated.

Oh, and Nancy - are your plants still alive, or did you get frost? I noticed this year that the fruits keep growing, albeit slowly, even at cool temperatures (we had a lot of 12 degrees C in August).

The 2025 tomato growing results are here, and it basically boils down to SUCCESS!

So, to start at the end of the story, I just opened up most of the tomatoes, which were harvested before we left the land for the year (end of September), and have been after-ripening indoors for about three weeks. It was a bit nervous, many of them looked ripe, but I was half expecting that the seeds would all be tiny, shrunken things since the fruits were harvested unripe. As it turns out, some, but not all, of the direct-seeded ones (which was most of them this year) did have a fair few tiny shrunken seeds, but almost all of the fruits that looked to be anywhere near full size also had some good-looking seeds. Yay!!!

Back to the beginning. I started the growing year in late May, by sowing a massive disorganized mix of tomato seeds. I also planted out the two best plants from last year, which were kept alive indoors over winter. The seeds germinated okay, even though it took a while. Then nothing much happened for the next month or so, with either the direct-seeded plants or the transplanted ones, due to an unusually cool and rainy June. We went around most of the month hoping for a shift in the weather, and, well... Careful what you wish for, it might come true.

A week or so into July, it stopped raining, and the temperatures went up to around 30 C. Then it stayed like that for a month. I'm not joking, we did not get ONE DROP OF RAIN in a MONTH. On the Norwegian coast. There were a few thunder storms, but they all passed us by. I think the maximum temperature was 34 C. A neighbour, who's been living in the area his whole life, said he's never seen anything like it.

The heat was a very mixed blessing. On the one hand, it was too hot to get much done in the daytime (for us wimpy cold-weather people), we had to be extremely careful with fire, and we had to haul water to our hilltop garden every day. On the other hand, it was brilliant to go swimming every day, and some plants got a real kick. Including the tomatoes.

The first of the tomato plants started flowering in the end of July (I think). One interesting thing is that the transplanted plants didn't really start flowering much earlier than the direct-seeded. There might have been a couple of days difference between one of the overwintered plants (almost certainly 'Blue Ambrosia') and a few of the earliest direct-seeded.

Since I sowed all the seeds intermixed, I don't really have anything except educated guesses when it comes to what's what. The first direct-seeded plant to start flowering was a yellow cherry tomato of some kind (no idea what it might be called). Then there were several potato-leaved plants that developed what looked like small, red beefsteak tomatoes. These might have been lofthousers, since I don't know that I got seeds for anything else beefsteak-like. Some sort of wild tomato, probably a cheesmaniae, was also among the earliest.

In order to stir up the genetics, I emasculated one or a couple of flowers on each plant once a few plants had started flowering, scraped some pollen off each anther cone, and dabbed mixed pollen on each stigma. This was done twice, with a week or so between. I also put pollen on the exposed stigma of other 'Blue Ambrosia' flowers.

A bit into August, the weather did another complete U-turn, and it went back to being mostly cool and rainy. The tomato plants didn't seem to mind too badly, the fruits kept growing, although the leaves on many plants started looking quite sad after a while.

The weather stayed cool and rainy until the end of August, when it turned again, and we got a mostly warm September. None of the tomatoes really developed any colour until a week or so after being harvested and moved indoors. Some are still ripening (notably the wild tomato mentioned above) so I'll give them a bit more time. The rest have had their seeds harvested and set to ferment.

All in all, the weather this year was definitely not "normal", so I don't know if this will work as well a more ordinary summer. I'll take any help I can get this early in the process, though. Hopefully, there are some hybrids between the earliest-blooming individuals among the seeds, so the population next year might be a bit better adapted. Fingers crossed!

Ooh, that's clever! I also ran into this problem, and ended up sort of avoiding it by not jumping on the shovel and instead just hacking away using my arm muscles. It works, but it is a bit tiring. I might need to build something like this.

Kathleen Sanderson wrote:
The kale - I'm not sure about. It's a good choice in a lot of respects. Daughter tolerates sauerkraut well (and dill pickles); it seems likely that kale could be made into sauerkraut, though it would be a little different....

In my very limited experience, kale is no good for sauerkraut. It makes a horrible-smelling mess. I've understood that this happens when what you ferment contains too many leafy greens (too much chlorophyll maybe?) compared to the amount of available carbs. I remember reading a book where someone described the smell as "the most horrible dead thing you can imagine", but I personally thought it smelled more like some kind of poo. Hopefully someone with more fermentation experience than me will chime in. A thought occurs to me though: If the problem really is the ratio of chlorophyll to carbs, then a mix of kale and sunroots might work just fine? Hmm...