2023-12-05 07:24:57 <KipIngram   > I see - like a Riemann sphere but only for reals.
2023-12-05 07:27:35 <KipIngram   > It's never really particularly bothered me that 0 has no inverse.  It's a bit like us having a large dance floor, but there is a hole over there we might step through.  So we put a little guard rail around it, and then the rules are just "go anywhere you want, except you can cross that barrier - there's trouble on the other side."
2023-12-05 07:27:44 <KipIngram   > ugh - s/can/can't/
2023-12-05 07:28:02 <KipIngram   > Just don't go there and everything works just fine.
2023-12-05 07:29:06 <KipIngram   > And as things turn out, inablity to reach that one little part of the dance floor doesn't cause us trouble as we go about our business.
2023-12-05 07:30:10 <KipIngram   > This is a bit of a sidetrack (though an interestng one) - the main point the other day is that regardless of whether 1/0 exists or not, it's absolutely not 0.
2023-12-05 07:30:32 <KipIngram   > If it's anything at all, it's infinity.
2023-12-05 07:31:07 <KipIngram   > The rest of our discussion here is about whether "infinity" is something tangible or not.
2023-12-05 07:32:07 <KipIngram   > In the normal numerical field, infinity isn't in any way a number - it's kind of just an idea.  Riemann sphere, wheels, etc. let us treat it "a little more" like a number, but as you note still with some limitations.
2023-12-05 07:32:39 <KipIngram   > You can at least point right at it on a Riemann sphere.
2023-12-05 07:33:09 <KipIngram   > Whereas you can't in the more standard field of numbers.
2023-12-05 07:34:14 <KipIngram   > Roger Penrose does some neat stuff, where he maps the universe onto a diagram where "infinity" is at the outer edge.  Lets him paint the whole universe on a finite manageable drawing.
2023-12-05 07:36:10 <KipIngram   > This sort of mapping:
2023-12-05 07:36:13 <KipIngram   > https://imgs.search.brave.com/JWwrKTawxKPzZi6HEpZfr4N7Kq2eqf6WFU9vxhmlC00/rs:fit:860:0:0/g:ce/aHR0cHM6Ly9tLm1l/ZGlhLWFtYXpvbi5j/b20vaW1hZ2VzL0kv/NTFBaGFITlcrY0wu/anBn
2023-12-05 08:26:41 <user51      > That looks more evil than I expected :P
2023-12-05 08:27:22 <KipIngram   > :-)  Yeah.  It makes sense in a way - stuff "further away" is "more compressed," and the region near you is presented in most detail.
2023-12-05 08:28:15 <KipIngram   > Cosmologists have kind of a tough row to hoe - they have to somehow address "everything."
2023-12-05 08:29:12 <KipIngram   > I still struggle with significant parts of Penrose's work; the level of mathematics he works out is just out of my current reach.
2023-12-05 08:29:17 <KipIngram   > works "at"
2023-12-05 08:31:44 <KipIngram   > He theorizes that in the VERY far future, after the last black hole evaporates, the universe will contain no  matter at all - only photons.  And according to him that state is mathematically identical to the Big Bang state, since photons don't "register" distance or time passage.  So he says that then things will just "bang again."  No phase of contraction back to a point - just an endless cycle of Big Bangs,
2023-12-05 08:31:46 <KipIngram   > expansion, and eventual lose of all matter that repeats over and over.
2023-12-05 08:32:01 <KipIngram   > So, cyclic cosmology without any contraction phases.
2023-12-05 08:32:40 <KipIngram   > It's not a well-accepted theory, but he claims there is some supporting observational evidence.
2023-12-05 08:33:03 <KipIngram   > He calls each cycle an "aeon."
2023-12-05 08:33:46 <KipIngram   > And claims that at least in principle information could be delivered from one aeon to the next.
2023-12-05 08:34:19 <KipIngram   > If that had been done in the last aeon we'd theoretically find it in the cosmic microwave background.
2023-12-05 08:34:30 <KipIngram   > Seems like there are some good sci fi stories there.
2023-12-05 08:37:24 <KipIngram   > In the novel version of Contact, at the end after the whole story was over the chick played by Jodie Foster had moved on from SETI to looking for messages in the digits of pi.  In a modern spin that could have been looking for messages encoded in the CMB instead.  That would have seemed a little more plausible to me.  :-)
2023-12-05 08:37:39 <KipIngram   > Seems like only God could arrange a message in pi.
2023-12-05 08:38:26 <KipIngram   > I think it's pretty fascinating what they can learn studying the CMB.
2023-12-05 08:40:55 <KipIngram   > Those pictures you see of the CMB, by the way, are highly exaggerated.  The color indicates temperature, basically, but the total variation across the whole sky is really just one part in 100,000.  If you just "looked at it," it would look like an entirely flat, even glow.  They have to really stretch the data to get the images as usually shown.
2023-12-05 08:41:47 <KipIngram   > And also red and blue shifts arising from our solar system's motion in the galaxy and so on has been calculated out.
2023-12-05 08:42:57 <KipIngram   > You always read in physics that there's no "special frame of reference" which is "really" at rest, but in fact the CMB actually does define such a frame.
2023-12-05 08:43:31 <KipIngram   > "Rest" is the state that makes the CMB glow isotropic.
2023-12-05 08:49:28 <KipIngram   > Of course it's still not special in any "fundamental physics" sense.
2023-12-05 13:02:28 <KipIngram   > Wow, the Wikipedia article on the history of tokamak development is very detailed and interesting.
2023-12-05 13:14:57 <thrig       > written by nerds, for nerds
2023-12-05 13:35:13 <rendar      > #def double * 2 #end
2023-12-05 13:35:22 <rendar      > this is how you define new words in my Forth
2023-12-05 13:48:47 <KipIngram   > https://www.nature.com/articles/d41586-023-03854-1
2023-12-05 13:49:11 <KipIngram   > It's not RPN?
2023-12-05 13:49:57 <KipIngram   > #def == : and #end ==  ; is fine if it suits you better.
2023-12-05 13:50:37 <KipIngram   > ^^ 1000-bit quantum computer just announced by IBM.
2023-12-05 13:52:55 <KipIngram   > Still prone to errors, though.
2023-12-05 15:09:43 <KipIngram   > Toying with the idea of making a fuel cell.
2023-12-05 15:09:51 <KipIngram   > Just for the education.
2023-12-05 16:04:59 <KipIngram   > This is pretty interesting material:
2023-12-05 16:05:02 <KipIngram   > https://fusor.net/files/Ligon-QED-IE.pdf
2023-12-05 16:05:18 <KipIngram   > I had no idea such work had been done at the low end.
2023-12-05 16:05:35 <KipIngram   > Apparently you can do fusion in your garage; the problem is that it's way below breakeven.
2023-12-05 16:56:57 <zelgomer    > i'm so stupid
2023-12-05 16:57:36 <zelgomer    > create actions 8 cells allot  ... :noname  ... ;  actions !  :noname  ... ;  actions cell+ !  ( and so on )
2023-12-05 16:57:56 <zelgomer    > ah, damn, nevermind. it does have to be that way
2023-12-05 16:58:23 <zelgomer    > i was going to say it's real ugly and i only just realized i can use  create actions  :noname .. ; ,  :noname .. ; ,
2023-12-05 16:58:47 <zelgomer    > but turns out i can because i still write junk header info for :nonames. dang
2023-12-05 16:58:54 <zelgomer    > s/can/can't
2023-12-05 16:58:59 <zelgomer    > i should fix that in v2
2023-12-05 17:05:38 <zelgomer    > if you have a word that adds bit fields to a  variable mask   would you call it  >mask  or  mask!  or  >mask!
2023-12-05 18:55:19 <KipIngram   > You mean it sets bits in a cell?
2023-12-05 18:56:45 <KipIngram   > I'd call a word that sets bits in a cell |! and one that clears bits in a cell &! (or ~&! depending on polarity).
2023-12-05 18:57:55 <KipIngram   > But I like symbols.  :-)
2023-12-05 19:46:08 <zelgomer    > well, it's more specific than that
2023-12-05 19:46:42 <zelgomer    > it sets a specific field, not general purpose
2023-12-05 19:47:43 <zelgomer    > and as for | and &, i've been tempted to use those, but it feels a bit too c-ish
2023-12-05 19:51:37 <KipIngram   > Oh, the bits to act on are specified in some other way?
2023-12-05 20:08:39 <zelgomer    > let me revise my example.   variable file-mode  : >owner! file-mode dup @ rot or swap ! ;  or something like that
2023-12-05 23:05:01 <KipIngram   > You know, I'd never thought about how difficult it might be to bring the grid back online after a widesprerad power outage.  I assume they have some ability to disconnect sections of the grid, but it's probably not incredibly fine-grained.  You have no idea when you start to fire up the power how many switches out there are on and how many are off.
2023-12-05 23:05:42 <KipIngram   > All those big rotating machines are intended to be running continuously.  Trying to start them all up at once would be "interesting," to say the least, and starting just one might expose it to more load than it could service.
2023-12-05 23:05:48 <KipIngram   > So I bet it's quite a juggle.
2023-12-05 23:06:12 <KipIngram   > Obviously they know how to do it, but I figure it takes more planning that I'd ever thought about.
2023-12-05 23:16:14 <KipIngram   > ah, I see.  A subset of the power stations in a grid are 'black start' plants.  They can turn themselves on using backup power sources.  And they can then power up other plants in the network.  And yeah - they can disconnect the cities and towns and stuff from the transmission line networks needed for that.
2023-12-05 23:16:38 <KipIngram   > So they switch everyone out, fire up the black start paths, fire up the other plants, and then brings the loads back into the network.
2023-12-05 23:16:44 <KipIngram   > black start plants
2023-12-05 23:17:56 <KipIngram   > Hydroelectric plants are often used for black starts, because they don't have to spin up their generator rotors - the water will do that.  They only need a small amount of electricity to run their monitoring and control equipment during startup.
2023-12-05 23:20:08 <KipIngram   > Another thing most people don't think about is that all of the generators connected in parallel in a section of the grid have to be phase matched.  It wouldn't do for them to try to drive out-of-phase voltages onto the grid.  Once they're all running they are controlled to stay in phase, but that's another thing that's tricky during a full startup.
2023-12-05 23:24:42 <KipIngram   > Wow - initial load on a system when it's first brought back online can be 8-10 times its normal average.  Every air conditioner, every refrigerator, every water heater, etc. - they all want to run at the same time.  And every induction motor out there will start drawing its inrush current.
2023-12-05 23:24:55 <KipIngram   > It can be half an hour before the demand starts to come back down toward normal.