Later On

A blog written for those whose interests more or less match mine.

Archive for June 19th, 2020

Eating-ware Toccato & Fugue in D Minor, Bach

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Written by LeisureGuy

19 June 2020 at 6:16 pm

Posted in Music, Video

Computation All the Way Down

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From Edge, and worth reading in full. In passing, I will point out that Plato already said that the universe is constructed from the basic reality of mathematics (cf. Timaeus). The talk begins:

We’re now in this situation where people just assume that science can compute everything, that if we have all the right input data and we have the right models, science will figure it out. If we learn that our universe is fundamentally computational, that throws us right into the idea that computation is a paradigm you have to care about. The big transition was from using equations to describe how everything works to using programs and computation to describe how things work. And that’s a transition that has happened after 300 years of equations. The transition time to using programs has been remarkably quick, a decade or two. One area that was a holdout, despite the transition of many fields of science into the computational models direction, was fundamental physics.

If we can firmly establish this fundamental theory of physics, we know it’s computation all the way down. Once we know it’s computation all the way down, we’re forced to think about it computationally. One of the consequences of thinking about things computationally is this phenomenon of computational irreducibility. You can’t get around it. That means we have always had the point of view that science will eventually figure out everything, but computational irreducibility says that can’t work. It says that even if we know the rules for the system, it may be the case that we can’t work out what that system will do any more efficiently than basically just running the system and seeing what happens, just doing the experiment so to speak. We can’t have a predictive theoretical science of what’s going to happen.

STEPHEN WOLFRAM is a scientist, inventor, and the founder and CEO of Wolfram Research. He is the creator of the symbolic computation program Mathematica and its programming language, Wolfram Language, as well as the knowledge engine Wolfram|Alpha. His most recent endeavor is The Wolfram Physics Project. He is also the author, most recently, of A Project to Find the Fundamental Theory of Physics. Stephen Wolfram’s Edge Bio Page

COMPUTATION ALL THE WAY DOWN

The question that I’m asking myself is how does the universe work? What is the lowest level machine code for how our universe works? The big surprise to me is that over the last six months or so, I think we’ve figured out a path to be able to answer that question.

There’s a lot of detail about how what we figured out about the path to that question relates to what’s already known in physics. Once we know this is the low-level machine code for the universe, what can we then ask ourselves about why we have this universe and not another? Can we ask questions like why does this universe exist? Why does any universe exist? Some of those are questions that people asked a couple thousand years ago.

Lots of Greek philosophers had their theories for how the universe fundamentally works. We’ve gotten many layers of physics and mathematics sophistication since then, but what I’m doing goes back to these core questions of how things fundamentally work underneath. For us, it’s this simple structure that involves elements and relations that build into hypergraphs that evolve in certain ways, and then these hypergraphs build into multiway graphs and multiway causal graphs. From pieces of the way those work, we see what relativity is, what quantum mechanics is, and so on.

One of the questions that comes about when you imagine that you might hold in your hand a rule that will generate our whole universe, how do you then think about that? What’s the way of understanding what’s going on? One of the most obvious questions is why did we get this universe and not another? In particular, if the rule that we find is a comparatively simple rule, how did we get this simple-rule universe?

The lesson since the time of Copernicus has been that our Earth isn’t the center of the universe. We’re not special in this or that way. If it turns out that the rule that we find for our universe is this rule that, at least to us, seems simple, we get to ask ourselves why we lucked out and got this universe with a simple rule. I have to say, I wasn’t expecting that there would be a good scientific answer to that question. One of the surprises from this project to try to find the fundamental theory of physics has been that we have an understanding of how that works.

There are three levels of understanding of how the universe works in this model of ours. It starts from what one can think of as atoms of space, these elements that are knitted together by connectivity to form what ends up behaving like the physical space in which we move. The first level of what’s going on involves these elements and rules that describe how elements connected in a particular way should be transformed to elements connected in some other way. This connectivity of the elements is what makes up when we look at, say, 10100, 10400 of these elements. That’s what behaves like space as we’re familiar with it, and not only space but also all of the things that are in space—all the matter and particles—are all just features of this underlying structure and its detailed way of connecting these elements together.

We’ve got this set of transformation rules that apply to those underlying elements. In this set up, space is a very different thing from time. One of the wrong turns of 20th-century physics was this idea that space and time should always be packaged together into this four-dimensional spacetime continuum. That’s wrong. Time is different from space. Time is the inexorable operation of computation in figuring out what the next state will be from previous states, where our space to something that is a more specific extent of, in this particular case, the hypergraph that knits together these different elements.

From the idea of this hypergraph being rewritten through time, when you are an observer embedded within that hypergraph, the only thing you are ultimately sensitive to is the question of which events that happen inside this hypergraph affect which other ones. What are the causal relationships between different events in this process of time evolution? From that, you get what we call a causal graph of what events affect what other events. It turns out that special relativity and then general relativity emerge basically from properties of that causal graph.

In our way of thinking about fundamental physics, there are three levels of description that end up corresponding to general relativity—the theory of space and time and gravity—quantum mechanics, and then the third level, which is something different.

In the lowest level of these models that we’re constructing, the only thing we know about all of these elements is that they’re just things. We know which things are related to which other things; for example, if we say that there are relations that involve pairs of things—binary relations—then we can say we’ve got these things and there are pairs that are related. We can draw that as a mathematical graph or a network, where we’re just putting down points and joining them by a line. We happen to need a slight generalization of that, usually called a hypergraph in mathematics, where instead of just having relations between pairs of things, you can have relations between triples or quadruples of things.

You can’t represent that with just a line between two things. It’s like a bag of things that corresponds to each hyperedge. But that’s a detail not really important to the big picture. The thing that is relevant is that the underlying rules just say that some collection of elements that are related in a certain way are transformed to some other collection of elements related in some other way.

The whole operation of the universe consists of just rerunning that particular rule a gazillion times. Maybe the gazillion is about 10400 for our universe, I’m not sure about that—that’s based on one estimate of how this might work.

The first level is to understand, as you apply these rules, what are the causal relationships between applying a rule in one place, then that rule produces certain output, and that output gets used when the rule is applied again in the same place or in a nearby place. You can draw this network, this graph, of the causal relationships of what output is needed to feed the input to another updating event. That causal graph turns out to be our representation of space and time.

That causal graph has properties that reproduce special relativity and then general relativity, the theory of gravity. That’s a feature of these models, that in the limit of a very large number of these little update rules, with certain assumptions—like the assumption that the limiting space of our universe is finite dimensional—it follows that what happens satisfies Einstein’s equations for general relativity. Then the next level of this is to apply these transformations to this hypergraph, to this collection of relations. But there might be many possible places where a particular transformation might apply, which one should I run? Which one should I do? The next piece of these models is to do all of them, and what you’ll build is what we call a multiway graph, which represents all possible updates that you can have done.

If you do one update it might allow you to do another update. If you don’t do that update, it wouldn’t allow you to do another update. It’s not saying just do everything. There’s still a lot of structural information in what could happen after what, and what can happen at the same time as what. So, this multiway graph turns out to be a representation of what in quantum mechanics people have thought about as the path integral. In classical mechanics, say you throw a ball, the ball moves in a particular definite trajectory. In quantum mechanics, the ball has many possible trajectories it follows, which are all weighted in a certain way, and what we observe corresponds to, say, some weighting or some combination of those trajectories.

In our models, that corresponds to what happens in this multiway graph, that there are these many possible paths that can be followed in the multiway graph. In quantum mechanics, we believe we measure definite things. It turns out it’s very elegant and wonderful that in relativity we’re used to this idea of reference frames, observers thinking about the universe in terms of their reference frame. Are they at rest? Are they traveling at a certain velocity? Are they accelerating? What is their state of motion? In quantum mechanics, we have this analog of reference frames, which we call quantum observation frames (QOF) that represent the way we’re choosing to experience this multiway system of possibilities.

In any case, one can reproduce the various results of quantum mechanics. We’re busily going through and trying to reproduce all the different things that show up in quantum mechanics. One of things we can do is take, for example, quantum computers and compile all that formalism into these multiway graphs. If you’ve got a quantum computer that’s described in the standard formalism of quantum computing in this way, then you just run this program and you’ll get a multiway graph that basically implements the same thing. So that’s proof that these multiway graphs reproduce the physics of quantum computing.

In spacetime, a big result are Einstein’s equations, which say that the curvature of space depends on the presence of matter. If you have a thing that is following a straight line, let’s say you shoot a laser in some direction. Normally, you think the light from a laser just goes in a straight line. But when there’s a massive object, like a star or a black hole, the path of that laser light will be turned by the presence of that mass. Einstein’s equations describe how that turning works. They say that the curvature of space, the amount of turning, depends on the amount of energy momentum that exists in space.

In our multiway graph, we also think about paths through the multiway graph. We can also think about the presence of energy momentum in the multiway graph, the presence of energy momentum in the quantum system that is described by this multiway graph. Something really amazing happens, which is that Einstein’s equations in the classical idea of space and time turns out to be exactly Feynman’s path integral in quantum mechanics.

These various paths that are representing the possibilities in quantum mechanics are effectively being turned in this multiway space by the presence of energy momentum, or more specifically, by the presence of the Lagrangian density, which is a relativistically invariant analog of energy momentum. In other words, the core of quantum mechanics, which is the way that the phases work in the path integral, is the exact same phenomenon as the core of classical general relativity, the way that trajectories are turned by the presence of energy momentum in spacetime. That’s a pretty cool thing that I’m excited about.

When we think about this multiway system, we’re saying that . . .

Continue reading.

Written by LeisureGuy

19 June 2020 at 5:56 pm

Posted in Math, Science

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Hanger steak vs. Flat-iron steak

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Hanger steak is tougher/chewier and has more flavor. Flat-iron steak is pretty tender and very good.

Written by LeisureGuy

19 June 2020 at 5:47 pm

Posted in Daily life, Food, Low carb

Esperanto progress

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I have now completed 62 consecutive days of study of Duolingo, and in the process I’ve learned a fair amount of Esperanto — mainly reading, writing, and listening, with essentially no speaking, with the result that I am very uneasy about my (unpracticed) speaking skills. However, there’s a Zoom meet-up tomorrow and beginners (a) are welcome and (b) not compelled to speak if they don’t feel like it. Think: “Mia nomo estas Micjo. Mi estas Esperantisto.” That sort of thing, I think.

Although among languages Esperanto is quite easy to learn, it still is a language, and thus one must learn vocabulary and ways to express in Esperanto the thoughts you have. That takes practice, which in turn takes time. My goal now is to complete a 365-day streak and take stock of where I am after one full year. I’ll run out of Duolingo lessons well before that, but then I will finish the Lernu.net course, and after that dive into the podcasts, YouTube videos, and on-line publications in Esperanto, and also look for more Zoom opportunities.

The goal is to find out what it’s like to be truly bilingual, and Esperanto is the easiest route to that.  Eventually I might try doing one post a day in Esperanto.

Written by LeisureGuy

19 June 2020 at 5:12 pm

Posted in Esperanto

Trump administration paid millions for test tubes, got unusable mini soda bottles

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Incompetence wastes money.  J. David McSwane and Ryan Gabrielson report in ProPublica:

Since May, the Trump administration has paid a fledgling Texas company $7.3 million for test tubes needed in tracking the spread of the coronavirus nationwide. But, instead of the standard vials, Fillakit LLC has supplied plastic tubes made for bottling soda, which state health officials say are unusable.

The state officials say that these “preforms,” which are designed to be expanded with heat and pressure into 2-liter soda bottles, don’t fit the racks used in laboratory analysis of test samples. Even if the bottles were the right size, experts say, the company’s process likely contaminated the tubes and could yield false test results. Fillakit employees, some not wearing masks, gathered the miniature soda bottles with snow shovels and dumped them into plastic bins before squirting saline into them, all in the open air, according to former employees and ProPublica’s observation of the company’s operations.

“It wasn’t even clean, let alone sterile,” said Teresa Green, a retired science teacher who worked at Fillakit’s makeshift warehouse outside of Houston for two weeks before leaving out of frustration.

The Federal Emergency Management Agency signed its first deal with Fillakit on May 7, just six days after the company was formed by an ex-telemarketer repeatedly accused of fraudulent practices over the past two decades. Fillakit has supplied a total of more than 3 million tubes, which FEMA then approved and sent to all 50 states. If the company fulfills its contractual obligation to provide 4 million tubes, it will receive a total of $10.16 million.

Officials in New York, New Jersey, Texas and New Mexico confirmed they can’t use the Fillakit tubes. Three other states told ProPublica that they received Fillakit supplies and have not distributed them to testing sites. FEMA has asked health officials in several states to find an alternative use for the unfinished soda bottles.

“We are still trying to identify an alternative use,” said Janelle Fleming, a spokeswoman for the New Jersey Department of Health.

Fillakit owner Paul Wexler acknowledged that the tubes are normally used for soda bottles but otherwise declined to comment.

It’s my first day

The Fillakit deal shows the perils of the Trump administration’s frantic hiring of first-time federal contractors with little scrutiny during the pandemic. The federal government has awarded more than $2 billion to first-time contractors for work related to the coronavirus, a ProPublica analysis of purchasing data shows. Many of those companies, like Fillakit, had no experience with medical supplies.

The U.S. has lagged behind many European countries in its rate of testing people for the coronavirus, partly because of supply shortages or inadequacies. Epidemiologists say testing is vital to tracking the virus and slowing transmission. In at least one state, the shipment of unusable Fillakit tubes contributed to delays in rolling out widespread testing.

“They’re the most unusable tubes I’ve ever seen,” said a top public health scientist in that state, who asked to remain anonymous to protect his job. “They’re going to sit in a warehouse and no one can use them. We won’t be able to do our full plan.”

In a written response to questions, FEMA said it inspects testing products “to ensure packaging is intact to maintain sterility; that the packing slip matches the requested product ordered, and that the vials are not leaking.” It said that “product validation” that medical supplies are effective “is reinforced at the state laboratories.”

The agency did not answer questions about the size and lack of sterilization of Fillakit’s tubes or about why it sought an alternative use for them.

Fillakit is one of more than 300 new federal contractors providing supplies related to COVID-19. A ProPublica analysis last month found about 13% of total federal government spending on pandemic-related contracts went to first-time vendors. FEMA said last month that it only pays for products once they have been delivered, minimizing the risk of wasting taxpayer dollars.

“FEMA does not enter into contracts unless it has reason to believe they will be successfully executed,” it said.

How do preforms perform?

Preforms, the small tubes also known in the plastics industry as “baby soda bottles” or “blanks,” have a following among elementary school science teachers and amateur scientists, but they don’t meet rigorous laboratory standards. They’re much cheaper than glass vials and can be sealed off with a soda bottle cap. When inflated with high-pressure air, the soft plastic expands to the size of a 2-liter soda bottle.

The preforms arrive at Fillakit’s warehouse in a huge shipping container. The tubes are then shoveled into smaller bins. Workers add the saline solution and screw on caps. The tubes are then loosely piled in bags and sent to FEMA, which forwards them to the states. Typically, test tubes are individually packaged to guard against contamination.

Washington state, an epicenter of the first outbreak of the virus, got more than 76,000 Fillakit vials from FEMA. None can be used.

“They were packaged unusually,” said Frank Ameduri, a spokesman for the state Health Department. “Not in a way we’re used to seeing, and they were not labeled. Some of them have been sent to our lab for quality control. None of the vials will be used until we’ve identified what’s in them and that they are safe for use.”

About 140,000 Fillakit tubes are also shelved in Texas, where officials were slow to roll out testing. The number of confirmed cases in Texas has increased by more than one-third in the past two weeks, according to data gathered by The COVID Tracking Project.

“There were issues with the labeling, and they use saline rather than viral transport medium, so we have not used them for our testing efforts,” said Chris Van Deusen, a spokesman for the Texas health department.

The only solution

The US Food and Drug Administration has only validated one solution, known as viral transport medium, as reliable in preserving the coronavirus RNA from decay or destruction by substances in the container. However, because that medium is in short supply, the FDA has also granted an emergency authorization for other products it believes can keep the virus intact for up to three days.

Fillakit has been squirting one of the alternatives into its tubes, phosphate buffered saline, which the FDA says should be placed into “a sterile glass or plastic vial.” . . .

Continue reading.

Written by LeisureGuy

19 June 2020 at 9:04 am

Meißner Tremonia Woody Almond, the V2OC, and Floïd, with reasonable menthol

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Woody Almond has the bitter-almond fragrance I associate with Italian shaving soaps, but modulated by a soupçon of cedar (though my nose is not so sensitive that I can determine state of origin). It’s a very nice fragrance, and it makes a very nice lather, this morning aided by the Wet Shaving Products Monarch.

I really like the Parker 24 (or Parker 26: same head) and Maggard Razors offers an identical clone, their Version 2 Open-Comb, universally referred to as the V2OC. Here it’s mounted on one of Maggard’s own handles, the MR-7. I prefer the MR-7 handle to the Parker handles, so that’s the combination I kept.

The result was a very smooth finish following a very comfortable shave. I was thinking as I shaved that men who have beards don’t know what they’re missing — having a beard strikes me as the equivalent of eating only raw food: you can do that, but you’re missing many fine and pleasurable experiences. (I speak from the perspective of someone who had a beard for more than 30 years. I’ll never go back to that.)

A splash of Floïd finished the job. Floïd is mentholated, but unlike the “chill” and “frost” aftershaves, the menthol amount is modest: enough to notice but not demanding your full attention. In that regard, it’s similar to Alt-Innsbruck, which I’ll use tomorrow.

Written by LeisureGuy

19 June 2020 at 8:41 am

Posted in Shaving

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