Life, the Universe, and Everything

Book review: The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos, by Brian Greene.

This book has a lot of overlap with Tegmark’s Our Mathematical Universe

Greene uses less provocative language than Tegmark, but makes up for that by suggesting 5 more multiverses than Tegmark (3 of which depend on string theory for credibility, and 2 that Tegmark probably wouldn’t label as multiverses).

I thought about making some snide remarks about string theory being less real than the other multiverses. Then I noticed that what Greene calls the ultimate multiverse (all possible universes) implies that string theory universes (or at least computable approximations) are real regardless of whether we live in one.

Like Tegmark, Greene convinces me that inflation which lasts for infinite time implies infinite space and infinite copies of earth, but fails to convince me that he has a strong reason for assuming infinite time.

The main text is mostly easy to read. Don’t overlook the more technical notes at the end – the one proposing an experiment that would distinguish the Many Worlds interpretation of quantum mechanics from the Copenhagen interpretation is one of the best parts of the book.

Ambronite

Yet another soylent competitor has appeared: Ambronite.

It’s higher quality and high price than Soylent or MealSquares. It has more B12 than MealSquares even though it’s vegan.

It’s low enough in saturated fat that I probably want to add an additional source of saturated fat to my diet, but that’s a nice problem to have – I’d want to add chocolate anyway. My biggest reservation is the high level of polyunsaturated fat – if I could get a version without the walnuts I’d probably be satisfied there.

Most ingredients look like what our ancestors evolved to eat, but the first two ingredients listed are oats and rice protein.

Book review: Our Mathematical Universe: My Quest for the Ultimate Nature of Reality, by Max Tegmark.

His most important claim is the radical Platonist view that all well-defined mathematical structures exist, therefore most physics is the study of which of those we inhabit. His arguments are more tempting than any others I’ve seen for this view, but I’m left with plenty of doubt.

He points to ways that we can imagine this hypothesis being testable, such as via the fine-tuning of fundamental constants. But he doesn’t provide a good reason to think that those tests will distinguish his hypothesis from other popular approaches, as it’s easy to imagine that we’ll never find situations where they make different predictions.

The most valuable parts of the book involve the claim that the multiverse is spatially infinite. He mostly talks as if that’s likely to be true, but his explanations caused me to lower my probability estimate for that claim.

He gets that infinity by claiming that inflation continues in places for infinite time, and then claiming there are reference frames for which that infinite time is located in a spatial rather than a time direction. I have a vague intuition why that second step might be right (but I’m fairly sure he left something important out of the explanation).

For the infinite time part, I’m stuck with relying on argument from authority, without much evidence that the relevant authorities have much confidence in the claim.

Toward the end of the book he mentions reasons to doubt infinities in physics theories – it’s easy to find examples where we model substances such as air as infinitely divisible, when we know that at some levels of detail atomic theory is more accurate. The eternal inflation theory depends on an infinitely expandable space which we can easily imagine is only an approximation. Plus, when physicists explicitly ask whether the universe will last forever, they don’t seem very confident. I’m also tempted to say that the measure problem (i.e. the absence of a way to say some events are more likely than others if they all happen an infinite number of times) is a reason to doubt infinities, but I don’t have much confidence that reality obeys my desire for it to be comprehensible.

I’m disappointed by his claim that we can get good evidence that we’re not Boltzmann brains. He wants us to test our memories, because if I am a Boltzmann brain I’ll probably have a bunch of absurd memories. But suppose I remember having done that test in the past few minutes. The Boltzmann brain hypothesis suggests it’s much more likely for me to have randomly acquired the memory of having passed the test than for me to actually be have done the test. Maybe there’s a way to turn Tegmark’s argument into something rigorous, but it isn’t obvious.

He gives a surprising argument that the differences between the Everett and Copenhagen interpretations of quantum mechanics don’t matter much, because unrelated reasons involving multiverses lead us to expect results comparable to the Everett interpretation even if the Copenhagen interpretation is correct.

It’s a bit hard to figure out what the book’s target audience is – he hides the few equations he uses in footnotes to make it look easy for laymen to follow, but he also discusses hard concepts such as universes with more than one time dimension with little attempt to prepare laymen for them.

The first few chapters are intended for readers with little knowledge of physics. One theme is a historical trend which he mostly describes as expanding our estimate of how big reality is. But the evidence he provides only tells us that the lower bounds that people give keep increasing. Looking at the upper bound (typically infinity) makes that trend look less interesting.

The book has many interesting digressions such as a description of how to build Douglas Adams’ infinite improbability drive.

Nutritional Meals

I’ve been thinking more about convenient, healthy alternatives to Soylent or MealSquares that are closer to the kind of food we’ve evolved to eat.

Here’s some food that exceeds the recommended daily intake of most vitamins and minerals with only about 1300 calories (leaving room for less healthy snacks):

  • 4 bags of Brad’s Raw Chips, Indian
  • 1.5 bags of Brad’s Raw Chips, Sweet Pepper
  • 6 crackers, Lydia’s Green Crackers (vitamin E)
  • 1 oz Atlantic oysters (B12, zinc) (one 3 oz tin every 3 days)
  • 1 brazil nut (selenium)

Caveats: I’m unsure how accurately I estimated the nutrition in the processed foods (I made guesses based on the list of ingredients).

This diet has little vitamin D (which I expect to get from supplements and sun).

It’s slightly low in calcium, sodium, B12, and saturated fat. I consider it important to get more B12 from other animal sources (sardines, salmon or pastured eggs). I’m not concerned about the calcium or sodium because this diet would provide more than hunter-gathers got and because I don’t have much trouble getting more from other food. And it’s hard not to get more saturated fat from other foods I like (e.g. chocolate).

I don’t know whether it has enough iodine, so when I’m not having much fish it’s probably good to add a little seaweed (I’m careful to avoid the common kinds that have added oil that’s been subjected to questionable processing).

It has just barely 100% of vitamin E, B3, and B5 (in practice I get more of those from eggs and sweet potatoes).

It’s possibly too high in omega-3 (10+ grams?) from flax seeds in the Raw Chips (my estimate here is more uncertain than with the other nutrients).

The only convenient way to get oysters that keep well and don’t need preparation is cans of smoked oysters, and smoking seems to be an unhealthy way to process food.

Note that I chose this list without trying to make it affordable, and it ended up costing about $50 per day. I don’t plan to spend that much unless I become too busy to cook cheaper foods such as sweet potatoes, mushrooms, bean sprouts, fish, and eggs.

In practice, I’ve been relying more on Questbars for convenient food, but I’m trying to cut down on those as I eat more Brad’s Raw Chips.

The Quantified Self 2013 Global Conference attracted many interesting people.

There were lots of new devices to measure the usual things more easily or to integrate multiple kinds of data.

Airo is an ambitious attempt to detect a wide variety of things, including food via sensing metabolites.

TellSpec plans to detect food nutrients and allergens through Raman spectroscopy.

OMsignal has a t-shirt with embedded sensors.

The M1nd should enable users to find more connections and spurious correlations between electromagnetic fields and health.

Ios is becoming a more important platform for trendy tools. As an Android user who wants to stick to devices with a large screen and traditional keyboard, I feel a bit left out.

The Human Locomotome Project is an ambitious attempt to produce an accurate and easy to measure biomarker of aging, using accelerometer data from devices such as FitBit. They’re measuring something that was previously not well measured, but there doesn’t appear to be any easy way to tell whether that information is valuable.

The hug brigade that was at last year’s conference (led by Paul Grasshoff?) was missing this year.

Attempts to attract a critical mass to the QS Forum seem to be having little effect.

There was a large shift in our ancestors diet about 3.5 million years ago to food derived from grasses and/or sedges. This has potentially important implications for what diet we’re adapted to. Unfortunately, the evidence isn’t specific enough to be very useful:

The isotope method cannot distinguish what parts of grasses and sedges human ancestors ate – leaves, stems, seeds and-or underground storage organs such as roots or rhizomes. The method also can’t determine when human ancestors began getting much of their grass by eating grass-eating insects or meat from grazing animals.

Book review: Paleofantasy: What Evolution Really Tells Us about Sex, Diet, and How We Live, by Marlene Zuk

This book refutes some myths about what would happen if we adopted the lifestyle of some imaginary hunter-gather ancestor who some imagine was perfectly adapted to his environment.

I’m a bit disappointed that it isn’t as provocative as the hype around it suggested. It mostly just points out that there’s no single environment that we’re adapted to, plus uncertainty about what our ancestors’ lifestyle was.

She spends a good deal of the book demonstrating what ought to be the well-known fact that we’re still evolving and have partly adapted to an agricultural lifestyle. A more surprising point is that we still have problems stemming from not yet having fully evolved to be land animals rather than fish (e.g. hiccups).

She provides a reference to a study disputing the widely held belief that the transition from hunter-gatherer to farmer made people less healthy.

She cites evidence that humans haven’t evolved much adaptation to specific diets, and do about equally well on a wide variety of diets involving wild foods, so that looking at plant to animal ratios in hunter-gather diets isn’t useful.

Her practical lifestyle advice is mostly consistent with an informed guess about how we can imitate our ancestors’ lifestyle (e.g. eat less processed food), and mainly serves to counteract some of the overconfident claims of the less thoughtful paleo lifestyle promoters.

Anti-Paleo Diet

Soylent is an almost pure chemical diet, whose most natural looking ingredients are olive oil and whey protein. It provides the FDA recommended nutrients from mostly purified sources of the individual nutrients. The creator claims to have experienced improved health after adopting it (after previously eating something slightly better than a typical US diet).

This seems like a very effective way to minimize the poisons in our diet.

It’s also cheaper than most diets (he claims less than $2/day, but that seems questionable). He claims it tastes good, although eating the same thing day after day would seem a bit monotonous.

FDA recommendations are known to be suboptimal – too little vitamin D, too much calcium.

He seems confused about the fiber requirements, and is a bit reckless about his omega-6/omega-3 ratio. But these are easily improved.

He almost certainly misses some important nutrients that haven’t yet been identified, but that can be partly compensated for by adding a few low-risk foods such as salmon, seaweed, spinach, and sweet potatoes (the four S’s?).

I’m giving some thought to replacing 25-50% of my calories with something along these lines.

Talking20

Talking20 is an ambitious startup attempting to make a wide variety of blood tests available at the surprisingly cheap price of $2 per test. Getting the drop of blood needed will still be a pain, but doing it at home and mailing in a postcard will simplify the process a lot.

If this succeeds it would dramatically increase our knowledge of things such as our cholesterol levels.

But I get the impression that they are being rather optimistic about how quickly they can get enough sales volume to make money.

Their attempt to use Indiegogo doesn’t appear to be as appropriate to their needs as seeking angel or VC investment would be.

I’m also concerned that the institutions they would compete with will try to get them regulated in ways that would drastically increase their costs.

I’m somewhat tempted to order something from them via Indiegogo, but I’m not confident in their ability to deliver.

Book review: How to Measure Anything, by Douglas Hubbard.

I procrastinated about reading this book because it appeared to be only relevant to a narrow type of business problem. But it is much more ambitious, and aims to convince us that anything that matters can be measured. It should be a good antidote to people who give up on measuring important values on grounds such as it’s too hard or too subjective (i.e. it teaches people to do Fermi estimates).

A key part of this is to use a sensible definition of the word measurement:

A quantitatively expressed reduction of uncertainty based on one or more observations

.

He urges us to focus on figuring out what observations are most valuable, because there are large variations in the value of different pieces of information. If we focus on valuable observations, the first few observations are much more valuable than subsequent ones.

He emphasizes the importance of calibration training which, in addition to combating overconfidence, makes it hard for people to claim they don’t know how to assign numbers to possible observations.

He succeeds in convincing me that anything that matters to a business can be measured. There are a few goals for which his approach doesn’t seem useful (e.g. going to heaven), but they’re rarer than our intuition tells us. Even vague-sounding concepts such as customer satisfaction can either be observed (possible with large errors) via customer behavior or surveys, or they don’t matter.

It will help me avoid the temptation of making Quantified-Self types measurements to show off how good I am at quantifying things, and focus instead on being proud to get valuable information out of a minimal number of observations.