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John Baez
Works at Centre for Quantum Technologies
Attended Massachusetts Institute of Technology
Lives in Riverside, California
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John Baez

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The President's favorite books

It's nice having a president who reads fiction, including science fiction, and shares books with his children.  Here's part of an interview he did on Friday:

These books that you gave to your daughter Malia on the Kindle, what were they? Some of your favorites?

I think some of them were sort of the usual suspects, so “The Naked and the Dead” or “One Hundred Years of Solitude,” I think she hadn’t read yet.  Then there were some books I think that are not on everybody’s reading list these days, but I remembered as being interesting, like “The Golden Notebook” by Doris Lessing, for example. Or “The Woman Warrior,” by Maxine Hong Kingston.

Part of what was interesting was me pulling back books that I thought were really powerful, but that might not surface when she goes to college.

Have you had a chance to discuss them with her?

I’ve had the chance to discuss some. And she’s interested in being a filmmaker, so storytelling is of great interest to her. She had just read “A Moveable Feast.” I hadn’t included that, and she was just captivated by the idea that Hemingway described his goal of writing one true thing every day.

How has the speechwriting and being at the center of history and dealing with crises affected you as a writer?

I’m not sure yet. I’ll have to see when I start writing the next book. Some of the craft of writing a good speech is identical to any other good writing: Is that word necessary? Is it the right word? Is there a rhythm to it that feels good? How does it sound aloud?

I actually think that one of the useful things about speechwriting is reminding yourself that the original words are spoken, and that there is a sound, a feel to words that, even if you’re reading silently, transmits itself.

So in that sense, I think there will be some consistency.

But this is part of why it was important to pick up the occasional novel during the presidency, because most of my reading every day was briefing books and memos and proposals. And so working that very analytical side of the brain all the time sometimes meant you lost track of not just the poetry of fiction, but also the depth of fiction.

Fiction was useful as a reminder of the truths under the surface of what we argue about every day and was a way of seeing and hearing the voices, the multitudes of this country.

Are there examples of specific novels or writers?

Well, the last novel I read was Colson Whitehead’s “The Underground Railroad.” And the reminder of the ways in which the pain of slavery transmits itself across generations, not just in overt ways, but how it changes minds and hearts.

It’s what you said in your farewell address about Atticus Finch, where you said people are so isolated in their little bubbles. Fiction can leap —

It bridges them. I struck up a friendship with the novelist Marilynne Robinson, who has become a good friend. And we’ve become sort of pen pals. I started reading her in Iowa, where “Gilead” and some of her best novels are set. And I loved her writing in part because I saw those people every day. And the interior life she was describing that connected them — the people I was shaking hands with and making speeches to — it connected them with my grandparents, who were from Kansas and ended up journeying all the way to Hawaii, but whose foundation had been set in a very similar setting.

And so I think that I found myself better able to imagine what’s going on in the lives of people throughout my presidency because of not just a specific novel but the act of reading fiction. It exercises those muscles, and I think that has been helpful.

And then there’s been the occasion where I just want to get out of my own head. [Laughter] Sometimes you read fiction just because you want to be someplace else.

What are some of those books?

It’s interesting, the stuff I read just to escape ends up being a mix of things — some science fiction. For a while, there was a three-volume science-fiction novel, the “Three-Body Problem” series —

Oh, Liu Cixin, who won the Hugo Award.

— which was just wildly imaginative, really interesting. It wasn’t so much sort of character studies as it was just this sweeping —

It’s really about the fate of the universe.

Exactly. The scope of it was immense. So that was fun to read, partly because my day-to-day problems with Congress seem fairly petty — not something to worry about. Aliens are about to invade. [Laughter]

There were books that would blend, I think, really good writing with thriller genres. I mean, I thought “Gone Girl” was a well-constructed, well-written book.

I loved that structure.

Yeah, and it was really well executed. And a similar structure, that I thought was a really powerful novel: “Fates and Furies,” by Lauren Groff.

I like those structures where you actually see different points of view. Which I have to do for this job, too. [Laughter]

Have there been certain books that have been touchstones for you in these eight years?

I would say Shakespeare continues to be a touchstone. Like most teenagers in high school, when we were assigned, I don’t know, “The Tempest” or something, I thought, ‘My God, this is boring.’ And I took this wonderful Shakespeare class in college where I just started to read the tragedies and dig into them. And that, I think, is foundational for me in understanding how certain patterns repeat themselves and play themselves out between human beings.

The intervier was Michiko Kakutani, chief book critic for The New York Times, and the whole interview is here:
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Pay attention

The basic trick in stage magic is to distract the audience.  While we were staring at Trump's antics, Republicans in the House of Representatives did something outrageous.  As usual, they passed a rule saying the Congressional Budget Office must estimate the cost of any law.  But they put in an exemption for a law repealing Obamaare

Why don't they want the CBO to estimate the cost of repealing Obamacare?

... because the last CBO “cost analysis of repealing Obamacare” (2015) found it would increase the deficit by $353 billion. It is an important point because besides unnecessarily stripping healthcare from tens-of-millions of Americans and increasing the deficit, Republicans will use “budget reconciliation” to repeal the healthcare law that requires any legislation that increases the deficit to expire after 10 years. It is precisely why the Bush-era tax cuts for the rich had to expire after 10 years; they blew up the deficit and Republicans knew it was going to happen just like they know that repealing the ACA [that is, Obamacare] will.

The article gets it a bit wrong by claiming the CBO is prohibited from estimating the cost of repealing Obamacare.  I'm not sure this makes a difference in practice.

Thanks to +Russ Abbott for pointing out this article.

The rule is here:

On page 25 it says:


The Director of the Congressional Budget Office shall, to the extent practicable, prepare an estimate of whether a bill or joint resolution reported by a committee (other than the Committee on Appropriations), or amendment thereto or conference report thereon, would cause, relative to current law, a net increase in direct spending in excess of $5,000,000,000 in any of the 4 consecutive 10-fiscal year periods beginning with the first fiscal year that is 10 fiscal years after the current fiscal year.

[... and then...]


This subsection shall not apply to any bill or joint resolution, or amendment thereto or conference report thereon—

(A) repealing the Patient Protection and Affordable Care Act and title I and subtitle B of title II of the Health Care and Education Affordability Reconciliation Act of 2010;

(B) reforming the Patient Protection and Affordable Care Act and the Health Care and Education Affordability Reconciliation Act of 2010; or

(C) for which the chair of the Committee on the Budget has made an adjustment to the allocations, levels, or limits contained in the most recently adopted concurrent resolution on the budget.
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According to this Politifact article, it's not as bad as it looks, and this story is a result of a misreading of the new rules.

I'm not sure one way or the other at the moment, but I hope it's not as bad as feared.
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Why did Putin help Trump?

Here's one possibility: in his many dealings with Russian business, Trump has become compromised in some way, which gives Putin leverage over him.  That would explain why Trump constantly bends over backward to be nice to Putin.  And it would certainly explain why Putin wanted  Trump to be president.

Recently Buzzfeed published a dossier detailing the explosive — but unverified — claim that Russia had been “cultivating, supporting and assisting” Trump for years and held compromising information about him.  You can read that dossier here. 

The passage starting here is where it gets really nasty:

...there were other aspects to TRUMP's engagement with the Russian authorities.  One of them which had borne fruit for them was to exploit TRUMP's personal obsessions and sexual perversion to in order to obtain "kompromat" (compromising material) on him.

Read on at your own risk.

We don't know that these claims are true!   But last week, the Director of National Intelligence James Clapper, the FBI Director James Comey, the CIA Director John Brennan, and the NSA Director Admiral Mike Rogers briefed Obama and Trump about these claims:

One reason the nation's intelligence chiefs took the extraordinary step of including the synopsis in the briefing documents was to make the President-elect aware that such allegations involving him are circulating among intelligence agencies, senior members of Congress and other government officials in Washington, multiple sources tell CNN.

These senior intelligence officials also included the synopsis to demonstrate that Russia had compiled information potentially harmful to both political parties, but only released information damaging to Hillary Clinton and Democrats.

These last quotes are from CNN:

For more on the dossier obtained by Buzzfeed, see:

Trump's lawyer has argued against the dossier:
Source document contributed to DocumentCloud by Jeremy Singer-Vine (BuzzFeed).

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Figuring out quantum gravity - it ain't easy!

Read this story by Bob Henderson.  Life as a grad student in theoretical physics can be very tough.  Smarts and hard work are important, but persistence in the face of difficulty is also crucial. 

My own experience - doing mathematical physics in a math department, actually - looks great in hindsight.  But I accomplished much less than I wanted in my thesis, and by the end I almost convinced myself I should switch to music or philosophy.  Only the practical need to find a job made me go on to a postdoc... and I'm very glad that I persisted.  Most of my education came after my PhD.

Of course, persistence in the face of obstacles is not always the right decision.

Here's just a snippet:

That summer, I moved. A fellowship I’d had had run out, so I’d have to start earning my keep as a teaching assistant and living off a stipend that went from a subsistence wage to a sub-subsistence wage. I left the old woman’s house for the relative bargain of a basement of another house in a seedier neighborhood. Its tiny windows up by the ceiling furnished its one room with feeble light and a bug’s-eye view of weeds. Its concrete walls seeped with damp. The bed was a mattress on the floor, with a plastic tarp under it to keep it dry. I kept a pair of running shoes next to it, for whacking the giant centipedes that regularly wriggled by. Dad, who never seemed bothered by sleeping on the shared cots in his dingy police station, or by nights spent in the rat-infested warehouses where he moonlighted as a security guard, was incredulous the first time he came. “I don’t know how you can live like this,” he rasped in his Bronx accent, looking both concerned and amused.

Eh. Living in squalor was just part of the adventure.

And I’d be spending all my waking hours in [the physics department] anyway, working on quantum gravity with Rajeev, exploring the sort of intellectual frontier that Zen and the Art of Motorcycle Maintenance had called the “high country of the mind.”

What will I find there? I wondered.

Answer: a series of surprises, each more disquieting than the last. The first was how much [my thesis advisor] Rajeev already knew about the problem, even before we started. And I don’t just mean background knowledge, but instead the actual answer to our project’s main question, at least in broad strokes.

If you were to picture Rajeev and me as explorers in the high country, facing some misty mountain range that we needed to cross, Rajeev was the one scanning the landscape, making mental calculations, and pointing the way. What struck me most was how he somehow knew that our ultimate destination, call it a river, lay on the other side. The “river” in our case was a detailed answer to the quantum gravity question Rajeev had posed over dessert at the Faculty Club. Its exact location and shape would remain a mystery until we’d found it, but Rajeev never doubted it was there.

That made me the scout. We’d convene in Rajeev’s little office and, like our first meeting, I’d focus on following his logic and asking questions while he paced back and forth, thought out loud, and banged out equations on the board. At some point, after three or four hours, he might say something like “What else could it be?” that signaled that he was happy enough with the direction he’d found to let me forge ahead on my own, meaning I’d spend the next day or two in my office doing the detailed calculations that he’d speculated would take us to the next landmark. Sometimes I’d find the route clear; other times an obstacle in the way. Either way, I’d report back and then we’d sink back into another session. Thus research advanced, by a system reminiscent of the directions on a shampoo bottle: Meet. Calculate. Repeat.

Thanks to +Peter Woit for pointing out this story.  As a thesis advisor, I would never give a student a problem if I didn't already know the answer in broad strokes.  Otherwise you're throwing them into the pool without a life preserver!  I haven't thought enough about how this can be "disquieting".  But I've certainly noticed how my students perk up when I get completely confused about something!

Have you ever been happy?” My girlfriend asked me that question, after work over drinks at some shiny Manhattan bar, after another…
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+Vlad Levin​​​​​​ Regarding Germany vs the US, see +John Baez​​​​​​'s comment preceding my previous one for an accurate reflection of the prevailing attitudes in the US. For Americans in academia, the sentiment expressed in the article below would have been considered heresy just a decade ago, even though some people had already started to sound the alarm at that time:

In Germany, as I understand it, there was a time when the privatdozent system operated, under which docents taught for free and had to wait their turn to be promoted to a salaried post of assistant professor. It's like telling adjuncts now to work for free. That's probably why there's less clinging on to dreams of academia in Germany: they've internalised the fact that there's no money in it for most people.

That, and many PhDs in Germany went into industry and made good careers out of it, so that German employers started realising the value of PhD holders. The US is probably on the road to something similar, but there's anti-intellectualism in the mix as well, which complicates matters.

For the options you've mentioned:

- Teaching: Requires another degree, which is expensive to get.

- Biotech: Ditto.

- Engineering: Only if he's willing to accept junior jobs AND employers are willing to take him in. His PhD work wasn't in engineering, so it'd have been harder to make the case for more senior positions.

- Software: Time is needed to learn new skills and build a portfolio.

So being a quant was probably the easiest/quickest option, and at the time, Wall Street was basically vacuuming up all the PhDs it could get.
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How to fairly share a square cake among 5 people

Suppose you have a square cake of arbitrary height and want to divide it into 5 pieces that all have the same amount of cake and the same amount of icing.

The icing makes it hard.  If there were no icing on the cake, or only icing on top, we could cut the cake in 5 strips of equal thickness. 

But let's assume there's icing on the sides of the cake too!  Since we don't know how tall the cake is, we want to slice the cake vertically into pieces that have equal area on top and contain equal amounts of the outside edge. 

This solution by Tim, a math teacher in Wisconsin, is quite impressive.  Divide each side into 5 parts as shown and cut straight to the center of the cake at C. 

Puzzle 1.  But is this solution correct?

You can see other answers here:

The question was raised by Steven Strogatz on Twitter, and I heard about it from +Alok Tiwari, who heard about it from +Ian Agol.  Some of the answers on the original Twitter thread are really dumb, some are really smart.  It's fun to see them all.

The fun, of course - let's come out and say it! - arises from the gnarly and complicated relationship that the numbers 4 and 5 have with each other.  Squares and regular pentagons don't play nicely, and here Tim is trying to pentisect the square.

Puzzle 2. What's the easiest way to construct a segment of length sqrt(5/4) using ruler and compass?

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+Michael Shipwash I really like the icing. Can I have one of the edge pieces?
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At noon today in Washington DC, all mentions of "climate change" and "global warming" were eliminated from the White House website.

Well, not all. The word "climate" still shows up here:

President Trump is committed to eliminating harmful and unnecessary policies such as the Climate Action Plan....

Luckily, at the Azimuth Climate Data Backup Project, we've been preparing for exactly this. We've been racing to save publicly available climate data at NASA, NOAA, and other agencies that Trump now controls.

Please visit our Kickstarter page, learn more about what we've done, contribute some money, and help us out!

We plan to make our data publicly available, so we need money for servers and storage. Right now we can afford to hold it for about 3 years. 8 would be better.

Luckily, this week the head of U. C. Riverside's Computing and Communications department, Danna Gianforte, said they would commit to hosting our data over the long term! So, we will also work to transfer it there and set up a usable interface.

We're part of a larger initiative, Different teams are saving different databases. For example, the End of Term Archive has saved Obama's White House web pages.

You can read more about these efforts here:

In the comments below, I will list some people who have helped the Azimuth Backup Project with their donations. One person contributed $2000, three contributed $1000 and two contributed $500. That's wonderful, and I thank these people immensely! But most of our success is due to large numbers of smaller contributions.

To see how "climate change" has now vanished from White House website, go here:

Welcome to the new era.
We're backing up US government databases on climate change and the environment before Trump takes office on January 20th.
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I just realized what +John Baez​ is saying about making it easy for people to participate. While I don't have huge amounts of time myself, I can certainly focus the little I have to make it easier for you all who are reading this to contribute. This means next time I have a moment for the project I will use it to make it easier to join and to help us, including the friendly language and not just technical instructions - although the technical instructions are what most people actually need.
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448 million distracting social media posts per year

No, I'm not talking about Facebook!  I'm talking about posts put out by the Chinese government. 

They're often called 50c posts, since rumors say people are paid 50 cents for each post.  There's a huge army of people writing these posts!   I learned about them from this new paper, which did a lot of experiments to study them:

How the Chinese Government Fabricates Social Media Posts for Strategic Distraction, not Engaged Argument

The Chinese government has long been suspected of hiring as many as 2,000,000 people to surreptitiously insert huge numbers of pseudonymous and other deceptive writings into the stream of real social media posts, as if they were the genuine opinions of ordinary people. Many academics, and most journalists and activists, claim that these so-called “50c party” posts vociferously argue for the government’s side in political and policy debates. As we show, this is also true of the vast majority of posts openly accused on social media of being 50c. Yet, almost no systematic empirical evidence exists for this claim, or, more importantly, for the Chinese regime’s strategic objective in pursuing this activity.

In the first large scale empirical analysis of this operation, we show how to identify the secretive authors of these posts, the posts written by them, and their content. We estimate that the government fabricates and posts about 448 million social media comments a year. In contrast to prior claims, we show that the Chinese regime’s strategy is to avoid arguing with skeptics of the party and the government, and to not even discuss controversial issues. We infer that the goal of this massive secretive operation is instead to distract the public and change the subject, as most of the these posts involve cheerleading for China, the revolutionary history of the Communist Party, or other symbols of the regime.  We discuss how these results fit with what is known about the Chinese censorship program, and suggest how they may change our broader theoretical understanding of “common knowledge” and information control in authoritarian regimes.

The conclusion is spelled out in more detail near the end:

Distraction is a clever and useful strategy in information control in that an argument in almost any human discussion is rarely an effective way to put an end to an opposing argument. Letting an argument die, or changing the subject, usually works much better than picking an argument and getting someone’s back up (as new parents recognize fast).

It may even be the case that the function of reasoning in human beings is fundamentally about winning arguments rather than resolving them by seeking truth. Distraction even has the advantage of reducing anger compared to ruminating on the same issue. Finally, since censorship alone seems to anger people, the 50c astroturfing program has the additional advantage of enabling the government to actively control opinion without having to censor as much as they might otherwise.

The paper is here:

• Gary King, Jennifer Pan, and Margaret E. Roberts, How the Chinese government fabricates social media posts for strategic distraction, not engaged argument, American Political Science Review, 2017. Copy at

The people who write these social media posts are often called the 50c army - but I doubt most of them wear uniforms as in this picture!

Thanks to +Lauren Weinstein for pointing this out!
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+John Baez given enough eyeballs, all bugs are shallow
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Good news from the President

Barack Obama just came out with an article in Science!   It's about climate change and clean energy.   Here it is, minus the references, which you can see in the original.

The irreversible momentum of clean energy

The release of carbon dioxide (CO2) and other greenhouse gases (GHGs) due to human activity is increasing global average surface air temperatures, disrupting weather patterns, and acidifying the ocean. Left unchecked, the continued growth of GHG emissions could cause global average temperatures to increase by another 4°C or more by 2100 and by 1.5 to 2 times as much in many midcontinent and far northern locations. Although our understanding of the impacts of climate change is increasingly and disturbingly clear, there is still debate about the proper course for U.S. policy — a debate that is very much on display during the current presidential transition. But putting near-term politics aside, the mounting economic and scientific evidence leave me confident that trends toward a clean-energy economy that have emerged during my presidency will continue and that the economic opportunity for our country to harness that trend will only grow. This Policy Forum will focus on the four reasons I believe the trend toward clean energy is irreversible.


The United States is showing that GHG mitigation need not conflict with economic growth. Rather, it can boost efficiency, productivity, and innovation. Since 2008, the United States has experienced the first sustained period of rapid GHG emissions reductions and simultaneous economic growth on record. Specifically, CO2 emissions from the energy sector fell by 9.5% from 2008 to 2015, while the economy grew by more than 10%. In this same period, the amount of energy consumed per dollar of real gross domestic product (GDP) fell by almost 11%, the amount of CO2 emitted per unit of energy consumed declined by 8%, and CO2 emitted per dollar of GDP declined by 18%.

The importance of this trend cannot be overstated. This “decoupling”  of energy sector emissions and economic growth should put to rest the argument that combatting climate change requires accepting lower growth or a lower standard of living. In fact, although this decoupling is most pronounced in the United States, evidence that economies can grow while emissions do not is emerging around the world. The International Energy Agency’s (IEA’s) preliminary estimate of energy related CO2 emissions in 2015 reveals that emissions stayed flat compared with the year before, whereas the global economy grew. The IEA noted that “There have been only four periods in the past 40 years in which CO2 emission levels were flat or fell compared with the previous year, with three of those — the early 1980s, 1992, and 2009 — being associated with global economic weakness. By contrast, the recent halt in emissions growth comes in a period of economic growth.”

At the same time, evidence is mounting that any economic strategy that ignores carbon pollution will impose tremendous costs to the global economy and will result in fewer jobs and less economic growth over the long term. Estimates of the economic damages from warming of 4°C over preindustrial levels range from 1% to 5% of global GDP each year by 2100. One of the most frequently cited economic models pins the estimate of annual damages from warming of 4°C at ~4% of global GDP, which could lead to lost U.S. federal revenue of roughly $340 billion to $690 billion annually.

Moreover, these estimates do not include the possibility of GHG increases triggering catastrophic events, such as the accelerated shrinkage of the Greenland and Antarctic ice sheets, drastic changes in ocean currents, or sizable releases of GHGs from previously frozen soils and sediments that rapidly accelerate warming. In addition, these estimates factor in economic damages but do not address the critical question of whether the underlying rate of economic growth (rather than just the level of GDP) is affected by climate change, so these studies could substantially understate the potential damage of climate change on the global macroeconomy.

As a result, it is becoming increasingly clear that, regardless of the inherent uncertainties in predicting future climate and weather patterns, the investments needed to reduce emissions — and to increase resilience and preparedness for the changes in climate that can no longer be avoided — will be modest in comparison with the benefits from avoided climate-change damages.  This means, in the coming years, states, localities, and businesses will need to continue making these critical investments, in addition to taking common-sense steps to disclose climate risk to taxpayers, homeowners, shareholders, and customers.  Global insurance and reinsurance businesses are already taking such steps as their analytical models reveal growing climate risk.


Beyond the macroeconomic case, businesses are coming to the conclusion that reducing emissions is not just good for the environment — it can also boost bottom lines, cut costs for consumers, and deliver returns for shareholders.

Perhaps the most compelling example is energy efficiency. Government has played a role in encouraging this kind of investment and innovation.  My Administration has put in place (i) fuel economy standards that are net beneficial and are projected to cut more than 8 billion tons of carbon pollution over the lifetime of new vehicles sold between 2012 and 2029 and (ii) 44 appliance standards and new building codes that are projected to cut 2.4 billion tons of carbon pollution and save $550 billion for consumers by 2030.

But ultimately, these investments are being made by firms that decide to cut their energy waste in order to save money and invest in other areas of their businesses. For example, Alcoa has set a goal of reducing its GHG intensity 30% by 2020 from its 2005 baseline, and General Motors is working to reduce its energy intensity from facilities by 20% from its 2011 baseline over the same timeframe. Investments like these are contributing to what we are seeing take place across the economy: Total energy consumption in 2015 was 2.5% lower than it was in 2008, whereas the economy was 10% larger.

This kind of corporate decision-making can save money, but it also has the potential to create jobs that pay well. A U.S. Department of Energy report released this week found that ~2.2 million Americans are currently employed in the design, installation, and manufacture of energy-efficiency products and services. This compares with the roughly 1.1 million Americans who are employed in the production of fossil fuels and their use for electric power generation. Policies that continue to encourage businesses to save money by cutting energy waste could pay a major employment dividend and are based on stronger economic logic than continuing the nearly $5 billion per year in federal fossil-fuel subsidies, a market distortion that should be corrected on its own or in the context of corporate tax reform.


The American electric-power sector — the largest source of GHG emissions in our economy — is being transformed, in large part, because of market dynamics. In 2008, natural gas made up ~21% of U.S. electricity generation. Today, it makes up ~33%, an increase due almost entirely to the shift from higher-emitting coal to lower-emitting natural gas, brought about primarily by the increased availability of low-cost gas due to new production techniques. Because the cost of new electricity generation using natural gas is projected to remain low relative to coal, it is unlikely that utilities will change course and choose to build coal-fired power plants, which would be more expensive than natural gas plants, regardless of any near-term changes in federal policy. Although methane emissions from natural gas production are a serious concern, firms have an economic incentive over the long term to put in place waste-reducing measures consistent with standards my Administration has put in place, and states will continue making important progress toward addressing this issue, irrespective of near-term federal policy.

Renewable electricity costs also fell dramatically between 2008 and 2015: the cost of electricity fell 41% for wind, 54% for rooftop solar photovoltaic (PV) installations, and 64% for utility-scale PV. According to Bloomberg New Energy Finance, 2015 was a record year for clean energy investment, with those energy sources attracting twice as much global capital as fossil fuels.

Public policy — ranging from Recovery Act investments to recent tax credit extensions — has played a crucial role, but technology advances and market forces will continue to drive renewable deployment.  The levelized cost of electricity from new renewables like wind and solar in some parts of the United States is already lower than that for new coal generation, without counting subsidies for renewables.

That is why American businesses are making the move toward renewable energy sources. Google, for example, announced last month that, in 2017, it plans to power 100% of its operations using renewable energy — in large part through large-scale, long-term contracts to buy renewable energy directly. Walmart, the nation’s largest retailer, has set a goal of getting 100% of its energy from renewables in the coming years. And economy-wide, solar and wind firms now employ more than 360,000 Americans, compared with around 160,000 Americans who work in coal electric generation and support.

Beyond market forces, state-level policy will continue to drive clean-energy momentum. States representing 40% of the U.S. population are continuing to move ahead with clean-energy plans, and even outside of those states, clean energy is expanding. For example, wind power alone made up 12% of Texas’s electricity production in 2015 and, at certain points in 2015, that number was >40%, and wind provided 32% of Iowa’s total electricity generation in 2015, up from 8% in 2008 (a higher fraction than in any other state).


Outside the United States, countries and their businesses are moving forward, seeking to reap benefits for their countries by being at the front of the clean-energy race.  This has not always been the case. A short time ago, many believed that only a small number of advanced economies should be responsible for reducing GHG emissions and contributing to the fight against climate change. But nations agreed in Paris that all countries should put forward increasingly ambitious climate policies and be subject to consistent transparency and accountability requirements. This was a fundamental shift in the diplomatic landscape, which has already yielded substantial dividends. The Paris Agreement entered into force in less than a year, and, at the follow-up meeting this fall in Marrakesh, countries agreed that, with more than 110 countries representing more than 75% of global emissions having already joined the Paris Agreement, climate action “momentum is irreversible”. Although substantive action over decades will be required to realize the vision of Paris, analysis of countries’ individual contributions suggests that meeting mediumterm respective targets and increasing their ambition in the years ahead — coupled with scaled-up investment in clean-energy technologies — could increase the international community’s probability of limiting warming to 2°C by as much as 50%.

Were the United States to step away from Paris, it would lose its seat at the table to hold other countries to their commitments, demand transparency, and encourage ambition. This does not mean the next Administration needs to follow identical domestic policies to my Administration’s. There are multiple paths and mechanisms by which this country can achieve — efficiently and economically — the targets we embraced in the Paris Agreement. The Paris Agreement itself is based on a nationally determined structure whereby each country sets and updates its own commitments. Regardless of U.S. domestic policies, it would undermine our economic interests to walk away from the opportunity to hold countries representing two-thirds of global emissions — including China, India, Mexico, European Union members, and others — accountable. This should not be a partisan issue. It is good business and good economics to lead a technological revolution and define market trends. And it is smart planning to set long term emission-reduction targets and give American companies, entrepreneurs, and investors certainty so they can invest and manufacture the emission-reducing technologies that we can use domestically and export to the rest of the world. That is why hundreds of major companies — including energy-related companies from ExxonMobil and Shell, to DuPont and Rio Tinto, to Berkshire Hathaway Energy, Calpine, and Pacific Gas and Electric Company — have supported the Paris process, and leading investors have committed $1 billion in patient, private capital to support clean-energy breakthroughs that could make even greater climate ambition possible.


We have long known, on the basis of a massive scientific record, that the urgency of acting to mitigate climate change is real and cannot be ignored. In recent years, we have also seen that the economic case for action — and against inaction — is just as clear, the business case for clean energy is growing, and the trend toward a cleaner power sector can be sustained regardless of near-term federal policies.

Despite the policy uncertainty that we face, I remain convinced that no country is better suited to confront the climate challenge and reap the economic benefits of a low-carbon future than the United States and that continued participation in the Paris process will yield great benefit for the American people, as well as the international community. Prudent U.S. policy over the next several decades would prioritize, among other actions, decarbonizing the U.S. energy system, storing carbon and reducing emissions within U.S. lands, and reducing non-CO2 emissions.

Of course, one of the great advantages of our system of government is that each president is able to chart his or her own policy course. And President-elect Donald Trump will have the opportunity to do so. The latest science and economics provide a helpful guide for what the future may bring, in many cases independent of near-term policy choices, when it comes to combatting climate change and transitioning to a clean energy economy.


The full article with references is here, open-access:

The references give sources for all the numbers he mentions.

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+James Salsman You are correct. Even without actions, a large portion of the military expenses is made necessary by the need to defend faraway oil sources. Moreover, the troublemaking countries of the world are almost all powered by oil revenues. Including the one who has a controlling interest in the illegitimate president elect.
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This red nova - brighter than an ordinary nova but not as bright as a supernova - could be the brightest thing in the north hemisphere night sky in 2022... if  it happens in a season when it's in the Earth's night sky.

As Egan said in a comment on the original post:

Given that nobody knows exactly when this will happen, the main thing that determines how many people are likely to be able to see it is the declination, 46° N. So anyone in the northern hemisphere will have a good chance ... while for someone like me, at 31° S, the odds aren't great: it will never rise higher than 13° above the northern horizon, for me.

Right ascension is the celestial equivalent of longitude, but without knowing the season in advance (and the error bars on the current prediction are much too large for that) we can't tell if the sun will be too close to the object, drowning it in daylight to the naked eye.

If that happens, I guess the only comfort is that there are still sure to be telescopes able to make observations, maybe including both Hubble and James Webb.

For more on red novae, see:

where we read:

The luminosity of the explosion occurring in luminous red novae is between that of a supernova (which is brighter) and a nova (dimmer). The visible light lasts for weeks or months, and is distinctively red in colour, becoming dimmer and redder over time. As the visible light dims, the infrared light grows and also lasts for an extended period of time, usually dimming and brightening a number of times.

Red nova

A "red nova" due to two stars merging might take place in 2022, and would likely be visible from Earth. (Alas, the linked article illustrates this with a picture of two merging bluish stars.)

The stars have been observed orbiting each other with an exponentially increasing angular velocity over the last three years, and they are believed to already be surrounded by a shared envelope of gas. If they are seen merging, this will be the first case of such an event being predicted in advance, making it possible to study the pre-collision phase.

Thanks to +Peter da Silva

The full paper is here:
Astronomers predict a death spiral ending in a red nova
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Save me a seat!
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Don't say "ox" to your mother-in-law!

The world is full of weirdness.  From Bryant Rousseau:

A geographically widespread practice known as avoidance speech, or “mother-in-law languages,” imposes strict rules on how one speaks — or doesn’t — to the parents of a spouse, with daughters-in-law typically bearing the brunt of such limits.

In parts of Africa, Australia and India, some societies restrict the words a person can say after marriage. Some cultures have even barred all direct communication with parents-in-law.

Some married women who speak the Kambaata language of Ethiopia follow ballishsha, a rule that forbids them from using words that begin with the same syllable as the name of their father-in-law or mother-in-law.

This rule can complicate a conversation, but there are workarounds. Certain basic words in the vocabulary come in synonymous pairs. “One is the normal term, used by everybody; one is the term used by women who are not allowed to say that word,” said Yvonne Treis, a linguist at a French research institute, Languages and Cultures of Sub-Saharan Africa.

Euphemisms are another frequent solution: If the word “ox” is taboo for a wife to say, she may refer to “the one that plows” instead. The Kambaata language also has a word akin to “whatchamacallit” in English, useful in a pinch as either a noun or verb when no other alternative is available.

Avoidance speech is also practiced by speakers of some of the Bantu languages of southern Africa, including Xhosa and Zulu. Married women are forbidden from using their father-in-law’s name, or any word that has the same root or similar sound.

Bantu speakers often get around this restriction by borrowing synonyms from other languages spoken nearby. Some linguists think that is how click consonants found their way into Bantu speech: in words borrowed from Khoisan languages, which use clicks extensively.

In parts of India, a daughter-in-law is not allowed to use words that begin with the same letters as her in-laws’ names, requiring her to use a parallel vocabulary.

Avoidance speech was a common feature of many aboriginal languages in Australia. The custom has largely faded in some areas, but it is still widely practiced in the Western Desert region and Arnhem Land, according to Claire Bowern, a professor of linguistics at Yale.

For more, see his New York Times article:

and for more, the wonderful Wikipedia:
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Wen Su
+John Baez It's in Chapter 2 of the book where a person is telling another the structure of the main family featured in the book, and near the end of the chapter, he mentioned that the mother of the other person's student is member of the family and her maiden name. The teacher reflected that it made sense since his student would mispronounce the character in her mother's name and wrote it a few strokes short.
I have to say I only heard of this type of practice from this book but nowhere else. But the Culture Revolution has got rid of many ancient traditions, so I have no idea how commonly this was practiced.
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Somebody's beating everyone at go - and nobody knows who!

Except that now we do!  Read the article and click on the "update".

But it's fun to read about the original mystery before reading the solution.  For example:

The account is simply called "Master", and since the start of the new year it has made a habit out of trashing some of the world's best Go professionals. It's already beaten Ke Jie twice, who is currently the highest ranked Go player in the world.

A European professional Go player, Ali Jabarin, wrote on Facebook that Ke Jie was "a bit shocked ... just repeating it's too strong".

....there's been no official confirmation as to the mystery player wrecking online Go. The only thing anybody knows for sure is that the world's best Go players have been getting slapped around by something.

Thanks to +Alexander Kruel for pointing this out.
Right now, there's a player lurking in the depths of the online Go scene that is laying waste to some of the best players in the world. It's called...
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What a human child is doing is actually very interesting. For about the first year or so, the human brain is wiring itself to in order to be better at learning to learn what it has to learn.
A monkey for example acquires the notion of object permanence a lot earlier than a human. Humans take so long because they actually come with fewer structural priors than all other animals. There's nothing even approaching that human capability in AI right now.
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I'm a mathematical physicist.
  • Centre for Quantum Technologies
    Visiting Researcher, 2011 - present
  • U.C. Riverside
    Professor, 1989 - present
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Riverside, California
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I teach at U. C. Riverside and work on mathematical physics — which I interpret broadly as ‘math that could be of interest in physics, and physics that could be of interest in math’. I’ve spent a lot of time on quantum gravity and n-categories, but now I'm starting to work on more practical things, too.

Why? I keep realizing more and more that our little planet is in deep trouble! The deep secrets of math and physics are endlessly engrossing — but they can wait, and other things can’t.
  • Massachusetts Institute of Technology
    Mathematics, 1982 - 1986
  • Princeton University
    Mathematics, 1979 - 1982
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