Nuclear power is the only green solution (2004) - <AUTHOR> http://www.jameslovelock.org/nuclear-power-is-the-only-green-solution/ <comment><USER5> In 2004 solar power was still far too expensive to be a viable option, to the point where he didn't even bother to mention it: "there is no chance that the renewables, wind, tide and water power can provide enough energy and in time." This is no longer true; installing new photovoltaic generation capacity is now cheaper than continuing to run _existing_ coal plants in much of the world, and although the humans still need to ramp up production capacity to build enough panels, it looks like they are on track to make the switch in the 2020s. The total solar resource is about three orders of magnitude larger than marketed world energy consumption.

We shouldn't fault James for not seeing this in 2004, but now we know he was wrong, as many of us were.

[https://en.wikipedia.org/wiki/Growth_of_photovoltaics](https://en.wikipedia.org/wiki/Growth_of_photovoltaics)

Edited to add: competitive-bid power purchasing agreements hit a new low this week of US$15.67 per MWh in Qatar [https://archive.fo/UBWWi](https://archive.fo/UBWWi) but there are projects in many equatorial parts of the world hitting similar lows. This is a factor of 10 less than what end-users currently pay for electricity in California and roughly a factor of 3 less than the average wholesale cost there.

<comment><USER6> But coal plant as opposed to solar plant has a reliable, predictable output and works after dusk. Nuclear power plant also has these characteristics.

<comment><USER7> We do not have to limit ourselves to just one source. Blocking nuclear in favor of some sort of pie in the sky global power network and huge renewable infrastructure is common for some reason.

We can use any and all power sources that are clean.

<comment><USER8> > We can use any and all power sources that are clean.

I completely agree with you on that. Of course, the disagreement hinges on whether you can consider nuclear power "clean"...

<comment><USER9> There's enough data today to show that it absolutely is. No air pollution, very little CO2, almost no deaths/TWh compared to other sources.

Accidents have been bad but recall that fossil while operating normally kills 3.8 million/year and causes climate change. In comparison to that nuclear is absolutely pristene.

Germany's choice to phase nuclear out and leave coal on straight up kills a few thousand people per year.

<comment><USER10> _> Germany's choice to phase nuclear out and leave coal on straight up_

Often repeated, but still wrong: Germany also phased out coal.

<comment><USER9> Incorrect. Here's some live data for you to gander at: [https://www.electricitymap.org](https://www.electricitymap.org)

They still run over 40 GW of coal.

<comment><USER10> Yeah, sorry, native German speaker here, I got the tense wrong. Germany is in the process of phasing out coal, just as with nuclear. [https://www.latimes.com/world/europe/la-fg-germany-coal- powe...](https://www.latimes.com/world/europe/la-fg-germany-coal- power-20190126-story.html)

<comment><USER9> Yup. They promised to phase coal out later and phased nuclear out today. Literalling killing a few thousand per year by air pollution while they're at it. It's a great anti-scientific tragedy of our times due to fear of radiation and inability to judge actuarial statistics correctly.

<comment><USER10> I'm not at all disagreeing. The coal phase-out should have happened a) before the nuclear phase-out and b) decades earlier. Processes like these tend to be pretty sluggish, the political discussions for both date back to the 1970s. Chernobyl was a big thing in German politics, and there are still some species of mushrooms that can't be eaten in the country. The actual health problems were negligible, but this isn't how politics work.

<comment><USER9> Gotcha. Yeah the mental effects of Chernobyl melded with all the fears about nuclear weapons fallout, which Russians and American had been scaring people with for years at that point.

The nuclear industry totally failed to recover from a PR point of view, and since then has hid under a rock rather than explained how low carbon and safe it is.

</comment></comment></comment></comment></comment></comment></comment></comment></comment></comment></comment><comment><USER11> Nothing about the greenest and most sustainable solution: reducing consumption. Most Americans could drop their consumption by 75% purely improving their lives, before difficult decisions, many of which would also improve their lives. Several nations, like Thailand, have lowered birth rates purely voluntarily, increasing prosperity and abundance.

Without reducing, new power sources will repeat what led Norman Borlaug said on receiving the Nobel Prize for his part in the Green Revolution:

"The green revolution has won a temporary success in man's war against hunger and deprivation; it has given man a breathing space. If fully implemented, the revolution can provide sufficient food for sustenance during the next three decades. But the frightening power of human reproduction must also be curbed; otherwise the success of the green revolution will be ephemeral only. Most people still fail to comprehend the magnitude and menace of the "Population Monster"...Since man is potentially a rational being, however, I am confident that within the next two decades he will recognize the self-destructive course he steers along the road of irresponsible population growth..."

We haven't made much progress stemming growth. Projections to 2100 still show our population growing, yet our global footprint is greater than one Earth.

<comment><USER12> Our consumption isn't about things like turning off lights in your house. In the developed countries every human consumes about 10kW. You can actually graph energy consumption per capita and a quality of life index and they will correlate basically one to one. The bulk of that energy goes to power agricultural machinery that produces the food we eat and the transportation of that food from the mid west states to the coasts. There is little you can do to reduce that consumption because geography doesn't allow for it. Local farms aren't much better. They often times use old pickup trucks which are way less efficient than trains to deliver food. Even if you don't use any power at all in your life, no heat, no lights, no transportation, you still would be in the 7-9kW range as long as you eat food.

<comment><USER13> > Local farms aren't much better. They often times use old pickup trucks which > are way less efficient than trains to deliver food.

This doesn't really make sense to me. Trains don't deliver from foreign farms to my door. You have to drive the food from those farms to the train, and drive the food from the train to its final destination. I don't see how that can possibly be less resource-intensive than getting food from local farms. And that's not even mentioning the difference between monoculture industrial agriculture and small-scale organic farming.

In any case, if you're worried about your resource consumption, you can always make more of your diet plant-based, drive your car less, and avoid flying when possible. In every carbon impact calculator I've used [1], these things make a significant impact. And I agree with the above poster that these decisions can, far from being sacrifices, greatly improve your life.

[1] [https://footprint.wwf.org.uk/#/](https://footprint.wwf.org.uk/#/)

<comment><USER14> Large farms move their crops in larger, more efficient vehicles. The efficiency offsets, to some degree, the distance.

You also are conflating organic and polyculture farming. Most organic farming is monoculture and much of it is industrial.

<comment><USER13> > Large farms move their crops in larger, more efficient vehicles. The > efficiency offsets, to some degree, the distance.

Yes I understand this. My point was that it's not as simple as comparing trains to old pickup trucks, which seemed like a strawman. But I've been doing some research and was surprised to learn that food-miles are a relatively small portion of the emissions associated with food, so point taken.

> You also are conflating organic and polyculture farming. Most organic > farming is monoculture and much of it is industrial.

I didn't mean to conflate them, I meant that monoculture + industrial is more resource-intensive than organic + small-scale. But I guess I was using "organic" as a catch-all for sustainable farming practices, e.g. polyculture, rather than literally "USDA organic".

Debate about "local produce" aside (which I probably should have let go), my more important point is that it's definitely possible to reduce your carbon footprint meaningfully.

</comment></comment></comment></comment></comment><comment><USER15> " Published in The Independent, 24 May 2004."

16 years later coal generated electricity is still huge and 80% of the world's electricity is still generated by fossil fuels.

I imagine if we'd used nuclear instead, the world would have bought itself an extra decade or two to solve the problem.

<comment><USER16> Some of the blame for this should lie at the feet of activists with good intentions like Jane Fonda.

I don't think she realizes the damage she's responsible for. Lots of the fossil fuel usage she is now against only happened because of her cause in the 70s.

<comment><USER17> Hell, I've seen "green energy" proponents NOW oppose nuclear because they want to push their own favorite (solar or whatever). Instead of saying "I support anything that's not fossil fuels, but I prefer solar", their stance is "It's either solar or nothing (where 'nothing' is fossil fuels)".

<comment><USER18> And certain green energy opponents oppose wind energy because it causes cancer, unlike "clean coal" that they love.

<comment><USER17> Wait, how can wind energy possibly cause cancer?

Also, there must be a name for the fallacy where you oppose one thing for some reason, without considering that the only alternative is much worse.

<comment><USER18> Didn't you hear about that? Or is there too much other stuff happening that it distracts from important issues like protecting children from windmill cancer?

[https://www.washingtonpost.com/lifestyle/style/the-story- of-...](https://www.washingtonpost.com/lifestyle/style/the-story-of-donald- trumps-feud-with-his-one-true-nemesis- windmills/2019/08/15/f637980a-be9e-11e9-b873-63ace636af08_story.html)

[https://qz.com/1291269/the-scottish-wind-farm-donald- trump-t...](https://qz.com/1291269/the-scottish-wind-farm-donald-trump-tried- to-block-is-now-complete/)

[https://www.youtube.com/watch?v=Q0s5Zqmb09g](https://www.youtube.com/watch?v=Q0s5Zqmb09g)

</comment></comment></comment></comment></comment></comment><comment><USER19> 1) The article does not mention consuming less energy/stuff - whether by being mush more efficient for the same result (huge potential there !) or with more sobriety

2) "there is no chance that the renewables, wind, tide and water power can provide enough energy and in time" was true in 2004, now this totally an option : this is cheaper and faster to deploy than nuclear

3) "Opposition to nuclear energy is based on irrational fear" in only partly true... 1% of all nuclear power plant did had a super serious problem (Fukushima, Three Mile Island, Chernobyl)... And there are other unsolved issues around the short term and long term security

<comment><USER20> 4) Nuclear is and always was _incredibly_ expensive to set up. There is a reason why nuclear plants are never paid for in their entirety by any private firm/operator and heavily subsidized (at least in the EU)

5) I am still fascinated by the lack of awareness regarding waste (particularly since it is with well educated/smart people)

Yes, I know, there are alternative nuclear power sources where we don't need to safely store nuclear waste for millions of years. But those are not readily available.

We still do not have a _real_ solution for nuclear waste. Just dumping something so dangerous for _thousands_ (or millions) of years is mindbogglingly reckless. And loudly asking to increase this amount by plastering waste-producing facilities everywhere... That's like pouring poison in the floor below your own garden, hoping the next guy will have a solution for it.

But I guess good ol' America, where dumping _any_ waste is not considered a problem, there is simply no awareness for this practice. Just because you don't see it, doesn't mean it has no effect.

Dumping. is. not. a. long-term. solution. And just because _You_ don't need to care about it anymore, doesn't mean nobody has to.

<comment><USER21> All of the used fuel ever produced by the commercial nuclear industry since the late 1950s would cover a football field to a depth of less than 10 yards.

[https://www.nei.org/fundamentals/nuclear- waste](https://www.nei.org/fundamentals/nuclear-waste)

<comment><USER22> Without disputing that assertion, you might not have chosen the most unbiased source to back it up.

<comment><USER21> Upvoted :) I'll concede that point.

</comment></comment></comment></comment></comment><comment><USER23> That was indeed in 2004 – long before nuclear stopped being cost-competitive with renewable energies.

Oh, and renewables are also faster to deploy than nuclear plants (which take years to build).

<comment><USER17> But renewables are very bursty and don't allow you to plan well, so we need both.

<comment><USER24> The intermittency of renewables means nuclear doesn't help. Nuclear needs a constant market at a good average price to make sense. Renewables, even when they do not cover 100%, crash the price often enough to kill nuclear's business case.

As renewables build out, the prospects for nuclear will only get worse. At this point, it's a delaying action by utilities to try to get their existing reactors profitable enough to keep from shutting them down. New reactors are not close to making economic sense, and the effective CO2 taxes that would be needed to make them so would be very large.

<comment><USER17> Isn't that because we're using fossil fuels for the base load? What happens when all we have is renewables?

<comment><USER24> Fossil fuel baseload is also incompatible with renewables, although not as badly because more of its costs are variable. This is one of the reasons coal is hurting.

Think carefully about the economics. Suppose we want to use nuclear to cover the (say) 20% of the time renewables + short term storage might not cover. Nuclear's cost of power would be greatly inflated over what it would be if it were baseload. The effective CO2 tax to make that cheaper than (say) gas turbines burning natural gas would be outrageous, over $1000/ton. A vast array of CO2-reducing changes would occur before that. It would also likely be cheaper to use renewable hydrogen (from electrolysis, stored underground) in gas turbines for that last bit. The round trip efficiency would be lousy, but it would still be cheaper than using nuclear there.

View it another way: if we have really cheap power most of the time, insisting we use nuclear then, just so nuclear would be available in that other 20%, would incur a huge opportunity cost. That cost should properly be assigned to the place nuclear is being depended on (that 20%).

<comment><USER9> I'm sure you're aware that nuclear heat and electricity could be stored and/or distributed just like renewable stuff in the vast energy storage system of the future.

I still would like an answer from you on EROI

<comment><USER24> There is no point charging batteries with expensive nuclear energy when cheap renewable energy can be used. And the operator of a battery can shift when they are charged, making nuclear even less likely to be the cheapest source available at any time. So this doesn't save nuclear.

Heat is difficult to transport any great distance, and the reactors we have today produce only moderate grade heat, which isn't very valuable. And if PV becomes a bit cheaper, then the cost per joule of its power will become comparable to the cost per thermal joule of natural gas. In that situation, consumers will shift to resistive heat, and be able to bank that heat in large thermal stores. This will provide enormous cheap storage capacity for that solar energy.

EROI of renewables is just fine, some horribly flawed claims to the opposite notwithstanding. In particular, the EROI of PV was estimated to be about 8 in Europe -- but that assumes one puts the solar-powered PV factories IN EUROPE, rather than in a location with more sun. The real issue there is that energy- intensive industry will flee Europe in a solar-powered world.

</comment></comment></comment></comment></comment></comment></comment><comment><USER25> He writes in the context of the UK. In January 2008 the UK Government gave the go-ahead to build a nuclear power station. This is Hinkley Point C. It might be producing power in 2023. It could cost as much as £22 billion. This kind of project is certainly not the solution.

</comment><comment><USER24> That piece is from 2004. The installed cost of utility scale PV has fallen by an order of magnitude since 2004. The conclusions he reached then are not relevant now.

</comment><comment><USER26> Nuclear power is the only green solution that allows necessary power density and a constant power output. Too bad it has so much negative press, mostly by journalists interested in sensational scary stuff.

<comment><USER24> "Necessary" power density? Please explain why the power density is necessary.

</comment></comment><comment><USER27> Great (great!) podcasts about nuclear fusion reactors (the second one is an interview with a physicist at ITER, being built in the South of France):

[http://omegataupodcast.net/22-nuclear-fusion-at-mpi-fur- plas...](http://omegataupodcast.net/22-nuclear-fusion-at-mpi-fur- plasmaphysik/)

[https://omegataupodcast.net/157-fusion-at- iter/](https://omegataupodcast.net/157-fusion-at-iter/)

</comment><comment><USER28> Nuclear critics seem to ignore, at least when discussing the dangers, that the world is _currently_ producing 10% of its energy from ~440 nuclear power plants in ~50 countries. France for example, derives about 75% of its electricity from nuclear energy. This is not some spooky new technology to be wary of. It's doing fine. All we need is to scale by a single factor of 10 compared to what we have now to go 100% green. [0]

In terms of public perception of danger, Nuclear vs Coal is akin to Flying vs Driving. In both the latter kills many many more people, although little by little. The former has disasters extremely rarely, and even then they are not _that_ bad [1][2][3], but when they do its all anyone can talk about for a long time, and they cement an erroneous perception of danger. "Coal is responsible for over 800,000 premature deaths per year globally and many millions more serious and minor illnesses." [4]

The only real issue is cost. While its very competitive to run a NPP, its very expensive to build one. Note how the number of plants has grown exponentially(?) until 1986 and then just plateaued. [0]

Considering the crisis we are in, I think its only logical we subitize NPPs, take extra care of them (for example in Fukashima the right protocols were in place and so the death toll as a result of radiation is "1" [5]), deal with the waste problem later, and work on perhaps better solutions in the ensuing decades.

Sure it's not perfect, but its our best bet.

[0] [https://www.world-nuclear.org/information-library/current- an...](https://www.world-nuclear.org/information-library/current-and-future- generation/nuclear-power-in-the-world-today.aspx) [1] [https://en.wikipedia.org/wiki/List_of_nuclear_and_radiation_...](https://en.wikipedia.org/wiki/List_of_nuclear_and_radiation_accidents_by_death_toll) [2] [https://en.wikipedia.org/wiki/Deaths_due_to_the_Chernobyl_di...](https://en.wikipedia.org/wiki/Deaths_due_to_the_Chernobyl_disaster) [3] [https://ourworldindata.org/what-is-the-safest-form-of- energy](https://ourworldindata.org/what-is-the-safest-form-of-energy) [4] [https://endcoal.org/health/](https://endcoal.org/health/) [5] [https://en.wikipedia.org/wiki/Fukushima_Daiichi_nuclear_disa...](https://en.wikipedia.org/wiki/Fukushima_Daiichi_nuclear_disaster_casualties)

<comment><USER24> > Nuclear critics seem to ignore, at least when discussing the dangers, that > the world is currently producing 10% of its energy from ~440 nuclear power > plants in ~50 countries.

We don't ignore it, we recognize that it is irrelevant. You seem to be saying that if a choice was the correct one at one time, it will always be correct. But that's nonsense.

</comment></comment><comment><USER29> Suppose you exhaustively incorporated all risk when engineering power plants, and you designed such that exhaustive risk was equal across all power plants.

That would mean risks from climate change were included in the engineering of coal plants, and the engineering of nuclear plants therefore needed to match the exhaustive risk of coal plants including climate change risk.

That would mean nuclear plants could be engineered to accept higher risk, to match the exhaustive risk of coal plants.

If a nuclear plant might render a region uninhabitable due to radiation, that would be matched against a coal plant rendering a region uninhabitable due to sea level rise, etc, all risks exhaustively incorporated.

How much cheaper would a nuclear plant be if it was engineered to an exhaustive risk-mitigation standard commensurate with the exhaustive risk of other industrial plants like coal-fired power plants, mines, chemical plants?

</comment><comment><USER30> One negative aspect of nuclear reactors that I found is rarely discussed is their vulnerability to military attacks. Wind, water and solar are distributed much more. Of course there are other single points of failure, but at least those failures don't involve risk of nuclear contamination.

</comment><comment><USER31> Does anyone have a good cost comparison of nuclear, gas, coal/lignite ? Total cost, with decommission. My understanding is that even with Carbon Tax coal is cheaper.

From HN comment: > Take the average IPCC meta-analysis numbers [1] at face value: 820 gCO2-eq/kWh for coal, 490 for gas. Those are both extraordinarily high. This is because they both combust carbon in the presence of oxygen to form energy and CO2. They're both very high-carbon fuel sources. If we are trying to reduce carbon emissions, we need to build things that do not combine C + O2 to make CO2 + energy. Options with less than 50g CO2-eq/kWh (in decreasing order of emissions) include solar (41), geothermal (38), hydro (24), tidal (17), nuclear (12), and wind (11).

<comment><USER32> The investment analysis firm Lazards publishes detailed reports on LCOE every year. These are current costs per MWh without subsidies [1]:

      Nuclear            : $118 to 192
      Solar with storage : $102 - 139
      Gas                : $44 - <USER2>
      Wind               : $28 - <USER3>
      Solar PV           : $32 - <USER4>

They don't include carbon pricing which will increase solars price a bit, it should also push its carbon output from manufacture down as it will be more economical to optimize it.

[1] [https://www.lazard.com/perspective/lcoe2019](https://www.lazard.com/perspective/lcoe2019)

</comment></comment><comment><USER33> I mean yes - if I was playing Civ this is the route I would go.

But I look at the current landscape of both political opinion and technological progress and think: we should go all-in on Solar and storage.

I look at practical-minded organizations like the US Navy (who certainly have access to nuclear reactors in a more streamlined way than civilian utilities) and yet they still put in a 21 MW solar farm at NAS Oceana [1].

1 - [https://navysustainability.dodlive.mil/energy/repo-3/project...](https://navysustainability.dodlive.mil/energy/repo-3/projects- page/nas-oceana-solar-facility/)

</comment><comment><USER34> How green is it when we've had it for 70 years and already created two* exclusion zones on earth. How many more exclusion zones will we have created with our hubris that we can create a perfect system?

I understand that my entire career (IT) depends on nuclear, but I can't ignore the fact that we have a giant reactor at the center of our solar system. We should focus on using that instead.

*not counting all the fallout from weapons.

</comment><comment><USER35> _But with six billion, and growing, few options remain; we can not continue drawing energy from fossil fuels and there is no chance that the renewables, wind, tide and water power can provide enough energy and in time._

I beg to differ. So far in China's electricity mix renewables have contributed much more than nuclear.

And it's poised to stay that way given how difficult it really is to build nuclear power in practice.

<comment><USER36> Right. Although, arguing China's side of the discussion as an example seems very very disproportionate at this point. See these giant, graphite-black sectors on the 2017 diagrams listed? [https://en.wikipedia.org/wiki/Electricity_sector_in_China](https://en.wikipedia.org/wiki/Electricity_sector_in_China)

<comment><USER35> My point is that China having the fastest growing nuclear program in the world is still not getting more energy from that source than renewables.

Nuclear appears to be simply too slow to roll out.

</comment></comment></comment><comment><USER37> The problem is the kind of nuclear reaction used. Fission reactors are bad, but once we got fusion reactors, we'll have an almost perfect energy source: clean, reliable and cheap.

The project Iter ([http://iter.org/](http://iter.org/)) is building the first fusion reactor. It's a big challenge but I'm glade that this project exists at all.

<comment><USER24> Fusion is going to be more expensive than fission, if it works at all. The idea that it would be cheap has no rational basis. The power density of ITER that you reference there is 400x worse than a PWR. Fusion reactors will be monstrous expensive things.

</comment></comment><comment><USER38> If we were to build reactors to replace existing fossil fuel plans there would not be enough uranium cheap enough that it makes sense to use it.

</comment><comment><USER39> Someone on HN recently posted this link [https://en- roads.climateinteractive.org/](https://en-roads.climateinteractive.org/)

I don't have a full read on how accurately the figures backing this tool reflect reality, but one thing that really stood out to me while playing with it was how small an impact nuclear has on the overall outcomes.

</comment><comment><USER40> Ideally the future is nuclear fission transitioning to fusion, with hydrogen fuel cell vehicles.

Lithium battery production and recycling is still very damaging to the environment, even if it stopped relying on coal for energy[1][2].

Hydrogen vehicles also have a longer lifespan and range compared to electric vehicles, while needing less time to refuel[3]. Now if only we invested as much in hydrogen harvesting technology as we are investing in lithium batteries.

[1][https://amp.theguardian.com/sustainable- business/2017/aug/24...](https://amp.theguardian.com/sustainable- business/2017/aug/24/nickel-mining-hidden-environmental-cost-electric-cars- batteries)

[2][https://www.weforum.org/agenda/2017/11/battery-batteries- ele...](https://www.weforum.org/agenda/2017/11/battery-batteries-electric- cars-carbon-sustainable-power-energy/)

[3][https://www.sciencedirect.com/topics/engineering/hydrogen- fu...](https://www.sciencedirect.com/topics/engineering/hydrogen-fuel-cell- vehicle)

<comment><USER41> I am sorry you are so misinformed.

Lithium is a common abundant resource and battery packs are easily recycled but more importantly there is a financial incentive to do so.

Manufacturing technology for cells is improving rapidly. Much faster than the pace of innovation in Hydrogen fuel cells. Most are focusing on reducing Cobalt and other techniques to reduce or eliminate chemicals and energy used in wet electrode processes.

Hydrogen is pretty much DOA for cars. This is a good video on the subject: [https://youtu.be/f7MzFfuNOtY](https://youtu.be/f7MzFfuNOtY)

<comment><USER42> "common abundant"

> Even though 365 years of reserve supply sounds very comforting, the point of > the EV and stationary storage revolutions is that current demand will shoot > up, way up, if these revolutions do happen. The 100 Gigafactories scenario > could come true. And if that happens, the 365-year supply would be less than > a 17-year supply (13.5 million tons of reserves divided by 800,000 = 16.9 > years).

[https://www.greentechmedia.com/articles/read/is-there- enough...](https://www.greentechmedia.com/articles/read/is-there-enough- lithium-to-maintain-the-growth-of-the-lithium-ion-battery-m)

Is 17 years "common and abundant" ?

> But very little recycling goes on today. In Australia, for example, only > 2–3% of Li-ion batteries are collected and sent offshore for recycling, > according to Naomi J. Boxall, an environmental scientist at Australia's > Commonwealth Scientific and Industrial Research Organisation (CSIRO). The > recycling rates in the European Union and the US—less than 5%—aren't much > higher.

[https://cen.acs.org/materials/energy-storage/time-serious- re...](https://cen.acs.org/materials/energy-storage/time-serious-recycling- lithium/97/i28)

</comment></comment></comment><comment><USER43> The article is old and outdated.

Since Nuclear does not scale, it is no solution to climate change, for example.

The World Nuclear Status Report says:

[https://www.worldnuclearreport.org/The-World-Nuclear- Industr...](https://www.worldnuclearreport.org/The-World-Nuclear-Industry- Status-Report-2019-HTML.html)

\--- Non-Nuclear Options Save More Carbon Per Year. While current nuclear programs are particularly slow, current renewables programs are particularly fast. New nuclear plants take 5–17 years longer to build than utility-scale solar or onshore wind power, so existing fossil-fueled plants emit far more CO2 while awaiting substitution by the nuclear option. Stabilizing the climate is urgent, nuclear power is slow. \---

Just look at the electricity production trends of China:

[https://en.wikipedia.org/wiki/Electricity_sector_in_China#/m...](https://en.wikipedia.org/wiki/Electricity_sector_in_China#/media/File:Electricity_Production_in_China.png)

<comment><USER44> worldnuclearreport.org is an anti-nuclear activist organization, FYI. They are not an official body of any kind.

There are a number of flaws in the conclusions they advocate.

1\. They compare raw _generation_ costs, but always neglect storage costs for renewables - which is the MAJORITY problem with most renewables.

2\. They claim that nuclear takes long and is expensive, while continuing to advocate regulations to make nuclear more expensive and take longer. I call this the "push someone off a cliff and then accuse him of being clumsy" strategy.

3\. Nuclear scales better than any other solution. Storage (at least in North America) is trivial - we have a massive facility capable of storing ALL the waste from the US & Canada, just sitting closed because of politics and fearmongering.

4\. Building a nuclear plant takes 10-15 years. The most ambitious "New Green Deal" plan from environmentalists has a timeline of 10 years (despite have no solution to the storage problem). Frankly, if we get to 100% nuclear and hydro in 20 years, that is very much in line with preventing climate change. Note also that China is currently building 24 GenIII nuclear plants.

<comment><USER43> > Note also that China is currently building 24 GenIII nuclear plants.

Too slow. What is it? 30 GW production capacity? 40? 50?

China is going in the direction of total 1300 GW production capacity with just coal.

> Building a nuclear plant takes 10-15 years.

A single one. I was taking about scale. To replace the coal power plants of China, one would need to build 1000 reactors.

<comment><USER44> > A single one.

You think they are built in series? Like one after the other? Do you place that same requirement on renewable plants?

> To replace the coal power plants of China, one would need to build 1000 > reactors.

The Chinese plants under construction will bring nuclear from 2% of the current grid to 20% by 2030. So, no, it's not 1000 reactors, it would be 100 - which is entirely doable. ...and indeed they are planning for an additional 1500GW of nuclear power construction AFTER this current set is finished.

[source]([https://en.wikipedia.org/wiki/Electricity_sector_in_China#Nu...](https://en.wikipedia.org/wiki/Electricity_sector_in_China#Nuclear_power))

<comment><USER43> > You think they are built in series?

They need a ramp up. Which is much easier for renewable.

> The Chinese plants under construction will bring nuclear from 2% of the > current grid to 20% by 2030

Renewable is there already.

See here for nuclear:

[https://en.wikipedia.org/wiki/Nuclear_power_in_China](https://en.wikipedia.org/wiki/Nuclear_power_in_China)

\--- As of March 2019, China has 46 nuclear reactors in operation with a capacity of 42.8 GW and 11 under construction with a capacity of 10.8 GW.[4][5] Additional reactors are planned for an additional 36 GW. China was planning to have 58 GW of capacity by 2020.[3] However, few plants have commenced construction since 2015, and it is now unlikely that this target will be met.---

Nuclear will be far from providing 20% in 2030. Probably not even 10%:

[https://www.world-nuclear.org/information-library/country- pr...](https://www.world-nuclear.org/information-library/country- profiles/countries-a-f/china-nuclear-power.aspx)

\---By 2030 nuclear capacity will be 120 to 150 GWe, and nuclear will provide 8% to 10% of electricity.---

</comment></comment></comment></comment></comment><comment><USER45> While being better than coal and petroleum, nuclear is still based on non- renewable uranium.

How abundant is uranium compared with coal and petroleum? How destructive and energy intensive are the extraction and refinement processes compared with fossil fuels?

<comment><USER21> The world's present measured resources of uranium (5.7 Mt) in the cost category less than three times present spot prices and used only in conventional reactors, are enough to last for about 90 years. [1]

There are an estimated 1.1 trillion tonnes of proven coal reserves worldwide. This means that there is enough coal to last us around 150 years at current rates of production. In contrast, proven oil and gas reserves are equivalent to around 50 and 52 years at current production levels. [2]

[1] [https://world-nuclear.org/information-library/nuclear- fuel-c...](https://world-nuclear.org/information-library/nuclear-fuel- cycle/uranium-resources/supply-of-uranium.aspx)

[2] [https://www.worldcoal.org/coal/where-coal- found](https://www.worldcoal.org/coal/where-coal-found)

<comment><USER45> Thanks for the details. Out of curiosity, are those industry-neutral organizations that made those estimates?

<comment><USER21> > Are those industry-neutral organizations that made those estimates?

Do neutral organizations still exist when even school children have strong opinions on coal power? I don't believe neutrality is thing for coal anymore and it hasn't been for nuclear for a long time. Thus, by definition, these cannot be neutral sources.

Even if these were the best estimates possible, how would anyone else authenticate it? With an audit? Like how Arthur Andersen audited Enron?

I feel we are post-truth and thus nothing can be claimed to be unbiased.

</comment></comment></comment></comment><comment><USER46> nuclear power is not scalable though [https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=6021978](https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=6021978)

</comment><comment><USER47> It's an overly centralized solution in that it takes control away from the individual citizens and property owners, who have to foot the bill for costs, taxes, bonds, overruns, and profits for corporations not to mention possible payoffs to politicians. Including costs that are cleverly kept off the official pronouncements with accounting tricks.

Technically it may have come a little by way but small individual solutions like solar panels with battery systems have huge advantages when it comes to freedom and self determination.

</comment><comment><USER48> Nuclear is probably the best solution, but it only works if you somehow manage to calibrate its impact on people's psychology (or just hope for no disaster to happen in the next 100 years, which is hard to to be sure about). The standard procedure in case of disaster involves a massive evacuation, cleanup, and confinement, which are costly[1], deathly[2], and traumatizing for the population[3]. All of that is probably still worth it in comparison to the consequences of global warming in regards to many factual metrics (number of deaths, purchasing power, etc), but I'm not actually sure it's worth it in regards to the only metric that actually matters: how much of a disastrous state people perceive their environment to be in.

In the case of Fukushima, Japan, which was beforehand in the process of switching more and more of its energy to nuclear, changed their stance overnight to switch back to all-fossile, because of pressure from the public opinion. If a nuclear disaster would come to happen in a country like France, the situation would probably be an absolute disaster, with people on a major psychosis and a state unable to realistically switch to another form of energy.

[1] The cost of a nuclear disaster in France (similar to the one in Fukushia) has been estimated at 430 billions euros, which is 20% of the country's economic output. ([https://www.reuters.com/article/us-france-nuclear- disaster-c...](https://www.reuters.com/article/us-france-nuclear-disaster- cost-idUSBRE91603X20130207))

[2] Fukushima's evacuation caused 1,600 deaths, that is more than the deaths caused by the tsunami itself.

[3] Following the Chernobyl disaster, there was a large increase of PTSD instaces, psychosomatic diseases, alcoholism, suicide, etc. ([https://en.wikipedia.org/wiki/Radiation_effects_from_the_Fuk...](https://en.wikipedia.org/wiki/Radiation_effects_from_the_Fukushima_Daiichi_nuclear_disaster#Psychological_effects_of_perceived_radiation_exposure))

TL;DR: you need to somehow make people chill about nuclear if you want to argue that nuclear is a satisfying source of energy. It might still be the best option nonetheless.

<comment><USER36> I'm with you. But, we should see to evolve nuclear reactors to a point that they can be abandoned at any point of time without any catastrophy at all. If we have to sacrifice efficiency to do so, let's solve the issues we agree on and then push on the efficiency front towards or even beyond the previous outputs.

</comment></comment><comment><USER18> I posted this about David MacKay's book "Sustainable Energy - without the hot air", which advocates nuclear energy, to a discussion about solar panels, and llukas pointed out that solar power development has exceeded MacKay's expectations, and linked to a page with updates, and dane-pgp also posted some interesting criticisms and links.

If Solar Panels Are So Clean, Why Do They Produce So Much Toxic Waste? (forbes.com)

[https://news.ycombinator.com/item?id=18751049](https://news.ycombinator.com/item?id=18751049)

[https://www.forbes.com/sites/michaelshellenberger/2018/05/23...](https://www.forbes.com/sites/michaelshellenberger/2018/05/23/if- solar-panels-are-so-clean-why-do-they-produce-so-much-toxic- waste/#2a1c244a121c)

[https://news.ycombinator.com/item?id=18751049](https://news.ycombinator.com/item?id=18751049)

DonHopkins on Dec 24, 2018 [-]

The late David MacKay's book "Sustainable Energy - without the hot air" is available free online:

[http://www.withouthotair.com/](http://www.withouthotair.com/)

Here's the chapter about solar energy:

[http://www.withouthotair.com/c6/page_38.shtml](http://www.withouthotair.com/c6/page_38.shtml)

Here's a 1000 word synopsis he wrote for his talk to the House of Lords:

[http://www.inference.org.uk/sustainable/book/SUMMARY](http://www.inference.org.uk/sustainable/book/SUMMARY)

David MacKay also invented the Dasher text input system:

[http://www.inference.org.uk/dasher/](http://www.inference.org.uk/dasher/)

llukas on Dec 24, 2018 [-]

Very good book but tech went lot further than David expected in many places (ie. solar power efficiency vs price).

This page tried to keep it updated:

[https://www.carboncommentary.com/blog/2017/3/30/l6qcqgoedse1...](https://www.carboncommentary.com/blog/2017/3/30/l6qcqgoedse1wmjjz87t09usoq6jva)

dane-pgp on Dec 24, 2018 [-]

David MacKay has done some great work, but I feel I need to present some of the criticism he has received, for balance. In particular, there is a perception that he is biased towards nuclear energy (understating its drawbacks, while also being unnecessarily dismissive of renewables).

People can consider these articles for themselves:

[https://www.thetimes.co.uk/article/professor-david-mackay- br...](https://www.thetimes.co.uk/article/professor-david-mackay-britain-must- go-nuclear-to-control-climate-bgtjk0j6wh9)

"Professor David MacKay: Britain 'must go nuclear' to control climate"

[https://www.theguardian.com/environment/2016/may/03/idea- of-...](https://www.theguardian.com/environment/2016/may/03/idea-of- renewables-powering-uk-is-an-appalling-delusion-david-mackay)

"Idea of renewables powering UK is an 'appalling delusion' – David MacKay"

The latter, from 2016, includes the line:

"There is this appalling delusion that people have that we can take this thing that is currently producing 1% of our electricity and we can just scale it up..."

For reference, according to:

[https://www.independent.co.uk/environment/wind-solar- overtak...](https://www.independent.co.uk/environment/wind-solar-overtake- nuclear-electricity-source-uk-first-time-renewable-energy-a8281656.html)

"Renewables' share of electricity generation shot up to 29 per cent, while nuclear sources accounted for around 21 per cent."

benj111 on Dec 24, 2018 [-]

I think when he was writing, solar wasn't competitive, and neither really was wind. With that in mind nuclear had a place in zero carbon fuel mix, we should perhaps be thankful that other renewables have made such amazing strides.

He isn't around anymore to update his book, but I'm not sure it matters. For me anyway, it was the approach not the specifics that mattered.

Id rather be reading MacKay's 10 year old book for advice rather than those people who think banning straws is going to save the world.

<comment><USER24> That was the book that assumed solar included very large usage of land for biomass, right? Biomass is extraordinarily inefficient at converting sunlight to usable energy, so it's no surprise he concluded the UK could not be solar powered.</comment></comment>


The Coming Change in Monetary Policy - <AUTHOR> http://avc.com/2015/06/the-coming-change-in-monetary-policy/ <comment><USER3> They will raise rates very slowly this time. Greenspan even admitted that jerking the rates up was partly to blame for the 2008 crisis. They put rates near zero, then jacked them up a few years later. Then had an oh-shit moment and dropped them to zero.

[https://en.wikipedia.org/wiki/Federal_funds_rate#/media/File...](https://en.wikipedia.org/wiki/Federal_funds_rate#/media/File:Federal_Funds_Rate_1954_thru_2009_effective.svg)

Mortgage rates follow but don't match the fed funds rate. Home prices vary inversely with interest rates. Falling rates generally mean rising home prices. So with rates near zero, there is only one thing for housing prices to do - fall when they raise rates. The only hope is that inflation will balance the fall in home prices caused by raising the rates. Otherwise, prepare for crisis part II.

<comment><USER4> Another major concern in 2008 was how little equity homeowners had in their property. If they had financed 100% of their loan, had exotic loans, or paid interest only, etc., then they weren't actually losing any money to walk away from a property. We're now seven years on, which means a hypothetical homeowner who financed 100% in 2008 may now hold about a 15% equity stake. That home could lose 15% of its value and the owner could still sell it to pay off their loan.

<comment><USER5> [http://www.calculatedriskblog.com/2015/03/zillow-negative- eq...](http://www.calculatedriskblog.com/2015/03/zillow-negative-equity-rate- unchanged.html)

"In the fourth quarter of 2014, the U.S. negative equity rate – the percentage of all homeowners with a mortgage that are underwater, owing more on their home than it is worth – stood at 16.9 percent, unchanged from the third quarter. Negative equity had fallen quarter-over-quarter for ten straight quarters, or two-and-a-half years, prior to flattening out between Q3 and Q4 of last year.

While this may not seem very notable (after all, overall negative equity didn't go up, merely flattened out), this represents a major turning point in the housing market. The days in which rapid and fairly uniform home value appreciation contributed to steep drops in negative equity are behind us, and a new normal has arrived. Negative equity, while it may still fall in fits and spurts, is decidedly here to stay, and will impact the market for years to come. "

<comment><USER4> The peak of negative equity was in 2012 [1], and it has since fallen to a level more on par with historic norms; chart 5 in [2] shows that pre-2004 vintage loans experienced mid-teens negative equity rates.

Even so -- the raw percentage of homeowners experiencing negative equity is not a good predictor of the impact of raising interest rates and falling housing prices. Negative equity doesn't trigger a distressed mortgage, or force an owner to abandon the property. But _positive_ equity _does_ have an anchoring effect.

[1] [http://www.zillow.com/research/zillow-negative- equity-q3-201...](http://www.zillow.com/research/zillow-negative- equity-q3-2013-5801/)

[2][http://www.newyorkfed.org/research/epr/09v15n1/0907haug.pdf](http://www.newyorkfed.org/research/epr/09v15n1/0907haug.pdf)

<comment><USER5> > Negative equity doesn't trigger a distressed mortgage, or force an owner to > abandon the property.

Disagree. As soon as a property has negative equity, a homeowner begins to contemplate strategic default. As their property tips ever more into negative equity territory, the benefits of default rise dramatically, whether the mortgage is recourse or not.

Don't take my word for it; the Federal Reserve did a study on it:

"Our results suggest that while strategic default is fairly common among deeply underwater borrowers, borrowers do not ruthlessly exercise the default option at relatively low levels of negative equity. About half of defaults occurring when equity is below -50 percent are strategic but when negative equity is above -10 percent, we find that the combination of negative equity and liquidity shocks or life events drives default. Our results therefore lend support to both the "double-trigger" theory of default and the view that mortgage borrowers exercise the implicit put option when it is in their interest."

[http://www.federalreserve.gov/pubs/feds/2010/201035/201035pa...](http://www.federalreserve.gov/pubs/feds/2010/201035/201035pap.pdf)

<comment><USER4> Your quote from the Federal Reserve directly supports my statement; it just quantifies that ~10% negative equity + a liquidity shock is a good predictor of default. Put another way, I was suggesting that there is hysteresis in the response to negative equity. That said, my statement would have been much less confusing if I had explicitly acknowledged the connection. Perhaps, "Negative equity doesn't _immediately_ trigger a distressed mortgage, or..."

Furthermore, my central claim -- that the total fraction of houses with negative equity is a poor predictor of default risk -- is unaffected either way. It would be more useful to know the distribution of negative equity for those houses, or summary statistics like the mean or median negative equity. (If we knew that the median negative equity were 10%, then we could predict that about half of the 16.9% of all properties that are upside down are at risk of default if they experience a liquidity shock.)

<comment><USER5> My mistake then! Here is more data. I believe anyone in the 100% to 120% LTV will stay current on their mortgage; anyone else above 120% LTV? Highly possible they'll default.

From Zillow:

"Nationally, of the homeowners who are underwater, around half are only underwater by 20 percent or less, which is to say they are close to escaping negative equity. (Figure 2) On the other hand, 1.9 percent of all owners with a mortgage remain deeply underwater, owing at least twice what their home is worth. Of the largest metro areas, markets with above average rates of deeply underwater homeowners include Las Vegas (3.8 percent), Chicago (3.8 percent), Atlanta (3.5 percent), Detroit (3.3 percent) and Miami (2.8 percent)"

Almost half of the borrowers with negative equity have a LTV of 100% to 120% (8.2% in Q4 2014). Most of these borrowers are current on their mortgages - and they have probably either refinanced with HARP or their loans are well seasoned (most of these properties were purchased in the 2004 through 2006 period, so borrowers have been current for ten years or so). In a few years, these borrowers will have positive equity.

The key concern is all those borrowers with LTVs above 140% (about 5.2% of properties with a mortgage according to Zillow). It will take many years to return to positive equity ... and a large percentage of these properties will eventually be distressed sales (short sales or foreclosures).

</comment></comment></comment></comment></comment></comment></comment><comment><USER6> As Fred says, the Fed has been telegraphing their rate increases for a while, which means that the market has largely priced them in. For example the market basically did not react at all to Yellen's press conference last week.

The whole point of the Fed deciding to raise interest rates is that it means that the Fed believes that the economy is strong enough to start removing fiscal support. If they are right, then there should actually be not a huge effect on valuations.

<comment><USER7> " [...] which means that the market has largely priced them in." ... In theory yah.

</comment></comment><comment><USER8> Not addressed: that artificially low interest rates have a ruinous effect on savings, and therefore affect old people disproportionately.

</comment><comment><USER9> Does this mean that insane valuations (like Uber) will either get reduced, or start to make sense?

<comment><USER10> It may take a dive, but I doubt it will be by that much - Uber makes money which is always a good argument for having a high price.

That said I seem to remember Sequia talking about the party being over years ago and utterly nothing came of that.

<comment><USER11> Link to Sequoia's presentation: [http://www.scribd.com/doc/73886447/R-I-P- Good-Times-10-7-08-...](http://www.scribd.com/doc/73886447/R-I-P-Good- Times-10-7-08-Final)

</comment></comment></comment><comment><USER12> If you really want to understand what's happening in the economy, with advance notice, read [http://mises.org](http://mises.org). That site has hundreds of economics books for free (great reading!) but also regular news articles.

For instance, in 2001, before 9/11 (IIRC) there was an article there about how as a response to the DotCom boom the low interest rates plus changes in the CRA would be causing a housing boom and bubble over the next decade.

In 2001 there was no boom, and after 9/11 the economy was bad. But that advice proved true, and gave me 6 years to time to invest based on the housing bubble hypothesis (alas I never found a way to short houses and wasn't the kind of person who could have bought CDOs against the foolishness) ... and I got out of the market very near its peak in 2007.

Unlike what politicians would want you to believe, Economics is a science and the consequences of actions in economics are pretty close to those in physics. They can pretend like one president or another is responsible. (the Housing Bubble was the result of the actions of Clinton and Bush, and actually Obama who was a lawyer in the lawsuit that claimed "lending only to people who can afford to repay the loans is racist"... and like economics predicted (That banks want money and will disregard race) in the end it turned out that they weren't being racist but were lending based on likelihood of repayment... and the winners in Obama's class action lawsuit got their loans... and defaulted.)

The consequences of the terrible actions in 2008- from the bailouts to the giving of one private bank (the federal reserve) the power to forcibly merge other banks (without regard to conflict of interest-- say one of the owners of the federal reserve wants to buy a smaller bank, he can just use the fed to force it to merge with him on terms he agrees to.... no way this will be abused, right?) .... these consequences are still playing out and have made the game much more dangerous than 2008.

One thing I've noticed is that the "Black Swan" events-- like 2008 which people said "Tehre's no way you could see this coming" despite the popular sentiment in 2006 being "there's no way there's a housing bubble!" showing that people did, in fact, see it coming-- really are pretty predictable at least in terms of risk.

And the risk of a Black Swan has only been going up given the past 3 decades of irresponsible governance (under congresses and presidents from both parties.)

Don't look to VCs for economic perspective. They don't have it. All they know how to do is raise funds and collect a carry. Don't look to political hacks like "A housing bubble would be good for the economy" Paul Krugman, or any politicians.... look to actual economists. (Even Keyenes disagrees with the monetary policy we've been following for these decades, even though the politicians claim its his idea. IT isn't, it's not what he said at all.)

The current bubble is the dollar, and they can't raise interest rates without popping it. Whether they intend to pop it I don't know.

<comment> vezzy-fnord _Unlike what politicians would want you to believe, Economics is a science and the consequences of actions in economics are pretty close to those in physics._

Huh. Austrian economics argues _the exact opposite_ , which is generally correct for most things at a higher level than chemistry, especially something as stochastic as economic modeling.

 _One thing I 've noticed is that the "Black Swan" events-- like 2008 which people said "Tehre's no way you could see this coming" despite the popular sentiment in 2006 being "there's no way there's a housing bubble!" showing that people did, in fact, see it coming-- really are pretty predictable at least in terms of risk._

Austrian economists are wary of making predictions in general, which goes hand in hand with their overall distaste for econometrics. Not to say that the more naive ones don't yell about incoming collapse all the time.

 _Even Keyenes disagrees with the monetary policy we 've been following for these decades, even though the politicians claim its his idea. IT isn't, it's not what he said at all._

We've come a long way since Keynes. Like we've debunked the marginal propensity to consume since then, for instance, despite the fact that most laymen and politicians keep making the same fallacy.

<comment><USER13> A lot of economists will be very surprised to hear that MPC has been "debunked." Last time I looked it's still considered a mainstream idea - mainstream enough to appear in introductory econ texts, anyway.

Steve Keen makes the - IMO interesting - point that there are different kinds of consumption, and lumping consumption under a single Benthamite label is a gross oversimplification.

But MPC is a simple measure of economic freedom. It's not what you spend your extra earnings on that matters, because - unless you're burning banknotes - <USER2> all goes towards increasing GDP anyway.

Where things get fuzzy is a lack of appreciation for the fact that spending measures current economic activity, but savings, credit, and investment all measure faith in future economic activity.

Because faith is based on an irrational thing called "sentiment", you have a huge chunk of the economy based on hope, fear, and desire - which is maybe not the most practical and useful way to make the economy work for everyone.

<comment><USER14> GDP is a weak measure of prosperity/utility. War had very high GDP, but has very low utility. It doesn't burn banknotes, but it burns everything banknotes buy, so the result is similar. The only thing economically good about war is that it gives political cover for deficit spending, which encourages productive activity (which GDP measures poorly)

</comment></comment></comment></comment><comment><USER15> Party is over.</comment>


Why Roslyn is a Big Deal - <AUTHOR> http://joshvarty.wordpress.com/2014/03/09/why-roslyn-is-a-bigdeal/

<comment><USER2> "Most people familiar with Roslyn understand that it marks the first real change in compilers in recent memory." and then goes on to describe llvm...

<comment><USER3> Also old news in Javaland; I'd nominate Eclipse's ECJ as the great innovator.

<comment><USER4> Isn't ECJ just an incremental compiler?

As far as I know, there is nothing like Roslyn in Java.

</comment></comment></comment><comment><USER5> It's interesting to see what doors Roslyn can open for us in the craft of software development. And I'm also really looking forward to seeing some of Bret Victor's ideas implemented [1]

[1] [http://ermau.com/making-instant-c-viable- part-1/](http://ermau.com/making-instant-c-viable-part-1/)

</comment><comment><USER6> Seems pretty cool, and it'll definitely be interesting to see what people will do with it.

However, some parts of this (introspection and modification of ASTs) are already possible in other languages, such as Scala (through the presentation compiler and the macro system) or even Smalltalk (which doesn't have code in text files).

</comment><comment><USER7> Aaha! So THAT is how they made dotnetfiddle. I've got to get into this.

<comment><USER8> scriptcs, too: [http://scriptcs.net/](http://scriptcs.net/)</comment></comment>


Git from the bottom up [pdf] - <AUTHOR> http://ftp.newartisans.com/pub/git.from.bottom.up.pdf <comment><USER2> Linus is a hacker, not an academic, so there is no clean high-level abstraction of git; no _algebra of git_. OTOH, it is ridiculously fast and ridiculously useful (for Linus, and for anyone who goes to the trouble to understand its execution model).

I think there'd be a paper or two in attempting to infer an algebra of git. There wouldn't be a clean one, so you could propose modifications of git to facilitate a clean algebra, in the way that physicists and biologists hypothesize laws to explain the observed universe.

<comment><USER3> I disagree, this paper outlines the algebra quite clearly. A series of commits in Directed acyclic graph layout, with the ability to modify this graph however you please.

<comment><USER2> Yes, that's the underlying execution model. The approach of the article "git from the bottom up" is that one needs to understand this in order to use it, rather than being able to understand it in terms of the UI. Taking a lateral step towards the ease-of-adoption and learning of a tool, there's an intriguing aspect of git that I want to articulate further:

 _To understand part of git, you must first understand all of it._

Several aspects of git are interconnected; some design decisions don't make sense in isolation; and you need to know the detailed and apparently incidental behaviour of some commands in order to be able to use them. It's an _expert tool_.

As an ideal (perhaps unrealizable), a tool has a learning curve, with a series of "closed" subsets of functionality, such that each subset is complete in itself. Learn a subset, and you are a master of that aspect. (I'm using "closed" not in the strict mathematical sense of the results of operations being in the domain of their operands, but to mean that you don't need to go outside that subset). It's a similar concept to minimizing coupling between modules.

e.g. you can play UT without knowing about alternate fire; you can using basic reg exps without knowing all the weird clever stuff; you can write C in C++. Languages especially have this quality - you can write procedural code in an OO language, you can use one library without using all the libraries.

Git doesn't do this.

As an example, if you want to change the message of a commit, you need to create a new commit with the new message. This immutability is important (I infer) so that other instances of the repository can remain in sync (the new commit will have a different hash from the old one (with a very high probability), because the message is different). Thus, the apparently simple operation of "changing a message" is interconnected with the distributed nature of the tool.

If you want to change the message of the _first_ commit (at the root of the DAG), it is more complex. First you 'change' the message of that first commit, via making a copy (as above) - but the rest of the DAG is still pointing to the old root, not your new one. Therefore, you _rebase_ (disconnect and reattach a node) the child from the old root to the new root. Finally, _rebase_ does not actually disconnect and reattach - it makes copies (immutability again). You haven't changed the old DAG, but created a new one.

Changing a message is not as simple as one might expect.

An additional problem is that the documentation (man pages) doesn't always define terms, and not always clearly. But they are obvious to someone who already knows how it works (and doesn't need the man pages, except for reference). BTW: I found that some terms are defined at the end of the options section (the definitions aren't always complete or unambiguous, but they help); and it's helpful to think of the _type_ of the arguments (though the man pages don't use that term)

Please don't take this as a disparagement of git - it is an expert tool, tackling and solving some extremely difficult problems of a master. I understand it took Linus years of coping with the problem, and of having the brilliant example of _bitkeeper_ before he could whip up git overnight. I've invested quite a bit of time to reach the (limited) understanding that I have so far, and each step teaches me more about the problems and solutions of serious distributed version control. It is complicated because the problem is complicated; and it _remains_ complicated because a master already grasps the problem, and can cope with that complexity.

<comment><USER3> your example is a great point, and something that just isn't practically possible. Changing history is impossible once it's been pushed without making chaos for anyone else that uses your code. And in git, commit messages are part of history, not just annotation to it.

perhaps in other ways though, the closed subsets do exist. as long as what you want to do isn't "complex" in git. things like commits, pushes etc.

Most importantly I would say is the fact that branching merging and sharing that branched history _is_ a closed subset. If you only ever use the commit/push/fetch/merge commands (with pull being the same as pull+merge), and perhaps local branching as well, then you have a relatively simple tool for sharing code and history of that code. by far you don't need to understand the plumbing to work within that work flow, and I think I could explain it to someone in a short hour or so of explanation and example.

</comment></comment></comment></comment><comment><USER4> It took a lot of time for me to really _get_ Git, and reading this document I finally got it. Genuinely recommended.

I also like PeepCode's "Git Internals" <http://peepcode.com/products/git- internals-pdf> .

</comment><comment><USER5> Being new to git I found this document very helpful. _git stash_ was new for me, and I am glad to have learned it.

</comment><comment><USER6> This looks very helpful. I've had some trouble migrating from a GUI Subversion client to command-line Git.

<comment><USER7> Everyone I know seems to have. :-)

Personally, I'm a bit disgusted with the git hype. I love the git idea but the interface is horrible.

<comment><USER8> By interface, I assume you mean git's command-line interface? I agree; it's terrible.

My impression is that projects like grit are far enough along that it should be possible to build an entirely new git front-end/porcelain on a clean technology stack. Something with more sane exposure. I don't know if anybody's actually working on something like this right now?

<comment><USER9> David Roundy (author of Darcs, a DVCS that predates git and has one of the nicest command-line interfaces) is working on a git porcelain that has the same user interface and semantics as Darcs:

<http://github.com/droundy/iolaus>

<comment><USER8> Thanks for the pointer -- I played with Darcs back in the day. This looks interesting.</comment></comment></comment></comment></comment>


GitHub announces 3D File Diffs - <AUTHOR> https://github.com/blog/1633-3d-file-diffs <comment><USER2> Not sure why but from just reading the title I was expecting a new way to view diffs of normal files in some funky 3D mode

<comment><USER3> As much as I don't like meta comments I'm going to have to make one finally, because I think about it every day and just need to get it out there to at least relieve the pressure in my head.

Why is the top voted comment so often about the title of the story? I guess it's because it's the first thing we interact with and it frames our expectations, but man alive, the title is probably the least interesting thing about _any_ article posted to HN but consistently I see top rated comments talking about the title. Maybe it's just lowest-common-denominator.

And it's not that I think the comments themselves are bad, it's just weird to me that I consistently see them at the top of the page.

Apologies for the meta rant, it won't happen again, at least from me. (In fact the reason we have a lot of meta comments might be the same as the reason we have a lot of title-comments making me a bit hypocritical, but I digress.)

<comment><USER4> I think it's because people upvote most often when they share a particular opinion -- and your first opinion is mostly about the title of the article.

For example. I saw the title, clicked through (also opened comments), gave the page a once-over (didn't even read) -- came back here, and saw that first post. I also agree with the guy said, I thought they came up with some amazing new way to view regular diffs in 3D. So, I would have upvoted. Maybe it's just me, but I'm guessing far more people do that

</comment></comment></comment><comment><USER5> This is a small step into a big open field. Collaboration in the hardware design space is moving slowly. It's not even at the SVN/CVS level now.

Has an architect ever forked an open source building? Has an biomedical engineer ever forked a open source prosthetic hip implant? Has a civil engineer forked an open source bridge? They will.

<comment><USER6> Solidworks has had a svn-like system built into it for the last few years: [http://www.solidworks.com/sw/products/product-data- managemen...](http://www.solidworks.com/sw/products/product-data- management/revision-and-version-control.htm)

<comment><USER5> Yeah, but it's probably expensive. The pricing isn't even public: [http://www.solidworks.com/sw/purchase/quote.htm](http://www.solidworks.com/sw/purchase/quote.htm)

<comment><USER7> We have just got SolidWorks PDM at work and I am in the process of setting it up. I know a little about it.

There is two different solidworks PDM products, workgroup and enterprise. We went with workgroup which is cheaper and probably better for smaller teams. Workgroup is about £1000 + £200pa per seat and no cost for the server. Enterprise from memory was about 50% more per seat and you have to a few grand for the server, plus pay someone to 'configure' it for you.

PDM workgroup is actually pretty similar to SVN, you check files out, work on them and check them back in again. Except it understands relationships between files and their meta data so you can check out an assembly in its 'as built' state and it will checkout the correct old version of the parts.

Enterprise goes much further and creates work flows for you company. Documents go through different stage gates with different people being able to make changes and approve them. It is very much design for large teams with rigourous QA. It also appears as a network drive with some nice shell extensions on Windows.

Suprisingly neither of them have a Diff built in, although solidworks does itself have that sort of tool.

As a market it is definitely ripe for disrupting, although to succeed there would need to be tight integration with the software packages (solidworks, creo, inventor etc)

I anyone on here is looking to do something in this area I would love to hear from you.

<comment><USER8> I hear you.

But as we all know it's been a ripe area for disruption since the 1970's. :)

At the moment it's less to do with software as it is to do with the way we share the resultant information, of which there are emerging international standards. MCAD is not my speciality but I don't think I've seen a standard for handling parametrics. Unfortunately closed standards are hard enough to get governments and industry to adopt let along open ones.

If you want a solid object modeller with parametrics that's open source and you can compile yourself, check out BRL-CAD.

</comment></comment></comment></comment></comment><comment><USER9> I would unironically love a GitHub developer's conference where they get to do a keynote presenting all the awesome features they churn out at record pace.

I feel more people who aren't unrepentant nerds should get to see what these guys (and gals) are doing.

\---

 _EDIT:_ They could just do something simple at a local, informal event (say a bar) with a few dozens of people. it doesn't have to be something huge.

It'd also be a great way for everyone at GitHub to get some training in making and delivering presentations, and it's great to have on your resumé.

I'd definitely want to try something like that out as a CEO, and I imagine it'd make it even more fun to work at a playful place like GitHub.

<comment><USER10> They did a conference a long time ago: CodeConf. It was a blast.

</comment></comment><comment><USER6> A neat feature but I wish they had support for 3d source file types instead of exported "binary", for lack of a better term, file types. If you wanted to truly open source your mechanical project you'd need to add an extra step to delete the previously exported STL and export a new one every time you commit. You also lose color/texture data when you export to STL.

<comment><USER10> STL files are the source file for most 3D printers, which is probably the vast majority of 3D files on GitHub, I'd imagine.

<comment><USER6> Yes, it's the output from a CAD tool and used for 3d printing but STL is a binary file type and not easy to edit. Committing STL files to a repo is analagous to commiting EXE files instead of source code or PDF files instead of TEX.

<comment><USER11> What about ASCII STL files? I'd say they're "pretty easy" to edit. I wouldn't want to write an entire one, but I've tweaked values in one before.

<comment><USER6> What I mean is ease of editing in a typical CAD tool: Solidworks, AutoCad, Sketchup, etc. STL is imported as a solid blob and you lose all the individual features from the source model.

</comment></comment></comment></comment></comment><comment><USER12> Cool, that's one wishlist feature down.

[https://news.ycombinator.com/item?id=5519676](https://news.ycombinator.com/item?id=5519676)

(hehe "Wow. That's a stupidly large amount of work, barfed out with seeming ignorance to the cost of implementation." Yes, well.... libffi helps out a lot.)

<comment><USER13> Sometimes, open source actually helps mitigate the work issue.

:)

</comment></comment><comment><USER14> This is nice, but, it feels like a splashy visual tool that took a lot of dev resources and will only be used significantly by a small user base. I personally feel that they would make a lot more users happy by spending a little on improving their existing code diff interface. Some ideas:

\- make the context button "..." for the code diff actually do something

\- side-by-side diffs

\- syntax highlighting

<comment><USER15> They're doing it before a significant user base grows that precipitates a github-for-3D startup. Building this feature also fosters growth of open source 3D modeling and printing, which is a net positive thing.

<comment><USER16> It is a net positive, I just wish they would focus more on their core users. Their basic code diff tool could use a lot of love to make it on par with the diffs generated from other tools.

</comment></comment></comment><comment><USER17> They had diffs for typefaces at some point: [http://i.liketightpants.net/and/how-it-has-come-about- that-c...](http://i.liketightpants.net/and/how-it-has-come-about-that-code- hosting-site-github-offers-visualisations-of-typeface-development)

I originally suggested it to them, and was kind of sad that they did away with this feature—that being said, it makes sense they want to streamline their platform.

Then, I've found it hard to create these kind of things myself, selfhostable FOSS solutions like Gitorious don't offer enough possibilites to build upon (no real API)

</comment><comment><USER18> I wonder if they have any plans to add support for other 3D filetypes (.ma, fbx, obj, etc)? It would be great to use this with more organic VFX-type models where some of the intricate detail updates are hard to discern at first glance.

Blue sky thinking, it would even be awesome to have something like this as a plugin in Maya where we could load in a previous version of the model and onion-skin between them with a slider like in the demo.

Going to check out the links in the article. Very cool!

</comment><comment><USER19> This is so great! I'm always working with STL's and always asking myself, "what's different in these models?" I'd love to see meta data and other 3D file types like VRMLs or SolidWorks parts included in the future as well.

<comment><USER12> SolidWorks seems really difficult to implement unless you're licensing a Windows server + SolidWorks software licenses or running wine and hacking up their dlls.. I would be curious to hear ideas on how to do it.

<comment><USER19> This is true. I think it would require working directly with SolidWorks to make it happen since everything of theirs is so proprietary.

</comment></comment></comment><comment><USER20> Wow, I love how Github is transforming into the a great tool maker for the digital world.

</comment><comment><USER21> This certainly makes Github a viable option compared to Thingiverse. Hopefully we'll see OpenSCAD file support in the future!

</comment><comment><USER22> Meanwhile, still no side by side diffs :(

<comment><USER23> GitHub: Doing the Work That Matters(tm)

</comment></comment><comment><USER24> And.... they're down.

edit: back up yay!

<comment><USER13> This is why we can't have nice things.

</comment></comment><comment><USER25> This is great! Historically, studios has shunned dvcs; github moving in his direction - even if motivated by personal 3d printing projects - may open some eyes and change some minds.

<comment><USER26> That would be great ... but I think the bigger thing is, just as open-source software has taken over much of the Internet, this is a critical step in helping open-source hardware take over ... well, everything else.

</comment></comment><comment><USER27> In a similar vein: [http://3drepo.org/](http://3drepo.org/)

</comment><comment><USER28> A friend and I built [http://www.bld3r.com](http://www.bld3r.com) as a vastly more open 3d file sharing platform than thingiverse. We welcome this move, as we prefer files to be hosted on open platforms like github. I thought I'd plug the site for anyone who wants an alternative. We are still in beta, but are finishing that soon.

<comment><USER12> I wouldn't call github an open platform. Maybe you meant gitorious or cgit or gitweb?

<comment><USER28> I mean open in the sense that they have clear terms such that they don't effectively own your content. In building a 3d printing social network, not having to trust us was important to our design.

<comment><USER29> If github would make import/export a lot easier than it is today it would qualify as an open platform. Right now only the 'git' part of it is open (and git was open all along).

<comment><USER30> you mean besides all of the APIs they expose?

</comment></comment></comment></comment></comment><comment><USER31> Mike Skalnik (post author) will be at RobotsConf [http://robotsconf.com](http://robotsconf.com) and available to talk about this and other similar initiatives going on (make-me, etc). Still a few tickets left. Saw a couple comments about conferences and such, figured it would be worth mentioning.

</comment><comment><USER32> I wonder what percent of Github users store 3D files, to make this worth the effort. I imagine less than 0.5% if that?

<comment><USER33> With 3D printers becoming more common, I think they are positioning themselves for the future, rather than fulfilling a strong demand that exists today.

</comment></comment><comment><USER34> I haven't seen anyone mention binary space partitioning since using quake3's bsp toolchain a few years ago.

[http://www.mralligator.com/q3/](http://www.mralligator.com/q3/)

<comment><USER35> I'm wondering why they ended up using BSP as a data structure for boolean mesh operations. Is there an advantage over Octrees I'm not aware of in this case?

<comment><USER35> Aparently, yes: [http://onlinelibrary.wiley.com/doi/10.1111/j.1467-8659.2009....](http://onlinelibrary.wiley.com/doi/10.1111/j.1467-8659.2009.01609.x/abstract)

<comment><USER35> Just for the record: The original paper in which they found that merging the trees of binary space partition yields set operations: [http://www.cse.yorku.ca/~amana/research/bsptSetOp.pdf](http://www.cse.yorku.ca/~amana/research/bsptSetOp.pdf)

</comment></comment></comment></comment><comment><USER36> I wonder if this feature is targeting the growing consumer 3D printing market. Being the goto place for collaborating, and versioning, 3D designs would be a good play for them.

</comment><comment><USER37> It could be great to have something like this for SVG!

</comment><comment><USER38> Can we have side-by-side diffs of code first, please?

<comment><USER39> Yes. With maybe support for viewing full files instead of just the diffs. None of the Chrome/Browser Extensions really do this.

</comment></comment><comment><USER40> this is great, comes just in time as I'm desiging a custom 3d scientific part. [https://github.com/ityonemo/imsocultured/blob/master/device....](https://github.com/ityonemo/imsocultured/blob/master/device.stl)

<comment><USER41> What's it do - presumably it's a connector, glass rod to rubber hose (ie tubing)?

Edit: ah, found this [https://github.com/ityonemo/imsocultured/commit/08b57107b757...](https://github.com/ityonemo/imsocultured/commit/08b57107b75761f2d8d274b6ac8d17bbf1bcd8ce) \- "oral microbiome community culturing apparatus" \- so the complete apparatus is for culturing whatever bacteria and such you find in your mouth in a mini biome?

<comment><USER40> the oral microbiome model system is an anaerobic community; this apparatus allows you to connect a pH probe using the screw side for continuous pH monitoring (we already have a device that does this; but it's suboptimal for other reasons too) plus a second port that will be fitted with a septum to draw gas, draw samples, or add to the medium.

</comment></comment></comment><comment><USER42> Does anybody know of a 2D diff for diagrams? a lot like [http://www.diffplug.com/](http://www.diffplug.com/)

</comment><comment><USER43> This is very cool. Rather obviates my own site. ([http://fabfabbers.com](http://fabfabbers.com)) Ho hum ;)

</comment><comment><USER26> This is aweomse. It's a small, but critical step in making the design for things versionable and forkable.

</comment><comment><USER44> Hmm, github.com is throwing a 500 error at the moment. I wonder if this is somehow related?

</comment><comment><USER45> In other (possibly related) news, the entire website is now throwing an error.

</comment><comment><USER46> And they still didn't implemented a visualization for SVG ?

</comment><comment><USER47> Sometimes more is less

</comment><comment><USER48> awesome addition..althgh am little confused looking for changes..but revision wise looks quite descriptive....

</comment><comment><USER49> Now I'm feeling in the future

</comment><comment><USER50> Oh Github, you're wonderful</comment>