svedlin

"Assuming there are 500 reactors in use in the world, the above CDF estimates mean that, statistically, one core damage incident would be expected to occur somewhere in the world every 40 years for the 2003 European Commission estimated average accident rate or every 100 years for the 2008 Electric Power Research Institute estimated average accident rate." [1]

"5 serious accidents in 60 years represents an actual historic global annual risk of 1/12 or 8.3% per annum" [2]

"If no cooling system is working to remove the decay heat from a crippled and newly shut down reactor, the decay heat may cause the core of the reactor to reach unsafe temperatures within a few hours or days, depending upon the type of core."

[1] https://en.wikipedia.org/wiki/Core_damage_frequency

[2] https://silo.tips/download/complexity-implies-unknowable-ris...

[3] https://en.wikipedia.org/wiki/Decay_heat

"The sample of premodern populations shows an average modal adult life span of about 72 years, with a range of 68-78 years (Table 4). While modal age at death is not the same as the effective end of the life span, because modal age refers to a peak in the distribution of deaths, it may reflect an important stage in physiological decline. [...]

"Our approach is to assess and analyze available demographic data on extant hunter gatherers and forager-horticulturalists (i.e. peoples who mix hunting and gathering with swidden agriculture). In order to understand the processes that shaped the evolution of our life course, it would be useful to have data on mortality and fertility profiles across populations and over evolutionary time. Given that these data do not exist, we utilize and critically evaluate data on modern groups, as one ‘imperfect lens’ into our past." [1]

[1] Gurven, M., & Kaplan, H. (2007). Longevity among Hunter-Gatherers: A Cross-Cultural Examination. Population and Development Review, 33(2), 321-365. Retrieved from www.jstor.org/stable/25434609

Paper: http://www.cell.com/cell/fulltext/S0092-8674(17)30538-X

"Facial images can be linearly reconstructed using responses of ∼200 face cells."

Only 15 plants in operation have gen-3 passive cooling features and these systems are hardly fail safe.

http://www.ucsusa.org/sites/default/files/legacy/assets/docu...

Downvotes are often attached to inconvenient truths.

The safety of nuclear power is based mainly on wishful thinking. It's the classic folly of chasing short-term cost savings and ignoring long-tail risks.

Professor Grimm's death is a horrible tragedy and a major blow to the community. He will be greatly missed by those who were fortunate enough to know him.

Perhaps institutions that issue grants should require that the receiving organization ban "quotas" from their internal policies.

Condolences to Prof. Grimm's family and friends.

David Mermin wrote a classic paper that illustrates the strange statistical properties of entanglement in a way that doesn't require any physics knowledge.

http://web.pdx.edu/~pmoeck/lectures/Mermin%20shorter.pdf

"A simple device is described, based on a version of Bell's inequality, whose operation directly demonstrates some of the most peculiar behavior to be found in the atomic world. [...] The extraordinary implications of its behavior should be evident to anyone."

A quick search also turned up this animation that demonstrates Mermin's device:

http://faraday.physics.utoronto.ca/PVB/Harrison/BellsTheorem...

As an analogy, I would say a law against counterfeiting money shouldn't apply to things which aren't currencies (like counterfeiting a designer handbag or forging Linden dollars in Second Life...). If the law's purpose is to protect and maintain the legitimacy of certain bedrock instruments the public relies on (cash, real estate titles), I think it's overreaching to extend it to every aspiring virtual (or even gaming) currency...

I think for most people, bitcoin isn't particularly user-friendly yet. By comparison, selling a used phone on eBay or craigslist is pretty easy...

Interestingly, the law specifically includes "foreign currency" in the definition of monetary instrument.

The claim is that the term "funds" included in the definition of "financial transaction" [1] covers bitcoins.

"Funds" typically denotes cash or an asset that is highly liquid, not just anything which can be purchased or sold. Black's Law Dictionary defines "fund" as a "sum of money or other liquid assets established for a specific purpose."

Bitcoins, at this stage, are accepted almost nowhere, recognized by few people as currency, and represent a tiny, highly volatile and risky niche compared to other markets. It's much easier to convert a used iPhone (the top search on eBay) into cash, sell concert tickets on craigslist, or trade collectibles, than it is to convert bitcoins into legal tender, but no one would mistake those goods for "funds." The law isn't intended to cover anything which can be exchanged for cash. In fact, it specifically enumerates the following types of property separately when defining the scope of "financial transaction": "real property, vehicle, vessel, or aircraft." [1]

Because currency is accepted nearly everywhere as payment, the government considers it difficult to police and subject to special penalties when used for criminal ends. Goods like collectibles or bitcoins don't operate at that scale, since they're accepted by relatively few businesses and specialized experts as payment. If a tiny (in comparison to the economy at large) experiment like bitcoin is "funds", then almost any object bought or sold in a zillion stores and marketplaces can be construed as "funds". Any quid-pro-quo could be considered laundering, which broadens the law beyond its intended scope.

The ruling says:

"Ulbricht's alleged conduct is more akin to a builder who designs a house complete with secret entrances and exits and specially designed traps to stash drugs and money; this is not an ordinary dwelling, but a drug dealer's 'dream house.'" [2]

It's not illegal to build a house with secret entrances and compartments. Such a house could be used by anyone who wanted to hide their own possessions on their own property. The fact that someone might use it for illicit purposes doesn't implicate the owner or builder. It must be proved separately that the owner or builder knowingly entered into some kind of agreement with another conspirator to facilitate a crime [3]. Merely hosting a chat room isn't a conspiracy.

Unfortunately, this is just a perpetuation of the same pointless drug war. The prosecution's position is wildly overblown. The alleged activities are akin to operating a motel where a victimless offense might have been committed by a third party.

Drug prohibition is ineffective and is on the way out in favor of treatment and social programs that are more effective.

[1] http://www.law.cornell.edu/uscode/text/18/1956

(4) the term “financial transaction” means

(A) a transaction which in any way or degree affects interstate or foreign commerce

(i) involving the movement of funds by wire or other means or

(ii) involving one or more monetary instruments, or

(iii) involving the transfer of title to any real property, vehicle, vessel, or aircraft, or

(B) a transaction involving the use of a financial institution which is engaged in, or the activities of which affect, interstate or foreign commerce in any way or degree;

[...]

[2] http://www.scribd.com/doc/233234104/Forrest-Denial-of-Defens...

[3] http://conspiracy.uslegal.com/elements-of-the-crime/intent/

An interesting response to the fluid experiments discussed in the article:

http://arxiv.org/abs/1405.0466

Comment on Y. Couder and E. Fort: "Single-Particle Diffraction and Interference at a Macroscopic Scale", Phys. Rev. Lett. (2006)

"Those sent to work in town often had some input in their choice of master and some, like Frederick Douglass, were allowed to live on their own upon surrender of satisfactory wages." [1]

That was probably far from the norm in the 1830's. Frederick Douglass was no less in bondage though.

Later in life, Mr. Douglass said:

"[E]xperience demonstrates that there may be a slavery of wages only a little less galling and crushing in its effects than chattel slavery, and that this slavery of wages must go down with the other". [2]

"Frederick Douglass was an African-American social reformer, orator, writer and statesman. After escaping from slavery, he became a leader of the abolitionist movement[.]" [3]

(upvoted you)

[1] http://books.google.com/books?id=jI4euhKoEaEC&pg=PA65

[2] http://books.google.com/books?id=nOt7au3N8FUC&pg=PA676

[3] http://en.wikipedia.org/wiki/Frederick_Douglass

A nice related puzzle involving a choice between only 2 numbers: http://plus.maths.org/content/mathematical-mysteries-getting...

There's been a lot of discussion about the "completion rates" in online courses. A study in January reported that "only 4 percent of people who register for MOOCs actually finish them" but that "MOOCs still have considerable impact" because "nearly two-thirds got at least something out of the experience." [1]

One possible solution to this - instead of measuring progress against a single completion date, split courses up into a continuous series of milestones or smaller units. A student could cover 1 or more units.

While it's true some courses are considered prerequisites for others, the requirements could be made more granular (e.g.: course B unit 4 requires course A units 5 and 6). Discovering these dependencies could potentially be automated by text data mining the course material.

Courses are designed around a traditional college semester and reflect the amount of material that can be reasonably covered in that time period. However, that constraint shouldn't necessarily be the benchmark for all study programs.

[1] http://hechingerreport.org/content/harvard-mit-despite-low-c...

Paper:

http://www.nature.com/nature/journal/v508/n7497/full/nature1...

http://arxiv.org/abs/1402.4848

The Google APIs Client Generator is an awesome tool that automates this process. It takes a service description and generates a complete client library:

https://code.google.com/p/google-apis-client-generator/

The service is defined in a platform-neutral discovery document, which can be used by any provider:

https://developers.google.com/discovery/v1/reference/apis

There are generators for Python, Java, .NET, Objective-C, PHP, Go, GWT, Node.js, Ruby, and others.

Folks interested in HFT might like this - HFT firm Virtu has a nearly flawless daily trading record over the past 3.4 years:

http://www.businessinsider.com/virtu-hft-only-one-losing-day...

Prospectus:

https://www.sec.gov/Archives/edgar/data/1592386/000104746914...

Looking at the S&P 500, it was positive for 55.8% of the trading days between 2010 and 2013:

http://www.crestmontresearch.com/docs/Stock-Yo-Yo.pdf

BofA had 10 trading day losses in 2013:

http://blogs.marketwatch.com/thetell/2014/02/28/goldmans-tra...

US equity HFT revenues are around $1.3 billion, making it a pretty small niche compared to wider market activity: "TABB Group estimates that US equity HFT revenues have declined from approximately $7.2 billion in 2009 to about $1.3 billion in 2014."

University of Michigan researchers proposed a "centralized call market" to mitigate fragmentation (inconsistent pricing and order handling across different exchanges) and latency disadvantages:

http://www.ns.umich.edu/new/releases/21535-high-frequency-tr...

Haim Bodek discusses how certain exchanges provide special order types that give traders priority over others:

http://online.wsj.com/news/articles/SB1000087239639044398920...

Of course HFT is just a small part of the built-in asymmetries in the markets. Firms exploiting their own clients, conflicted investment advice, corrupt fund management, routinized insider trading, retail bucket shops, hidden fees, payment for order flow, specialist/MM privileges, etc. are all ways that investors and beneficiaries can be disadvantaged.