cmsmith

If it is truly a 1G maneuver, then the answer would be:

    9.8 m/s^2  *  (1-cos(\theta))

Where \theta is the angle off of level flight. So when you are fully inverted, the plane would be accelerating at 2 G's downward (one to feel like you were in free-fall inside the cabin, and then one more to push you back into your seat).

In the film, the roll takes about 12 seconds. A quick numerical integration shows that by the end of the turn you would be 700m lower than you started, and have a downward velocity of 120m/s. I'm not a pilot, but I'm sure that the best practice here would be to start with an upward velocity, and not to really keep 1G throughout the turn. Those could both lessen your loss of altitude.

>This is of relevance to the question because there are a lot of people who think the bombing of Hiroshima is justified, but when you get into the question of Nagasaki it gets more murky. Three days is not adequate time for a government to make a major decision; it is not really even adequate time for a government to assess what has happened (whether it was really an atomic bomb, what the damages were like, etc.).

TFP

The article's focus on the temptation for collusion seems overblown to me. Yes, the interests of Pepsi+Coke's index shareholders are served if the companies avoid cannibalizing each other's value, but those shareholders have no way to apply pressure on the companies to do that. Index shareholders do not vote, and by their nature cannot sell shares of a company that they are displeased with.

The other concern seems more well-placed. An efficient market requires that shareholders buy and sell companies in response to performance. Index funds buy and sell companies in response to the performance of the fund, or the market as a whole, or some other arbitrary factor. If 50% or 80% or 90% of a company is owned by 'dumb' funds, what does that do to their market value? And how could that affect the choices of the CEO?

>Apparently the normal 30,000 feet cruising altitude is not higher because the reduced oxygen levels at higher altitudes impact the gasoline combustion too much.

If this is true, wouldn't it make more sense to bring liquid oxygen up with you to burn with the fuel? That would only reduce your fuel energy density by a factor of 2 or 3, instead of the factor of 30-100 being claimed for batteries.

Of course that would not make sense, and rockets don't become the most efficient way to travel until you are a few times higher than 30,000 ft. But it's useful to put the idea of batteries in perspective.

>Even though HBO and the different TV providers ... The paradox is that Netflix's UI is on average worse than theirs, so my preference of browsing shows on Netflix is not a usability thing, it's an emotional thing.

I would disagree very strongly with regard to Netflix vs HBO UI. HBOgo tries much too hard for a stylish UI, but makes it more difficult to find the things I want to watch. Relative to netflix, their search is very literal and slow, they make no attempt to remember which series I'm rewatching at the time, they can't seem to remember which episode I'm on in that series or what place I paused in a given episode, and the act of trying to jump to a certain time in the video randomly sends me back to the beginning.

Wild guess: Boston is a densely populated city with geographic restrictions (due to the bodies of water around it). The ratio of roads needing to be cleared vs available snow dump areas might be a lot higher than in most places in Canada. Also this was a very extreme snow year for them, so it wouldn't make sense to set aside this much land for snow dumps every year.

This article does a pretty good job of synthesizing why I'm fairly optimistic about climate change despite believing the scientific models. I think that there is an austerity/flagellant meme within environmental circles that states that we have sinned against the environment, and unless the solution involves a heroic self-sacrifice (a la Kyoto protocol) then we cannot be saved.

In reality, all power is solar power, and innovation and market forces will eventually make it more efficient to skip the fossil-fuel middleman. The process could be accelerated by a carbon tax, but it will happen either way.

Responding to the 'Climate is still screwed' point, once we're on track to stabilizing emissions, geo-engineering methods that were dismissed as stopgaps can always be used to hold the climate over for the next century.

1. 3/4 of energy usage is outside the transportation sector.

2. If we switch 3/4 of energy production away from fossil fuels, that will make a huge dent and make renewables even cheaper.

3. Once renewables get cheap enough, it may be cheaper to use a few kWh of solar to produce one kWh of ethanol than it will be to dig 1 kWh of oil out of the ground.

Hence my parenthetical. But since you mentioned amendments, you should look into the Corwin Amendment [1], which was written to preclude its own repeal. The amendment was an all-in attempt to appease the slave states and prevent the Civil War, but was too little and too late. The purpose may be distasteful to the modern reader, and may not have held up in court ('Can Jesus microwave a burrito so hot that he cannot eat it?'), but it's there.

[1] http://en.wikipedia.org/wiki/Corwin_Amendment

And the corporations only hold out for a repatriation holiday because there has been one in the past, and there is a decent chance of there being one in the near future. This is a slippery legislative cliff - once you indicate a willingness to have the holiday, there is no point in not just dropping the tax rate permanently since no one will bring their billions in otherwise.

I wonder what would happen if we passed an un-repealable law (if such a thing existed) that prohibited tax holidays for the next thirty years?

And what happens to the local farmers and roofers when you start shipping in goods and handing them out for free? They have a few more bags of rice but are out of business, and dependent on the next aid shipment for their other necessities. If you want to ship goods, then ship them to the harbor and sell them to local truck drivers for slightly more than the locally produced equivalent.

FYI, and not making any judgement, but this is how they pay for office space and for research that is too esoteric/risky to get external funding.

>Investigators are looking for evidence to demonstrate Uber Canada is violating the tax law by not collecting GST and QST on behalf of its drivers to UberX.

For those who don't want to google translate. Further down it says that this is one of those things Uber doesn't think it has to do because it's an app, not an employer. Quebec seems to disagree and be willing to follow up.

>Many traditional real estate investors are perplexed by WeWork’s $5 billion valuation. With that kind of money, you could build the world’s most expensive skyscraper—One World Trade Center, which at 3 million square feet has roughly the same cumulative amount of office space as WeWork—and still have $1 billion left over.

I'm as dismissive of ridiculous startup valuations as anyone, but this seemed like a weird way to evaluate whether their value was justified.

For reference, here are a couple of other similar statistics:

* There are about 250M Apple devices in use (100M/yr * 2.5 yr lifespan). At 750B market cap, they're worth $3000 per i____ out there, or enough to buy every one of their users an iPhone and still have $500B left over.

* There are about 200,000 active Uber drivers, and they're valued at $50B. That's $300,000 per driver, or enough to buy every one of their drivers a Tesla and still have $40B left over.

80 years is a very long time. It's long enough for two or three generations to grow up, decide what they want to do for their career, notice their dad's career outlook doesn't seem to be on the rise, and go to work in a factory or office.

If the number of truck drivers goes down by 90% in the next 80 years, that would be fine. If it goes down by 90% in the next 8 years, then we'll have a lot of mis-trained ex-truck drivers out there, and that's nothing to scoff at.

This is a bit of a Godwin's switcheroo - where in a historical discussion about Nazis someone will inevitably try to use it to win points in a modern political argument.

>just as much if you are doing it to get to or from your home that is on the road as if you are using it to get between two points that the road happens to connect

This is exactly the point and where the problem lies.

If I live on the road, and am one minute from home, and know that my neighbor's kid likes to ride his bike there - then I'm going to be very careful while driving down it.

If I'm still 30 minutes from home, and using the road to get from one 50mph main road to a different 50mph main road, I'm going to be in a hurry and not respect the residential speed limit as much.

It's human nature, and we can fight it by [1] having police speed traps in every neighborhood (expensive), [2] having speed bumps everywhere (annoying), or [3] adjusting the dials on Waze's optimization function.

I'll be the first to say here that if this effect is actually supported by data, and not just anecdotes, then the councilman has a good point. It's rude and dangerous to cut through residential neighborhoods to save one or two minutes off of your car trip, and mapping apps shouldn't be so quick to direct you to do so.

Pedestrians and cyclists have already lost access to major roads (see invention of jaywalking, etc), but it was OK since we could still take walks in our neighborhood. If every road is open to its full traffic capacity, the only safe place to be is in a car.

A great video, and I noticed the actual linked article here suspiciously follows the exact same structure and examples that Feynman does in his explanation. It would have been nice to acknowledge the fact that the author was probably watching Feynman explain it while writing. But it seems to be a student fun journal, and has made a few hundred people think, so why get upset?

It seems to me that we need the legal system to recognize computer-processed 'big data' as what it is, which is a totally new kind of information that doesn't fit neatly into our existing privacy framework. I think it's good that this technology exists (especially if my car were to be stolen), but I don't see how it would be harmful to the public interest to require police to get a warrant before looking me up.

Of course there are edge cases, where it's hard to draw the line between automated and semi-automated data collection, but that's why we have judges. However, it is troubling that this new technology is hitting its stride during a time which is not great for privacy rights in general.

I don't really get the constant focus of the energy conversation on transportation (< 1/3 of total energy use). If, as you say, we can get solar energy to the grid for less than coal then we're getting close to the time when no one will ever build a coal plant again. Then accelerating economies of scale will cause the price to fall to the point where we're shutting down fossil fuel plants, then to the point where we can make biofuels with solar rather than fossil fuels. Now GHG emissions are down 75-90% with a set of mostly evolutionary technical advancements.

Some environmentalists might not like that process because it's market-driven and doesn't involve any economy-shrinking monastic self-sacrifice (e.g. Kyoto protocol), but it is the reason I'm reasonably optimistic about climate change.

>This is great. More competition is great for me, the consumer. Recently Lyft and Uber have bother offered flat rate rides for $5-7 anywhere in SF. When people ask me how it can be so cheap, I always joke it's because it's a $15 ride but you're splitting it with a venture capitalist.

Competition to reduce prices by increasing efficiency is great for the consumer. Competition to increase market share by offering things at below market value by burning VC money or taking advantage of drivers is fine in the short run, but will have long term problems.[1] The other shoe has to drop, and it will either look like a huge price increase to make these companies profitable or investors losing a bunch of money.

[1] see Groupon et al.

For an extreme example, it's generally considered a bad idea to let people get paid for 'donating' organs. In addition to the practical problem (paid donors are more likely to lie about the condition of the donation), there is an ethical problem - the rich can buy health at the expense of the poor. The actual cost to the donor is related to the chance they might need that lung or kidney in 30 years, and is nearly impossible to quantify or for the donor to give informed consent.

Of course, we do let 18 year olds pose naked for magazines without considering the cost of not being able to run for political office in 30 years. In that case the long term cost is lower and easier to anticipate.

Prostitution is somewhere between those examples. It attracts those without other options, who might not be able to rationally weigh the risks of future medical or psychological harm against a current financial gain.

This is how we express rare events which threaten buildings and bridges. For example, the design level earthquake is chosen such that it has a 10% chance of being exceeded over a 50 year time span (475 year return period). The maximum considered earthquake has a 2% chance of occurring over 50 years (2475 year return period). Fifty years is around the typical lifespan of a structure.

I'm not a very experienced ice skater, but it seems like the flatness of a frozen canal is what makes it nice to skate on. The renderings in the article show frozen over sidewalks, which presumably have at least small slopes to them. Would that make it to challenging to skate long distances?

As a side note, I live in Washington DC where we've had a few weeks of sub-freezing temps, and was out on the frozen C&O canal last weekend. Unfortunately our canal doesn't go anywhere interesting, so it wouldn't make much of a commuter trail.

It's a bit disappointing that they went to the trouble of building a radio into it and didn't just connect it to the NIST atomic clock radio time signal WWVB.

Specifications and annotations on construction drawings are typically all caps, as well. In that context, it looks more official and also more legible at various magnification levels.

Your statement, which is just accepting an internet-rumor as true, contrasts very strongly with the article itself, which is about going to great effort to learn things from hard data.

>It might be nice to live in a world in which poets had the audiences of pundits. And maybe the making of carrot carnations should be an Olympic event.

I take the opposite message from all of this. It is nice to live in a world with such absurd levels of human productivity that people have the education and time for half a dozen "frivolous" hobbies. As a middle class person, I can learn carrot carving and wood turning and painting without expecting any financial gain, then stop at a free local art gallery on my way to hear some free live music at a bar.

Maybe the author thinks that the past was the time of greatness in the arts because the only people who could afford to participate in the arts were great.

I'm not terribly clear on this either, but who exactly will actually have a quantifiable/taxable gain by this demerger? Yahoo the company used to have some Alibaba, and now they will not. Yahoo the shareholders used to have some Yahoo+Alibaba, now they have some Yahoo and some Alibaba. I'm honestly curious, what would be appropriate to tax here?