Pay with Your Fingerprint

 

Samsung’s Galaxy S5 is the first smartphone that can use a fingerprint to authorize payments in stores and online.

• By Tom Simonite on April 2, 2014

Why It Matters

Using fingerprints to authenticate payments could significantly improve security and ease of use.

Anyone with an iPhone 5 can use its fingerprint reader to unlock the device and pay for apps or music in Apple’s iTunes store. Owners of Samsung’s latest flagship device, the Galaxy S5 smartphone, which launches on April 11, will be able to make much broader use of their fingerprints to pay for things. If they visit a website or app that accepts PayPal using the device, they can authorize payments by swiping a finger across the phone’s home button. And PayPal’s own mobile app can be used to pay for goods in some physical stores in the U.S.

Fingerprint payments are likely to be offered on many more smartphones in the near future. The Galaxy S5’s payments system is the first commercial deployment of a new protocol developed by the FIDO Alliance, a group founded by tech companies to end our reliance on insecure passwords (see “PayPal, Lenovo Launch Campaign to Kill the Password”). Indeed, fingerprint readers are expected to become commonplace on mobile devices over the next year or so (see “A Technological Assault on the Password”).

“Today people are having to type in nine-digit passwords everywhere, including one-handed on the subway,” says Joel Yarbrough, senior director of global product solutions at PayPal. This leads many people to use simple passwords and to reuse them across multiple services. This, in turn, makes it easier for criminals to take control of accounts. “Building a smart biometric experience solves both usability and dramatically increases the security level,” says Yarbrough.

To start using your finger for payments on the new Samsung phone, you have to go through a short setup process that registers the identity of the device, based on its cryptographic chip, and links your fingerprint to a PayPal account. Afterward, PayPal’s software asks for a fingerprint swipe anytime an app or site would usually show a log-in screen.

Fingertip swipe: The fingerprint sensor in Samsung’s upcoming flagship smartphone can be used to make PayPal payments online, in mobile apps, and in physical stores.

The FIDO protocol is designed so that a record of your fingerprint never leaves your device. Instead, the fingerprint reader’s output is used to generate cryptographic keys that are combined with those from the device’s cryptographic chip to create a new key that can’t be used to copy the fingerprint used to make it.

The Galaxy S5 is so far the only device to support PayPal’s new FIDO-based fingerprint system, and PayPal is cagey about how soon others might appear. But Yarbrough acknowledges that Samsung isn’t the only gadget maker looking at fingerprint readers. “It’s our impression that a lot of manufacturers are investing time in this technology,” he says. Brett McDowell, senior security advisor at PayPal and vice president of the FIDO alliance, says widespread adoption is “core to the mission of the alliance.”

The FIDO Alliance was launched in early 2013, and now has over 100 members, including Microsoft, Google, device manufacturers such as Lenovo and LG, and representatives of the payments industry such as PayPal and Mastercard. Apple, which has its own fingerprint authentication technology, is not a member of the FIDO Alliance.

Sebastien Taveau, formerly chief technology officer of Validity, a fingerprint sensor company acquired in October by Synaptics, says fingerprint sensors will soon be widespread. Apple and Samsung—the two largest mobile device makers—have now made fingerprint authentication major features of their flagship devices, he points out, and competitors will likely follow their lead. “It is expected that other devices, like tablets, will be incorporating a sensor.”

Most of the core technology needed for biometric authentication has been around for years. Taveau says that cultural change means we are now ready to embrace the idea. “With the transformation of user interactions with content from local to cloud-based and the collapse of trust in existing authentication mechanisms, a real change is happening,” he says, pointing to the public awareness of security flaws heightened by the NSA leaks and the Target debit card breach. “Trust in security and credentials need to be reëstablished.”

 

Does Musk’s Gigafactory Make Sense?

 

Tesla’s audacious plan to build a giant battery factory may mostly be a clever negotiating tactic.

• By Kevin Bullis on April 14, 2014

Why It Matters

Battery-powered cars could play a big role in reducing the world’s use of fuels that cause climate change.

Dream maker: Tesla Motors CEO Elon Musk hopes a massive factory will lead to cheap electric cars.

Lithium-ion batteries are just about everywhere—they power almost all smartphones, tablets, and laptops. Yet Elon Musk, CEO of Tesla Motors, says he intends to build a factory in the United States three years from now that will more than double the world’s total lithium-ion battery production. The plan is still in its early stages, but already four states are negotiating with Tesla in the hope of becoming the factory’s home.

People have come to expect bold plans from Musk. In addition to founding Tesla, he started his own rocket company, SpaceX, which now delivers supplies to the International Space Station. But even for him, the “gigafactory,” as he calls it, seems audacious.

First, Tesla sold 23,000 cars last year. The gigafactory, which would start production in 2017, would by 2020 make enough batteries for 500,000 electric cars. (It would produce enough batteries annually to store 35 gigawatt hours of electricity, hence the name). Second, battery companies normally announce factories only after they’re funded and a site is selected. And they typically scale up gradually. Why announce plans to build such an enormous factory —especially when electric car sales so far come nowhere close to justifying it?

The project seems more puzzling in light of the hard times at other electric car battery factories in the United States. In 2009, President Obama announced an ambitious $2.4 billion grant program intended to launch an electric car battery industry in the United States. That effort, so far, has failed—factories were built, but sales have been poor because electric car sales have been slow. All of the battery makers involved have struggled (see “Too Many Battery Factories, Too Few Electric Cars”), and one, A123 Systems, went bankrupt.

Musk is betting that Tesla can generate a much bigger market for electric cars. To keep the factory humming, he will have to sell more than 10 times as many electric vehicles in a year as Nissan managed last year (and Nissan has sold more electric cars than any other automaker). Musk has some reason for confidence—last year Tesla sold as many electric cars as Nissan in the United States, even though Tesla’s Model S costs two to three times as much as Nissan’s electric car, the Leaf. He seems to be betting that a huge factory will significantly reduce the cost of making batteries, which remain the most expensive part of electric cars. In the ideal scenario, that cost reduction would help Tesla produce a mass-market car similar in cost to the Nissan Leaf or Chevrolet Volt but that, crucially, will be able to go more than twice as far on a charge (the car would also be able to accelerate faster than the Leaf).

Yet it’s not clear that a huge factory would deliver the needed cost reductions. According to a presentation to investors, it would lower costs by 30 percent. Tesla has a good track record for reducing battery costs (see “Driving Innovation”), and even incremental improvements at conventional factories could reduce costs by 15 percent by 2020, says Menahem Anderman, president of Advanced Automotive Batteries. But it’s unclear where the remaining 15 percent might come from.

Economies of scale could help lower production costs to some degree, but Tesla says the unusual design of the gigafactory, with batteries built from raw materials rather than assembled, will also help.

Usually, the components of batteries are made in many different places. Electrolytes are often made at a large chemical plant and graphite electrodes at a plant that also makes graphite for tires and other applications. The electrolytes and electrodes are then packaged into cells at a plant dedicated to cell making, and the cells are assembled into complete battery packs—with cooling systems and electronic controls—in yet another factory.

Musk plans to bring almost all of this under one roof. Raw materials, processed into electrodes, electrolytes, containers and other parts, go in one end; complete battery packs come out the other. The factory will also be able to take old batteries apart to recycle the materials, and Musk even plans to use solar and wind to help power the factory.

Brett Smith, codirector for manufacturing, engineering, and technology at the Center for Automotive Research, says having control over every part of the process could indeed help reduce costs.

Tesla would need to bring in a great deal of expertise to make this work. What’s more, there are benefits to making different parts in different places. For example, it can be cheaper to make electrolytes in a large chemical plant that makes other chemicals, too. Panasonic, Tesla’s current battery cell supplier, benefits from the know-how of workers in Japan, many of whom have decades of manufacturing experience.

“Manufacturers have tried both approaches. Either approach can work,” says Jack Hu, a professor of industrial operations and engineering at the University of Michigan.

But Hu says such a plant would need to be flexible. “It is possible to build a gigafactory,” he says. “The key lies in the how. Battery manufacturing is a complex process involving many steps. If these steps are all dependent on each other, then the gigafactory would be a bad idea: difficult to run, a lot of down times; difficult to identify quality problems.”

Beyond the technical challenges, Tesla may struggle to convince partners to go along with the scheme. The factory would cost $5 billion, with $2 billion coming from Tesla. If Tesla can’t sell as many cars as it hopes, there would likely be no alternative market for those batteries, making it a risky investment. (One potential market, using batteries for storing electricity power on the grid, is still in early stages of development.)

Whether the gigafactory is actually built, and whatever the final factory looks like, the way Musk has been promoting it may prove to be a savvy business move. Announcing the factory at an early stage, and with an ambitious size, could be good for negotiations with states, especially given the proposed size of the factory. Some states are even reconsidering laws that restrict how Tesla can sell cars in their state, which could help open new markets for the automaker.

Proposing such a huge undertaking might also make it more likely that Panasonic or some other partner will later go along with a less ambitious plan—say, a factory to supply 100,000 cars. “Panasonic can’t afford to lose the business,” says Anderman.

And yet, as grand as Musk’s plan is, it’s worth noting that 500,000 cars is still a tiny fraction of the worldwide auto industry. GM sold nearly 10 million cars last year. If electric vehicles are ever to make a dent in the world auto market, then gigafactories will need to become a reality. 

 

What Should I Feed My Dog?

 

By Julie Hecht | April 14, 2014 |  

 

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How wonderful if you could pose this question just once in your dog’s life and receive a perfect answer that would last a lifetime. Imagine if there were a ‘right’ formula, and once you know it, you could feed your dog forever and ever on the same exquisite diet. Your dog, in return, would be the happiest and healthiest doggie camper there ever was.

Unfortunately, “What should I feed my dog?” is not the question we should be asking. In fact, “What should I feed my dog” is akin to the infomercial that comes on at 3 AM informing you that if you just buy this Mega-Blast Belt (for three low monthly payments of $19.99), six-pack abs will follow. Both fall into a quick-fix category — the “right” product, the “right” answer — that unfortunately doesn’t exist.

Instead, the question that will last you a lifetime is, “How should I feed my dog?”. This is where Linda Case, M.S. comes to the rescue. I don’t mean to be superhero-y about it, but Case’s new book, Dog Food Logic: Making Smart Decisions for Your Dog in an Age of Too Many Choices is a unique work designed to help readers make informed, science-based decisions on what and how to feed our beloved companion dogs. As one veterinarian offers, “Dog Food Logic cuts through the noise and chaos and provides pet owners with a rational, science-based approach to evaluating their pets’ dietary needs and their feeding choices” (The Skeptvet Blog).

Linda Case knows a thing or two about animal nutrition. She earned her B.S. in Animal Science at Cornell University and her M.S. in Canine/Feline Nutrition at the University of Illinois. She maintains the well-received blog, The Science Dog, and has written numerous books on companion animal nutrition, training and behavior. I had the pleasure of meeting her at the Cats in Context conference at Canisius College in 2013 (Case spoke on cat nutrition, and I gave a talk on research into whether dogs and cats in the home can be friends — they can).

But back to dog food. If you are expecting a dry read on dog nutrition and diet, you’ve come to the wrong place. Dog Food Logic is a page turner, jam-packed with real-world examples that you can easily relate to. Case unpacks label claims, fad diets and the wonderfully persuasive field of pet food marketing. What does it mean when a food is ‘recommended by veterinarians or breeders?’ Who is Chef Michael, and should you trust him? And who’s keeping our dog food safe?

Throughout the book, Case discusses research into canine nutrition and diet in a way that is easy to digest, if you’ll pardon the pun. For example, studies have investigated:

• Do large-breed puppies (say Great Danes or Newfoundlands) have different nutritional requirements than say, Chihuahuas? Should the big puppies eat the same type of food as the little ones? Or is it just a matter of quantity? Case provides the research.

• Can diet influence cancer progression? While a particular dog food brand won’t cure cancer, nutritional science and canine cancer research find that particular dietary compositions can be beneficial to dogs with cancer.

• What about age-related illnesses? Can they be prevented or delayed through nutrition?

This is just the tip of the iceberg, and since I can’t possibly summarize all the topics and findings covered in Case’s book, the above are intentional teasers. To find out more, read the book.

Importantly, Case doesn’t put canine nutrition in a vacuum. Early on, she acknowledges that feeding can have emotional underpinnings, and Dog Food Logic pulls in research from Human Psychology (particularly Social Psychology), Consumer Research and Marketing, and even the growing fields of Human-Animal Interaction and Anthrozoology (as I’ve mentioned before, not the study of ants). My only suggestion, if you were to twist my arm, is that the book could have discussed in more detail studies in the last 15 years exploring the complexity of the human-animal bond, particularly how people perceive their companion dogs. Research regarding whether dogs are ‘child substitutes’ or mediators of social support would complement Case’s look at what it means to have a dog as a family member, particularly in the chapter on pet food marketing. (If you’re unfamiliar with studies into the dog-human relationship, check out programs and abstracts from the International Society of Anthrozoology and the International Association of Human-Animal Interaction Organizations conferences. You’ll find short podcast interviews with human-animal science researchers on the Human Animal Science blog).

I think Case would agree that Dog Food Logic and the Dog Spies blog share a motto: “What good is all this research if it remains holed up in academic journals?” Case shares existing research on companion animal nutrition and well-being, in a style that is highly palatable (final pun). By the time you reach the appendices, you’ll gladly pore through the table of essential and nonessential amino acids for dogs (Appendix 2), get out your calculator to determine your dog’s daily energy needs (Appendix 3), and who doesn’t love a good dog food choice flow chart (Appendix 5)?

Now if you’ll excuse me, I have to go figure out how to feed myself.

How do you feed your dog?

Photo: Dreamin’… by Rob on Flickr creative commons.

References

Case, L. 2014. Dog Food Logic: Making Smart Decisions for Your Dog in an Age of Too Many Choices. Dogwise Publishing.

Case, L. The Science Dog blog.

Hecht, J. 2013. Dogs and Cats in the Home: Happiness for All? Dog Spies and Do You Believe in Dog?

McKenzie, B. The SkeptVet blog.

Heartbleed afeta dispositivos móveis e internet banking

 

1,3 mil apps conectados a servidores vulneráveis foram encontrados. Entre eles estão bancos, pagamentos online e e-commerce.

A gravidade do bug Heartbleed está dando trabalho para inúmeros sites e servidores. E, de acordo com a empresa de segurança Trend Micro, dispositivos móveis também foram afetados pela ameaça.

A empresa afirma que smartphones são tão vulneráveis ​​ao bug Heartbleed quanto sites. Isso porque os aplicativos se conectam a servidores e serviços web para completar várias funções, como o os apps de bancos e lojas online, por exemplo, que permitem fazer pagamentos via celular.

Cerca de 1,3 mil apps conectados a servidores vulneráveis foram encontrados. Entre eles estão 15 aplicativos relacionados a bancos, 39 a pagamentos online e 10 a compras online. Também foram identificados problemas em apps de uso diário como mensagens instantâneas e de saúde.

Sites afetados

Um teste realizado pelo serviço de web-hosting compartilhado Github mostrou que mais de 600 dos principais 10 mil sites da web (com base em rankings do Alexa) eram vulneráveis, incluindo Yahoo, Flickr, OkCupid e Rolling Stone.

Um levantamento feito pelo Top Level Domain (TLD) mostra ainda que os domínios com maior sites afetados foram da Coreia (.kr) e Japão (.jp), com cerca de 5% do total. Os menos afetados foram os de Porto Rico (.pr) e da França (.fr).

Proteção para usuários de Internet banking

De acordo com a empresa de segurança Vasco Data Security, o Heartbleed faz com que dados sensíveis trocados com seus bancos via Internet possam ter sido comprometidos. Por esse motivo, a primeira coisa a se fazer é trocar as senhas, uma vez que elas podem ter sido comprometidas.

Vale lembrar que isto só deve ser feito após o banco ter corrigido a falha no OpenSSL e expedido novas chaves privadas e novos certificados, pois de outro modo também as novas senhas podem ser acessadas indevidamente no futuro.

Caso a sua instituição ainda não tenha corrigido o problema, então não há muito o que fazer por enquanto, de acordo com a Trend Micro. A recomendação, por ora, é deixar de lado as compras online e também as operações financeiras por um tempo, incluindo as atividades bancárias, até que os desenvolvedores de aplicativos liberem uma atualização que esteja livre dessa vulnerabilidade.

Já os usuários que fazem seus acessos por senhas de uso único não precisam se preocupar com o comprometimento de suas informações. A natureza efêmera desse sistema assegura que a senha só pode ser utilizada por um curto período de tempo, não sendo aproveitadas pelo bug, segundo a Vasco Data Security.

Os bancos, por sua vez, devem, em primeiro lugar, verificar se as suas aplicações de e-banking empregam a versão com falha do OpenSSL. As versões Open SSL 1.0.1 até a 1.0.1f foram afetadas. Nesse caso, elas devem imediatamente atualizar seus servidores com a versão mais recente.

Em segundo lugar, elas devem assumir que as suas chaves privadas SSL/TLS podem estar comprometidas no caso de usaram versões afetadas do Open SSL. Além disso, as instituições financeiras devem ser cautelosas e substituir suas chaves existentes e os seus certificados por novos.

Por fim, devem verificar se dados sensíveis, como senhas de acesso, trocadas com os usuários do e-banking foram comprometidos. Em caso positivo, deve ser promovida a renovação dessas informações o mais rapidamente possível.

 

Google compra fabricante de drones Titan Aerospace

 

Zach Miners, IDG News Service

14/04/2014 - 17h31 - Atualizada em 14/04/2014 - 18h03

 

Os termos do acordo ainda não foram divulgados. Empresa foi anteriormente descartada pelo Facebook.

O Google está fechando a compra da fabricante de drone Titan Aerospace, um movimento que coloca a gigante um pouco à frente na sua estratégia de entrega aérea de serviços de dados e aplicativos de mapeamento, de acordo com o Wall Street Journal. Os termos do acordo ainda não foram divulgados.

Os veículos aéreos não tripulados da Titan, os quais são chamados de "satélites atmosféricos", são projetados para permanecer no ar por anos e podem fornecer serviços de dados e de voz, de acordo com a companhia, além de capturar imagens da Terra e carregar sistemas de sensores atmosféricos.

O Facebook estava negociando a compra da empresa no início deste ano, mas, em vez disso, a rede social disse que traria membros da equipe da Ascenta para se unir ao time. A Ascenta tem sede no Reino Unido e fabrica o seu próprio drone movido a energia solar.

A Titan possui 209 funcionários, os quais permanecerão baseados no Novo México, de acordo com o WSJ.

A equipe irá trabalhar lado a lado com o Project Loon, da Google. Talvez a Titan também trabalhe no projeto Makani da gigante das buscas. O Makani está dando os primeiros passos e visa o desenvolvimento de uma turbina aeólica para gerar energia de forma mais eficiente.

Nenhuma das duas empresas responderam imediatamente a um pedido de comentário.

Marco Civil: Dilma pressiona Senado

 

Publicada em 12/04/2014 11:11

Na próxima terça-feira, 15 de abril, acontece no Senado a segunda das três audiências públicas previstas para discutir o Marco Civil da Internet. A terceira está agendada para o dia 22 de abril, mas pode não acontecer, se os senadores concordarem em votar o projeto em plenário, na próxima quarta, dia 16 de abril. O objetivo do Planalto é o de que o Marco Civil já tenha se tornado lei antes da realização do NETmundial – Encontro Multissetorial Global sobre o Futuro da Governança da Internet, que acontece em São Paulo nos dias 23 e 24 de abril.

Na última quinta-feira, a presidente Dilma, seguindo conselhos do ex-presidente Lula, se reuniu com o presidente do Senado Renan Calheiros e o líder do governo no Senado, Eduardo Braga (PMDB-AM), além do presidente da Comissão de Constituição e Justiça e um dos relatores do Marco Civil, Vital do Rego Filho (PMDB-PB), para solicitar a votação na próxima quarta-feira. A princípio, os senadores concordaram. Mas…

A pressão interna para que o projeto tramite em três comissões da Casa, permitindo um amplo debate e algumas adequações, continua. O relator do projeto na Comissão de Meio Ambiente e Defesa do Consumidor, senador Luiz Henrique (PMDB-SC), defende que o Senado analise detalhadamente a proposta.O Senado tem até 1o dia 2 de maio para votar, sem que o projeto tranque a pauta.

“Acho que o Senado tem todo o direito de analisar detalhadamente o projeto, para que ele, que já é bom, receba aprimoramentos. De minha parte, eu vou devagar com o andor, por que o santo é de barro”, disse Luiz Henrique.

“Acho profundamente injusto ser imputado ao Senado um prazo para que nós não exerçamos na nossa plenitude, não o nosso direito, mas o nosso dever”,  disse o senador Vital do Rêgo (PMDB-PB), relator do projeto na Comissão de Constituição, Justiça e Cidadania (CCJ) , no dia seguinte da reunião com a presidente.

Renan Calheiros (PMDB-AL) terá que consultar os líderes partidários para marcar a data de votação. O senador Ricardo Ferraço (PMDB-ES) será o relator da matéria em Plenário.

Vale lembrar que se o projeto for votado com emendas, precisa voltar a ser apreciado pela Câmara.

A tese do PT, já apoiada por entidades da sociedade civil, é a de o projeto seja aprovado como está, uma vez que modificações posteriores podem ser apresentadas na forma de projetos de lei, já que o objetivo do Marco Civil é desenhar diretrizes e não esgotar todos os assuntos relativos à internet.

Uma modificação necessária é alvo de duas emendas: uma apresentada durante o prazo regimental, de autoria do senador Aloysio Nunes Ferreira (PSDB-SP) e outra após o prazo regimental, de autoria do Senado Humberto Costa (PT-PE). Com propostas de redação um pouco diferentes, ambas trocam a figura “autoridades administrativas”, no parágrafo 3 do artigo 10, por “delegado de Polícia e Ministério Público”. Só eles teriam competência legal para a requisição de dados cadastrais de investigados, independentemente de autorização judicial.

Proposta de Aloysio Nunes

Proposta de Humberto Costa

A audiência pública conjunta de terça-feira será realizada às 14h. Os interessados poderão participar enviando perguntas e sugestões pelo portal E-Cidadania e pelo Alô Senado.  Estão convidados, entre outros, Eduardo Moreira, diretor do Sindicato Nacional das Empresas de Telefonia e de Serviço Móvel Celular e Pessoal; José Francisco Lima, conselheiro da Associação Brasileira de Emissoras de Rádio e Televisão (Abert); Marcel Leonardi, diretor do Google do Brasil; e Renato Cruz, colunista do jornal O Estado de São Paulo.

Não acontecendo a votação na próxima quarta-feira, dia 16 de abril, a sugestão de alguns senadores petistas, como Walter Pinheiro, é a apresentação de um pedido de urgência urgentíssima no dia 22 de abril, para que seja entregue à Presidente Dilma para sanção no seguinte, durante a realização do NETmundial.

A sorte está lançada!

 

5 Tips for Faster Mental Division (Part 2)

 

The Math Dude: Quick & Dirty Tips to Make Math Simpler

Apr 13, 2014 |By Jason Marshall

 

Scientific American presents Math Dude by Quick & Dirty Tips. Scientific American and Quick & Dirty Tips are both Macmillan companies.

Quick, what's 54 / 3? How about 324 / 6?

Wait, don't go searching for your calculator or smart phone—believe it or not, you can do these problems and countless others quickly and easily in your head.

In Part 1 of our mental division series, we learned the first 3 tips to becoming a mental division maestro. Today we're going to finish things off with the 2 most powerful mental division tips that are sure to help you kick your calculator dependency forever.

Tips #1-3 Recap
If you haven't yet absorbed, practiced, and perhaps even fallen in love with the first 3 mental division tips that we talked about last time, I highly encourage you to do that before continuing to today's tips. As you'll see, the tricks and tips for today build upon those that we talked about last time, so your efforts will be doubly rewarded.

> Continue reading on QuickAndDirtyTips.com

 

5 Tips for Faster Mental Division (Part 1)

 

Have you ever wished you could divide numbers quickly and easily in your head? Believe it or not, you can! Over the next two weeks, we'll be learning my top 5 tips to help you become a mental division maestro.

 

If you're anything like me, you don't exactly love doing long division. Which is exactly why I avoid it as much as I can. Of course, one way to avoid doing division the old fashioned way with paper and pen is by using a calculator. Most of the time, that's exactly what I do.

But the truth is that sometimes calculators—or phones with calculators—are inconvenient. And sometimes you need to do division right there on the spot in your head. How can you do it? Keep on reading to learn 5 simple things that you can do to take your mental division skills to the next level.

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Tip #1: Approximate If You Can

The first thing you can do to speed up a lot of the mental division problems you'll encounter is to stop and think about just how accurate you need the answer to be. Sometimes you need an exact answer, or perhaps an answer that's accurate to two decimal places, or three decimal places, or something else specific like that. But a lot of the time you really just need a ballpark estimate.

If you only need an approximate answer, don't waste time figuring out the exact answer…make a quick and dirty estimate instead.

In those cases where you only need an approximate answer, don't waste your time by figuring out the exact answer. Instead, make a quick and dirty estimate. How? Well, let's say you work in a coffee shop and you want to figure out the average amount spent by your customers. So far you've collected $164 from 26 people. What's the average—or more technically the mean—bill? Well, $164 is pretty close to $150, and 26 people is pretty close to 25 people. So instead of calculating $164 / 26 people, let's start by calculating something that's close to that: $150 / 25 people. That's a much easier problem to solve! It says that the answer is roughly $6 / person.

No, this technique doesn't give exact values, but if you estimate wisely it'll give you answers that are pretty close…and with a fraction of the work.

 

Tip #2: Simplify Before You Start

The rest of today's tips are all things that you can do when an approximate answer just isn't good enough. When faced with such problems, the first thing you should do is.....check if you can simplify the problem before you start doing any division. In particular, if the number you're dividing into (aka, the dividend) and the number you're dividing by (aka, the divisor) are both even, you should start by dividing both by 2. For example, in the problem 164 / 26, start by dividing both the top and bottom by 2 to obtain the simplified (but otherwise identical) problem 82 / 13. Why is that helpful? Simply because it's almost always easier to work with smaller numbers.

But that's not the only way a division problem can be simplified. In a problem like 93 / 27, the dividend and divisor are not both even numbers—so we can't simplify the problem by dividing both by 2. But both are divisible by 3 (in other words, 3 is a factor of both 93 and 27). Which means that in this case we can divide both the dividend and divisor by 3 to obtain the simplified problem 31 / 9.

The quick and dirty tip here is to always look for factors common to both the dividend and the divisor, and then to divide both by each common factor before you do anything else.

 

Tip #3: Multiply Before Dividing

There are times in life when doing the opposite of what you should be doing is bad. But there are other times when it's actually very, very good. This is one of those times because when it comes to mental division, it turns out that it's often helpful to multiply instead.

Like many mental math tricks before it, this one relies upon the fact that dividing by 10 (or 100, or any other power of 10) is easy—just move the decimal point one position to the left for each power of 10. And since it's so easy to divide by powers of 10, we should strive to do it as often as possible—even when we're supposed to be doing something like dividing a number by 5. But how can we possibly do that? We use the fact that 5 = 10 / 2.

For example, let's imagine you're back working in your coffee shop and you've decided to calculate the average amount of money you make each day of a 5-day work week. In other words, you need to divide the total amount of money you bring in over those 5-days—let's say it's $1,677—and divide it by 5. But instead of calculating $1,677 / 5, let's use the fact that 5 = 10 / 2 to turn this problem into $1,677 / (10 / 2). Using what we've learned about how to divide fractions (remember invert and multiply?), we see that this is the same as $1,677 × 2 / 10. In other words, we've managed to turn a hard problem of mentally dividing by 5 into two simple problems. First, multiply $1,677 by 2 to get $3,354. And second, divide the result by 10 to find that the average income for each day of the week is $3,354 / 10 = $335.40.

Does this trick only work for division by 5? No! You can use the same idea to turn division by 20 into multiplication by 5 followed by division by 100, or division by 25 into multiplication by 4 followed by division by 100, and lots and lots of other things, too. And when combined with today's first tip about making approximations, this trick becomes even more powerful. Just remember to stop and think before you start working on a problem, and you'll often see that there's a much easier way to the solution.

 

Wrap Up

Okay, that's all the math we have time for today. Of course, those are only 3 of my top 5 tips for faster mental division. So be sure to check back next time to learn the last—and most powerful—pair of tips!

Be sure to check out my mental math audiobook called The Math Dude’s 5 Tips to Mastering Mental Math. And for even more math goodness, check out my book The Math Dude’s Quick and Dirty Guide to Algebra.

Remember to become a fan of the Math Dude on Facebook where you’ll find lots of great math posted throughout the week. If you’re on Twitter, please follow me there, too. Finally, please send your math questions my way via Facebook, Twitter, or email at mathdude@quickanddirtytips.com.

Until next time, this is Jason Marshall with The Math Dude’s Quick and Dirty Tips to Make Math Easier. Thanks for reading, math fans!

Mental division image from Shutterstock.

How to Solve Global Warming: It's the Energy Supply

 

Carbon storage has to expand rapidly, or coal burning has to cease, if the world is to avoid dangerous climate change

Apr 13, 2014 |By David Biello

The world is on track for dangerous climate change, having nearly lost room for further pollution in the mix of gases that make up the atmosphere. Despite a rise in clean, renewable energy supplies in certain countries, and a partial shift from coal to natural gas in others, global greenhouse gas pollution continues to rise—and at an increasing pace in the most recent years.
"Economic and population growth are drivers for emissions and they have outpaced the improvements of energy efficiency," said Ottmar Edenhofer, economist at the Potsdam Institute for Climate Impact Research in Germany and co-chair of Working Group III of the Intergovernmental Panel on Climate Change (IPCC). Edenhofer spoke at an April 13 press conference in Berlin, where IPCC's Working Group III released its report on the subject of how to mitigate the climate problem.
Nations worldwide have to make major change in energy supply, soon, if they are to restrain climate change to no more than 2 degrees Celsius, Edenhofer and others said. That is a threshhold beyond which serious harm is likely to occur to human civilization as well as the natural world, by the IPCC and other's scientific judgment.
Geoengineering will probably also be required to solve the planet’s global warming pollution problem, Edenhofer and the report noted. The world will also need a crash course in technologies to capture carbon dioxide—the primary greenhouse gas— from the atmosphere to restrain global warming. Without such CCS hopes of restraining climate change to no more than 2 degrees C warming are "no longer feasible," Edenhofer argued. "In the end, two degrees means the phase out of fossil fuels without CCS entirely in the next few decades."

Energy mix
Climate change is an energy problem. Burning fossil fuels to produce electricity or heat is responsible for roughly half of global warming pollution. Tacking on industry in general, including producing cement, steel, plastics and chemicals, accounts for 78 percent of greenhouse gases, which invisibly accumulate in the atmosphere and trap extra heat.  Such climate changing pollution continues to increase—in 2010, the world emitted some 49 billion metric tons of greenhouse gases, thanks largely to increased coal burning in countries such as China. The number has continued to increase in recent years. In fact, human society added half of the global warming pollution that is in the atmosphere in just the last 40 years.
Restraining global warming to no more than 2 degrees Celsius will require changing how the world produces and uses energy to power its cities and factories, heats and cools buildings, as well as moves people and goods in airplanes, trains, cars, ships and trucks, according to the IPCC. Changes are required not just in technology, but also in people's behavior. "We can reduce through substantial behavioral change and lifestyle change the demand for energy and the consumption of energy," noted Ramon Pichs-Madruga, economist at Cuba's Center for the Investigation of the Global Economy and co-chair of the Working Group III report. And that change "allows for greater flexibility when we come to [choose] technology options. If we leave it all up to technology the costs and risks will be much greater."

The initial IPCC report in this series, released last September, noted that the atmosphere could bear only 800 to 1,000 billion metric tons of greenhouse gases, in order to restrain global warming to 2 degrees Celsius by century's end. The world has already emitted in total roughly 515 billion metric tons. At present rates of pollution then, human society would blow through its carbon budget in the next decade or so.
Such pollution has already doubled just since 1970 and the rates of pollution have been increasing by roughly 1 billion metric tons per year in recent years, a pace that must slow and stop soon. To hold global warming in check requires reducing current emission levels by as much as 70 percent by 2050, compared with 2010 levels, and nearly eliminating such pollution by 2100. Instead, "over the last decade, we have seen increasing use of coal," the fossil fuel that when burned results in the most CO2, Edenhofer noted.
That pace of pollution now needs to slow and then reverse, likely requiring technologies that could pull CO2, the primary greenhouse gas, back out of the atmosphere. Such geoengineering could include technologies ranging from burning trees or grasses and capturing and storing the resulting CO2 from smokestacks to artificial trees that suck CO2 out of the sky directly for storage or re-use. "This group of technologies is essential for low stabilization targets," Edenhofer said.
The problem is that none of this technology exists or, where it does as in the case of CCS, has not been deployed at a large enough scale, because it costs much more than the alternative: freely polluting the atmosphere. More aggressive geoengineering techniques—blocking sunlight and the like—remain too uncertain and fraught with risks to properly evaluate, this IPCC panel argued.

At the same time, emissions from traditional energy supplies must be zeroed out, either through CCS or replacement with less polluting energy sources, whether emissions-free wind and sun or lower carbon nuclear energy. Most of that change will have to take place in the developing world, whether replacing China's new coal-fired power plants or building wind, solar or geothermal facilities to power development in African countries. Fracking to free more natural gas from shale can help displace even more polluting coal in more developed countries such as the U.S. but can only serve as a bridge—and a very short bridge—to the zero-greenhouse-gas pollution future, unless also outfitted with carbon capture and storage to eliminate pollution. Fortunately, scientific surveys indicate that there is enough below-ground storage capacity in the Earth to accommodate humanity's swelling CO2 pollution.

Social change
All of this will also require a major change in investment, reducing money that continues to pour in to dig up fossil fuels by 20 percent per year (thus devaluing those deposits as well) and growing investment in, say, renewables by 100 percent per year. The cost of this transformation is not entirely clear. The IPCC suggests that the median estimate of paying for the change would take off 0.06 percent from global economic growth per year, a small part of a predicted minimum 1.6 percent annual growth globally, but still a restraint. "It's a delay of economic growth but it is not sacrificing economic growth," Edenhofer noted, adding that this calculation does not take into account related benefits, such as a reduction in deadly air pollution and saved human lives, or salvaged nature. "It does not cost the world to save the planet."
Long-term climate stability would require "unprecedented" global cooperation, with countries agreeing to a plan that would set a global price on such pollution. As it stands, the countries of the United Nations Framework Convention on Climate Change have agreed to draft a global treaty by 2015, which would take effect in 2020. At the same time, the 1.3 billion people without access to electricity and the 3 billion or so who still rely on burning wood or dung to fuel cooking or heating would need modern energy supplies, although this might prove to have minimal impacts on climate change through saving forests and other side effects.

Without any action, the world is on track to achieve at least 4 degrees C warming of global average temperatures by 2100, as the world hits 450 parts-per-million of greenhouse gases in 2030 and goes on to put out enough greenhouse gas pollution to achieve as much as 1300 ppm by 2100. Even restraining warming to just 3 degrees C would require substantial transformation. "What has to be done over the next 20 to 30 years or so does not change even if one relaxes the temperature target," Edenhofer said. "Irrespective of the long-term mitigation goal, we have to start to bring the mitigation train onto the track."

The IPCC suggests that atmospheric concentrations of greenhouse gases should not exceed 450 ppm to meet nations' expressed aspiration to hold temperature rise to 2 degrees C or less. Already, atmospheric concentrations of just CO2 have reached 400 ppm at times and all greenhouse gases put together are now at 430 ppm. As a result, global average temperatures have already increased by 0.85 degree C. "If we really want to bring about a limit of the temperature increase to no more than two degrees," said IPCC chair Rajendra Pachauri, "the high-speed mitigation train would need to leave the station very soon and all of global society would need to get on board."
The tracks that train would run on remain mostly unlaid and the exact route on the IPCC's map as presented here is not entirely clear. The route must go through the world's swelling cities, which provide the biggest opportunity to lock in pollution reductions, and the direction and speed—greenhouse gas pollution going down soon and fast—are apparent. This report "provides hope, modest hope," Edenhofer said. "We have the means to do this but it remains a huge, huge challenge."

 

Autoimmune disorder

 

An autoimmune disorder is a condition that occurs when the immune system mistakenly attacks and destroys healthy body tissue. There are more than 80 different types of autoimmune disorders.

See also: Immune response

Causes

Normally the immune system's white blood cells help protect the body from harmful substances, called antigens. Examples of antigens include bacteria, viruses, toxins, cancer cells, and blood or tissues from another person or species. The immune system produces antibodies that destroy these harmful substances.

In patients with an autoimmune disorder, the immune system can't tell the difference between healthy body tissue and antigens. The result is an immune response that destroys normal body tissues. This response is a hypersensitivity reaction similar to the response in allergic conditions.

In allergies, the immune system reacts to an outside substance that it normally would ignore. With autoimmune disorders, the immune system reacts to normal body tissues that it would normally ignore.

What causes the immune system to no longer tell the difference between healthy body tissues and antigens is unknown. One theory is that some microorganisms (such as bacteria or viruses) or drugs may trigger some of these changes, especially in people who have genes that make them more likely to get autoimmune disorders.

An autoimmune disorder may result in:

• The destruction of one or more types of body tissue
• Abnormal growth of an organ
• Changes in organ function

An autoimmune disorder may affect one or more organ or tissue types. Organs and tissues commonly affected by autoimmune disorders include:

• Blood vessels
• Connective tissues
• Endocrine glands such as the thyroid or pancreas
• Joints
• Muscles
• Red blood cells

A person may have more than one autoimmune disorder at the same time. Examples of autoimmune (or autoimmune-related) disorders include:

Symptoms

Symptoms of an autoimmune disease vary based on the disease and location of the abnormal immune response.

Symptoms that often occur with autoimmune diseases include:

Exams and Tests

The health care provider will do a physical exam. Signs depend on the type of disease.

Tests that may be done to diagnose an autoimmune disorder may include:

• Antinuclear antibody tests
• Autoantibody tests
• CBC
• C-reactive protein (CRP)
• Erythrocyte sedimentation rate (ESR)

Treatment

The goals of treatment are to:

• Reduce symptoms
• Control the autoimmune process
• Maintain the body's ability to fight disease

Which treatments are used depends on the specific disease and your symptoms.

Some patients may need supplements to replace a hormone or vitamin that the body is lacking. Examples include thyroid supplements, vitamins such as B12, or insulin injections.

If the autoimmune disorder affects the blood, you may need blood transfusions.

People with autoimmune disorders that affect the bones, joints, or muscles may need help with movement or other functions.

Medicines are often prescribed to control or reduce the immune system's response. They are often called immunosuppressive medicines. Such medicines may include corticosteroids (such as prednisone) and nonsteroid drugs such as azathioprine, cyclophosphamide, mycophenolate, sirolimus, or tacrolimus.

Outlook (Prognosis)

The outcome depends on the disease. Most autoimmune diseases are chronic, but many can be controlled with treatment.

Symptoms of autoimmune disorders can come and go. When symptoms get worse, it is called a flare-up.

Possible Complications

Complications depend on the disease. Side effects of medications used to suppress the immune system can be severe, such as infections that can be hard to control.

When to Contact a Medical Professional

Call your health care provider if you develop symptoms of an autoimmune disorder.

Prevention

There is no known prevention for most autoimmune disorders.