Quantum key distribution (QKD) uses individual light quanta in quantum superposition states to guarantee unconditional communication security between distant parties. In practice, the achievable distance for QKD has been limited to a few hundred kilometers, due to the channel loss of fibers or terrestrial free space that exponentially reduced the photon rate. Satellite-based QKD promises to establish a global-scale quantum network by exploiting the negligible photon loss and decoherence in the empty out space. Here, we develop and launch a low-Earth-orbit satellite to implement decoy-state QKD with over kHz key rate from the satellite to ground over a distance up to 1200 km, which is up to 20 orders of magnitudes more efficient than that expected using an optical fiber (with 0.2 dB/km loss) of the same length. The establishment of a reliable and efficient space-to-ground link for faithful quantum state transmission constitutes a key milestone for global-scale quantum networks.
Private and secure communications are fundamental human needs. Traditional public key cryptography usually relies on the perceived computational intractability of certain mathematical functions. In contrast, quantum key distribution (QKD)1 proposed in the mid-1980s—the best known example of quantum cryptographic tasks—is a radical new way to offer an information-theoretically secure solution to the key exchange problem, ensured by the laws of quantum physics. QKD allows two distant users, who do not share a long secret key initially, to produce a common, random string of secret bits, called a secret key. Using the one-time pad encryption, this key is proven to be secure by Shannon2 to encrypt (and decrypt) a message, which can then be transmitted over a standard communication channel. In the QKD, the information is encoded in the superposition states of physical carriers at single-quantum level, where photons, the fastest flying qubits with their intrinsic robustness to decoherence and ease of control, are usually used. Any eavesdropper on the quantum channel attempting to gain information of the key will inevitably introduce disturbance to the system, and can be detected by the communicating users.
Original article: Satellite-to-Ground Quantum Key Distribution
Born in 384 BC in Stagira, a small town on the northern coast of Greece, Aristotle’s is argua1bly one of the most well-known figures in the history of ancient Greece. He was a popular pupil of famous ancient Greek philosopher Plato. But unlike Plato and Socrates, Aristotle displayed an instinct to conclude about his study of nature using scientific and factual reasoning – a trait his predecessors routinely discarded in favor of their philosophical discerns. Perhaps it was his unyielding fascination for nature, logic and reason that he went on to make some pivotal contributions that are still reflected today in modern day mathematics, metaphysics, physics, biology, botany, politics, medicine and many more. He truly earns the honor of being called the “First Teacher” in the west. Further delving into the details of his achievements, here is a list of top 10 contributions of Aristotle.
Invented the Logic of the Categorical Syllogism
Syllogism represents a certain form of reasoning where a conclusion is made based on two premises. These premises always have a common or middle term to associate them together, but this binding term is absent in the conclusion that is decided upon. This procedure of logical deduction invented by Aristotle, perhaps, lies at the epitome of all his famous achievements. He was the first person to come up with an authentic and logical procedure to conclude a statement based on the propositions that are at hand. These propositions or premises are either provided as facts or simply taken as assumptions provided beforehand. For instance – Socrates is a man. All men are mortal. These two premises can be concluded as – ‘Socrates is mortal.’
The logic behind finding a reasoning based on a proposition and an inference that has something common with the said proposition is clearly pretty straight forward. Its deductive simplicity and ease of use catapulted Aristotle’s theory of syllogism to attain an unparalleled influence on the history of western logic and reasoning. Although in the post renaissance era leading up to the modern age, we came up with logical approaches that were based more on mathematical deductions (and were far more accurate), and less on the uncertainty of non-plausible premises. That being said, Aristotle’s logical theory of categorical syllogism attained a stature that makes it far more than a mere historical curiosity.
Classification of Living Beings
In his book, History of Animals (Historia Animalium), Aristotle was the first person in human history to venture in the classification of different animals. He would use the traits that are similar among certain animals to classify them under similar groups. For example – based on the presence of blood, he would make two different groups such as animals with blood and animals without blood. Similarly, based on their habitat, he classified animals as ones that live on water and ones that live on land. In his perspective, life had a hierarchical make up and all the living beings could be grouped in this hierarchy based on their position from lowest to highest. He placed human species at the highest strata in this hierarchy.
He also devised the binomial naming convention. Using this system, all living organisms now could be given two different sets of nomenclature defined by name of organism’s ‘genus’ and ‘difference’. Aristotle meant the ‘genus’ of a living being to represent its collective family/group as a whole. The name of the ‘difference’ is what makes the living organism different other members of the family it falls within.
Founder of Zoology
Aristotle is also known as the father of Zoology. As evident from his classification of living being, all his classification procedures and several other treatises he wrote primarily involved different species of animal kingdom only. He wrote a number of treatises that revolved around different aspects of zoology. Some of his popular treatises such as ‘History of Animals’, ‘Movement of Animals’, ‘Progression of Animals’ and others, were based on study of different land, water and aerial animals. Unlike his predecessors who merely documented their routine observations of nature, Aristotle worked on outlining specific techniques that he would use to make specific observations.
He used these empirical methods to carry out, what we could call in modern age designation, several proto-scientific tests and experiments to study the flora and fauna around him. One of his early observational experiments included dissecting the bird eggs throughout different stages of embryo development inside the egg. Using his observations, he was able to study the detailed growth of different organs as the embryo develops into a fully hatched youngling.
Contributions in Physics
To put it out rather bluntly, it is true that while Aristotle established new frontiers in the field of life sciences, his escapades in physics fall shorter in comparison. His studies in physics seems to have been highly influenced from pre-established ideas of contemporary and predecessor Greek thinkers. For instance, in his treatises On Generation and Corruption and On the Heavens, the world setup he described had many similarities with propositions made by some pre-Socratic era theorists. About the makeup of the universe, he tardily embraced Empedocles’ view that everything was created from different compositions of four fundamental elements – earth, water, air and fire.
Similarly, Aristotle believed that any kind of change meant something was in motion. In a rather self-contradicting way (at least the initial interpreters found it to be so), he defined the motion of anything as the actuality of a potentiality. In its entirety, Aristotle understood physics as a part of theoretical science that was in sync with natural philosophy. Perhaps a more synonymous term to adhere with Aristotle’s interpretation would be ‘physis’ or simply the study of nature.
Influences in History of Psychology
Aristotle was the first to write a book that dealt with the specifics of psychology – his book De Anima (in translation read as ‘On the Soul’) being the first book on psychology. In his book, he proposes the idea of abstraction that reigns over body and mind of a human being – they exist within the same being, intertwined such that mind is one of the many basic functions of the body. In his more detailed psychological analysis, he constitutes the human intellect into two essential categories – the passive intellect and the active intellect.
According to Aristotle, it is in human nature to imitate something that, even if on a mere superficial level, provided us with a sense of happiness and satisfaction. Perhaps the highlight of his psychological observations has been the delicate connection that binds the human psychology with the underlying human physiology. His contributions take a giant leap from where the pre-scientific era psychology stood before him, into an age of far more precise qualitative and quantitative analysis.
Advances in Meteorology
For his contemporary time and age, Aristotle was able to put forth a detailed analysis of world around him. At present, the term meteorology specifically encompasses the interdisciplinary scientific study of atmosphere and weather. But Aristotle made a far more generalized approach wherein he also covered different aspects and phenomenon of air, water and earth within his treatise Meteorologica or Meteora.
In his treatise, in his own words, he lays out details of ‘different affections’ that are common in between air and water, as well as the different kinds and parts of the earth, and the affections that associate those parts together. The highlight of his ‘Meteora’ treatise are his accounts for water evaporation, earthquakes, and other common weather phenomena. His analysis for these different meteorological occurrences is one of the earliest representations of such phenomena. Though that doesn’t say much about the accuracy of his meteorological studies. Aristotle believed in the existence of ‘underground winds’ and that the winds and earthquakes were caused by them. Similarly, he categorized thunder lightning, rainbows, meteors and comets as different atmospheric phenomena.
An attempt to summarize the rich details of Aristotelian ethics within the bounds of a couple of paragraphs will only put it short. Having said that, Nicomachean Ethics stand as the major highlight of Aristotelian ethics. It represents the best-known work on ethics by Aristotle – a collection of ten books maintained based on notes taken from his various lectures at the Lyceum. The Nicomachean Ethics lays out Aristotle’s thoughts on various moral virtues and their respective details.
Aristotelian ethics outline the different social and behavioral virtues of an ideal man. The confidence one bears in the face of fear and defeat stacks up as courage. The ability to resist the temptations of physical pleasures stand out as a person’s temperance. Liberality and magnificence speak the volumes of wealth one can give away for the welfare of others. Any ambition can never be truly magnanimous unless it attains an impeccable balance between the honor it promises and the dues it pays. These, along with other pivotal excerpts, build the groundwork for Aristotle’s endeavors in ethics. In this ethical essence, Aristotle believed that ‘regardless of the various influences of our parents, society and nature, we ourselves are the sole narrators of our souls and their active states.’
Aristotelianism is the biggest exemplary to the influence Aristotelian philosophy has had on the entire subsequent philosophical paradigm itself. Aristotelianism represents the philosophical traditions that takes its roots from the various works of Aristotle in philosophy. This route of conventional philosophy is highly influenced from different aspect of various Aristotelian ideologies including his view on philosophical methodology, epistemology, metaphysics, aesthetics, ethics and many more.
The fact remains that Aristotle’s ideas have become deeply engraved in the social and communal thought structure of overall civilization that followed in the western world. His philosophical works were first rehearsed and defended by the members of Peripatetic school. The Neoplatonist followed suit soon after, and made well documented critical commentaries on his popular writings. Historians also point out major references of Aristotelianism in early Islamic philosophy where in contemporary Islamic philosophers such as Al-Kindi, Al-Farabi and others translated and incorporated Aristotle’s work in their learning.
The word politics is derived from the Latin word ‘polis’ which in ancient Greece simply represented any city-state. Aristotle believed that ‘polis’ reflected the topmost strata of political association. Being a citizen of a polis was essential for a person to lead a life of good quality. Attaining the stature of such a citizen meant you needed to make necessary political connections to secure a permanent residence. In Aristotle’s view, this very pursues concluded the fact that ‘man is a political animal.’
Without a doubt, the various ventures of Aristotle’s life helped shape up his political acumen in ways his predecessors and contemporaries could not. His progressive adventures in the biology of natural flora and fauna are quite visible in the naturalism of his politics. He divides the polis and their respective constitutions into six categories, of which three he adjudges as good and remaining three as bad. In his view, the good ones are constitutional government, aristocracy, and kingship, and the bad ones include democracy, oligarchy and tyranny. He believes that the political valuation of an individual directly depends on their contributions in making the life of their polis better.
Many of the records of Aristotle’s take on art and poetics, much like many other documents of his philosophical and literary works, were composed around 330 BCE. Most of these exist and survive to this day because they were duly noted down and preserved by his pupils during his lectures. Aristotle’s insight in poetics primarily revolve around drama.
Perhaps in one of those subsequent periods when Aristotelianism was gaining more ground around the world, his original take on drama was divided into two separate segments. The first part now focused on tragedy and epic, and the second part discussed the various details of comedy. According to Aristotle, a good tragedy should be able to involve the audience and make them feel katharsis (a sense of purification through pity and fear).
It has been more than 2300 years since the last day of Aristotelian era in ancient Greece, yet the research and work of Aristotle remains as influential in this time and age. From fields that significantly incline towards a structurally scientific orientation such as physics and biology, to the very minute details about the nature of knowledge, reality and existence – his multitudinous all-around contributions truly make him one of the most influential people in human history.
Original article: Ten Contributions by Aristotle
‘My great fear,” Neil deGrasse Tyson told MSNBC’s Chris Hayes in early June, “is that we’ve in fact been visited by intelligent aliens but they chose not to make contact, on the conclusion that there’s no sign of intelligent life on Earth.” In response to this rather standard little saw, Hayes laughed as if he had been trying marijuana for the first time.
All told, one suspects that Tyson was not including either himself or a fellow traveler such as Hayes as inhabitants of Earth, but was instead referring to everybody who is not in their coterie. That, alas, is his way. An astrophysicist and evangelist for science, Tyson currently plays three roles in our society: He is the director of the Hayden Planetarium at the New York Science Museum; the presenter of the hip new show Cosmos; and, most important of all perhaps — albeit through no distinct fault of his own — he is the fetish and totem of the extraordinarily puffed-up “nerd” culture that has of late started to bloom across the United States.
One part insecure hipsterism, one part unwarranted condescension, the two defining characteristics of self-professed nerds are (a) the belief that one can discover all of the secrets of human experience through differential equations and (b) the unlovely tendency to presume themselves to be smarter than everybody else in the world. Prominent examples include MSNBC’s Melissa Harris-Perry, Rachel Maddow, Steve Kornacki, and Chris Hayes; Vox’s Ezra Klein, Dylan Matthews, and Matt Yglesias; the sabermetrician Nate Silver; the economist Paul Krugman; the atheist Richard Dawkins; former vice president Al Gore; celebrity scientist Bill Nye; and, really, anybody who conforms to the Left’s social and moral precepts while wearing glasses and babbling about statistics.
The pose is, of course, little more than a ruse — our professional “nerds” being, like Mrs. Doubtfire, stereotypical facsimiles of the real thing. They have the patois but not the passion; the clothes but not the style; the posture but not the imprimatur. Theirs is the nerd-dom of Star Wars, not Star Trek; of Mario Kart and not World of Warcraft; of the latest X-Men movie rather than the comics themselves. A sketch from the TV show Portlandia, mocked up as a public-service announcement, makes this point brutally. After a gorgeous young woman explains at a bar that she doesn’t think her job as a model is “her thing” and instead identifies as “a nerd” who is “into video games and comic books and stuff,” a dorky-looking man gets up and confesses that he is, in fact, a “real” nerd — someone who wears glasses “to see,” who is “shy,” and who “isn’t wearing a nerd costume for Halloween” but is dressed how he lives. “I get sick with fear talking to people,” he says. “It sucks.”
A quick search of the Web reveals that Portlandia’s writers are not the only people to have noticed the trend. “Science and ‘geeky’ subjects,” the pop-culture writer Maddox observes, “are perceived as being hip, cool and intellectual.” And so people who are, or wish to be, hip, cool, and intellectual “glom onto these labels and call themselves ‘geeks’ or ‘nerds’ every chance they get.”
Which is to say that the nerds of MSNBC and beyond are not actually nerds — with scientific training and all that it entails — but the popular kids indulging in a fad. To a person, they are attractive, accomplished, well paid, and loved, listened to, and cited by a good portion of the general public. Most of them spend their time on television speaking fluently, debating with passion, and hanging out with celebrities. They attend dinner parties and glitzy social events, and are photographed and put into the glossy magazines. They are flown first class to university commencement speeches and late-night shows and book launches. There they pay lip service to the notion that they are not wildly privileged, and then go back to their hotels to drink $16 cocktails with Bill Maher.
In this manner has a word with a formerly useful meaning been turned into a transparent humblebrag: Look at me, I’m smart. Or, more important, perhaps, Look at me and let me tell you who I am not, which is southern, politically conservative, culturally traditional, religious in some sense, patriotic, driven by principle rather than the pivot tables of Microsoft Excel, and in any way attached to the past. “Nerd” has become a calling a card — a means of conveying membership of one group and denying affiliation with another. The movement’s king, Neil deGrasse Tyson, has formal scientific training, certainly, as do the handful of others who have become celebrated by the crowd. He is a smart man who has done some important work in popularizing science. But this is not why he is useful. Instead, he is useful because he can be deployed as a cudgel and an emblem in political argument — pointed to as the sort of person who wouldn’t vote for Ted Cruz.
“Ignorance,” a popular Tyson meme holds, “is a virus. Once it starts spreading, it can only be cured by reason. For the sake of humanity, we must be that cure.” This rather unspecific message is a call to arms, aimed at those who believe wholeheartedly they are included in the elect “we.” Thus do we see unexceptional liberal-arts students lecturing other people about things they don’t understand themselves and terming the dissenters “flat-earthers.” Thus do we see people who have never in their lives read a single academic paper clinging to the mantle of “science” as might Albert Einstein. Thus do we see residents of Brooklyn who are unable to tell you at what temperature water boils rolling their eyes at Bjørn Lomborg or Roger Pielke Jr. because he disagrees with Harry Reid on climate change. Really, the only thing in these people’s lives that is peer-reviewed are their opinions. Don’t have a Reddit account? Believe in God? Skeptical about the threat of overpopulation? Who are you, Sarah Palin?
First and foremost, then, “nerd” has become a political designation. It is no accident that the president has felt it necessary to inject himself into the game: That’s where the cool kids are. Answering a question about Obama’s cameo on Cosmos, Tyson was laconic. “That was their choice,” he told Grantland. “We didn’t ask them. We didn’t have anything to say about it. They asked us, ‘Do you mind if we intro your show?’ Can’t say no to the president. So he did.”
One wonders how easy it would have proved to say “No” to the president if he had been, say, Scott Walker. Either way, though, that Obama wished to associate himself with the project is instructive. He was launched into the limelight by precisely the sort of people who have DVR’d every episode of Cosmos and who, like the editors of Salon, see it primarily as a means by which they might tweak their ideological enemies; who, as apparently does Sean McElwee, see the world in terms of “Neil deGrasse Tyson vs. the Right (Cosmos, Christians, and the Battle for American Science)”; and who, like the folks at Vice, advise us all: “Don’t Get Neil deGrasse Tyson Started About the Un-Science-y Politicians Who Are Killing America’s Dreams.”
Obama knows this. Look back to his earlier backers and you will see a pattern. These are the people who insisted until they were blue in the face that George W. Bush was a “theocrat” eternally hostile toward “evidence,” and that, despite all information to the contrary, Attorney General Ashcroft had covered up the Spirit of Justice statue at the Department of Justice because he was a prude. These are the people who will explain to other human beings without any irony that they are part of the “reality-based community,” and who want you to know how aw-shucks excited they are to look through the new jobs numbers.
At no time is the juxtaposition between the claim and the reality more clear than during the White House Correspondents’ Dinner, which ritzy and opulent celebration of wealth, influence, and power the nation’s smarter progressive class has taken to labeling the “Nerd Prom.” It is clear why people who believe themselves to be providing a voice for the powerless and who routinely lecture the rest of us about the evils of income inequality would wish to reduce in stature a party that would have made Trimalchio blush: It is devastating to their image. Just as Hillary Clinton has noticed of late that her extraordinary wealth and ostentatious lifestyle conflict with her populist mien, the New Class recognizes the danger that its private behavior poses to its public credibility. There is, naturally, something a little off about selected members of the Fifth Estate yukking it up with those whom they have been charged with scrutinizing — all while rappers and movie stars enjoy castles of champagne and show off their million-dollar dresses. And so the optics must be addressed and the nomenclature of an uncelebrated group cynically appropriated. We’re not the ruling class, the message goes. We’re just geeks. We’re not the powerful; we’re the outcasts. This isn’t a big old shindig; it’s science. Look, Neil deGrasse Tyson is standing in the Roosevelt Room!
Ironically enough, what Tyson and his acolytes have ended up doing is blurring the lines between politics, scholarship, and culture — thereby damaging all three. Tyson himself has expressed bemusement that “entertainment reporters” have been so interested in him. “What does it mean,” he asked, “that Seth MacFarlane, who’s best known for his fart jokes — what does it mean that he’s executive producing” Cosmos? Well, what it means is that, professionally, Tyson has hit the jackpot. Actual science is slow, unsexy, and assiduously neutral — and it carries about it almost nothing that would interest either the hipsters of Ann Arbor or the Kardashian-soaked titillaters over at E!
Politics pretending to be science, on the other hand, is current, and it is chic.
It’s useful, too. For all of the hype, much of the fadlike fetishization of “Big Data” is merely the latest repackaging of old and tired progressive ideas about who in our society should enjoy the most political power. Outside of our laboratories, “it’s just science!” is typically a dodge — a bullying tactic designed to hide a crushingly boring orthodox progressivism behind the veil of dispassionate empiricism and to pretend that Hayek’s observation that even the smartest of central planners can never have the information they would need to centrally plan was obviated by the invention of the computer. If politics should be determined by pragmatism, and the pragmatists are all on the left . . . well, you do the math.
All over the Internet, Neil deGrasse Tyson’s face is presented next to words that he may or may not have spoken. “Other than being a scientist,” he says in one image, “I’m not any other kind of -ist. These -ists and -isms are philosophies; they’re philosophical portfolios that people attach themselves to and then the philosophy does the thinking for you instead of you doing the thinking yourself.” Translation: All of my political and moral judgments are original, unlike those of the rubes who subscribe to ideologies, philosophies, and religious frameworks. My worldview is driven only by the data.
This is nonsense. Progressives not only believe all sorts of unscientific things — that Medicaid, the VA, and Head Start work; that school choice does not; that abortion carries with it few important medical questions; that GM crops make the world worse; that one can attribute every hurricane, wildfire, and heat wave to “climate change”; that it’s feasible that renewable energy will take over from fossil fuels anytime soon — but also do their level best to block investigation into any area that they consider too delicate. You’ll note that the typical objections to the likes of Charles Murray and Paul McHugh aren’t scientific at all, but amount to asking lamely why anybody would say something so mean.
Still, even were they paragons of inquiry, the instinct would remain insidious. The scientific process is an incredible thing, but it provides us with information rather than with ready-made political or moral judgments. Anyone who privileges one value over another (liberty over security, property rights over redistribution) is by definition indulging an “-ism.” Anyone who believes that the Declaration of Independence contains “self-evident truths” is signing on to an “ideology.” Anyone who goes to bat for any form of legal or material equality is expressing the end results of a philosophy.
Perhaps the greatest trick the Left ever managed to play was to successfully sell the ancient and ubiquitous ideas of collectivism, lightly checked political power, and a permanent technocratic class as being “new,” and the radical notions of individual liberty, limited government, and distributed power as being “reactionary.” A century ago, Woodrow Wilson complained that the checks and balances instituted by the Founders were outdated because they had been contrived before the telephone was invented. Now, we are to be liberated by the microchip and the Large Hadron Collider, and we are to have our progress assured by ostensibly disinterested analysts. I would recommend that we not fall for it. Our technology may be sparkling and our scientists may be the best in the world, but our politics are as they ever were. Marie Antoinette is no more welcome in America if she dresses up in a Battlestar Galactica uniform and self-deprecatingly joins Tumblr. Sorry, America. Science is important. But these are not the nerds you’re looking for.
From Nation Review: Neil deGrasse Tyson
So-called scientists who roundly misquote better scientists and pompously dismiss all the other science that contradicts them…
Naturalism is dead. Has been for over seventy years. Anyone still peddling it is a grave robber.
A new Walmart just opened up a couple miles from my home. I’m not a fan of Walmart. I fought against allowing this Walmart to be built at all. Now that it’s open, though, I did go in just so I could try out the new high-tech future of shopping:
The concept is pretty simple. Using the provided scanners or the Walmart Scan & Go app on your smartphone, just scan everything as you put it in the cart. The app maintains a running total of the items in your cart. You can simply click a button to pay for your goods right from the app, and you’re done. Well, almost. You do still have to have a Walmart employee verify the receipt on your smartphone and clear you before you can leave. I’m not sure how it works with the in-store hand scanners, but I assume you would just hand the scanner over to a cashier and then pay whatever the total is.
Using the smartphone camera as a scanner worked more or less flawlessly. It quickly detected and identified the bar code and added the item to my cart. If you buy more than one of the same thing you can choose to scan each one individually, or you can just adjust the quantity in the cart after you scan the first one.
I was curious how Walmart could be sure I had scanned everything. I mean, there is a bit of an honor system in place and there was more than one occasion I threw something into the cart out of habit and had to pull it back out to scan it. Nobody is actually sifting through your cart or going through the list of items you’ve paid for in the app. They just look to see that you’ve paid and send you on your way—sort of like the useless receipt verification you’re subjected to when you try to leave Costco.
A Walmart employee explained that they conduct random periodic checks of customers to keep people honest, and suggested that there may be some customer profiling going on as well. Basically, the implication was that if someone looks “shady” they’re more likely to be singled out for a more thorough inspection. Walmart will also perform a more thorough check if you try to purchase any alcohol or age-restricted items like spray paint using the Scan & Go process.
The new and improved Walmart Scan & Go experience is currently available at only three of the Walmart stores. One in Arkansas, one in Florida, and the one near my home here in the Houston area. Walmart says that it is working on expanding to other stores, so keep your eyes open and maybe it will be available soon at a Walmart near you.
I will still gladly drive farther and pay more just so I don’t have to step foot in a Walmart or give the company any of my money. I do have to admit, though, that Scan & Go is pretty cool. I look forward to other retail chains that aren’t awful (I’m looking at you Target) adopting similar technologies to modernize my shopping experience and welcome the high-tech future of retail. Either that, or I can just continue shopping on Amazon and having items magically show up on my porch two days later.
From Forbes: Walmart Scan and Go
I recently got to use this great app in-store and it was wonderful.
No more checkout lines.
Great integration of tech into the shopping experience.