( CNN ) -- It 's hard to believe , but there was a time when Apple 's computers were accused of being strictly last generation . Their computers were made with clunky Power PC processors , and Windows PC owners smirked at the wheezing Mac platform . Michael Dell even famously said the whole company was so behind the times that if it were up to him , he 'd euthanize it . How things change . While the rest of the industry was counting Apple out , a Steve Jobs newly returned to Apple spent the early part of the last decade quietly assembling a time machine . Following the iPad , iPhone and MacBook Air before it , the retina-display MacBook Pro announced Monday at the Worldwide Developers Conference in San Francisco is just the latest time traveler Apple has sent back to us from the future . It 's a machine so shiny , so shimmering , so futuristic , so unlike anything else out there that it will take the PC-making competition at least a year to release a truly competing product . How did this even happen ? How did Apple assemble its time machine , and why ca n't the likes of Sony , HP , Dell , Acer and Lenovo seem to catch up ? Apple announces high-res laptops . There 's no flux capacitor involved , and although Apple 's design team , led by Jony Ive , is truly visionary , there are lots of companies with revolutionary visions of the future of computing . The difference between Apple and other computer makers is that Apple can actually build the revolutionary , magical machines it dreams up . That 's Apple 's real mojo . They can actualize . Apple can say to themselves that they are going to revolutionize the professional laptop , or the smartphone , or the tablet , and then not only follow through with an enviable purity of design , source all of the parts and manufacture their product in utter secrecy , then ship the resulting en masse and sell them at unheard of profit margins . No one else can . It 's all in Apple 's mastery of the supply chain , which is Tim Cook 's particular genius . His strategy is simple : When Apple decides to go ahead and make a revolutionary new product , it buys up literally almost all of the world 's stock of the components that define the gadget . This not only gives Apple massive discounts in component prices , because they are buying in extreme bulk , but it also prevents the competition from quickly releasing clones of Apple 's iconic machines , or matching Apple in price without cutting corners . It happens time and time again . When Apple first released the iPhone , it took the smartphone industry a year to release a phone that was even competitive , spec-for-spec , by which time Apple had already unveiled the iPhone 3GS . Hardware manufacturers trying to compete with Apple constantly discover that they can only build competing devices off of Apple 's rejected parts , or else build new factories from the ground up to manufacture the parts they need . Look at the iPad . It has no competition , 2Â½ years in . Last quarter , Apple sold almost 12 million iPads . Comparatively , Apple 's biggest competitor -- Samsung -- sold 1.1 million tablets . Why ? Companies simply ca n't build products as good , or Apple 's stranglehold on the manufacturing supply chain prevents them from doing so . Then there 's a MacBook Air . We 're starting to see competitive ultrabooks a year and a half after Apple unveiled the second-gen Air , but that 's only after Intel reportedly set up a massive $ 500 million subsidy fund to help PC makers build a MacBook Air clone . The new retina-display MacBook Pro is another such product . It 's a beast of a machine all around , but its defining feature is a high-resolution display with 220 pixels per inch , each smaller than the acuity of the human eye . It 's far and away the best display of any notebook or even desktop on the market , and you can bet that Apple is in control of most of the world 's supply of the panels necessary to make a machine that even comes close to competing . There 's a famous Ray Bradbury story called `` A Sound of Thunder '' in which a man travels into the prehistoric past , accidentally squashes an insect underfoot and thus indelibly changes the future forever . Apple is that time traveler . The prehistoric insect is the competition . Apple crushes it underfoot with calculated purpose , and that is how the future of computing is once again forever changed . The opinions expressed in this commentary are solely those of John Brownlee .
Brownlee : Unveiling of a new Apple is another sign of Apple 's competitive advantage . He says Apple does more than innovate ; it controls supply chain and freezes out competitors . Apple 's products can then be sold at extraordinarily high profit margins , he says . John Brownlee : MacBook has a virtual `` time machine '' with which it 's able to stay at least a year .