You may have heard that unmanned drones will eventually be making your Amazon deliveries. The idea seems so crazy, it's bound to raise a few questions. Is it really possible? What kind of obstacles will Amazon chief executive (and Washington Post owner) Jeffrey Bezos have to overcome? And how will his plan shape the future of drone technology? Answers to these and more are below.

First things first. What does Amazon have in mind?

In as little as five years, Amazon says, it's going to field a fleet of drones that will deliver anything you order — so long as it's under five pounds —  in minutes.

What? That's crazy. How would that even work?

Conveniently, Amazon has these giant distribution centers scattered around the country. Most of the company's deliveries start out from these facilities; the drones would simply be cutting out the truck drivers who deliver your packages today.

Jeff Bezos has lost it, hasn't he?

You'd have to be crazy not to think that drone deliveries might play some role in the future of shipping. Amateurs — and some companies, too — have already proven very willing to take on the challenge. So it's only natural that Amazon also sees an opportunity here.

Okay, maybe he's not crazy. But what kind of opportunity are we talking about?

Traditional retailers compete on the strength of their products. But Amazon, increasingly, is competing on the basis of time — fulfilling our wishes as close to instantaneously as possible. The drone strategy promises to cut what's currently a one- or two-day shipping window down to 30 minutes or even less. Drones have an advantage over delivery trucks in that they can use a more direct route, rather than having to follow winding streets. That saves time.

What do we know about Amazon's drones?

Bezos has told us that the drones will be able to carry a five-pound payload for about 10 miles. It's not completely clear whether Bezos expects the drones to come back to the facility in half an hour or if he's only counting outbound travel time. But experts estimate that a 15-minute flight out, followed by a 15-minute flight back, would call for average speeds of 40 miles an hour. That's pretty zippy.

Are current drones even capable of all that?

That depends on what drone researchers call SWaP — size, weight and power. This is essentially a physics problem: The larger your payload, the more lift you need. The more lift you need, the larger your battery has to be, which further adds to the weight, which adds to the power requirements, and so on.

After analyzing Amazon's promotional video, Christopher Vo — a robotics researcher at George Mason University — estimates that Amazon's "octocopter" drone probably uses a 10,000-mAh, 22-volt lithium ion polymer battery made up of six or 10 cells. These batteries are a lot like the ones that power a laptop, except that their chemistry allows for a much greater energy draw. You can find these easily on hobbyist Web sites. And, in fact, according to Vo, you can actually buy an octocopter resembling the one in Amazon's video for about $24,000.

What about larger payloads? Five pounds doesn't sound like much.

It's possible, but improbable, at least for now. Some private drones can carry more than a dozen pounds of weight. But in the "60 Minutes" interview Sunday, Bezos acknowledged that "we're not going to deliver kayaks or table saws that way."

Where we might actually see faster progress is in the way that companies ship things internally. Big 747s and other cargo planes can already fly on autopilot, for the most part. From there, it's not too far of a leap to convert them into fully autonomous aircraft.

Bezos predicts the Amazon drones will take off in about five years. How realistic is that?

It's optimistic but not unrealistic. A spokesperson for the Federal Aviation Administration says that while current rules prohibit Amazon from rolling this out today, a three- to five-year target "kind of lines up" with an FAA process to relax those regulations. Last month, the agency released a roadmap charting out how those regulations will be rewritten. By next August, the FAA expects to have rules ready for consumer drones, followed by guidelines for commercial drones a few years later.

Here's something else to think about: The United States may not actually be the best place to test this program out. Given how long it's taken for the FAA to loosen its policies on commercial drones, we might see Amazon turn to other countries first. Timothy Reuter, who heads a D.C.-based drone hobbyists' group, says Canada might be an attractive choice. "It's not so far away, but they're much more permissive," says Reuter.

Are these drones going to crash into my dogs and kids?

The risk will probably be pretty low, at least at the outset. But that's only because the drones will likely be controlled by humans.

What you're really asking about are fully autonomous drones. The big obstacle is, well, detecting obstacles. Human pilots instinctively know to avoid trees and buildings. Drones don't. For that, they need something called sense-and-avoid technology — which is pretty good at the moment, but not great enough that we can trust an entire machine to fly itself exclusively. Until then, Amazon will probably hire drone pilots to fly each individual drone. Then it might graduate to a system where one overseer is monitoring a handful of machines at once from a control center.

Another way to solve the sense-and-avoid problem, says Vo, is to reduce the number of variables that the drone will have to contend with near the ground. You could do this by building some kind of helipad on people's rooftops so that the drone never has to interact with your doorstep. Maybe this will even become standard across most new homes so that other companies — FedEx, UPS, etc. — could take advantage of it, too.

So, you're saying these things will be equipped with cameras? 

Yep. And that raises a whole range of privacy issues, says Reuter.

"From the video [Amazon] shot, they only showed this thing flying over wide open fields, not anyone's head," says Reuter. "Obviously, the safety risk there was very low. The reality is, they'll be flying over many inhabited areas if this is going to be meaningful. Where this is going to make a lot of sense is in dense urban areas. But that's the hardest nut to crack from a safety and privacy perspective."

(The drones will also presumably need to operate in inclement weather, not only in the clear, sunny skies shown in the corporate video.)

Sounds creepy. I don't want to be watched by an Amazon drone. Wait here -- I'm getting my shotgun.

Whoa, okay. That actually points to something else Amazon will have to think about — how to protect its unmanned vehicles. You're not the only person who's thought about shooting these things down; residents of one Colorado town have even considered giving out actual hunting permits for unmanned vehicles. There are all sorts of other ways you could tamper with airborne delivery devices. For years, the FAA has been battling troublemakers who shine lasers into the eyes of human pilots while they're at the controls. What if somebody tried to blind an Amazon drone?

Then there's the question of how to secure the data link between Amazon's drones and the ground control station that monitors them. You don't want your delivery to get hacked and stolen, or worse — turned into a flying weapon.

"Currently most of the [ground control system] feeds in the consumer space are unencrypted," says George Mason's Vo. "But even if they are encrypted, you can still deny service by radio jamming and other kinds of activities like that."

Hang on. Didn't Amazon just announce a deal with the U.S. Postal Service? Won't these drones supersede them?

That's a possibility. But remember, this future is still years away. Amazon's experiment with drone technology suggests it may be looking at drones as simply one part of a broader delivery system that integrates multiple technologies. There are other emerging new technologies, such as 3D printing and self-driving cars, that might help Amazon tighten up any lags in its supply chain and get items to consumers more quickly.