Follow Slashdot blog updates by subscribing to our blog RSS feed

 



Forgot your password?
typodupeerror
DEAL: For $25 - Add A Second Phone Number To Your Smartphone for life! Use promo code SLASHDOT25. Also, Slashdot's Facebook page has a chat bot now. Message it for stories and more. Check out the new SourceForge HTML5 Internet speed test! ×

Comment Re:1 truck, better than 20+ shoppers... (Score 1) 100

One approach is to have "delivery points" spaced about two blocks apart. These can be in stores (preferably ones with late hours), or street-accessible boxes. Packages are left at the delivery points, rather than to every individual's door. This worked well when I lived in an apartment complex. Packages were delivered to the office, not to every apartment, so the delivery trucks weren't cluttering up the streets. In fact, they had dedicated parking spots at the office for deliveries.

If the trucks are dropping multiple items at a delivery point, they are spending less total time on the street, and it's not out of your way to pick up on the way home. Bonus points if the delivery point is a pizza place or restaurant that already does home delivery. For a bit extra they can bring the package to your door, if you are lazy, because they are already set up for it.

Comment Re:The truth is.... (Score 3, Informative) 100

> Huge malls need to die.

Here in Atlanta, the nearby enclosed mall *did* die. It's now warehouses and a film studio. However the large regional "inverted" shopping center (parking in the middle, stores on the perimeter) is doing well. This reflects the change in people's shopping habits. Rather than spending a day wandering an enclosed mall, lugging stuff from store to store, people would rather drive right to the stores they want to visit, load stuff in their car, then move to the next. Less carrying, and faster.

This is all part of the same trend that online shopping and the success of of super-centers reflects. People don't have as much time to shop, so they want to do it faster and more conveniently.

Comment Re:The problem (Score 1) 141

Quads can't, no variable pitch blades.

And you don't see the solution to that?

It's really simple. Regulators mandate safety standards so that - in real world conditions - you don't have cars constantly falling out of the sky due to failures or running into buildings. Engineers determine the designs to meet those standards. If they can't, they don't get to sell it.

Comment Re:EBooks (Score 1) 147

As far as I'm concerned, they don't make ebooks to be as user-friendly as regular books. I want a folding two-page ebook, that I can hold in both hands just like a regular book. The "next page" button would do the equivalent of flipping a regular-book-page, thus showing two new pages on the two-page ebook. Then the ebook can be advantageous by being thinner and lighter than the regular book (because many such books have quite-large numbers of pages). The ebook obviously needs a light-powered low-power display; I THINK that the "IMOD" display can be layered over the top of a solar-cell layer, and if so, the net result would be an ebook such that if you have enough light to see it, then you have enough light to use it (just like a regular book).

Comment Re:I agree, but not for the same reasons as Musk (Score 1) 141

Congratulations, you have it entirely backwards.

The maximum efficiency of a prop, in newtons per watt, is 1 / (v_wake + v_freestream), where velocity is in meters per second. The faster you're moving (the freestream velocity), the less thrust you get per watt. Which is why large props are more efficient (more air moved at a lower wake speed), particularly at low speeds, and same for high bypass jet engines.

Now, in terms of "energy per 100km" or "miles per unit energy", obviously a hover yields "infinite joules per 100km" and "0 miles per joule", because you're not going anywhere. But that's an entirely different situation than propulsive efficiency. If you want to start factoring in motion, then your cross section / drag coefficient / L:D ratio / altitude (and thus density) and so forth come into play, and the optimum speed comes down to a balance between a wide range of factors - the faster you go, the less time you spend flying, but your drag increases quadratically, and your prop efficiency drops (the rate of drop relative to the difference between the freestream and wake velocities). Airplanes maximize this balancing point by having extremely low drag coefficients (Cd), far less than cars tend to have.

Comment Trendy (Score -1) 147

People are being trendy. Old farts have decided to do a "digital detox" for a while. In ten years it will have as much meaning as their Atkins diet. In the end, we all try to limit our unproductive time - but reading is reading, and cutting out your reading just because it is on a "screen" is straight-up retarded. Or trendy. Whatever, I need a smoothy cleanse.

Comment Re:Really? (Score 1) 141

The assumption is that if flying cars were common, there would be vastly more locations. As they basically function like helicopters (in most conceptions - VTOL), they need only something equivalent to a helipad, not an airport. Which is much cheaper and smaller footprint than an airport.

To get to the point of allowing takeoff and landing from, say, a driveway, you'd have to have a long track record of excellent proven safety, and levels of noise reduction that current technology doesn't yet support. It's certainly conceivable in the future, but is anything but a first step for companies working on flying cars today.

I personally view flying cars as pretty much inevitable (although not around the corner) regardless of whether or not they're pursued directly at present. Namely because of delivery drones. Businesses are not going to stop pushing for them because there's such an economic case for them (not having to drive a big truck around city streets, pairing trucks with drones to not have to go down each sidestreet or stop at each location, etc), and they'll advance the technology as needed to get approval - starting small. But economics will continually push them toward making larger and larger models, and the technology to get approval for those. And eventually you'll have models large enough to carry people around, wherein the question will inherently arise, "Why, exactly, aren't they carrying people?"

Comment Re:Really? (Score 1) 141

So your concept is that something statistically likely to crash and injure people would be approved by regulators, rather than manufacturers being forced to prove reliability in real-world usage conditions before being granted approval?

Comment Re:Really? (Score 1) 141

The assumptions involved in your post:

1) Flying cars would be allowed to just take off and land wherever they want.
2) People would be manually piloting them.

I don't know where you're getting your concept of flying cars, but none of the flying car advocates I've ever heard from advocate for either of those things.

Comment Re:The problem with flying cars is... (Score 2) 141

I don't want to think of what they would be like as pilots

Yes, because when people talk about flying cars, they totally mean manual piloting.

I don't even want to consider those traffic jams.

Um...

Waterfall Sr.: Our peace ring has 'em trapped like a tiger in a washing machine!
[The engine of the Planet Express ship flares up.]
Leela: Get ready!
Protestor #1: Look out!
Protestor #2: Hold on!
Waterfall Sr.: Here they come!
[The ship rises up from the middle of the peace ring and tows the tanker over the top of the protestors. It flies away.]
Leela: When you were planning this peace ring, didn't you realise spaceships can move in three dimensions?
Waterfall Sr.: No, I did not.

Slashdot Top Deals

Sendmail may be safely run set-user-id to root. -- Eric Allman, "Sendmail Installation Guide"

Working...