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Comment Re:Surely You're Joking (Score 1) 337

Meanwhile, in another anecdote, a history professor I know was on a review committee for a junior high-level history textbook used in Texas (among other states, I believe); they did fully review the textbook, only to have a significant portion of their suggested corrections ignored. Also, I don't believe he was lavished much in the way of free dinners, vacations, etc. (maybe they save that for the physicists).

Comment Not Blue Origin's first rocket launch! (Score 3, Informative) 76

This was the first developmental test flight of their New Shepard, but they've been launching rockets since 2006. From

Second test flight: 13 November 2006, 06:30 (Goddard)
Third test flight: 22 March 2007 (Goddard)
Fourth test flight: 19 April 2007 (Goddard)
Fifth test flight: 6 May 2011 (New Shepard propulsion module (PM2))
Sixth test flight: 24 August 2011 (PM2, failure, loss of vehicle)
Pad escape test flight: 19 October 2012

(Their first test flight was a jet-powered controls testbed, so their first rocket flight was on the second test flight.)

Comment Re:What are they doing to that truck!?! (Score 1) 129

To be spending $0.70/mile on a vehicle putting down 50k+ miles a year, means spending over $35,000 a year on vehicle maintenance.

Much of this cost will be energy cost. Electric powertrains are about three times as efficient as conventional combustion engine powertrains, and on top of that, electricity is cheaper per kilowatt-hour than gas or diesel. Regenerative braking, and not having to idle the engine, would improve the mileage as well.

Comment Re:Why don't they use a single rotor? (Score 1) 129

And yes, it's technically possible to add technology to single-rotor design systems to automate the corrective actions to keep them stable. But by using an octocopter, you can do it a lot more cheaply and more easily.

That's not true; multicopters are computer-stabilized by necessity - they are much harder to manually control than a conventional helicopter configuration. I don't believe it would be significantly more expensive or difficult to add computer stabilization to a conventional R/C helicopter. The main difference is that multicopters are much simpler mechanically, and multicopters with many rotors are more failure-tolerant (e.g., if you have 8 motors and one fails, you can still fly with control and stability on the remaining 7).

Comment Re:Coal power cars make little sense (Score 1) 257

When you punch an electric motor, it stay 98% efficient. When you punch an internal combustion engine, its already miserable efficiency drops into the single digits.

I'm not sure where you're getting your data for this, but I don't think this is typically true. If you look at specific fuel consumption curves (which are inversely proportional to efficiency), most internal combustion engines seem to lose maybe 20% of their efficiency (e.g., from 28% efficient* to 22% efficient) from their peak to "punching" - certainly not dropping into the single digits.

Also, if you're going to make a fair comparison to an electric motor in this context, you need to account for the battery efficiency, which is maybe 85% - gasoline doesn't lose any significant energy on its way from the gas station pump to the car's gas tank to the engine, but an electric car will experience some energy loss from the plug to the battery to the motor (e.g., the batteries heat up under charge and discharge, which is an energy loss, and more energy may be required to cool them back down to keep them comfortable).

*I'm estimating the efficiency of the uninstalled engine, not including drivetrain losses, accessory losses, etc.

Comment Re:Blastoff From the Past (Score 2) 19

Looking at Bezos's New Shepherd Vertical Takeoff Vertical Landing vehicle you might think that somewhere along the line Jeff caught a glimpse of Boeing's old design.

I assume you're talking about the right image in the Encyclopedia Astronautica link - that is an educated (and ultimately incorrect) guess by Encyclopedia Astronautica of what the vehicle would look like, from years before actual images were released (see

Comment Re:I don't think the cypher is the problem. (Score 1) 270

Incorrect. The F-22 and F-35 have both active and passive seekers, and they're able to determine range, altitude, and bearing with just their passive seeker.

What passive seeker are you referring to on the F-22? It doesn't have much, relatively, and certainly nothing like the F-35's infrared search and track/electro-optical targeting system. The F-22 normally relies on either datalinked targeting information from another aircraft or its own LPI (low-probability-of-intercept) radar.

Comment Re:I don't think the cypher is the problem. (Score 1) 270

the only passive seeker that will always remain effective is IR band, because they kinda need the engines to fly. but its also rather short range, wont give real accurate RAB (RAB being only really relevent for BVR) and if you're that close and can pickup his tailpipes, you already know where he's at, and which way hes going.

Actually, modern infrared search and track systems ( are quite capable - the range is less than radar, but can be dozens of miles, which is plenty of distance to acquire and track a target and launch a missile, which could also employ a passive seeker.

Comment Re:Occam's Razor (Score 1) 339

The fact that they don't even produce a 4th generation fighter of their own design (most of their fighters are copied/adapted from Russian designs) and suddenly they unveil this supposed 5th generation fighter supposedly without any foreign technology.

This statement would have held weight 15 years ago, but China's been modernizing their military quickly. They have recently designed (and put into service) the capable J-10 themselves, including a modern updated version (J-10B), as well as the JF-17 with Pakistan.

Comment Re:No surprise (Score 2) 339

Technology stolen would probably include anti-radar coatings and perhaps engine and avionics.

The J20 is simply too big to be very stealthy.

Size has little to do with stealth. The B-2 is about seven times as big as the F-117, but still manages a radar cross-section of 0.1 square meters.
Not to mention that we don't actually know the J-20's dimensions or weight. It may not be any bigger than an F-22.

Anti-radar coatings is a reasonable guess, but China has access to much more modern engine and avionics technology via Russian fighter jets.

Comment Re:Since when... (Score 1) 371

You mean like ... china, paper, woodblock printing, gunpowder, compass, the fork, fireworks, go, maglev wind power generators, negative numbers, menus, tea, toilet paper or the toothbrush?

I mean, granted, not all of these are new things - in fact most of them are all fairly old (the maglev being the exception), but I really doubt any of us would want to go without them.

You mean the maglev that was designed and built by Germans?

Comment Re:Key Points (Score 1) 215

1. They are not talking about autonomous UAVs. These UAVs are essentially remote-controlled aircraft piloted by real pilots. I think some people assume these things think for themselves but that's not the case. Now that doesn't automatically discount concerns of safety, but "skynet" is not the case here.

Well they're not really remote-controlled aircraft; instead of responding to, say, pitch, roll, and throttle commands, you tell them where to go and what to do and they figure out how to get there themselves. This has worked out very well for the military, but the FAA hasn't trusted UAVs enough to allow them to prove themselves in large-scale civil usage. For example, the military wanted to use their UAVs to help out with Katrina efforts, but since it was in civil airspace, they weren't allowed to.

2. This is not specifically for military only. Many uses for UAVs exist outside of military applications such as basic transport. Of course they'll use them for surveillance, but they already do that with aircraft. UAVs can simply linger longer because one pilot can take over during flight. Similar to how large aircraft do it now with redundant crew members.

I think initially these are going to be used to supplement/replace things like news, traffic and police aircraft/helicopters. NASA's already been using some for years to help with monitoring California wildfires.

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