Except that if you add the filtering to GPS receivers so they can reject that billions of times stronger Lightsquared signal in the adjacent band, there would be no GPS in your phone. In fact no handheld GPS receivers. Not to mention turning most of the installed base of GPS receivers into doorstops.

The whole point is that satellite signals are really weak, so we put all the satellite frequencies together and keep terrestrial broadcasters out. That's also why satellite frequencies are cheaper than terrestrial ones. But in today's "money trumps reason" world that means nothing -- after all, this science stuff is just a theory.

What's stopping me from selling numerous copies of my MP3s and retaining my original copies?

• 1. Your conscience.
• 2. It's illegal.

High power lasers are hard to reflect (or refract). For example if your mirror/lens is 99.9% efficient (much higher than real-world optics), it absorbs a thousandth of the beam's energy. In other words if you want to reflect a megawatt laser beam, the mirror has to dissipate a kilowatt.

I'm with you bro -- but it's not the place of the fucking government.

Here's a New Yorker cartoon, 1972.

A truly erroneous hard-left outlook, but stupidity is fitting given your account name. ... The primary driver of jihad is the desire to subjugate the entire world to the dictates of Islamic dictatorship.

Such busllshit. Apparently all you inbred mouth-breathing teabagging fascists are as dumb as Republicans. (How do you like them ad hominems?)

Do you actually know any radical muslims? (Any muslims?) Have you talked to a suicide bomber? The plain fact is that the vast majority of humans -- muslims, christians, or atheists -- really don't give a shit about subjugating worlds and craps like that, they just want to live their lives and raise their families. To get populations riled up to violence you have to invade their country and attack their families and communities. You know, like those 19 Saudi guys on that date that all you wackos fetishize. And like what we're doing right now in so many places around the world.

Scientists ought to seek out other countries for funding. ... China ...

Other countries, perhaps. But China? Why do you think a scientist will feel more free to speak his or her mind in China than in Canada?

For photos, it might make sense to use drones when they can get closer without attracting attention.

Never going to happen. The fundamental principle in the US National Airspace System is "see and avoid". If you're not actually in a cloud, you are responsible for avoiding other aircraft. If there's no pilot in the aircraft, it can't avoid others. (Remember that some aircraft do not even have electrical systems, let alone fancy shit like radios and transponders.)

The military can fly unmanned aircraft, but (supposedly) only in airspace that excludes non-participating aircraft.

Something tells me they had to get SOME kind of special permission for this:

Why do you think so? Right now you can go to your neighborhood airport and hire an aircraft and pilot for around $500 an hour, and take as many airport pictures as you like. Yes, even military airports and installations.

So, do you have to keep the whole number in the memory to calculate some more digits?

No, you don't even have to calculate the previous digits -- see spigot algorithms like the BBP algorithm.

There I was reading your message and agreeing with everything until

... what, was he hired by Google as a janitor?

This is not some random google engineer, this is Rob Pike . You should pay attention.

30,000 square meters = 30 square kilometers = 18.5 square miles

Whoa there, buddy! I know a meter is large, but not that large! 30,000 sq m is the area of a field that is 150 m by 200 m. Which is about 500 feet by 660 feet.

TeX 3.15 will get released.

You misunderstand TeX version numbering. It's 3, 3.1, 3.14, 3.141, ... you get the idea.

I bet that's the announcement: that the last bug is fixed and TeX is at version \pi.

You may be right about congress, but in this case we're not talking about laws but regulations. Regulations are enacted by agencies, and Congress passes appropriate laws so the agencies regulations have some teeth.

In the present case: the aviation regulations -- the FARs -- are all about exactly how things are done. Try reading an airline's Ops Spec sometime -- it spells out exactly what is to be done and how, for all operations conducted by the airline. The FAA specs on navigational beacons lay out everything about the system, not just what but how. This ensures that all users of the ATC system have the same view of reality.

So of course ATC (not "tower") cares about exactly how the information is sent from an aircraft to the system. ATC does in general care about what kind of nav system you're getting your info from, since the different systems have different error characteristics. (Also, this is an automated system, we're not talking about pilot reports.) All the information required for a company to implement the components of the system -- like the airborne transmitter -- is fully specified.

Radar doesn't require an active participant on the other end.

Not true. You're thinking of what's called "primary" radar, where the target reflects the transmitter's signal. The problem with primary radar is that range falls off as the inverse fourth power of signal strength -- inverse-square loss on the way to the target and another inverse-square from the target. That's why most ATC radar is "secondary" -- there is a specialized transmitter on the airplane (called a transponder) that the radar system interrogates, and the aircraft replies with its ID, altitude, and a couple of other things. Since it's an active system, it's ordinary inverse-square falloff, and it provides more information. (If you look carefully at airport radar installations, you'll notice that there are two antennas spinning together, one above the other. The "secondary" antenna is usually on top and flat; the primary is on the bottom and is usually paraboloid.

Today, in the US, primary radar is almost never used; most controllers configure their screens to not show "primary only" targets.

There really is no sound business model for making software of this caliber unless ...

If there is a conflict between a company's business model and ethics, it should mean that the company folds or changes its plan. (But the capitalist way is to convince people that ethics are outdated and then carry on.)