Don't normally reply to myself, but that was a Cut and paste out of another article here. :)

More likely someone doesn't know that there is a difference between a Ton and a Tonne, and figures they're just the british and american ways of spelling the same thing. The dragon capsule is rated to return up to 2500kg of mass to the earth, so it stands to reason that this is just a lack of pedantry on the part of the author.

Well, the drivers get the very real benefit of fewer vehicles on the roads. Even if we ignore Stockholm's (very good) subway system, a bus carrying 40 passengers probably means 15+ cars that are not on the road.

I think that many people forget the NSA's other mission: securing US Government communications. The easiest way to figure out how secure an algorithm is, is to take a look at what level of information it's authorized for. Despite everything that all the folks here say, the NSA and other agencies aren't stupid. They know full well that if they can break the algorithm, somebody else can as well.

The saddle patch is accepted by the scientists in the field to be a unique identifier. No two whales have ever been found to have identical saddle patches, and there is enough variation to indicate they are unique. So is it possible? yes. Likely? No.

Add to this the fact that the data from these old photos lines up with her offspring history, and it's a pretty solid case. In 1971, she was photographed with a male offspring who was already fully grown, so at least 20 years old. She was not seen with any other younger offspring, indicating that he was probably her last. Orcas go through the whale equivalent of menopause at age 40, so 20+40 gives her an age of 60 at the time, and thus 1911 as a birth year.

Anyhow, combine the two pieces of data (the 1930s photo, showing her fully grown) and the offspring data, and it's pretty compelling that she was born roughly 103 years ago, give or take a few.

This case is one of the usual case studies that make up many Engineering Ethics courses (at least it was brought up in mine). The nice thing about this case is that in the end, it all worked out for the better, and is a good news story rather than a disaster.

The other typical case studies are the Therac 25, Challenger Disaster, Hyatt Walkway Collapse and in Canada the Quebec Bridge collapse (which also lead to the creation of the Iron Ring.

There is a significant portion of the Engineering education that is dedicated to reminding prospective Engineers of their responsibilities to society, and the power they can potentially wield. Ethics is also a significant portion of the licensure to get one's professional designation.

The Annals of Improbable Research is quite reasonably priced, and a good read.

After all, where else could you read about "Homosexual Necrophilia in the Mallard Duck" or "Predicting when cows will lie down"?

I work with a number of locations that lack any form of high speed internet. They have enough internet to facebook, order the DVDs, etc... but nowhere near enough bandwidth to actually stream the movies. The DVD-by-mail option is their only option, if netflix et al were to shut down this service, they would be very unhappy.

"Stationary" satellites aren't really. They drift around within an approximately 30km x 30km x 30km box, and these movements are very well known. This isn't much, but is enough that you can locate an earth station to within a few miles if you have enough time. IN this case, they only have a few pieces of data, hence the larger solution.

There's often very little signal generation being done on the spacecraft itself. Putting complex electronics in the radiation environment of space, where it can't be repaired, and electrical power is at a premium, is generally a bad idea. With certain exceptions (Iridium et al), all the intelligence is done on the ground, where it can be maintained and repaired. Most satellites are just dumb bent pipes.

Years ago, I assisted a major satellite operator with geo-locating an interfering uplink. Based on the doppler shift caused by the motion of the satellite, and about 72 hours of repeated sensing and passes, they were able to narrow down the offending dish to within a 1 mile by 5 mile ellipse. That's small enough that they can go and "mow the lawn" with equipment on a helicopter or other aircraft to find the offender. As I recall, in the end the offender was a failed credit card clearing system on a gas station west of Detroit.

The communications system in question is likely based on TDMA (Time Division Multiple Access). While I have not worked with Inmarsat systems, all the other satcom systems I have worked with log each connection, and various pieces of information regarding the connection. One of these parameters that is logged is the frequency offset (ie the difference between the expected and actual frequency). This is useful from a troubleshooting perspective as it allows you to spot transmitter and receiver components that are drifting out of specification. Some of the more advanced satellite systems (iDirect) will actually log the geographic coordinates of the uplink site, as this plays into the timing requirements for the network. Unfortunately, Inmarsat isn't this aggressive with their timing, so time of flight isn't an issue).

This is pure speculation on my part, but I would wager they had to go back through significant amounts of logs in order to characterize the transmitter and receiver components on that particular aircraft. The doppler effect is going to be subtle compared to the thermal drift of the transmitter, so they need to factor that out before they can get at the thermal drift. Also every oscillator and transmitter is different, so they would need to characterize the transmitter that is on that specific aircraft (which is now of course missing).

Every so often, especially in certain times of a year, you get these massive natural electrical discharges called "lightning" that does quite a good job of starting forest fires.

Uhmm, not necessarily true. YVR, the second busiest airport in Canada, has all of its jet fuel trucked in from the Cherry Point refinery in Washington State. There is a proposal to lay a pipeline, but NIMBY is proving a pain to overcome. I'm sure this is the case for many other airports as well.

Actually, most flight tracking at least over land, is done via ACARS, which is a VHF radio system that beacons the aircraft position, altitude, etc... as well as allows sending of short messages. This is in addition to the radar transponder system.

Actually, the SPOT uses the Iridium Short Burst Data system, so it goes out via satellite, and will work anywhere on the planet, other than those where it's explicitly prohibited by local laws.