Let's think about this a bit first. At a place like Costco, you may be trying to feed 20+ registers at a busy time. In terms of average wait time, it's better to have each line constantly full rather than to have someone have to move over to a register and start putting things up on the conveyor belt only after someone else cleared said register. One solution to this is that you specify have exactly one customer waiting behind each register, starting to load goods onto the conveyor belt. First of all, you now have the exact unfairness issue that multiple lines causes since one person might be behind someone with one item, and another behind someone with dozens of items. Might as well let them pick lines since you have the same result anyways, and don't need as much space dedicated to people forming a long line. If you still want to consider a single line, what about those far away stations (there must be at least one register 10 stations away or more)? And what if someone at one of those far away locations only has one or two items? Maybe we should switch to two customers behind each register before forming a big line? And how does a single line affect traffic in the store when you have 40+ people jamming up your main aisle on one side? Maybe we should have a line on each side? Or maybe it's best to let the customers sort through the situation, and just focus on having all open registers used to capacity, as currently is done.

And there we have it. Maxwell's Demon, telling us how it all was done!

For those with Flash and too lazy to navigate the Honda website, here's a link to a nice 2 minute video commemorating ASIMO's birthday. Now when can we get one that has all the capabilities of Servo, the humanoid robot assistant in The Sims?

This isn't really my field, but I've given some thought to the use of water for this purpose. The biggest practical problem is the problem of getting the exact same water (in terms of isotope composition) to everybody. You presumably would use Vienna Standard Mean Ocean Water (VSMOW, itself a mix of distilled ocean waters from different locations) as your standard since our temperature definition is already tied to the triple point of VSMOW (defined as 273.16 Kelvin). But the triple point temperature is significantly less sensitive to isotopic composition than the mass is.

Based on the Wikipedia-reported tolerance for the isotopic composition of VSMOW, I calculate that VSMOW is defined with a tolerance for +/- 1 ppm average molecular weight difference. That roughly translates into a +/- 1 ppm difference in density. I doubt anyone at NIST (or at any other group) would find such a large error bar to be acceptable for a new definition of the kilogram. That probably is a major reason why silicon is favored: Thanks to all the research in the semiconductor industry, we're really good at getting pure silicon-28.

Speaking about patents broadly (and not just about software), yes, in theory patents should be for something novel, non-obvious, and useful at the time of the filing. The whole point of a patent is to protect the rights of an innovator, allowing the person/entity to exploit an invention, which may well become obvious to others once implemented. Non-obviousness does not mean that someone else couldn't do it.

Take a right-handed batter. The swing will turn the batter toward third, making the run toward first naturally start toward the inside of the diamond. On the other hand, a left-handed batter will naturally start on a more outward trajectory. I wonder if this is a quantifiable advantage in doubles statistics for left-handed batters after accounting for factors like the shorter distance to first base from the left-handed batter's box.

Magellan didn't just go along the equator, plowing his way through landmasses. The actual distance he travelled is significantly longer than the circumference of the earth. So his average distance covered per day is longer, too.

I wouldn't rule out an unmanned space probe launched in the lifetimes of the younger /. audience and headed toward a nearby solar system.

One can never prove a theory of everything, but one can validate the theory against all observables. If multiple theories emerge, all of which satisfy everything observed, then I would favor the simplest one (hopefully not a theory with more variables than there are atoms in the universe). Furthermore, the more complex one must predict something different from the simpler one, or else they would be fundamentally the same. So that would lead to a testable hypothesis to choose between different theories of everything.

Personally, I think a "theory of everything" with so many variables that it cannot be falsified (some string theory, for example) is a waste of time. Look at relativity. It's a paradigm changer, yet so simple that it can be expressed by a few basic assumptions. We need more theories of that sort, giving us deep insight into reality without throwing in tons of fudge factors.

If an alien species came to us, then it either is native to outer space, or got here by some sort of spaceship. Assuming the latter, the alien species obviously also is using transportation devices, and should have no trouble recognizing our cars as transportation just as we should have no trouble recognizing its spaceship as transportation. They'd likely find the person behind the wheel more interesting than the car. As long as they find the land most interesting, based on the human technological footprint on the planet, they likely would choose to contact humans. However, if they love water, they may well choose to contact a dolphin first.

Yes. He was quite popular with the chemistry and biology crowd at my institute. People always go to post-seminar receptions for the free food and beer. But in this case, much of the audience also chose to go so that they could continue to talk with him after the question-and-answer time had already run out. Nobel laureates excepted, I can't remember another time when so many people spent so much time with the speaker at the reception. It seemed as if it could be interesting talking with him for the whole afternoon, if only he didn't have to leave for the airport so early.

Dr. Consolmagno spoke at our decidedly non-religious institute (The Scripps Research Institute) back in February. He often represents Europe in international astronomy meetings, including when they were deciding whether to demote Pluto. In his seminar, he gave us a preview of his book, The Heavens Proclaim: Astronomy and the Vatican. It was mostly showing us pretty pictures in the book and telling us all sorts of interesting anecdotes from his experiences. He also covered a multitude of other topics, ranging from those of purely scientific concern (e.g. figuring out a way to determine the density of a meteorite) to historical controversies (e.g. the church and Galileo). It was one of the most interesting seminars I've attended this year. If given another chance to attend a seminar of his, I would gladly do so. In fact, if I were to know about it in advance, I might even buy a copy of his book for him to sign.

Sounds good to me. After all, all signals in your nervous system do exactly that. The nerve can only send one signal, and it's always the exact same strength. The signal is, if you will, a generic unladen swallow, identical to any other generic unladen swallow. All that a nerve is capable of modulating is when it sends its signals.

Alternatively, the above idea of using European and African swallows works.

You're thinking of the Atmos clock. I would love to have one someday. I doubt moving it around is much of an issue... it can't be worse than the handling during shipping. They're not that common simply because they're expensive novelties. Few people are willing to pay so much money for a clock, no matter how advanced.

Agree with points 2 and 3. However, point one is easy. GPS satellites are basically atomic clocks in orbit transmitting the time. Every time one uses GPS, one is relying on the results of atomic clocks, with both general and special relativity taken into account.