Perhaps longer. Jules Verne described the Nautilus power source as being Bunsen cells with a sodium-mercury amalgam for one of the electrodes. They were primary - not rechargeable batteries. Discharging the batteries consumed the sodium leaving the mercury for recycling.

This. The shuttles on display have really fake looking dummy engines (at least the one in the Smithsonian does) so that the real ones could be used for SLS.

This probably saved a tiny bit in proportion to the entire SLS cost.

If they really wanted to use this engine model they should have kept the line open and then they would have been available for an ongoing program.

The EPA would impound them all in the same warehouse.

That would save the Chinese the effort of collecting the tanks in one consolidated location.

Was tried. Turned out to be massively unpopular in practice. Was quickly repealed.

Might not be the same this time, but don't count on it.

Still exists in Wikipedia's history. Not on the current page unless somebody snuck it back in.

Lots of people have the same mass so it won't do a good job of distinguishing between people.
People's mass chages over time - some people even do it on purpose - so it won't do aq good job of recognizing the same person.

oh... wait....

And what is bill C-10? Bills in the US Congress have H- or S- numbers. Just curious.

Sounds like a positive feedback loop. A negative feedback loop would have reduced the problem.

Thanks, that confirms my original suspicion that there must be more than two possible values for an allele or marker.

I do wish I knew if I was conversing with one or two ACs.

If we make a stack of simplifying assumptions, first that each of 20 allele (marker? what is the best term?) occurs from 1 to 20 times, with each count equally probable then the probability of an individual match would be 1/20 or 5%, and the first AC's 0.05^20 probability for a perfect match becomes a reasonable calculation.

The real world isn't that neat and I wouldn't expect any of those assumptions to hold in real life. Each marker will have its own range of possible values with its own frequency distribution. The ideal of non-correlation between marker-values won't be perfectly met etc.

I need to go educate myself.

That would be worse, if true.

There would still only be 2^20 possible values of presence or absence, so only a little over one million possible results. Much like collisions between 20 bit checksums.

If the individual markers are rare than results with many markers present would be rare and the probability of a false match would be much higher than one in a million.

As a thought experiment, if the markers were so rare that it would be unusual for an individual to have more than one there would only be 21 likely results (including no marker present). Every city bus would have multiple false matches.

I rather suspect that there is something I'm not getting - but you haven't found it for me yet. I do appreciate the effort, however.

Presence or absence of 20 markers only gives a little over one million possible results. You need more possible values per marker than just presence or absence to get better than one in a million results.

I have long assumed that it isn't just presence or absence, but would like some confirmation from somebody that knows.

Add in the problem of possible corellation between markers. If value of one marker is correlated to the value of another marker the probability of a false match is increased.

Also add in the problem that values for markers may not be uniformly distributed. Absence of a rare marker does not really add much to the confidence of a match.

All of these factors can probably be controlled and accounted for to validate marker selection and procedures to get valid results. There needs to be assurances that this has been done, and done correctly over a large enough (and diverse enough) population for the results to be considered valid.

Fairfax County, Virginia, operates a fleet of 1,630 buses. I just checked the web site for the number. This is a major expense. The transportation department dictates bell schedules.

Every time somebody tries to get rational start times they come up with a bus routing plan that seriously increases expenses.

It doesn't make sense to me. If a bus can carry high school and then elementary school it should just as well make the same trips in a different order.

New printers are unlikely to need an update to cups, but a new or updated filter. Most likely a ghostscript update.

I'm a bit confused, I think you might be calling me a liar but we seem to agree on almost all the main points.

It was 1973, not 1970 - but that isn't wrong just less precise.

You were there, and so was I (but I didn't say so, I perversely liked waiting for the bus in the dark).

We agree that it didn't save energy.

I said it was widely unpopular, you were silent on popularity. Perhaps we differ here. Congress got enough heat that they called off the experiment early.

You called it a circle jerk, I didn't but I do agree with your assessment.

See https://www.mercurynews.com/20... for some history.

This was actually tried back in the 1970s as an energy saving tactic.

It didn't save energy and everybody hated it. Newspapers were full of stories about kids waiting in the dark for their school buses seeing their puppies run over before their very eyes.

Seriously.