It's not clear that will ever be needed. EV batteries don't just stop working (barring some unusual fault); they just gradually decline in capacity, and the decline is very slow after the first 1-2 years. So expect to have 95% of capacity after two years, 80% after a decade, 60% after two decades, 50% after three, etc.

So it's just a question of when the capacity drops so low that the vehicle no longer has enough range -- but over time charging infrastructure is going to get better and better, so long range will become less and less important. Also, batteries are going to get cheaper.

So, yeah, it seems entirely reasonable to me to replace the battery in 20 years (if you haven't replaced the vehicle by then). Especially since the fuel savings over that time will far more than cover the replacement cost, even if the replacement cost hasn't come down, which it will!

Not news to me, either, Drew.

The exponential growth achievable by Von Neumann probes that don't mind traveling for millions of years to get to the next galaxy make space small.

What are these scientifically-sound indicators?

Aaw, I should have told you. Thereâ(TM)s some equation that relates energy, mass, and the speed of light. Probably most physics postdocs have heard of it.

Thanks, Will-O. I quite remember this cia guyâ(TM)s rubber stamp collection with dozens of great stamps: NOFORN, EYES-ONLY, and different fonts of Secret and top secret. Damn, but the guard at the place seized my paper with all those stamps.

On the other hand, I still have a VIP parking pass for the CIA headquarters â" Lets ypu park right at the front steps. Valid, if you have a time machine going back to April 5, 1988.

My warm thoughts fly over to you, Kill (owatt-) Hour â" last weekâ(TM)s eclipse fund me beneath stratus clouds just east of Buffalo, having a wonderful (though cloudy) day with 4 generations of my family. Itâ(TM)s a joy to see how my home town has evolved â" memories of climbing the Michigan Avenue Lift Bridge at midnight and watching them tap the redhot coke ovens at Bethlehem/Lackawanna Steel mills.

Following up, I am honored by the attention and kindness of fellow nerds and online friends. When I first started on that chase in 1986, I had no idea wrhere it would lead me.

A curious accounting error led me through Unix internals, tcp/ip protocols, early Arpanet connections, and backwards to a group of computer hackers working for then Soviet & Stassi agencies. Along the way, I met people from the FBI, NSA, CIA, AFOSI, and plenty of very smart computer jocks.

It was a time of analog phones and dial up modems; when you would carry coins in your pocket to make calls on the street.

Since then, thanks to the support of online friends and math folk, I have explored and shared interests in topology and math. Along the way, Iâ(TM)ve made plenty of mistakes and bloopers; pretty much the same as student times. Goofups in grad school are easier to sweep aside!

To all my friends: May you burdens be light and your purpose high. Stay curious!

- Cliff

Iâ(TM)ve been away from slashdot for a while, and Iâ(TM)m now on a post-eclipse trip on the east coast.

With good fortitune (and Amtrak), Iâ(TM)ll be home in 10 days; Iâ(TM)ll then fill the tsunami of Klein bottle orders that havve arrived in the past few hours. Over a dozenâ" Iâ(TM)ll be catching up for a few days!

Smiles all around,
-Cliff on a rainy Saturday in Potsdam, NU

I suppose some of that may be down to the difference in the value of the change. It was worth about 2.5X what it is today back when I was working convenience store night shifts, so people might have cared more about getting it correct.

Even more, people at Starbucks are paying $7 for a cup of coffee, so they're clearly not very price-sensitive. If the customer doesn't bother to look to see whether they got the correct change, should the cashier waste everyone's time getting it right? I think yes, but I could see where people might disagree.

I know people at the convenience store got pissed when they got shortchanged, which is why cashiers who couldn't count change out got fired pretty quickly. They might last longer at Starbucks today. Especially since most customers don't pay with cash.

That's not new. I saw the same problem when I was working at a convenience store in the late 80s.

The fact that they can get a job in another country easily doesn't mean they don't fear being required to leave this one. Most immigrants like the US and don't want to leave it, and even if they didn't care about the US in particular they've often built lives here that they don't want to uproot. I've seen several really smart, talented people get booted out of the country over bizarre rules or immigration snafus, even with help from expensive immigration attorneys. It's stupid.

And, of course, many more are willing to be abused by their employers in order to stay. I don't see that problem so much, because although I work with a lot of people on H1Bs, my employer (Google) treats them well, pays them the same as citizens, etc. But it make sense that there is a lot of abuse in the broader industry.

That doesn't happen much, not unless the worker is forced to go back because of crappy H1B policies. The fact is that nearly all foreign workers would love to stay permanently.

Well, there is a non-zero probability that the Earth could enter a runaway warming cycle and become another Venus, with surface temperatures exceeding 400C. The planet wouldn't be destroyed, but life would probably be wiped out. AFAIK we haven't found any life form that can survive above about 120C.

That seems unlikely, though, given that Earth's hottest phases so far (after the crust cooled, anyway) have been considerably cooler than that.