Nit: The energy of an object going 2,000 m/s is 1/16th of that going 8,000 m/s, but since this is a rocket launching from Earth the energy for the rocket to get to 2,000 m/s is much greater than the energy to go from 2,000 m/s to 8,000 m/s [1].
Just look at how much larger the first stage (mass almost all propellant) is compared to the second stage (large fraction of the mass is the payload).
That has nothing to do with the rocket launching from Earth (A rocket in space follows the same rules), and everything to do with the fact that rockets expend most of their energy to push their own fuel.
That fact is incredibly relevant for getting to orbit - however, it is not at all relevant for surviving re-entry, where all that matters is your kinetic energy.
The Earth part was just shorthand for the fact that the atmosphere and gravity of Earth add about 1.3–1.8 km/s of delta v to achieving the pure kinetic delta v of 7.8 km/s needed to achieve LEO [1]. The first stage adds almost all of this "extra" delta v.
I was mostly just correcting your "one-sixteenth of the energy required for orbit" statement. I agree that reentering at 7.8 km/s is much more difficult than 2.0 km/s, but the second stage is smaller and more spherical than the first stage. That might make reentering it a bit easier than if it had the shape of the first stage.
I would suggest getting a "Benchmak Maps" atlas of the state you are traveling in. About $25 each. The whole state at 1:300,000 with comprehensive coverage of many features. You will find all the dirt roads and many trails. Good for driving into and around the back country. For hiking, especially off trail, I prefer good old 1:24,000 USGS maps.
When a city in America is destroyed by a nuclear explosion, Americans will re-learn why suburbia was so popular. Hopefully this won't happen for a long time and we will have a good stretch of city living. I love cities, but having millions of people concentrated enough to be killed by a single device; this is very different world than the one humans evolved in.
That's such a terrible reason not to live in a city. I don't see how it is significantly more likely for only a single incident like that to happen. If we really have a catasophre or act of war it will likely effect larger regions than just a single city.
If they made Google Maps better, users would replace Waze with it and their data collection would decrease. Since an app needs to run in the background to collect speed and location data, moving that feature to Google Maps would be a negative to most users.
Maybe at some point in the future there will be a universal app.
I think Google purchased Waze as a way to get up-to-date traffic information. Beyond that I don't think there is much integration between WAZE and Google Maps. Waze still uses community built maps for instance.
The journal article in Nature can be found here[1]. The abstract is publicly accessible with the article behind a paywall. I'm not familiar enough with the dating method to comment on the possible problems of the age determination, but it was calculated by the complicated method of "230Th/U radiometric analysis of multiple bone specimens using diffusion–adsorption–decay dating models indicating a burial date of 130.7 ± 9.4 thousand years ago."
