The number of people who are not covered by above-mentioned fiber/cell network, and can afford Starlink as it is priced now, will be extremely small (likely making Starlink unviable as a profitable business).
I love this type of articles where we can reconstruct what happened so long ago just based on careful observations.
Some other instances I've come across:
* The K-Pg extinction event that wiped off dinosaurs had the impact it did because the asteroid happened to impact a shallow water region. This kicked up a lot of sulfur (in gypsum) that further affected global climate: https://en.wikipedia.org/wiki/Chicxulub_crater#Effects
* Earth likely had rings ~466M years ago. We deduced this by looking at impact craters from that time period, and seeing that they all lie near the equator (accounting for continental drift): https://www.sciencedirect.com/science/article/pii/S0012821X2...
* Earth's rotation period was probably frozen at 21h, ~600M years ago, likely due to interaction between lunar and solar tides. This resonance could have been broken by ice ages (!!!). Amazing to think that global climate affects earth's rotation: https://en.wikipedia.org/wiki/Earth%27s_rotation#Resonant_st...
If PETM was due to large scale use of hydrocarbons, there should be evidence of depletion in the strata, right? For example, currently not all sources are uniformly exploited -- some coal seams and oilfields are all but depleted, others are currently being extracted, and others are yet to be found/exploited.
We should have seen signs of similar non-uniform usage in the strata from before that time period. I wonder if any research has been done on this.
> How many of them have liquid water without being super saturated with salts? What is the level of confidence we have?
We don't know the composition yet, just that a salty ocean supports the evidence we've seen. For example, Europa interacts with Jupiter's magnetic field in such a way that makes sense only if there is a large amount of electrically conducive material inside Europa. Given what we know about its formation, metallic stuff is unlikely. A salty subsurface ocean is a more suitable explanation. We'll know once Europa Clipper gets there (one of its missions is to 'taste' the ocean by flying past really close).
There are other reasons to suspect a subsurface ocean, such as signs of a geologically active body (like Enceladus), which in turn implies there is enough heat inside to have an ocean.
> Which are most likely to bear life given our current hypotheses around the origins of life?
Europa, maybe Enceladus. Note that our search for life is heavily guided (biased?) by our understanding of how we think life started here on Earth.
Specifically, we needed these ingredients (non-exhaustive):
* a liquid medium to act as shelter and transport medium (liquid water ocean)
* a source of energy, something that life can 'eat' (hydrothermal vents in the beginning, sunlight later)
* protection from space-borne threats (atmosphere, magnetic field)
* a home that isn't geologically dead (like the Moon, or Mercury), but also isn't too active (like Io)
Europa checks most of the requirements:
* suspected subsurface ocean
* geologically active. This is important because Europa and other moons are too far away for sunlight to be a big source of energy. There has to be another source. Radiogenic heating (released by radioactive isotopes) and primordial heating (left over from its formation) aren't enough for moons to sustain liquid water (especially 4.5 B years after formation). This means tidal flexing is what we should be looking for -- something we know Europa has.
* Europa's thick icy crust blocks pretty much all radiation. Barring a thick atmosphere (which only Titan has), a subsurface ocean underneath an icy crust is the best life can hope for out there, for protection against radiation.
* We don't know much about what goes on underneath the surface. If the bottom of the ocean contains geothermal vents, then that could harbor earth-like life.
Saturn's moon Enceladus checks many of these same boxes (tidal heating, abundant water, signs of a young surface indicative of geological activity).
JUICE and Europa Clipper missions should fill in many of these gaps, and help confirm our understanding.
Largest ocean in our solar system isn't even on Earth, apparently:
> ... Ganymede’s ocean is even bigger than Europa’s—and might be the largest in the entire solar system. “The Ganymede ocean is believed to contain more water than the Europan one,” he says. “Six times more water in Ganymede’s ocean than in Earth's ocean, and three times more than Europa.”
These AI assistants (Rabbit R1, Humane AI Pin), as they exist now, probably can be replaced by apps. However, if you give them the benefit of the doubt and think about what they're supposed to be (or eventually will be), owning the platform is a must.
An example: Google/Apple doesn't allow third-party apps access to call audio. So you couldn't implement live translation/transcription, by just being an app.
Google/Apple will jealously guard their turf in their ecosystems (to make space for their own AI assistants probably), so this level of third-party access is unlikely to be forthcoming.
India is rapidly expanding fiber internet connectivity, even in rural areas: https://en.wikipedia.org/wiki/Bharat_Broadband_Network
In addition, 4G/5G coverage is extensive: https://www.ookla.com/articles/india-mobile-connectivity-1h2...
See India in this 5G global coverage map: https://www.ookla.com/articles/5g-map-2026
The number of people who are not covered by above-mentioned fiber/cell network, and can afford Starlink as it is priced now, will be extremely small (likely making Starlink unviable as a profitable business).