David Kipping
@davidkipping
Astronomy, Exoplanets, Astrobiology, Cool Worlds Lab, Columbia University. Be kind to one another.
Don’t you think it’s a stretch to call this an “Earth-sized” planet, Corey? It’s 1.73 Earth radii. I don’t think we’d call a star 1.73 Solar radii “Sun-sized” with a straight face. And it’s not like the composition is Earth-like either, even the authors concede that
It’s hard to avoid the feeling that we’re in such a fragile position we couldn’t possibly absorb the shock of a major economic disruption for quite a while
With the two-hour marathon now broken, I wondered: how fast could humans ultimately run a marathon? Between a simple exponential and a stretched exponential model, the latter is favored implying humans could run 1h47m (!) one day (assuming same rules/no cheating).
I love all the astronauts but is it ok to have favorites in Glover and Koch?
“Burn down your cities and leave our farms, and your cities will spring up again as if by magic; but destroy our farms and the grass will grow in the streets of every city in the country.” William Jennings Bryan, 1896
Is the same thing happening in astronomy? Querying ADS, for collection:astronomy, property:published, I show here the number of unique authors per year/number of papers per year. Over 50 years, the average number of authors per paper has doubled, a compound growth rate of 1.6%/year.
The rise of “hyper-authorship” has neutered the correlation of publication metrics vs academic accolades. “The mean # of coauthors per pub, averaged across highly cited physicists, was 121 in 2004. It rose to 952 in 2019, with 10% of the scientists having >2,441 coauthors per pub on average”.
I did a double take on that because I don't remember his original article saying this and fortunately I had printed it out. Indeed, it looks he has edited the blog post, so he is responsive! I would of course prefer a clear bold erratum at the top conceding the original version's issues.
“If an explanation could easily explain anything, then it actually explains nothing. When theories are variable, experimental testing is useless. I call such theories bad explanations. Being proved wrong by experiment and changing to other bad explanations does not get one jot closer to the truth.”
New studies used JWST to probe TRAPPIST-1e, the most accessible potential Earth-like exoplanet. Data reveals the atmosphere is 1) Not hydrogen dominated (unsurprising)😌 2) Unlikely to be Venus-like🧐 3) Compatible with N2-rich😎 arxiv.org/abs/2509.05407 arxiv.org/abs/2509.05414
The magnetic field produces in this configuration could actually be useful in its own right, such as providing protection to a Mars base for example. And given these things weigh just ~kg, made of existing materials and powered solely by the Sun, we could make a lot of them.
We speculated that even faster speeds could be obtained by electrically charging the tips, providing a restoring force. This creates a rotating dipole that radiates and the new terminal speed is set by energy balance, and is ~1000 km/s (0.3% c!) - again just using the Sun!
A chipsat, similar to that proposed by Breakthrough Starshot, is released just before breakup, flying off in a tangential trajectory out of the Solar System. In principle we could boost the speeds by using eccentric orbits + Oberth effect, graphene sheets and gravity assists.
After ~3 years @ 1AU, TARS would spin up to 12.1 km/s which is the critical velocity when the centrifugal force exceeds the tensile strength of the CNT sheets. Adding on the quasite orbital velocity, the ends are moving at 40.4 km/s - exceeding the Sun's escape velocity.
The whole thing is scalable but our paper considers the example of a 63m x 7m x 2.6um design weighing 1.6 kg made of CNT sheets. The strange dimensions are required for stability against tumbling (T-handle effect). One could imagine TARS being folded up at launch then unfurling.
