Sapere Aude
Tag: images
The previous generation of night vision featured a greenish glow, because the images were generated by electrons traveling through a green phosphors tube. The Army’s new tech uses a white phosphors tube. Coupled with whatever secretive image-enhancing technology they’re using, the contrast in the rotoscoping-reminiscent images is startlingly good, and the resolution has been improved as well.
The glycoletters in the data set could have formed nearly 1.2 trillion different glycowords. Yet, surprisingly, the researchers’ results indicated that only 19866 distinct glycowords were present across all the available sequences. The evidence suggested that all organisms follow very similar rules in assembling them and use essentially the same biomolecular language to define their structure.
Counterfactuals do appear in existing laws, but these laws are regarded as second class. They are not incorporated wholeheartedly. Constructor theory puts counterfactuals at the very foundation of physics, so that the most fundamental laws can be formulated in these terms. Concepts like work and heat can’t be captured fully with trajectories and laws of motion, because in the standard conception they are considered emergent and approximate. In constructor theory we can talk about them using exact statements about possible and impossible transformations.
2023-05-04: Assembly theory is an intellectual cousin
Assembly theory started when Cronin asked why, given the astronomical number of ways to combine different atoms, nature makes some molecules and not others. It’s one thing to say that an object is possible according to the laws of physics; it’s another to say there’s an actual pathway for making it from its component parts. “Assembly theory was developed to capture my intuition that complex molecules can’t just emerge into existence because the combinatorial space is too vast”.
Assembly theory makes the seemingly uncontroversial assumption that complex objects arise from combining many simpler objects. The theory says it’s possible to objectively measure an object’s complexity by considering how it got made. That’s done by calculating the minimum number of steps needed to make the object from its ingredients, which is quantified as the assembly index (AI).
Complex mixtures of molecules made by living systems — a culture of E. coli bacteria, natural products like taxol (a metabolite of the Pacific yew tree with anti-cancer properties), beer, and yeast cells — typically had significantly higher average AIs than minerals or simple organics.The analysis is susceptible to false negatives — some products of living systems, such as Ardbeg single malt scotch, have AIs suggesting a nonliving origin. But perhaps more importantly, the experiment produced no false positives: Abiotic systems can’t muster sufficiently high AIs to mimic biology. If a sample with a high molecular AI is measured on another world, it is likely to have been made by an entity we could call living.
Cronin and Walker hope that assembly theory will ultimately address very broad questions in physics, such as the nature of time and the origin of the second law of thermodynamics. But those goals are still distant.
Classified as a Building Integrated Photovoltaics (BIPV) system, ClearVue’s solar PV windows are integrated within a building’s envelope, as opposed to conventional PV systems where modules had to be mounted on the top of existing roofs. This has a dual benefit: clear solar glass serves as an energy-efficient window product for any building, but also generates electricity for on-site use or export to the grid. This can provide savings in materials and electricity costs, reduce pollution, and add to the architectural appeal of a building.
2022-11-12: ultrathin organic solar cells hit new efficiency records
Organic photovoltaics (OPVs) are 10x lighter than silicon panels and cost 50% as much to produce. Some are even transparent, which has architects envisioning solar panels not just on rooftops, but incorporated into building facades, windows, and even indoor spaces. “We want to change every building into an electricity-generating building”. OPVs reach 9% efficiency. Prototypes have reached efficiencies of 20%, approaching silicon and alternative inorganic thin-film solar cells, such as those made from a mix of copper, indium, gallium, and selenium (CIGS). Unlike silicon crystals and CIGS, where researchers are mostly limited to the few chemical options nature gives them, OPVs allow them to tweak bonds, rearrange atoms, and mix in elements from across the periodic table. Yet, stability and high efficiency still won’t be enough. To make it in the market, solar cells also need to prove reliable for decades. Under intense exposure to the ultraviolet (UV) in sunlight, the organics in solar cells can degrade, much as our skin burns during a day at the beach.
Anyone who has walked through a jungle or wandered a grassland may already have guessed that humans are a pretty small part of Earth’s organic matter. The carbonaceous winners are plants, which make up 80% of all biomass on Earth. Bacteria comes in second at 13% and fungus is third at just 2%. Of the 550 gigatons of biomass carbon on Earth, animals make up ~2 gigatons, with insects comprising 50% of that and fish taking up 0.7 gigatons. Everything else, including mammals, birds, nematodes and mollusks are ~0.3 gigatons, with humans weighing in at 0.06 gigatons. “The fact that the biomass of fungi exceeds that of all animals’ sort of puts us in our place”
The New Yorker has long been known for their covers, which feature trenchant observations of society. Illustrator Tomer Hanuka, who teaches at SVA on the side, figured that would make a great assignment–and he was right
Davis was shocked to see that nearly 50% of the genes widely conserved across plant lineages had disappeared from Sapria. That’s more than 2x as many genes as are lost from the parasitic plants called dodders (genus Cuscuta), and 4x the losses in cereal-killing witchweeds (genus Striga). “We knew that there would be loss, but we didn’t think it would be on the order of 44% of its genes.”
An experiment on board the Mars Perseverance rover designed to produce breathable oxygen from carbon dioxide has been switched on and is working! On April 20 it produced 5 grams of oxygen — not a huge amount, but it’s designed to make as much as 10 grams per hour, and this is the very first time oxygen has been converted from native air on another planet. MOXIE by itself can’t produce that much, but again it’s not designed to actually do that, it’s just to make sure the tech works. Still, just 4 MOXIEs could keep a human breathing on Mars. That first amount it made, 5 grams, is enough for ~10 minutes worth of breathing for a single person.
Both Booster and Dragon spacecraft are flight proven for today’s Crew-2 flight to the ISS. NΛSΛ chooses flight-proven spacecraft and booster for its most precious missions. Dragon Pilot Megan McArthur is sitting in the very same seat that her husband Bob Behnken sat for the SpaceX DM-2 mission 11 months ago. Thank you for helping humanity raise its aspirations and dreams!
P.S. many years ago, when reusable boosters were an audacious dream, I heard them described as “used”, as in a used car. No, no, we should call them “flight proven” and I wagered that the long term data would show them to be safer than a first flight. “Would you want to be on the very first flight of a new airplane coming off the line?” I asked. The moniker became a meme.
By a truly unbelievable coincidence, I was recently out for a walk when I saw a small package fall off a truck ahead of me. As I got closer, the dull enterprise typeface slowly came into focus: Cellebrite. Inside, we found the latest versions of the Cellebrite software, a hardware dongle designed to prevent piracy (tells you something about their customers I guess!), and a bizarrely large number of cable adapters.
By including a specially formatted but otherwise innocuous file in an app on a device that is then scanned by Cellebrite, it’s possible to execute code that modifies not just the Cellebrite report being created in that scan, but also all previous and future generated Cellebrite reports from all previously scanned devices and all future scanned devices in any arbitrary way (inserting or removing text, email, photos, contacts, files, or any other data), with no detectable timestamp changes or checksum failures. This could even be done at random, and would seriously call the data integrity of Cellebrite’s reports into question.
Any app could contain such a file, and until Cellebrite is able to accurately repair all vulnerabilities in its software with extremely high confidence, the only remedy a Cellebrite user has is to not scan devices. In completely unrelated news, upcoming versions of Signal will be periodically fetching files to place in app storage. These files are never used for anything inside Signal and never interact with Signal software or data, but they look nice, and aesthetics are important in software. Files will only be returned for accounts that have been active installs for some time already, and only probabilistically in low % based on phone number sharding. We have a few different versions of files that we think are aesthetically pleasing, and will iterate through those slowly over time. There is no other significance to these files.
Gregor J. Rothfuss 