Centrifugal Force

white pill #32 // centrifuge experiment on ISS, gamma-ray hit, starship launch no. 2, mach diamonds, femtosecond lasers, pulsed fusion energy, fun stuff.
Brandon Gorrell

Space

Made with Dall-e

Made with Dall-e

Artificial gravity FTW. Bone density loss in low gravity environments, such as those experienced by astronauts in space, is well-documented. This physiological effect is not really complicated — in microgravity, there’s less mechanical stress on your body, and mechanical stress maintains your bones. More specifically, the reduced stress in space causes your body to do less bone formation and more bone resorption (the process by which bone tissue is broken down), which results in lower bone density, and the lower density your bones, the more brittle and prone to fractures and osteoporosis they are.

Even worse, in space, your bone density loss is dreadfully rapid and significant. On Earth, you lose like 1% of your bone density per year, it’s a natural part of aging. Astronauts in space can lose that same amount in just one month. So think about when we send people to Mars, of which a roundtrip journey will take a year and a half at absolute minimum (it will almost certainly take longer than this) — their skeletons will have been aged by 18 years when they get back home. Really bad!

So all this stuff we know about microgravity’s effects on the human body has put a big question mark on longer-duration space travel and interplanetary colonization. How do we do even a relative little bit of it without permanently wrecking our bodies? We can’t really scale human space exploration if it has the effect of cutting centuries off peoples’ skeletons. The answer to that question mark, it’s long been suspected, could be artificial gravity, and in mid-November, researchers at Harvard, NASA, and JAXA (Japan’s space agency) presented their results of a 35-day experiment they did on the ISS that put mice in centrifuges that simulated different levels of gravity. Incredibly, the results led them to conclude that artificial gravity as low as .33g (Mars is .38g, the moon is .165g) is sufficient to prevent most bone loss. In other words, the mouse bones at .33g for 35 days were just as, or nearly as, strong as the mouse bones at 1g for 35 days. Huge news if the data the team publishes backs this up! Abstract of their paper is here. (@Robotbeat)

Earth hit with gamma-ray burst. Like visible light, gamma rays are a form of electromagnetic radiation, but with a special distinction: they have the shortest wavelength and highest energy in the electromagnetic spectrum. This allows them to penetrate many kinds of materials, making them useful in medical imaging and treatment, industrial inspection, and astrophysics. But for the same reason, gamma rays are dangerous: they can cause damage at the cellular level, and this can cause radiation sickness, cancer, and other health issues.

Gamma-ray bursts (GRBs) are intense bursts of gamma-ray radiation, and they’re caused by insanely energetic explosions in distant galaxies. Think supernovas or neutron star mergers, where temperatures get as hot as several billion degrees Kelvin (for context, the core of our Sun is about 15 million degrees Kelvin). Temperatures like these — and other effects of such explosions — produce these GRBs, and they can last from a few milliseconds to several hours, though typically they last a few seconds.

A new paper published in Nature Communications on November 14 concludes that last year, the Earth’s ionosphere — an atmospheric layer between 37 and 590 miles (60 and 950 km) up, was affected by a massive gamma ray burst from two billion light years away (meaning it occurred during the Precambrian Era of Earth’s history, a two billion year stretch when, most significantly, life evolved from single celled prokaryotic organisms to multicellular life and our atmosphere filled up with oxygen). Because of the distance, the disturbance was extremely minor and not at all hazardous. But it serves as a reminder that we live in a dangerous, vast, spatiotemporally huge universe, where so far we’ve been strangely fortunate. (Ars Technica)

The moment Starship separated from Super Heavy using hot staging

Starship flies again. After much bureaucratic delay, the highly anticipated second flight of Starship took place on November 18th. Read our breakdown of why the launch, despite another rapid unscheduled disassembly, was an enormous success, and why Starship is such a big deal in the second issue of the White Pill. (SpaceX)

  • Phil Metzger (interviewed him here) did a thread on Mach diamonds (also known as shock diamonds), intriguing visual phenomenon produced by supersonic exhaust flows and atmospheric conditions. “Each nozzle has a plume (a jet) that is slightly mismatched relative to surrounding air pressure, so they oscillate in diameter, widening and narrowing to try to match pressure, but overshooting each time so they oscillate. These are the Mach diamonds.” Starship’s second launch created “the mother of all shock diamonds.” Worth reading.

More:

  • A solar storm (modeling above) scored a direct hit on Earth yesterday, with the NOAA observing strong (but not dangerous to people or infrastructure) geomagnetic storm conditions, and very high probability of aurora over places like Alaska. (@TamithaSkov)
  • Check out this video of a November 23 eruption on the Sun, featuring a “gorgeous flare arcade structure, complete with hot ‘Supra-Arcade Downflows’ (‘SADs’, colored cyan) above them.”
  • The Italian Space Agency (ASI) and Thales Alenia Space — “a joint venture between the French technology corporation Thales Group and Italian defense conglomerate Leonardo” HQ’d in Cannes — has officially begun working on the “world’s first permanent space habitat” as part of NASA’s Artemis program, after approval from NASA. Next step: complete the Mission Concept Review — a comprehensive evaluation to ensure that the mission concept is solid and feasible — which will be scrutinized by ASI and NASA, expected in the first quarter of 2024. Render of the habitat above. (Thales Alenia)

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Engineering, AI

1,000,000x’ing lasers. Though it still needs real world testing, simulations suggest a way to increase the intensity of laser pulses by up to a million times what is possible today — so strong that it could rip particles out of a vacuum.

(“Ripping particles out of a vacuum” aside: in a practical sense, extremely high-intensity laser pulses could create actual particles from the vacuum of space. Here’s how — in quantum field theory, a vacuum isn't completely empty, it’s filled with fluctuating energy fields that can momentarily create pairs of particles and antiparticles, known as "virtual particles." Normally, these particle pairs annihilate each other almost instantaneously, but laser pulses of sufficiently high intensity could separate them before they annihilate each other. If this happens, the particles become “real” — they gain enough energy to exist independently in the observable world. This process would essentially be turning the energy from the laser pulse into matter. 🫨)

Back to the topic at hand. The idea for 1,000,000x’ing lasers is to use plasma density gradients to channel photons together, much like cars sometimes bunch up when going up a hill. If successful, it could push the boundaries of understanding in physics, help commercialize fusion energy, and potentially even break the Schwinger limit. (Another aside: when you pass the Schwinger limit, light is expected to act differently, and more like a solid, resulting in inelastic scattering of photons off each other. Meaning that a beam of light might be able to block another beam of light crossing it? Does this sound like a precursor to light sabers to anyone else??) (Interesting Engineering)

More on lasers. Researchers just miniaturized a type of laser called mode-lock lasers, “a unique laser that emits a train of ultrashort, coherent light pulses in femtosecond intervals,” a quadrillionth of a second. Mode-lock lasers are vital for ferreting out nature’s secrets that occur in femtosecond timescales, like the formation or breaking of molecular bonds in chemical reactions. Current lasers are table-top only, limiting their use. This new breakthrough shrinks them to the size of a fingertip. “This achievement paves the way for eventually using cell phones to diagnose eye diseases or analyzing food and environments for things like E. coli and dangerous viruses.” (SciTechDaily)

AI-powered weather forecasting. Though better than they used to be, accurate weather forecasts are still difficult, and anything more than about a week out is sketchy at best. Google’s DeepMind AI may have just fixed that problem. In less than a minute, it can make a more accurate 10-day forecast than supercomputers (which take hours), using an algorithm that can be run on a desktop. It wasn’t just a little bit more accurate either, it outperformed the state of the art system “on more than 99% of weather variables in 90% of the 1,300 test regions.” (Space.com)

GPT is good. Here is a touching reddit thread of people answering the question “What’s the hardest real life problem you have solved with GPT-4, that you actually just couldn’t do yourself?” One example:

I have a difficult relationship with my former spouse and most communicate devolves into conflict. It's exhausting and I hate it but, even after several years and lots of therapy, it's something I have continued to struggle with.

We no longer talk on the phone regarding co-parenting and it's only via email now but conflict and strong emotions would still develop and result in tit for tat until a few months ago when I set up a prompt about communication and family systems and started copying and pasting emails into GPT. I asked GPT to measure emails with respect to temperature of the emails and to provide me with a reply that limits iteration and conflict. I also ask GPT to turn the temperature of my reply down to a 3. It's working and my stress and anxiety have been reduced significantly. I also appreciate the act of delegating to a third party which allows further emotional distance (and distress) for me.

Another example:

I have rather severe anxiety that often spikes at random points throughout the day and puts unrealistic scenarios into my mind that I can't shake.

I decided to build a web app where I could enter whatever I was worried about in the moment and it would respond with a score between 1 and 5 representing how serious/realistic my concern is. It then gives 3 reasons why it probably doesn't require as much worry as I'm giving it. It's been an incredible tool for me (and my specific kind of anxiety).

[If it detects that you are in real, immediate danger, it will tell you to seek help and refuse to respond further.]

I put it up (for free, and private) online with the hope it might help other people.

https://balance.dvy.io

(FWIW I tried that Balance app and it is indeed very good.) (Reddit)

AI image and video had a big month in November. Several astonishing AI imagery and video demos emerged last month. The pace at which this stuff is proceeding is frankly shocking.

  • Pika Labs revealed its stunning text-prompt to video generator, which will allow users to dictate style (e.g. anime, cartoon, 3d, etc), camera motion, aspect ratio, and more on text prompt-based videos, already-existing images, and already-existing videos (not sure how long these latter two features will last via copyright stuff, though). Join the waitlist here.
  • Runway revealed its motion brush, which animates any part of an image the user ‘paints’ over. Hard to put into words how cool this effect actually looks, watch a user’s demo here, and Runway’s own here.
  • Runway also revealed Runway TV, the world’s first (?) all AI-generated video on-demand ‘service’. Screencap of its ‘TV guide’ above.

More:

  • Airbus is testing AI for use in autonomous in-flight refueling. Difficult and rarely used, AI could make the process safer and more routine. Video above. (Interesting Engineering)
  • Contrary published a thoroughly researched deep dive exploring the mysteries and future of flight. Completely worth your time.
  • Have you been looking for a video of a 420,000 pound, 2,200 degrees Farenheit ingot being transferred to a 10,000 ton forge press for shaping? Look no further! Here it is.
  • MAKE IT COZIER! Someone on X asked an image generator to keep making a room cozier over 10 or so image iterations and wow, does that room get cozier (best four above, look right to left per row, thread here).
  • Bezos is building a 10,000-year clock called the Clock of the Long Now. Cool.

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The White Pill Investment Index

The White Pill Investment Index tracks investments in companies developing interesting, exciting, forward-thinking products. Deals are sourced using a combination of Pitchbook and reach outs to each company.

  • Better skin through biotechLinio Biotech, a company developing an injectable medication that stimulates skin tissue regeneration (it can be used to fix scars and burns, or to make skin look younger), raises $4.62 million in venture funding from ACME Investments, Harri Takanen, and Vesa Liljeqvist
  • Pulsed fusion energyNearstar, a company developing a “pulsed fusion” reactor that slams 50-gram tritium projectiles into the fusion chamber at supersonic speeds (they say this method is safer, simpler, and more commercially viable than other nuclear solutions), is raising $10 million in seed funding
  • Lights for better crop yieldsRED horticulture, a company developing LED wavelength-controllable lights that can adapt to a crop’s growth stage to maximize yield and plant health, raises a $17 million Series A led by ECBF Management
  • CO2 into VodkaAir Company, a startup that captures carbon dioxide in the air to produce impurity-free alcohols and fuels, raises a $30.39 million Series A led by Carbon Direct Capital Management
  • Industrial cleaning robotsLionsbot, a company developing autonomous robots for factories and offices (think of it as an oversized, industrial-grade Roomba), raises a $39 million Series A from Bejac Investment and other undisclosed investors

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Medicine

Steps forward in transplant technology. While stem cell or organ transplants save countless lives, most recipients need to take immunosuppressive drugs for the rest of their lives, increasing their risk of infection and cancer. To solve this problem, researchers genetically modified donor cells, “cloaking” them to the recipient immune system so they aren’t rejected. They succeeded with mice, transplanting the modified donor cells and finding that they successfully integrated into the recipients’ cells without the need of immunosuppressive medication. “Our work paves the way for an ‘off-the-shelf’ supply of cells for therapies that could be safely given to many patients,” said the senior investigator. The research is still early, but the applications are numerous and could have hugely positive impacts on patients if the technology is successfully matured. (Eureka Alert)

More:

  • Executive chair of XPrize Peter H. Diamandis will give you $101 million if you can develop a therapuetic treatment that can reverse human aging. Seems like a fair price. Details here.
  • A nanosized spinal cord implant may be able to help restore function to paralyzed patients. The flexible device is implanted by injecting it close to motor neurons — no surgery needed — and when activated is able to stimulate leg movement. It’s working well in mice, hopefully it can make the jump to human trials soon. (New Atlas)
  • The mRNA vaccine platform is a technology that can be leveraged to rapidly create vaccines to all sorts of viruses. One has just been developed that protects mice from catching tick-borne Lyme disease. An alternative of course, is just use gene drives to wipe ticks from existence, but vaccines are good too. (The Scientist)
    • Take a minute to read Mike’s Dominion, the canonical piece on gene drives — you won’t regret it.
  • The UK has become the first country in the world to approve a CRISPR gene editing therapy. This one is designed to treat sickle cell anemia and beta thalassemia. Human trials showed significant improvement of symptoms, with relatively mild side effects — none of them serious. (Nature)
  • 188 variations on CRISPR have been discovered by a machine learning algorithm that searched bacterial genomes. This is literally a treasure chest of tools that can potentially be used for all sorts of precision genetic engineering in humans or other organisms. (SciTechDaily)

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Finally, the fun stuff

  • Ayyy it’s an archive of Popular Mechanics covers! Linked are some from the 80s/90s era (the best era). Above are a few that caught my eye.
  • Trains.fyi shows every train in America, where they’re going, where they came from, and their current speed, on a map of the US.
  • A website called “Ancient Earth” lets you pick a time and location (say your home town, 150 million years ago) and see what dinosaurs and other extinct animals and plants lived there at the time. (Futurism)

Touch grass this weekend.

-Brandon Gorrell

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