Posts from Newtonmas Past

Saturday, December 25th, 2021

Please enjoy these posts of Christmas Past:

It would not be like the movies with intense dogfights

Sunday, November 21st, 2021

Physics would constrain space-to-space engagements. These five key concepts help explain how:

  1. Satellites move quickly.
  2. Satellites move predictably.
  3. Space is big.
  4. Timing is everything.
  5. Satellites maneuver slowly.

Warfighting on Earth typically involves competitors fighting to dominate a physical location:

Opposing military forces fight to control the land, sea, and air over a certain part of Earth to expand influence over people or resources. Space warfare does not follow this paradigm; satellites in orbit do not occupy or dominate a single location over time. Instead, satellites provide capabilities, such as communications, navigation, and intelligence gathering, to Earth-based militaries. Therefore, to “control space” is not necessarily to physically conquer sectors of space but rather to reduce or eliminate adversary satellite capabilities while ensuring one retains the ability to freely operate their own space capabilities.

[...]

Objects orbiting Earth have a strict relationship between altitude and speed. Orbital mechanics dictate that objects at lower altitudes will always move more quickly than those at higher altitudes. Any attempt to add or reduce a satellite’s speed will always lead to a change in altitude. Compare this relationship between speed and altitude to an aircraft, which often changes speed without affecting its altitude, and vice versa.

And that speed is fast. Satellites in commonly used circular orbits move at speeds between 3 km/s and 8 km/s (6,700 mph and 18,000 mph), depending on their altitude. In contrast, an average bullet only travels about 0.75 km/s (1,700 mph).

[...]

Also, because a satellite’s speed is tied to its altitude, a satellite will return to approximately the same point in its orbit at regular intervals (known as its period), regardless of the orbit’s shape and absent a maneuver to change the orbit.

[...]

To deviate from their prescribed orbit, satellites must use an engine to maneuver. This contrasts with airplanes, which mostly use air to change direction; the vacuum of space offers no such option.

[...]

Getting two satellites to the same altitude and the same plane is straightforward (though time and delta-V consuming), but that does not mean they are yet in the same spot. The phasing — current location along the orbital trajectory — of the two satellites must also be the same. Since speed and altitude are connected, getting two satellites in the same spot is not intuitive. Therefore, it requires careful planning and perfect timing.

One way to get close to another satellite is to perform a flyby. A flyby occurs when one satellite nearly matches the other satellite’s position without matching its orbit. Because the satellites are in different orbits, they will appear to speed past each other. These maneuvers are useful for inspection missions where the goal is not to destroy the target but to image it. Flybys often require minimal delta-V for an attacking satellite to perform since it can use natural intersection points of the two orbits to come close to its target. A related operation, known as an intercept, involves intentionally trying to match positions with the target, leading to the destruction of both satellites.

For two satellites in the same orbit, a common maneuver known as a phasing maneuver is required for one satellite to catch the other satellite. A phasing maneuver involves changing the satellite’s position in its orbit plane, either moving it ahead or behind of where it would normally be, similar to a train increasing or decreasing its speed to arrive at a destination sooner or later. Unlike a train, which can speed up or slow down without changing tracks, a satellite that changes speed also changes its altitude. This leads to the satellite entering into a new orbit known as a transfer orbit, an orbit used temporarily to move a satellite from an original orbit to a new orbit.

Phasing Maneuvers

Ground-based ASATs are missiles that rely on a rocket to deliver a small warhead to impact with a satellite. Because the rocket has a large delta-V capacity, the warhead itself is placed in the correct intercept trajectory and requires little propellant to reach its target — this makes them more intuitive as they behave more like traditional missiles.

[...]

In contrast, an orbital ASAT is basically a satellite that purposefully destroys other satellites. This can be done either with an RPO intercept or with onboard weapons. Unlike the ground ASAT missile, which can be launched without warning and at a moment’s notice, an orbital ASAT may be launched months to years ahead of a potential conflict.

[...]

Some counterspace threats utilize the electromagnetic spectrum to inflict either temporary (reversible) or permanent (irreversible) harm. These threats are attractive because the attacks happen from a distance, which adds a measure of deniability and lessens the burden of getting physically close. Intentional jamming can also be quite difficult to distinguish from unintentional interference, making attribution more challenging.

[...]

While there has never been a battle in space, we can still gauge what a war in space might look like. It would not be like the movies with intense dogfights. Instead space-based threats would be un-crewed and require slow and deliberate planning to get into position. Compared with the timing and flexibility limitations of on-orbit weapons, ground-based threats afford substantially shorter engagement execution timelines and the prospect of more numerous shots. The more we can internalize these insights, the better we can understand the stakes of a geopolitical fight in space.

It’s time for spooktacular links!

Sunday, October 31st, 2021

I’ve written about Halloween and horror quite a bit over the years:

Popular Posts of 2020

Friday, January 1st, 2021

I just took a look back at my numbers for 2020. Here are the most popular posts during that calendar year, six of which are new, four of which are older:

  1. Robert Conquest’s Three Laws of Politics
  2. It is difficult to understand why this should be such a formidable task (new)
  3. He disappeared into a room, and you didn’t see him again until it was done (new)
  4. There is no reason for concern (new)
  5. No One Left to Blame (from 2015, making a comeback)
  6. It’s a teacher’s dream (new)
  7. The Bob Rubin Trade
  8. The Pros and Cons of Empires
  9. Happy Secession Day! (the newest compilation of Fourth of July posts)
  10. Freeman Dyson appeared for more esoteric topics (new)

Here are the most popular posts actually from 2020 and not from an earlier year:

  1. It is difficult to understand why this should be such a formidable task
  2. He disappeared into a room, and you didn’t see him again until it was done
  3. There is no reason for concern
  4. It’s a teacher’s dream
  5. Happy Secession Day!
  6. Freeman Dyson appeared for more esoteric topics
  7. The larger strategic goal was to puncture the myth of communist inevitability
  8. N95 versus KN95
  9. Both sons also later attempted suicide
  10. That place is like Africa Light

Again, I’m not sure what to conclude.

Also, I should thank some of my top referrers: Reaction Times, Western Rifle Shooters Association, Instapundit, Borepatch, and Z Man.

God bless us, every one!

Friday, December 25th, 2020

Please enjoy these posts of Christmas Past:

I don’t discuss Thanksgiving nearly as much as Halloween

Thursday, November 26th, 2020

I don’t discuss Thanksgiving nearly as much as Halloween:

I have ascended to the third order of magnitude

Tuesday, March 31st, 2020

I have ascended to the third order of magnitude. I have 1,000 Twitter followers:

Isegoria 1,000 Followers

Popular Posts of 2019

Wednesday, January 1st, 2020

I just took a look back at my numbers for 2019. Here are the most popular posts during that calendar year, two of which are new, eight of which are older:

  1. Robert Conquest’s Three Laws of Politics
  2. He-Man Opening Monologue
  3. The Bob Rubin Trade
  4. The best hard science fiction he’d read in decades is a techno-thriller (new)
  5. The Father of Social-Science
  6. Fast Friends Protocol
  7. The Pros and Cons of Empires
  8. They are unable to decipher compound sentences (new)
  9. Summary of the Fate of Empires
  10. Observations from Actual Shootings

Here are the most popular posts actually from 2019 and not from an earlier year:

  1. The best hard science fiction he’d read in decades is a techno-thriller
  2. They are unable to decipher compound sentences
  3. A concerned citizen is largely helpless
  4. We should drop arithmetic
  5. One subgroup of scholars did manage to see more of what was coming
  6. The great vice of the Greeks was extrapolation
  7. The barbarian invaders had one thing the civilized Incas did not
  8. The whole point is sacrifice
  9. The tattoo has a profound meaning
  10. Superior recon trumps hypersonic missiles

Again, I’m not sure what to conclude.

Also, I should thank some of my top referrers: Z ManMapping The Dark Enlightenment, and Borepatch.

Joyeux Noël

Wednesday, December 25th, 2019

Please enjoy these yuletide posts of Christmas Past:

There’s a simple rule of simul-climbing

Tuesday, December 3rd, 2019

Rock-climber Emily Harrington was making a one-day free attempt on the 5.13 Golden Gate route up Yosemite’s El Capitan, when her foot slipped, and she fell:

Having Honnold on board as a belay partner was only one part of a strategy that would need to work perfectly in order for Harrington to become the first woman and fourth person to free climb Golden Gate in a day. She’d been working through the moves of the route for years. In 2015, she freeclimbed it in six days. And on November 7 of this year, she came heartbreakingly close, climbing all but the last 30 feet of the final 5.13 pitch before exhaustion overtook her. “It’s not about the hard pitches,” she explains. “It’s about the accumulation of fatigue. Even the 5.10 pitches are really physical, so it becomes this huge endurance challenge that a lot of climbers don’t quite grasp.”

[...]

To stack the deck in her favor, she and Honnold planned to use a technique called simul-climbing, a time-saving high-risk endeavor in which the leader and follower both advance at the same time. The leader places gear sparingly, “running it out,” as they say, while the follower cleans the gear. By leaving huge gaps between placements and climbing simultaneously, a team can cover four pitches with the amount of gear and time that it typically takes to finish one. The tradeoff is, of course, safety. If the follower slips, he pulls the leader off with him. If the leader falls, she takes an enormous fall that must be caught by a belayer who is focused on climbing.

“You have to conserve your gear,” says Harrington. “Instead of climbing the Freeblast in 12 pitches, we planned to climb it in four pitches.” The Freeblast, for people who remember the movie Free Solo, is the lower, less-than vertical-section of Freerider/Golden Gate where the climbing isn’t technically as difficult as the upper sections, but it’s slabby, slippery, and what Harrington generally characterizes as “insecure.”

“It’s dark. It’s cold. It’s easy for your fingers and feet to be numb and to slip unexpectedly,” says Honnold. When he made his abortive attempt on Freerider early in Free Solo, it was the Freeblast section that turned him around rather than the most difficult sections up high. Harrington is a 5.14 climber. When she slipped, she was making the last move of a 5.10c pitch while navigating a pair of twin cracks. Just a few feet above her was a fixed bolt she could have clipped for ultimate safety.

About 150 feet below, Honnold was belaying Harrington when he heard her scream. “I was sitting on the ground tying my shoes, getting ready to start simul-climbing,” says Honnold. “Tons of slack just pools on the ground, which is consistent with huge falls.” The phenomenon occurs when the leader is falling but still above her last piece of gear. “The rope is falling at the same speed as the climber,” says Honnold. “It’s just physics.”

Honnold was belaying with a gri-gri, a mechanical device that’s a little bit like the cams in a car seat belt. Its mechanism allows the rope to slide smoothly through it at low speeds but locks down tight if you try to pull the rope through it with any kind of jarring motion. But the energy of the fall never actually reached the gri-gri. In most circumstances, a belayer’s hand is never supposed to leave the rope. But at the highest echelons of simul-climbing, that’s just not an option. The follower has to climb and remove gear from the wall while also belaying the leader. That’s why there’s a simple rule of simul-climbing: don’t fall.

[...]

At the hospital, her injuries proved to be gruesome but largely superficial. Most shockingly, Harrington had somehow managed to get her neck caught in the rope during the fall and was left with a long bruise that made it look like she’d been strangled. Ultimately she was able to walk out of the hospital a day later.

[...]

Honnold, who is famously dry when it comes to assessing risk, doesn’t view it as a cautionary tale: “In a lot of ways, this shows that the techniques actually work,” says Honnold. “She took one of the worst possible falls on the whole route and still wound up basically fine.”

[...]

Ultimately, though, Harrington herself sees the accident as a validation, if a painful one: “The system worked. The rope caught me. My gear held,” she says. “I’ll try again in spring.”

Happy Turkey Day!

Thursday, November 28th, 2019

I don’t discuss Thanksgiving nearly as much as Halloween:

Happy Halloween

Thursday, October 31st, 2019

I’m always surprised by how much I’ve written about Halloween and horror over the years:

The best offenses use the width and the depth of the field

Monday, October 14th, 2019

NFL offenses averaged more points per possession and yards per play last year than ever before by challenging defenses to cover the entire football field:

Fifty years ago, college football was upended by an idea that began this way of thinking. It was a formation called the wishbone. Texas used it to win 30 consecutive games, and other powerhouses like Alabama and Oklahoma soon followed en route to national championships of their own.

The wishbone was based on the concept of the triple-option. A quarterback could hand off, run the ball himself, or later pitch it to another running back. Passing was a rarity. But this antiquated offense was also futuristic: it took advantage of the vast width of a football field. Running was no longer limited to a singular direction. Defenders had to make a choice between going after the guy with the ball, or the one who would later receive it.

But the wishbone shunted another dimension. Because passing was such an afterthought, wishbone teams didn’t push the ball vertically. When Texas went undefeated in 1969, the Longhorns ran for 3,630 yards and passed for only 1,091.

“The best offenses use the width—and the depth of the field,” McVay says.

Other scheming minds looked for an edge by revolutionizing the passing game. The “West Coast Offense,” which Bill Walsh used to win three Super Bowls with the San Francisco 49ers, attacked the edges of the field with a preponderance of higher percentage, shorter-length passes. Observers likened it to reconstructing the running game into a passing attack.

Other twists opened up the vertical element. In 1980, the Chargers broke the NFL record for most passing yards in a season, and by 1985 they had five of the six most prolific passing years ever. They did it with a self-explanatory offense called “Air Coryell.” Their coach, Don Coryell, wanted to air the ball as far down field as frequently as possible.

Still, there was a lingering question: how could an offense attack defenses in every direction on every play? The solution was hiding in plain sight—in college football. It just took shockingly long to trickle up to the pros.

In 2000, the same season the Ravens won the Super Bowl with one of the best defenses in NFL history, something far more important happened: Northwestern won a bunch of football games. The Wildcats didn’t invent the spread offense, but when a bunch of eggheads started using it to topple powerhouses, the whole football world had to pay attention. They beat No. 7 Wisconsin, thumped No. 18 Michigan State and then toppled No. 12 Michigan 54-51 in a nationally televised thriller.

“I saw them almost scoring at will,” Michigan coach Lloyd Carr said afterward.

Variations of the spread proliferated across college football. Teams lined up wide on every play with four or five receivers. They played almost exclusively out of the shotgun. The most radical teams adopted an extreme version known as the “Air Raid,” which played at hyperspeed and eschewed the idea of striking a balance between running plays and passing plays.

[...]

In 2001, NFL teams used the shotgun on just 14% of plays, according to Football Outsiders. In 2006, it was still just 20%. By last season, that had skyrocketed to 64%. [...] The Chiefs lined up in the shotgun on 81% of snaps last year.

A few years ago, Michael Lewis, author of Moneyball, looked at Texas Tech’s unorthodox offense.

Can the Aussies make punting interesting?

Tuesday, May 28th, 2019

Five years ago Steve Sailer got a neighbor’s tickets to the Rose Bowl and spotted an unusual punter on the Utah team. Watching Utah’s Hackett punt was “like watching golfer Phil Mickelson play around the green”:

For example, on one punt from inside the 50, the kind of situation where an American punter normally blasts it into the end zone for a touchback, Hackett took the snap, sprinted to his right like it was a fake punt, then blasted a diagonal punt across the field to his left, knocking it out of bounds around UCLA’s 10 yard line.

Hackett normally ran for one to two seconds with the ball before punting, which looked bizarre to this American football fan, but offered several advantages.

  • Running to his right could give him a better angle at kicking the ball over the left sideline within the 20.
  • It made it harder for the defense to plan to block the punt since he could pick a lane without defensive penetration.
  • He punted while running forward, while typical American punters punt while walking forward. This increased forward momentum translates into longer punts.
  • By not punting immediately, he gained the equivalent amount of “hang-time” for his teammates to get downfield and cover the punt. Hackett tended to kick the ball with a different trajectory from American punters who aim for height — his punts were like a 1970s Jack Nicklaus tee-shot, starting out low, then rising in arc. Some of his punts were designed to roll forward like a modern teeshot, while ones in danger of going over the goalline were crafted to roll backwards.

Now ESPN is writing about the Australian pipeline to American football, and Sailer is justly proud of his insight:

(This is one of the rare occasions I’ve been ahead of the curve on sports, so I’m tooting my own horn here.)

My guess is that in the long run, Americans will figure out how to teach their own kids these superior techniques, so in a few decades, Americans will once again dominate the ranks of NFL punters, just as the soccer-style kicker revolution in American football in the 1960s-1970s wound up with an influx of foreign Garo Yepremian-style kickers, but now is back to being predominately American kickers using the once foreign style.

Scientists are hoping to train the body to accept new organs

Monday, February 11th, 2019

Before the discovery of anti-rejection drugs, organ transplants were simply impossible, but anti-rejection drugs are immune-depressant drugs. Now scientists are hoping to train the body to accept new organs:

In 1953, Dr. Peter Medawar and his colleagues in Britain did an experiment with a result so stunning that he shared a Nobel Prize for it. He showed that it was possible to “train” the immune systems of mice so that they would not reject tissue transplanted from other mice.

His method was not exactly practical. It involved injecting newborn or fetal mice with white blood cells from unrelated mice. When the mice were adults, researchers placed skin grafts from the unrelated mice onto the backs of those that had received the blood cells.

The mice accepted the grafts as if they were their own skin, suggesting that the immune system can be modified. The study led to a scientific quest to find a way to train the immune systems of adults who needed new organs.

[...]

Many types of white blood cells work together to create and control immune responses. A number of researchers, including Dr. Markmann and his colleague, Dr. Eva Guinan of the Dana-Farber Cancer Institute, chose to focus on cells called regulatory T lymphocytes.

These are rare white blood cells that help the body identify its own cells as not foreign. If these regulatory cells are missing or impaired, people can develop diseases in which the body’s immune system attacks its own tissues and organs.

The idea is to isolate regulatory T cells from a patient about to have a liver or kidney transplant. Then scientists attempt to grow them in the lab along with cells from the donor.

Then the T cells are infused back to the patient. The process, scientists hope, will teach the immune system to accept the donated organ as part of the patient’s body.

“The new T cells signal the rest of the immune system to leave the organ alone,” said Angus Thomson, director of transplant immunology at the University of Pittsburgh Medical Center.

Dr. Markmann, working with liver transplant patients, and Dr. Leventhal, working with kidney transplant patients, are starting studies using regulatory T cells.

At Pittsburgh, the plan is to modify a different immune system cell, called regulatory dendritic cells. Like regulatory T cells, they are rare and enable the rest of the immune system to distinguish self from non-self.

One advantage of regulatory dendritic cells is that researchers do not have to isolate them and grow them in sufficient quantities. Instead, scientists can prod a more abundant type of cell — immature white blood cells — to turn into dendritic cells in petri dishes.

“It takes one week to generate dendritic cells,” Dr. Thomson said. In contrast, it can take weeks to grow enough regulatory T cells.

The regulatory T cells also have to remain in the bloodstream to control the immune response, while dendritic cells need not stay around long — they control the immune system during a brief journey through the circulation.

“Each of us is taking advantage of a different approach,” Dr. Markmann said. “It is not clear yet which is best. But the field is at a fascinating point.”