NerdGuy Fridays: Dispatches from a Writer's Brain - M. L. Buchman

NerdGuy #18: Bad Guys Need Good Weapons

The HEL-A laser.

Nope, not a Hell-uv-a laser, though it is one. Rather a High-energy Laser (Airborne). A weapon that I unleashed in my latest novel, Ghostrider. (I couldn’t be sure that HEL-A is the weapon’s real name, I only found one passing reference on that. But since it’s deeply shrouded in secrecy, I’m sticking to it.)

Lasers are just…cool!

Back in college we used to swipe a 5 mW laser (about the brightness of a cat toy, though higher quality) from the physics lab, take it up onto the roof of the science building, hunker down close by the twenty-foot dome for the long-barrel 10″ telescope, and “lead” people into dinner. Even from 4 stories up and a hundred feet to the side, it would cast a sparkling bright-red dot under an inch across. The wonders of coherent light.

NerdGuy Sidetrack: Coherent Light

First, while the opposite of “coherent” light is “incoherent” light, it doesn’t mean that it babbles meaninglessly like a politician. Light follows all the laws of physics and is rarely incoherent like so many humans.

Sidetrack to the sidetrack. “Non-coherent” light comes in two varieties.

1) UVC is the reason that the holes in the ozone layer are so scary. The ozone blocks Ultra-violet C light waves from reaching us. Which is good as it is carcinogenic and even deadly. The cool thing is, UVC also appears to kill things like Coronavirus and is used to decontaminate things (like airplane interiors) when no fragile humans are around.

2) LEDs are the other form of non-coherent light. Non-coherent technically means that the properties of phase and amplitude vary randomly in space and time. But we don’t care about these today.

Back to incoherent light. It just means that the light waves don’t line up. Imagine an old-fashioned filament light bulb. It just shines light every which way from its heated filament. Two different sections of it are just popping light right in your direction, even though they’re millimetres apart so nothing lines up. Neon lights do this even more because the whole length of the tube is filled with electrically charged gas to make it emit light in all directions. To get any useful brightness in one place, you need a reflector to aim all of the little photons.

Lasers aren’t like that. They go to a great deal of trouble to line up all of the little light waves so that they’re in perfect (-ish) alignment before releasing them into the wild. The light doesn’t spread much as it travels. Instead, it delivers very near its full brightness to the target, whether making your cat dance or confusing students foolish enough to go to dinner past the science building.

This was the 1970s, so folks knew what lasers were but had no experience with them (outside of our department). People would jump and dance aside. Sometimes, just like a cat, they’d follow it for a bit. Several people tried to stomp on it like a bug. Only a very few people would put out a hand to try and block the light to determine the direction of the beam. In either case, we’d always cover the output with our fingers the moment they did that, just to mess with them.

We put the spot in front of one physics major we saw going by. He didn’t even look up, just gave us the finger and kept going.

A Lot of Laser

According to Wikipedia, 1898 was a good year for lasers as weapons. H.G. Wells gave a “Heat-Ray” weapon to the invading Martians in The War of the Worlds. That same year Garrett P. Serviss gave a “disintegrator ray” to the heroes of Edison’s Conquest of Mars. (Mars and death rays must just go together.)

Star Trek of course brought this to the common culture with phasers and even James Bond was not above a laser gun battle in one of the franchise’s worst efforts Moonraker. (Coming in just one ahead of Die Another Day at the very bottom according to IMDB rating.)

Of course, this has not all remained in the land of fiction.


Because lasers fire a light beam very efficiently, they can make a blinding light. Literally blinding. So, in 1995 the United Nations banned anti-personnel Blinding Laser Weapons. The US finally signed on in 2009.

That didn’t stop us, and I’m sure many others, from finding a loophole.

Enter the PHASR rifle. Personnel Halting and Stimulation Rifle. Low-intensity. Temporary blindness…hopefully. Yeah, some loophole.

PHASR rifle
The Air Force Research Laboratory had this in 2005. Wonder what they have now!

Many Varieties

For a quick and amusing (in a strictly scientific manner) summary, check out THIS page on Wikipedia (summarized below). Some of these are merely “in development.”

  • Electro-laser – This ionizes the air along the path of the laser and then fires a high-voltage charge along that ionized path. (Set phasers (uh, Tasers?) to stun.)
  • Pulsed energy projectile – Pump enough energy into an infrared pulse to create a destructive plasma explosion at the target.
  • Dazzlers – like the PHASR rifle, but that can blind delicate sensors as well. (We know this is up and running.)
  • Weapons – that can burn holes in things. (Yeah, now we’re talking.)


Sure, there’s a whole history of land-based and ship-based testing of lasers, but let’s jump right to the fun part. The YAL-1.

747 Airborne Laser YAL-1 ATL
YAL-1 Airiborne Test Laser (in a 747)

Okay, now we’re talking. Take an old 747-400F (freighter), gut it, and jam a big laser-testing platform up its middle. Low-energy test in 2004, it was eventually able to down multiple test ballistic missiles, during their boost phase, before the project was cancelled and defunded.

Of course that didn’t mean the program of weaponizing lasers was done, it was just that YAL-1 had proven all it needed to. Sadly, after 4 years sitting in the Davis-Monthan boneyard, the one-of-a-kind beastie was scrapped.

Many generations of laser weapons continued under dozens of other names and were mounted on ships, trucks, and airplanes. A cool one was ZEUS, a nice little 10 kW laser mounted on the top of a Humvee for killing ordnance and IEDs from a safe distance.

I wasn’t able to find the power of the final YAL-1 laser, but an article on The International Society of Optics and Photonics describes a 1 MW (MegaWatt – million watts) laser (100 times more powerful than the IED killer and about 16,000 household lamps [back when they were incandescent]). However, it notes that the YAL-1 laser that took out a SCUD missile in testing was in “the kilowatt class.” Yes, it filled a Boeing 747-400 freighter, but this was in 2011. We’ve come a long way since then.


Skipping over all of the steps in between, the newest version of the Spooky/Spectre/Dragon AC-130-based line of gunships is the “Ghostrider.” And among its massive arsenal is a laser weapon.

A laser weapon that they aren’t talking about much, for obvious reasons. A lot of digging around and I was able to determine that it was probably past the 100 kW range, most likely around 150 kW (over 10,000 nice little LED bulbs…all at once). Now this may not sound like much (just 10-15x the ZEUS IED killer). But let’s backtrack a bit.

How much power do you need? Rockets, missiles, airplanes, satellites…these are all very fussy pieces of equipment that don’t perform well after holes have been burned in them. We know that 10 kW punches holes very nicely. 150 kW will do it 15x better.

There are three other big considerations:

  1. It has to fit inside an AC-130 airplane with a lot of other armament.
  2. You have to be able to fit its power supply on board too. (Another turbine engine?)
  3. It has to work.

That last point is actually the key limiting factor. Fire a laser through something thick, like…air (Worse, moist air. Very worst, clouds or sandstorms.) and you get a problem called “blooming.” The air, and water or whatever not only decreases the beams effectiveness (it is just light, after all, and needs to shine on its target), the moist-dirty air also heats up as it absorbs the energy of the laser beam. This superheats the air, creating turbulence and can even turn the air into a plasma that the laser will turn into an explosion in the air (see the Pulsed Energy Projectile idea above), rather than burning a hole in its target. Literally, lighting the air on fire.

So, 150 kW, is probably as much fun as a gunship needs at this point until we figure out more about how to fire smaller amounts of light–coherently–through that thick air stuff. In the meantime, it let my villains play a bit.

For a long second he looked in her eyes, then reached out and took her hand. Rather than squeezing it with some unwanted but expected sympathy, he moved it to the laser’s joystick. “Get a feel for tracking the vehicle. It’s moving fast, so you’ll need to keep it steady in the crosshairs for longer than you’d think.”

At first she was veering side-to-side. Finally she had a feel for how to keep it steady in the crosshairs, reasonably.

He tapped in a quick series of settings, called in a correction to the cockpit, then pointed at a red Fire button.

He sat back to watch her carefully. His face totally unreadable. 

She wanted him to think well of her.

But she wanted Vasquez dead. So much of the pain in her life—and Mama’s—had been his doing.

Why had a man who headed a cartel, a violent competitor of the one her father worked for, helped them out at all?

And then she knew what other price Mama had paid to Hector Vasquez for their safe passage.

Taz punched and held the Fire button.

His vehicle glowed brightly in the infrared as the supercar heated. It swerved left and right but she kept the beam steady…enough. Finally, perhaps in desperation to escape or perhaps while dying of heat stroke, it swerved too far and rolled.

When it came to rest upside down, she held her aim on the car.

A second later there was the massive bloom of an explosion as the gas tank ruptured.

NerdGuy Fridays: Dispatches from a Writer's Brain - M. L. Buchman

NerdGuy #16: Mama Espinoza’s

Sometimes it is the simplest things that bring a character to life. This time, it brought the antagonist character of Colonel Vicki Cortez to life and made her central to my newest Miranda Chase novel, #4, Ghostrider.


We’ll skim through the early days.

In the 1930s, 200 miles south of the US-Mexican border, El Rosario was a tiny farming community trying to scrape a living from the hard land. When a traveler did stray that far down coastal Route 1, Mama Espinoza would offer them a meal in her dining room from a red house that sprawled inside the turn as Route 1 shifted from north-south to east-west. Her food slowly became a destination for the more intrepid travelers.

A History of Flight

One cool story that didn’t make it in the book.

In November, 1961, low on fuel and flying in a dust storm, a pilot and 5 passengers from San Diego made a desperate landing near El Rosario. They were rescued and fed at Mama Espinoza’s. Locals drove them 30 miles north for a place to sleep and get medical help for one of the passengers (there were no doctors in the small town). The next day they retrieved them and refueled their plane.

But the doctor returned with them to the town and saw the villages’ desperate plight (even above and beyond the terrible drought that had killed their fields and was now decimating their livestock). With what few supplies he had, the doctor treated 22 patients before departing. He promised to return.

Six small planes returned before Christmas. They brought presents wrapped by the local Boy Scout troop, food, candy, and medical supplies. The trips by the doctors became a regular routine. In fact, it inspired the doctors and pilots to found the Flying Samaritans. Their 1,500 volunteers serve 19 clinics throughout the region with both permanent and fly-in clinics. Read the full story under About the Samaritans.

It all happened because of kindness to strangers.

Bit of a Race

1967 saw the founding of what is now one of the world’s most prestigious off-road races, the Baja 1000. And the scouts made the very first check point of the race…which it’s been for the 43 years since…and counting.

It was the making of Mama Espinoza’s not simply as a place to eat good, authentic Mexican food. But also as a destination in and of itself. Her entire house has become the restaurant.

Click here for their Facebook page.

It is totally worth spending looking at the photos on their Facebook Page.

Why? Because its interior has become filled with memorabilia and photos of one of the major off-road races in the world. Top riders would bring their cars and motorcycles there to be blessed by Mama before the race. Though she recently died at the age of 109, her legacy lives on through her family and their restaurant, just at the sharp bend in Route 1 about 10 miles after you leave the Pacific Coast and turn inland.

Taking Flight

Colonel Vicki “Taz” Cortez, Taz is short for Taser, earned her nickname fair and square. Despite being trim and under 5′ tall, she owns the ability to run over the opposition—ANY opposition. She is the primary weapon of the chief antagonist in my upcoming Miranda Chase #4 Ghostrider, three-star General Jorge Jesus “JJ” Martinez. Though he doesn’t figure into this NerdGuy.

I’m always intrigued by what characters come up with on their own. For Taz? It turns out that she has a gourmet tongue. She can find the best food, anywhere. Even in places she’s never been before.

So when I sent her to find a hideout for the general in deepest Baja, Mexico, it was she who took me on a side trip to Mama Espinoza’s. And that’s where she came to life on the page as well. That moment trickled back through the book in many ways. Even though it occurs late in the book, it’s the scene below that brought her to life while squatting in an untraveled valley deep in central Baja. (no spoilers)

When she’d first traveled here, she’d been driving. Fifty kilometers away, the nearest town, El Rosario, was a nothing place. Seventeen hundred people perched close by the Pacific, halfway down Mexico’s Baja Peninsula.

El Rosario was known for only two things.

It was traditionally the first rest stop in the six-day off-road rally race called the Baja 1000.

And it was the home of Mama Espinoza’s restaurant. Mama E. herself had died recently at the age of 109, but the kids had kept it going.

It was classic Mexico, except for the food being even better than usual. Since the 1930s, Mama E. had served meals in her home’s dining room. It had taken off in the ’60s, when it became the first checkpoint of the Baja 1000. And Mama E. had never looked back.

The house was now entirely restaurant. Painted brilliant red outside, with a half dozen long tables covered in plastic red-and-white checked tablecloths inside, it looked homey. Every wall was covered with photos of fifty years of racing. Mementos were everywhere, making it part museum as well. Racers had brought their motorcycles there to be blessed by Mama E. herself before the big races.

Taz could have moved in, if duty hadn’t called. However, she remembered the burrito trio: crab, garlic shrimp, and local lobster. She could definitely go through another set of those right now.

As she’d done all of her life, she shrugged off what couldn’t be and felt no regret. Her mother had taught her that. Take care of the now. Mama’s answer to everything. Taz had made herself an expert in dealing with the now.

Learn more about Taz in Ghostrider. Available everywhere June 23rd (including print & audio). Already on sale at Apple in a special promo.



Miranda Chase—the heroine you didn’t expect. Fighting the battles no one else could win.

More info →


NerdGuy Fridays: Dispatches from a Writer's Brain - M. L. Buchman

NerdGuy #15: Childhood songs into Gunships

Puff and Ghostrider – origins (for me)

“Puff, the Magic Dragon was a Peter, Paul, and Mary song I grew up singing along with. It was probably the first song I knew all the words to, maybe even before I had the alphabet down (the order of “J” vs. “K” still screws me up sometimes, I have to get a running start at “H” to be sure).

“(Ghost) Riders In the Sky” (The Outlaws Version) rang through my senior year at college (with the too twangy Johnny Cash version before that). During those years, Southern Rock was sweeping the campuses, even where I went to school up in Maine. Charlie Daniels Band, Marshall Tucker, Lynyrd Skynyrd, ZZ Top, Allman Brothers, and many others. “Riders” was a hard-dancing fixture at any number of parties.

The next time I ran into it were the endless trailers for the 2007 movie Ghost Rider with Nicholas Cage (a fairly poor Marvel movie before Marvel figured out what they were doing) and the heavy metal theme song by Spiderbait (screwed up from my familiar Southern Rock–not my fav).

AC-47 “Puff, the Magic Dragon”

This has a much more intriguing origin and is the core of today’s NerdGuy.

It actually all began back in the Vietnam War. The Air Force did some testing with a Convair C-131 that said you could point a gun out the side of an airplane and it would be fairly easy to bank in a circle above a target and shoot consistently at the same spot.

After a few false starts and stops, in 1964 the Air Force chose one of my favorite planes (it’s almost every fliers favorite), a Douglas DC-3 (which the Air Force calls the C-47). They side-mounted a line of three mini-guns aiming out the port (left) side, placed a firing button on the pilot’s control wheel, and made a grease pencil mark on his left window. It became the AC-47 Spooky. “A” for Attack.

AC-47D Puff the Magic Dragon
AC-47D (you can just see the 3 miniguns mounted behind the wing)
MXU-470 miniguns

A Pylon Turn is something that every beginning pilot practices (including me when I used to fly). The challenge is to retain steady, consistent control throughout a banked turn. The instructor would pick a point on the ground (like a water tank). When I came up even with it (not above it but off to the side), I’d try to circle around it and always keep it aligned with the tip of my left wing. The better I got, the steadier the tip of my wing was on that tank until I could keep it centered at the top of the tanks dome, not just the tank itself.

That’s what the grease pencil mark was on the inside of the pilot’s window. He sits too far ahead of the wing, and each pilot is a different height, so needs a different mark. But once set up, a one-second burst on the miniguns could deliver six thousand rounds into an area as small as a few dozen square yards–every time!

It completely changed the nature of many battles. When in close quarter combat with an enemy troop, an AC-47 Spooky could lay down a massive suppressive fire from an untouchable height above the battle. An immediate order went out for more of these aircraft…which they couldn’t provide because there were so few miniguns in existence at that time.  But those wrinkles were soon worked out.

They operated mostly at night. They’d drop a parachute flare to illuminate the enemy, bank, and spit fire at them from above. No suprise that it was nicknamed “Puff, the Magic Dragon” and often flew with the simple call sign of “Puff.”

Bigger Dragons are Spooky

So, if a small dragon was good, a big dragon might be better? Indeed it was.

The C-130 Hercules is perhaps the most successful cargo plane the world has ever known.  It is used in all walks of life from US Coast Guard Search-and-Rescue to fighting wildfires to…an AC-130 gunship.

By 1970, these had completely replaced Puffs in Vietnam. Where the Puff could fire three guns worth of 7.62 mm bullets (.308″), the AC-130s first added 20 mm rounds (3/4″) fired from a rotary autocannon, with 40mm (1-1/2″) following close behind.

The big change, literally, happened in 1971, when a 105 mm (4.1″) howitzer was adapted to the big plane. Now, instead of small bullets, high-explosive rounds weighing 15 kg (36 pounds) could be heaved down from above. A single mini-gun, a 40 mm cannon, and the big howitzer could hit the same point with devastating effect…at the same time!

The plane itself went through many names, Pave, Pronto, Aegis, Spooky, Stinger, Dragon Spear, even Surprise Package. But it was the squadron’s call sign that stuck. From the AC-130A to the AC-130U (only 6 of letters were used) , these gunships were all best known as the Spectre. (Yes, it is totally appropriate to have the James Bond theme playing in your head right now.)

Hercules meets Super Hercules

After sixty-five years (yes, 65) the C-130 Hercules is still going strong in many roles. At the turn of the century, at the age of 45, it received its first comprehensive end to end update with new engines and new avionics. The C-130J Super Hercules flies farther, faster, and higher than all of its older brothers. (I’d warn my older brothers, but I don’t have any. However, I have an older sister…who I learned ages ago to never ever mess with. Older sisters are scary!)

It was only natural that this was the time to rethink the AC-130 gunship. The main thought was, “Why would you use a slow, propeller-driven, fat plane into a battle zone?” The main answer, “Until we think up something better (a new plane design can take a decade or more), we need something.”

Ghostrider (I)

And along came the AC-130J Super Hercules “Ghostrider.” In addition to everything else it’s older brothers did so well, the Ghostrider has added a new trick, a HEL-A laser.

I’ll geek out about this at another time. Let’s just say that the FDA regulations kick in at 5 mW (milliWatts). A 1 W laser can instantly blind you or char your skin. The High-Energy Laser – Airborne in the AC-130J is rumored to be at or above the 150 kW range. That’s 30 million times brighter than your cat’s laser pointer. (Trying to imagine 30 million times? Pull out a one-dollar bill. If you had 30M of those, it would be a stack over 2 miles high.)

Cobra and Apache helicopters, A-10 Thunderbolt jets, the Russian…oh, wait…they’re just now developing their own copy of the C-130 because they couldn’t figure out how to do it better themselves.

Yes, this plane may have venerable origins, but it will still be a factor on battlefields for years to come, just as it has in every single conflict involving the USA since the Vietnam War.

Ghostrider (II)

So, when Miranda Chase went looking for her fourth major air-crash investigation, the conclusion to the Preflight Quartet begun with Drone, Thunderbolt, and Condor, she found…a Ghostrider. Coming June 23rd. (Special: Available from Apple starting June 9th!!!)

action-adventure thriller
Pre-order your eBook now! (print & audio on June 23rd)


NerdGuy Fridays: Dispatches from a Writer's Brain - M. L. Buchman

NerdGuy Fridays #13: Speed of Sound


Most of us were taught as kids to count seconds after a lightning flash until we heard thunder. Five seconds per mile. This is an okay estimate (5 seconds is actually 1.06 miles at at 20 deg C at sea level), especially as thunder can be a sharp crack or a low rumble that builds and we’re not exactly sure quite when it begins.


In space, sound doesn’t move at all. Think of sound as a shock wave. In space, there’s nothing for it to shock against. (Yes, UberNerds, a sufficiently low frequency note (read as “massive explosion”) would cause ripples through space dust that could propagate across distance over time. For other forms of “shockwave propagation, consider this:

The zippy sounds of passing spaceships in Star Trek? Not so much. The sudden shocking silence after a decompression during the first battle in the movie series reboot Star Trek. Cooly awesome!

For now, let’s stick with what we would normally think of as sound.


When I hit Geology in high school Earth Science, I discovered that sound really does move at different speeds. In fact, I went on to be a Geology major and wrote the first geophysics thesis ever at my school. My research actually covered the study of gravity in projecting subterranean rock formations, but there’s another way to do that.


Sound moves at different speeds through different materials. In fact, it can move at 16,000 kmph (10,000 mph) through rock, compared to its lazy meanderings around 1,200 kmph (750 mph in air). What’s more, it travels through different densities of rocks and metals at different speeds.

Much of what we know about the interior of the Earth comes from two sources, earthquakes and atomic bombs. These massive events actually send measurable soundwaves coursing into the Earth’s interior. By a whole series of observations, they have mapped some incredible information. Here’s a textbook chapter on the subject that’s just fascinating.

Even if you find this to be a little opaque, there’s a cool map on the fifth page of the pdf (p. 833) of the measured thickness of the Earth’s crust.


But what we typically care about is the speed of sound through air, and in the frequency bands that we can hear. It’s certainly the most useful when I’m trying to place someone in a character’s head in fiction.

So, in my upcoming novel, Ghostrider (Miranda Chase #4) I have someone make this statement.

“…when the world lit up like daylight. I live just back of the airport, two miles from the top of Snowmass, plus a mile down. Counted [xx] seconds before a big boom rolled in—real sharp.”

Calculating that distance should have been easy. A little Pythagorean Theorem of a^2 + b^2 = c^2. That’s a direct line of 2.23 miles from my crash site to my observer. But how long would that take for the sound to travel?

Air at sea level is denser than air at the Aspen Airport at 7,820′ elevation or the top of Snowmass ski area at 12,510′.

Sound moves at 343 m/s (1,125 ft/sec) through air at 20 deg C at sea level. But what is it doing up at Aspen?

Part of that answer lies in this neat little chart:

Speed of Sound at Altitude
Based upon: as modified for Wikipedia

At 7,000′ the speed of sound is typically ~312 m/sec. And at 12,500′ is ~295 m/sec.

So, I saw an opportunity to show just what an uber-nerd my heroine Miranda Chase can be. And how she uses that uber-nerdness to determine whether or not to trust someone.

Ghostrider Sound

Brett continued describing the explosion, “I live just back of the airport, two miles from the top of Snowmass, plus a mile down.”

A direct line of two-point-two-three miles—eleven seconds at the speed of sound.

“Counted thirteen seconds before a big boom rolled in—real sharp.”

Thirteen seconds would imply that his distances were inaccurate or his accelerated excitement level at the explosion had caused him to count inaccurately. Assuming he knew the elevation difference between his home and the top of Snowmass mountain, thirteen seconds would place his home two-point-four-five miles horizontally from Snowmass, not two miles.

Though such an inaccuracy seemed unlikely in Brett Vance’s case.

Oh! She’d neglected altitude. The speed of sound slowed in thinner air: nine percent slower at Aspen’s elevation and almost fourteen percent at Snowmass’ peak. If she integrated the speed of sound over the distance, thirteen seconds was surprisingly accurate for a human observer without a stopwatch or other aid.