The military loves to boast that we “own the night.” That’s mostly because we don’t sleep, but it’s also because we have night vision goggles. If you weren’t a grunt, then your night vision was probably halfway decent. If you were a grunt, then your night vision was probably as effective as putting a green piece of plastic on the end of an empty paper towel roll.
So, if you ask one of us what it’s like to use NVGs, you’ll likely get an unexpected response: It sucks.
You might be asking yourself, “but aren’t you guys supposed to get awesome gear?” Yeah, sure. But no one wants to pay for it.
So, they give us what they are willing to pay for, and that’s why we get a set of AN/PVS-14s. A monocular (for the ASVAB waivers out there, that means it has one lens) device that, for one reason or another, doesn’t want to work how or when you’d like it to.
Marines will talk sh*t about them all day, but these complaints surface most often:
Not the sun, though. The moon is the best.
(U.S. Marine Corps photo by Cpl. Gabino Perez)
They work best with natural light
This may not seem like a big deal — until you realize that a triple canopy jungle or a cloudy night sky are going to ruin any chance at having functional night vision. If you’re a grunt, the night sky is always cloudy and if you have to break the tree line, which you probably should, your NVGs are going to lose most of their ability.
Un-even weight distribution
Strapping that bad boy to your helmet is like taking a big rock and taping it to the side. It feels awkward and can throw you slightly off balance, which can be especially sh*tty as you’re trying to leap over ditches in the middle of the night.
They flood the hell out of your eye.
(U.S. Marine Corps photo by Cpl. Gabino Perez)
Unnatural light sources suck
If you have both eyes open (which you should) while you’re wearing these bad boys and you come across a glow stick or flashlight, your eyes’ sensitivity to light will be vastly different.
Your field of vision is severely reduced
If you’re peering into the night with both eyes open, you’ll see (hopefully) clearly with one eye, while the other is basically blind. Like we said before, it’s like looking through an empty paper towel tube — which doesn’t afford the best field of view.
Also, your command will give you 0 batteries.
(U.S. Marine Corps photo by Lance Cpl. Anne K. Henry)
They eat batteries
Not literally — not like that guy in your platoon from Nebraska (you know the one). But when you go out with the NVGs, you are required to carry spare batteries, which just means tacking on a few more, precious ounces to your load.
Area 51 is a restricted site in Nevada with an almost cult-like mythology surrounding it. Some people claim it’s a standard military operation site, but others swear that it within its gated walls exists proof about extraterrestrial life.
Before we get into public knowledge, I want to throw in my thoughts on this. I was an intelligence officer in the Air Force and I maybe shouldn’t post this on the internet but my final assignment was in a place that rhymes with Rational Maturity Agency, and while the government definitely does some cool classified work there, I can say with high confidence that no one would be able to keep aliens a secret. At least not the kinds of aliens we tell stories about. Maybe Area 51 has some petri dishes of extraterrestrial amoebas…but I really doubt it.
As the video below states, “No doubt aircraft are still being secretly built and tested there today.”
You can check declassified documents to learn about what has been tested on site in the past. In fact, because of the Freedom Of Information Act, U.S. citizens have the right to request access to federal agency records; there are limitations, of course, but it’s a fun pastime to ask the “Rational Maturity Agency” for documents concerning things like aliens or Elvis or other conspiracies.
We have all seen upsets in sports before. We might see a number one team in college football lose to an unranked bottom feeder, a team barely making the NBA playoffs sweeping the defending champs in the first round, a boxer throwing a desperate punch and knocking out a champion. But forty years ago today, on Feb. 22, 1980, the sports world was rocked to its core. The U.S. Men’s hockey team beat the mighty Soviet Union team at the 1980 Olympics in Lake Placid, NY.
This upset was truly a David versus Goliath upset. The Americans had no reason or chance to win… at least that is what everyone thought.
In the Olympics then, there were strict “amateur” rules on who was eligible. Professional athletes were not allowed to play. Hence Americans couldn’t send NBA or NHL players in the Olympics even if they wanted to. So, the USA (and most of the world) had to rely on college kids and other non-professionals. Once you were done with school, you got a job and trained on your own time. The Communist Bloc, however, found an obvious way around that. They more or less gave athletes bogus jobs and paid them to train all the time. They were essentially professionals.
The Soviets dominated the international hockey scene because of this. Prior to this game, they had won five Gold Medals and 14 World Championships. They had been playing together for years and were a well-oiled machine. In contrast, the Americans had only been together for a few months. They were college kids who usually only had one chance at the Olympic games because of the amateur rules.
In an exhibition at Madison Square Garden before the Olympics, the USA was trashed by the Soviets by a score of 10-3. The Soviets went into the Olympic games as a very confident team.
As the tournament progressed in the round-robin format, both teams played well. The Americans fought to a draw and several victories, while the Soviets steamrolled everyone they played.
People often forget, but it wasn’t the Gold Medal Game. And if you remember watching it live, you remember wrong — the game was on a tape delay by about three hours. Over 18,500 people packed the arena at Lake Placid, and there was a patriotic fervor in the air. People claim the U-S-A chant started that night.
Nowadays, we are used to the super-patriotic feelings at sporting events, but things were different back then.
America was in a bit of a rough spot.
There was still a pall hanging over the country over the lives lost in Vietnam, made worse when Saigon fell in 1975. There was inflation and gas shortages to deal with. The value of the dollar was low. There was stagnation in the economy. Urban decay and high rates of violent crime racked American cities. The Ayatollah in Iran was still holding Americans hostage after the embassy takeover.
The mood could best be described by a term that was applied to a Jimmy Carter speech – “malaise.”
Americans really needed a moment of pride. It came that night.
The USA played hard, scrappy, and didn’t back down. They went down three times and came back to tie three times. They went ahead in the third period on a Mike Eruzione goal to make it 4-3. When you look at the stats of the game, the U.S. was really outplayed in most aspects. They held off the Soviet attack 10 minutes, which probably seemed like an eternity.
As the time clicked off the clock, the crowd grew more insane, and the arena turned into a human pressure cooker ready to blow.
Al Michaels, feverishly counted down the time with one of the most iconic calls of all time.
“11 seconds, you’ve got 10 seconds, the countdown going on right now! Morrow, up to Silk. Five seconds left in the game. Do you believe in miracles? YES!”
The effect was immediate. Pandemonium reigned in the stands. Players exuberantly celebrated. The Soviets looked on in shock and awe. Coach Herb Brooks ran into the locker room and broke down in tears. When the players went in, they broke out into “God Bless America.” They then took a call from President Carter (and they still had a game to go to win Gold!).
Seriously this video will give you chills.
Sports Illustrated didn’t even have to put words on the cover. The picture alone told the story.
The country was gripped with patriotic fervor, and after what seemed like a long national nightmare, Americans felt that miracles do indeed happen, and good times were ahead.
WATM’s Ryan Curtis hits the streets with stunt driver Jim Wilkey, a Vietnam War vet whose Hollywood credits include “Die Hard With a Vengeance,” “Rush Hour,” “Inception,” “Mad Max: Fury Road,” and “The Dark Knight Trilogy.’ Jim’s experience in the Navy working with a wide range of equipment gave him the knowledge to get started as a stuntman and stunt driver.
Follow along as Jim (bravely) lets Ryan get behind the wheel and try his hand at the stunt course.
And that’s what made it so scary for the Air Force and Marine Corps F-15 pilots who realized that they’d stumbled into a sophisticated trap on the second day of the assault.
The F-15 is a stunning fighter that claims over 100 aerial kills with zero losses to enemy fire.
(U.S. Air Force photo by Senior Airman John Hughel)
Marine Corps Capt. Charles Magill was leading a flight of eight F-15s protecting a larger strike package headed into the contested airspace to destroy threats on the ground. The eight F-15s in the lead got a call from the E-3 Sentry aircraft on the mission.
Two MiG-29 Fulcrums were near the target area.
Magill decided to take three other F-15s with him to destroy the threat, leaving four behind to protect the main strike package.
Four-against-two odds, especially when the team of four has F-15s versus enemy MiGs, is a good setup — but the F-15s had been tricked. As they pursued the MiGs, the ground suddenly erupted with surface-to-air missiles, all locked on U.S. jets and racing to their targets.
MiG-29 were useful and capable fighters, even if they lacked all the capability of American F-15s.
(U.S. Air Force Tech. Sgt. Michael Ammons)
The American pilots were forced to jettison their external fuel tanks and take evasive actions. They deployed flares, put the planes through gut-wrenching turns, and, ultimately, avoided every missile fired against them. This left them in suddenly-safe skies once again — except for the two MiGs that had lured them. The Americans still smelled blood and decided to continue the pursuit.
As they drew close, the MiGs took a sudden turn towards the Air Force and Marine pilots, making the Americans think that the MiGs were prepared for a knockdown fight.
But, it turned out, the Iraqis had spotted a lone Navy F-14 Tomcat and were maneuvering to attack it, allowing the F-15 pilots to pursue the MiGs in turn. Magill took his shot immediately after Air Force Capt. Rhory Draeger. Magill, worried that his first missile had malfunctioned, took a third shot.
Draeger’s first missile flew true and shredded the Iraqi jet, while both of Magill’s missiles also made contact. The first missile tore the right wing from the Iraqi jet and the second missile flew into the resulting fireball and exploded. The strike package was safe once again to attack Iraqi ground targets and Operation Desert Storm continued unabated.
The Danish Royal Air Force posted a video on August 22 of two of their fighter jets intercepting a Russian bomber, Newsweek International first reported.
The video shows two Danish F-16s flanking a Russian Tu-95 on both sides, and one Danish pilot signaling towards the bomber, near the island of Bornholm, which is between Poland and Sweden according to Newsweek.
The Danish Air Force posted the video on Facebook, but did not detail when the incident took place.
The Iraqi Army has been pushing forward with its tanks and infantry but has not released exact numbers for what they gained on the second day of fighting. According to reporting in Al Jazeera, they liberated 20 villages in the first day.
Meanwhile, Kurdish Peshmerga forces attacked and cleared nine villages around the outskirts of Mosul, freeing 200 square kilometers from ISIS control, according to CNN.
Both the Kurdish and Iraqi commanders told reporters that they expected gains to slow after the first day. ISIS has buried IEDs along most major roads and throughout many of the nearby villages, forcing troops to slow down to avoid the explosives and to create clear paths.
Peshmerga Brig. Gen. Sirwan Barzani told CNN that it would take two months to clear the city.
The international coalition supporting the ground advance releases a daily list of targets struck by air and artillery. Four strikes were launched against ISIS forces near Mosul on Oct. 18.
The release claims that these four strikes destroyed 10 mortar systems; five artillery systems; four buildings; four fighting positions; four vehicles; two supply caches; two generators for radio repeaters; a factory for creating suicide car bombs; and a car bomb.
The coalition also hit targets around the nearby city of Qayyarah where Iraqi forces are moving towards Mosul from the south. Strikes there destroyed a mortar position, a building, a tanker truck, and a rocket-propelled grenade.
On Oct. 17, strikes in the same areas hit three tactical units, two staging areas, 12 assembly areas, a bridge, six tunnel entrances, five supply caches; four generators for radio repeaters; four solar panels; two artillery systems; two vehicles; two tunnels; and an anti-air artillery system.
All that seems to spell a pretty horrible first 48 hours for ISIS at Mosul.
One of the biggest reveals in “Star Wars: The Rise of Skywalker,” other than Rey’s identity, came at its very end when the character revealed she had her own new lightsaber with a distinctive yellow-orange hue.
What color exactly is the lightsaber and how did the visual effects team land on it?
“A fair number of colors have been used in lightsabers. So there was a design challenge there in terms of what color it should be,” “TROS” visual effects supervisor Roger Guyett told Insider Monday of the direction given for the lightsaber seen at the movie’s very end.
“There was an optimistic kind of quality to that, but we also wanted [Rey] to have a very unique color,” he added of coming up with the color we see on screen. “We ran some tests and decided in the end what color it would be.”
Rey prepares to slice through Kylo Ren’s ship with Luke Skywalker’s lightsaber.
Is there a specific name to Rey’s lightsaber color? We’re going with ‘yellow optimism.’
“That specific color yellow, if you go too pale — this is getting really in the weeds here — if you go too pale and you make it too light, it’s going to look white a lot of times,” Industrial Light Magic (ILM) visual effects supervisor Patrick Tubach said of one factor that helped them land on that precise color. “Colors on film, sometimes they bleed away depending on the exposure and the quality of the light in the scene.”
“Making it that more golden yellow gives you that optimistic feeling, and it also allows you to make it supersaturated and still feel like it’s in the ‘Star Wars’ universe,” he added.
Yellow sabers aren’t anything new to “Star Wars” lore, but they are uncommon. In the past, yellow lightsabers have mostly been limited to Jedi temple guards, who wielded double-bladed sabers.
Here’s Kanan Jarrus going up against a Jedi Temple guard on the animated series “Star Wars Rebels.”
When asked if they had a specific name for the color, optimism was a word that came up frequently to describe the tone they were going for with the look of Rey’s lightsaber.
“We definitely went for things like golden and sun and optimism,” said Tubach.
“I think the optimism carried that choice,” added Guyett.
“I’m going to paint my house ‘yellow optimism,'” joked creature and makeup effects creative supervisor Neal Scanlan.
Did the hilt of Rey’s lightsaber look familiar? It should have.
Rey’s lightsaber does include a yellow kyber crystal
“Yeah, it’s supposed to be a yellow crystal,” said Tubach.
It was not a clear crystal that changed color after chosen by Rey. Neither was it a purified version of a red kyber crystal as Ahsoka Tano did in the past to create her white lightsabers.
Insider thought Rey’s saber color may have contained a healed version of Kylo Ren/Ben Solo’s cracked red kyber crystal, but it seems that’s not the case.
Did the hilt of Rey’s lightsaber look familiar? It should have.
The small detail within Rey’s new lightsaber you may have missed: The hilt of her lightsaber comes from her original staff.
“That was the concept,” said Guyett of the inspiration behind the hilt of Rey’s lightsaber. “The art production design and the art department, we all contribute to the designs of various things… [director] J.J. [Abrams] just thought it was logical that she had the staff, and, therefore, the saber should somehow be linked to that.”
In hindsight, when you go back to “The Force Awakens,” Rey’s staff always looked like it could eventually be transformed into the perfect lightsaber hilt.
The CH-53K King Stallion is intended to be the new heavy-lift helicopter for the United States Marine Corps, replacing the CH-53E Super Stallion, which entered service in the 1980s. It’s currently being tested, and looks pretty impressive, to say the least. But the Marines may not be the only buyers.
Believe it or not, the German Luftwaffe (yes, the current German Air Force is still called the Luftwaffe, according to its official website) may end up a customer for this helicopter. Surprised? Don’t be. Germany actually operates a version of the CH-53, the CH-53G, a modified version of the CH-53D – a predecessor to the E models the Marine use. Sikorsky, a division of Lockheed, recently announced a strategic teaming agreement with Rheinmetall, a company Americans may know as the maker of the gun used on the M1A1 and M1A2 versions of the Abrams main battle tank.
A representative for Lockheed told WATM that the agreement means that “German suppliers will do the sustainment and maintenance of the aircraft. We will become a teammate to the German Armed Forces, to deliver what the customer wants – on time and parts assets they can rely on.” Lockheed also says that other partners may be added as the CH-53K competes with the CH-47F to replace the Luftwaffe’s fleet of CH-53Gs, which FlightGlobal.com notes totals 81 airframes.
WATM readers will note that the German CH-53Gs appeared in a recent article on the Wiesel, a small armored vehicle capable of packing the BGM-71 Tube-launched Optically-tracked Wire-guided missile. CH-53Gs can carry two of these tankettes internally, according to GlobalSecurity.org.
Israel is another export customer that uses earlier versions of the CH-53, and the Lockheed representative noted that it had expressed interest in the CH-53K. The United States Navy also operates 28 MH-53E airframes in the aerial minesweeping mission and for cargo delivery. Learn more about the Lockheed/Rhinemetall team-up and Germany’s possible purchase of CH-53Ks in the video below.
In March, parents across the country began hunkering down at home with kids of all ages. Stay-at-home orders going into effect across states at different times left many juggling both parenting and teaching, and trying to find a way forward.
As temperatures across the nation heat up, parents have taken to driveways and sidewalks to ease that at-home blues for their kids, letting creativity take the lead with sidewalk chalk designs.
For Abbey Tucker, a mom of four girls ages 3, 7, 11 and 13, the creativity began with her oldest child.
“My oldest daughter drew some balloons at the start of quarantine,” the Atlanta-area mom told We Are The Mighty.
“I took a photo of my 3 year old with them and loved it so we decided to try some more and it took off from there. The ideas come from lots of places – the internet, favorite Disney films or just things we would love to do that we can’t do right now.”
Heather Gibb, a central Pennsylvania mom of three, can relate.
“It all started with Ella asking me to draw her a princess carriage to sit in,” Gibb said, referencing her 5 year-old daughter. “So I Googled it because I actually am terrible at drawing unless I have a picture.”
Gibb said that the princess carriage led to her son, Rhett, wanting a crocodile.
“And that led to me getting 100 other ideas from Pinterest,” she shared.
When Heather Tenneson of Madison, Alabama had to cancel a much-anticipated family trip to Disney World, she took her daughters using chalk (and a little bit of imagination) in the driveway.
Tucker, Gibb and Tenneson are just three examples of parents taking their creativity outdoors.
When We Are the Mighty asked parents to share how they were getting creative with their kids outside, they delivered. Messages of hope and inspiration, Disney characters, stained-glass inspired works of art, learning tools and games came tumbling into our inbox from every corner of the country.
(Amber — California)
(Austin — Pennsylvania)
(Austin — California)
(Calvin — Sugar Hill, Georgia)
(Courtney — Kansas City)
(Declan — Honolulu, Hawaii)
(Jordan — Pennsylvania)
(Kayden — Harrisburg, PA)
(Kayden Willa — Harrisburg, PA)
(Lauren son Maddox, pictured — Littleton, CO)
(Max — Honolulu)
(Nicole — Las Vegas)
(Rachel — Oxford, MS)
(Rachel — Oxford, MS)
(Rachel — Oxford, MS)
(Robyn — Houston, Texas)
(Robyn — Houston, Texas)
(Robyn — Houston, Texas)
(Robyn — Houston, Texas)
(Robyn — Houston, Texas)
(Robyn — Houston, Texas)
Whether parents are encouraging creativity through art, looking for a family-friendly outdoor activity, or simply seeking another way to entertain kids at home, sidewalk chalk delivers.
She is what’s known as an “Arlington Lady,” officially representing the Chief of Staff and dedicated to the families of those who served. She’s not there to grieve, but to honor the fallen.
Since 1948, these ladies have attended every military funeral at Arlington to ensure that “no Soldier, Sailor, Airman or Coast Guardsman is buried alone.”
After World War II, Air Force Gen. Hoyt Vandenberg would attend Arlington funeral services with his wife. The general noticed that many of the funerals were attended only by a chaplain. According to Arlington’s website, the Vandenbergs formed a group to ensure a member of the Air Force was present at every airman’s funeral.
Slowly, the other branches caught on, creating their own groups. Army Gen. Creighton Adams’ wife Julia started the Army’s in 1973. The Navy started in 1985 and the Coast Guard in 2006.
The Marines have always sent an official representative of the Marine Commandant to every funeral of a Marine or retired Marine.
“It doesn’t matter whether we are burying a four-star general or a private,” Margaret Mensch, head of the Army ladies, told NBC News. “They all deserve to have someone say thank you at their grave.”
Mensch is married to a retired Army colonel. Many of the Arlington Ladies she organizes are also the spouses of veterans and soldiers.
Some of her ladies joined the Arlington Ladies after being visited by one, because they know first hand the crucial the role these women played when their own husbands died.
Joyce Johnson joined the Army Arlington Ladies in 2004. She lost her husband, Lt. Col. Dennis Johnson in the September 11, 2001, attack on the Pentagon.
“It was a way I felt I could honor my husband,” she told Soldiers Magazine. “I just wanted to help make someone else’s life better so I asked to join the Arlington Ladies. … It’s really an honor to be able to do this.”
Islamic State militants are developing their own social media platform to avoid security crackdowns on their communications and propaganda, the head of the European Union’s police agency said on May 3.
Europol Director Rob Wainwright said the new online platform had been uncovered during a 48-hour operation against Internet extremism last week.
“Within that operation it was revealed IS was now developing its very own social media platform, its own part of the Internet to run its agenda,” Wainwright told a security conference in London. “It does show that some members of Daesh (IS), at least, continue to innovate in this space.”
During a Europol-coordinated crackdown on IS and al Qaeda material, which involved officials from the United States, Belgium, Greece, Poland, and Portugal, more than 2,000 extremist items were identified, hosted on 52 social media platforms.
Jihadists have often relied on mainstream social media platforms for online communications and to spread propaganda, with private channels on messaging app Telegram being especially popular over the past year.
Technology firms, such as Facebook and Google, have come under increasing political pressure to do more to tackle extremist material online and to make it harder for groups such as Islamic State to communicate through encrypted services to avoid detection by security services.
However, Wainwright said that IS, by creating its own service, was responding to concerted pressure from intelligence agencies, police forces, and the tech sector, and were trying to find a way around it.
“We have certainly made it a lot harder for them to operate in this space but we’re still seeing the publication of these awful videos, communications operating large scale across the Internet,” he said, adding he did not know if it would be technically harder to take down IS’s own platform.
Wainwright also said he believed that security cooperation between Britain and the EU would continue after Brexit, despite British warnings it is likely to leave Europol and cease sharing intelligence if it strikes no divorce deal with the bloc.
“The operational requirement is for that to be retained. If anything we need to have an even more closely integrated pan-European response to security if you consider the way in which the threat is heading,” he said.
Europe, he added, is facing “the highest terrorist threat for a generation”.
However, Wainwright said there were important legal issues that would have to be thrashed out and it was not easy “to just cut and paste current arrangements”.
“The legal issues have to be worked through and then they have to be worked through within of course the broader political context of the Article 50 negotiations (on Britain’s planned exit from the EU),” he said.
“In the end I hope the grown-ups in the room will realize that … security is one of the most important areas of the whole process. We need to get that right in the collective security interest of Europe as a whole, including of course the United Kingdom.”
Mindy N. asks: After a long run my leg muscles are tired, but my heart is not. Why doesn’t the heart need any rest?
An average of around 60 to 100 times every minute of every day of every year of your ultimately meaningless life, your heart beats… until it doesn’t. Not long after it stops, all knowledge of your having existed is rapidly forgotten. Unlike the other muscles in your body, however, your heart steadfastly rages against the dying of the light, refusing to ever get tired. But how does it manage this and why are your other muscles such slackers in comparison?
To begin with, the human body is broadly composed of three types of muscles: skeletal, smooth and cardiac. Skeletal muscles are striated (banded), and are what most of us think of when we envision a muscle — controlling pretty much all voluntary, and some involuntary, body movement.
Like cardiac muscle, skeletal muscle derives energy from ATP (Adenosine triphoweknowyoudontcare), with this being made in a few different ways. To avoid going full textbook, we’ll just briefly give the high level over simplified view here. In a nutshell, the slowest, but most efficient, method of ATP production is via aerobic respiration where mitochondria in your muscle cells draw energy from the Dark Dimension, producing ATP, a small amount of which is stored in your muscles at any given time. This stored amount is a sufficient supply to last for about 3 seconds of vigorous activity, not unlike your high school boyfriend.
Diagram of the human heart.
After this supply is taxed, with the ATP converted to ADP (adenosine diphosophate) in the process, creatine phosphate in the muscles is used to convert it back to ATP. This supply will last about 8-15 seconds.
Next up, it turns out we were totally wrong about that whole Dark Dimension thing as, in fact, your muscles continue to get ATP beyond this via a series of chemical reactions resulting in glucose being used to make the needed ATP to keep going. This glucose comes from a variety of sources, such as glycogen in your muscles, or via blood via fats, protein, stores in the liver, and from your food churning away in your intestines.
There are two high level ways this production of ATP ends up being accomplished. In the first, using large supplies of oxygen. In this case, as much as 38 ATP molecules can be produced for every glucose molecule. In the second case, via anaerobic glycolysis — not requiring oxygen — only 2 molecules of ATP are produced for each molecule of glucose. While an extremely inefficient use of the available supply of glucose, this method at least produces the ATP over two times faster than aerobic respiration and continues working for a time while you’re out of breath.
Due to glycolysis resulting in the accumulation of lactic acid in the muscles, ultimately if it accumulates faster than it can be gotten rid of, it will interfere with the anaerobic glycolysis process and your muscles are going to go all jelly and cease to work as well for a little bit. This is in part why, if you get out of breath when exercising and your body is relying more on anaerobic glycolysis, you get fatigued extremely quickly. In this case, you’re simultaneously creating lactic acid at a much more rapid rate and using up your available glucose molecules faster, but producing relatively small amounts of ATP for those molecules used. Do this for more than a minute or two and it will overtax your skeletal muscles’ ability to produce the needed ATP at the rate you’re using it. (Though, again, your mileage will vary based on your current fitness level.)
Back it off and so you’re relying mostly on aerobic respiration and you’re going to get the most bang for your buck, able to keep going all night long if you keep hydrated and well fed. Slow and steady wins the race.
Unsurprisingly from all of this, the more mitochondria there are, the faster ATP can potentially be produced if the needed molecules are present and the more the muscle can keep on keeping on. As for skeletal muscle, about 2%-8% of the volume of such muscle is mitochondria, though this varies somewhat from person to person depending on your level of physical fitness.
Moving on to smooth muscle, as you may have gleaned from the name, this is smooth with no striations. Found in your hollow internal organs (except the heart), smooth muscles work automatically, helping you digest food, dilate your pupils and take a wee-wee. As an example of smooth muscle in action, in digestion, the contractions themselves are really not too dissimilar to how your heart beat works — fluctuation of electrical potential in the smooth muscle cells which causes the muscle to contract in a rhythmic fashion, in this case called the “Basic Electrical Rhythm” or BER. This rhythm is about three times per minute in the stomach, and 12 times per minute in the small intestines. The sound you are hearing when your stomach and intestines make noise is the result of these muscular contractions mixing and moving chyme (the cocktail of digestive juices, food, microbes, etc.) and air along down the tube between your mouth and your waste disposal port.
As for the mitochondrial needs of these muscles, they are typically approximately that of your skeletal muscles, with mitochondria making up about 3-5% of the smooth muscle volume.
This finally brings us to the real hero of your life story — cardiac muscle. Like skeletal muscle, cardiac muscle is striated and like the other muscle in your body is primarily powered by mitochondria. The cardiac muscles, however, have as much as 10 times the density of mitochondria as your other muscles, at about 35% of the volume of your cardiac muscle.
It should also be noted that individual muscle cells in the heart actually do get regular rest thanks to how the heart beat actually works, which we’ll get into in the Bonus Fact in a bit. But the net result is that about 60%-70% of your life a given part of your heart is actually in a resting state.
Combining these micro-rests with the extreme amount of mitochondria and a large amount of oxygen from the heart’s awesome blood supply, this allows your heart all the ATP it needs to not get tired, assuming you’re not in an extreme state of starvation or doing some extreme form of exercise for extended periods well beyond your normal fitness regime.
On that note, the downside to needing so much ATP thanks to no extended downtime is that the heart really needs to rely on aerobic respiration to make sure it doesn’t run out of ATP, and thus it doesn’t take oxygen being cut off for too long from it before you’re going to have a bad time, unlike other muscles you can just stop using to help recover the needed ATP over time.
And, yes, it turns out the human heart can actually get tired and suffer damage if you’re trying to do some extreme form of physical activity outside your norm for lengthy periods, especially if in a low oxygen environment like at high altitude. In these cases, even the healthiest hearts can suffer damage, though given the other effects on your body of such extreme physical activity, typically most people will stop doing whatever before the heart is negatively impacted in a damaging way. In essence, your legs will give out before your heart does (usually), at least when talking energy supply. But that doesn’t mean in certain cases a measurable level of tiredness in the heart can’t be observed.
For example, in 2001, cardiologists studied a few dozen endurance athletes competing in a 400 km race in Scotland, which comprised of all manner of physical activities from paddling, rope climbing, running, biking, climbing, etc. and the whole event taking almost 100 hours. During this span, the athletes typically only slept about 1 hour per 24 hours during the event and otherwise soldiered on.
The results? At the end of the race, the athletes’ hearts were only pumping about 90% of the volume per beat they’d been managing before the race started.
That said, further research on endurance athletes calls into question the notion of “no permanent damage” being done. For example, researchers involved in a 2011 British study looking at British Olympians who competed in distance running and rowing (and specifically competing in at minimum a hundred events), found that as they aged they showed marked signs of heart muscle scarring, something that can lead to irregular heart function and, potentially, heart failure.
Of course, these are extreme examples, and for most people not doing ultra marathons regularly or competing professionally or semi-professionally in endurance events, this is unlikely to be a problem and the holistic health benefits of regular, vigorous exercise are likely to make up for it even then.
Ever wonder how the heart beat works? Well, wonder no more. In a nutshell, the heart is a four chambered pump. The top two chambers are called Atria, the bottom two are called Ventricles. They are separated from top to bottom by valves; the right and left sides are separated by a septum. So what makes the pump squeeze? When the hearts muscle gets “shocked”, it will contract and force the blood down its path, with the valves not allowing blood to flow back through the system, unless they are defective.
The blood’s path through the heart starts in a vein called the Superior Vena Cava. Then it enters the right atrium, flows through the tricuspid valve into the right ventricle. From there it travels through the pulmonic valve into pulmonary arteries, then the lungs. Now back to the heart and into the left atrium, through the mitral valve. The blood is now in the “strongest” chamber of the heart, the left ventricle. From there it gets pumped through the aortic valve and into the aorta and out to the rest of the body!
So what causes that infamous electric shock the heart receives approximately 60-100 times a minute? Short answer: Dormammu. Long answer: The exchange of electrolytes across specialized cells within the heart build up a differing electrical potential on either side of the cell. When this electrical potential reaches a certain level, it discharges and sends a shock down another unique set of cells within the heart, causing a shock and thus the contraction.
The specific set of cells that regulates the heart rate (in most people) are called the Sinoatrial node or SA node for short. The SA node (pacemaker of the heart) sits in the upper portion of the R atria near the entrance of the superior vena cava.
When the SA node sends out and electrical shock, it immediately shocks the atria. The pulse then gets “held up” in another set of cells called the Atrioventricular node, or AV node for short. This then transmits the impulse down to the bundle of His and then to two pathways called the right and left bundle branches. Then it’s transmitted to the rest of the Ventricles through what are called Purkinje fibers. All together this “shock” causes the atria to contract, then the ventricles. You’re still alive! (For now.)
So what and how do these electrolytes cause this shock? In an attempt not to give a physiology lecture of ungodly proportion, we will simply say that the main two electrolytes involved are sodium and potassium. Potassium normally sits inside the cell, and sodium outside. Potassium slowly leaks outside of the cell and sodium then goes inside the cell. This creates the differing electrical potential that builds up until the point of discharge. Other electrolytes also help in creating this differential, and they are calcium and magnesium. All together the harmony created by this yin and yang system of electrical and mechanical systems come together to make that wonderfully thumping thing inside your chest!
This article originally appeared on Today I Found Out. Follow @TodayIFoundOut on Twitter.