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Qs people asked me on science and my replies to them - part 199

Q: Can a person survive lightening?

Krishna: Yes!

And of the roughly 500 people who are struck by lightning each year, about 90% survive.

But you will have to face some consequences, although you survive. A lot can happen in the three milliseconds it takes for a lightning bolt to course through your body.

As the lightning strikes and then exits your body, it will leave you with deep wounds, often accompanied with third degree burns. Your hair and clothing might singe or catch fire. Your clothes might even be shredded by the explosive force of the surrounding air being superheated to up to 50,000 degrees F. Steam will interact with it differently with different types of clothes depending upon what it’s made of. A leather jacket can trap the steam inside, burning the survivor’s skin. Polyester can melt with just a few pieces left behind, primarily the stitching that once held together the seams of a shirt or a jacket that’s no longer there. If you happen to be wearing any metal objects, , like necklaces or a piercings, they could channel the electric current, superheating and searing your skin.

And if the lightning exits through your feet, he force could literally knock your shoes off. Blood vessels bursting from the electric discharge and heat might create something called a Lichtenberg figure on your skin. They appear within an hour and usually disappear by 48 hrs.

Lichtenberg figure on skin Pic source: Pinterest

When the lightning enters your body, it short-circuits the small electrical signals that run the heart, lungs, and nervous system. This can lead to cardiac arrest, seizures, brain injury, spinal cord damage, and amnesia. The blistering heat, light, and electricity can also damage your eyes. For example, it can bore holes in your retina and cause cataracts, a clouding of the lenses. Unfortunately for men, lightning can also induce impotence and decrease libido in general. It's not uncommon for the blast to rupture your eardrums, leading to hearing loss. You might be faced with a lifetime of neurological afflictions. You might undergo personality changes, mood swings, and memory loss. you will suffer from chronic pain and constant Parkinson's-like muscle twitches.

As the lightning moves toward the surface of the body, it can force red blood cells out of your capillaries, into your epidermis like a bruise. These lightning strike scars are the earlier mentioned Lichtenberg figures.

When someone is hit by lightning, it happens so fast that only a very tiny amount of electricity ricochets through the body. The vast majority travels around the outside in a ‘flashover’ effect.

By way of comparison, coming into contact with high-voltage electricity, such as a downed wire, has the potential to cause more internal injuries, since the exposure can be more prolonged. A ‘long’ exposure might still be relatively brief – just a few seconds. But that’s sufficient time for the electricity to penetrate the skin’s surface, risking internal injuries, even to the point of cooking muscle and tissue to the extent that a hand or limb might need to be amputated.

Lightning’s ability to scramble the electrical impulses of the heart is well understood now. Lightning’s massive electrical current can temporarily stun the heart. Thankfully, though, the heart possesses a natural pacemaker. Frequently, it can reset itself.

The problem is that lightning can also knock out the region of the brain that controls breathing. This doesn’t have a built-in reset, meaning a person’s oxygen supply can become dangerously depleted. The risk then is that the heart will succumb to a second and potentially deadly arrest. If someone has lived to say, ‘Yes, I was stunned [by lightning],’ it’s probable that their respiration wasn’t completely wiped out, and re-established in time to keep the heart going.”

So what causes external burns? As lightning flashes over the body, it might come into contact with sweat or raindrops on the skin’s surface. Liquid water increases in volume when it’s turned into steam, so even a small amount can create a ‘vapour explosion’. “It literally explodes the clothes off.

However, shoes are more likely to be torn or damaged on the inside, because that’s where the heat build-up and vapour explosion occurs.

Q: How can we protect ourselves during thunderstorms?

Krishna: There are NO SAFE PLACES outdoors during a lightning storm. You simply are NOT safe outside. So stay indoors.

If camping, hiking, etc., far from a safe vehicle or building, avoid open fields, the top of a hill or a ridge top. Keep your site away from tall, isolated trees or other tall objects. If you are in a forest, stay near a lower stand of trees.

If you are camping in an open area, set up camp in a valley, ravine or other low area. Remember, a tent offers NO protection from lightning. If you are camping and your vehicle is nearby, run to it before the storm arrives.

Stay away from water, wet items such as ropes and metal objects, such as fences and poles. Water and metal are excellent conductors of electricity. The current from a lightning flash will easily travel for long distances.

When lightning strikes the earth, it branches out along the ground. The lightning bolt can be fatal up to 100 feet away from the point of strike.

These currents fan out from the strike center in a tendril pattern, so in order to minimize your chance of being struck, you have to minimize both your height and your body's contact with the earth's surface.

Small boats with no cabins are dangerous too. Large boats with cabins, especially those with lightning protection systems properly installed, or metal marine vessels are relatively safe. Remember to stay inside the cabin and away from any metal surfaces.

Lightning often strikes the tallest object in the area, so avoid open fields or any hilltops. Look for a low-lying area like a valley or ravine, preferably obscured from the rain. Take refuge here until the storm passes. Crouch down with your heels touching and your head between your knees: this will make you a smaller target.

Check weather forecasts early in the day, and avoid going to a swimming pool, river, lake, or beach on rainy days. If you find yourself in open water during a thunderstorm, return to land immediately. If you are in a boat and cannot return to safety, drop anchor and crouch as low as possible.

Taller objects are more likely to be struck by lightning. Wherever you are, don't become the highest object anywhere. Avoid standing under trees in a lightning storm, and stay away from tall objects like light posts. If you're in a forest, stay near a lower stand of trees. Umbrellas can increase your risk of getting hit if it is the tallest object in the area.

Metal conducts electricity, and you are much more likely to get hit. If you are carrying large metal objects, let them go. Small metal objects, like piercings or electronic devices, do not carry a large risk and are safe to hold. If you are riding a bicycle, drop the bike and crouch to the ground. Most bikes are made of metal and are excellent lightning conductors. Rubber shoes or other rubber objects will not actually protect you from metal's conducting properties.

When your choice is either outdoors or inside a car, your car is always the safest option. If caught in a thunderstorm, remain inside your car until the storm passes. Close your windows. Don't touch metal objects inside your cars. Don't handle GPS or radio systems.

If a bolt strikes your house or a nearby power line, it CAN travel into your house through the plumbing or the electric wiring! If you are using any electrical appliances or plumbing fixtures (INCLUDING telephones and computers), and a storm is overhead, you are putting yourself at risk!

During thunderstorms, lightning can travel through water pipes if it strikes your home. Do not bathe or shower until the storm has passed. If you have to use the sink, only do so in emergencies.

Turn off and stay away from wired electronics. Using electronic devices that plug into the wall is dangerous during a lightning storm. Avoid using TVs, washing machines, and corded phones during thunderstorms. Wireless electronics, like cell phones, are safe to use unless they are plugged into a charger.

Avoid standing next to open windows or doors during a thunderstorm. Although rare, lightning can travel through windows during storms. Glass is a good insulator, so it is unlikely that the window will be struck if closed.

Add a lightning rod to your roof. Lightning rods do not attract lightning but do provide a path of least resistance if lightning hits your house. This can prevent the electric current from damaging your home.

Q: what are some myths about lightening?

Krishna:

Myth: If you're caught outside during a thunderstorm, you should crouch down to reduce your risk of being struck.
Fact: Crouching doesn't make you any safer outdoors. Run to a substantial building or hard topped vehicle. If you are too far to run to one of these options, you have no good alternative. You are NOT safe anywhere outdoors. See this safety page for tips that may slightly reduce your risk.

Myth: Lightning never strikes the same place twice.
Fact: Lightning often strikes the same place repeatedly, especially if it's a tall, pointy, isolated object. The Empire State Building is hit an average of 23 times a year

Myth: If it’s not raining or there aren’t clouds overhead, you’re safe from lightning.
Fact: Lightning often strikes more than three miles from the center of the thunderstorm, far outside the rain or thunderstorm cloud. “Bolts from the blue” can strike 10-15 miles from the thunderstorm.

Myth: Rubber tires on a car protect you from lightning by insulating you from the ground.
Fact: Most cars are safe from lightning, but it is the metal roof and metal sides that protect you, NOT the rubber tires. Remember, convertibles, motorcycles, bicycles, open-shelled outdoor recreational vehicles and cars with fiberglass shells offer no protection from lightning. When lightning strikes a vehicle, it goes through the metal frame into the ground. Don't lean on doors during a thunderstorm.

Myth: A lightning victim is electrified. If you touch them, you’ll be electrocuted.
Fact: The human body does not store electricity. It is perfectly safe to touch a lightning victim to give them first aid. This is the most chilling of lightning Myths. Imagine if someone died because people were afraid to give CPR!

Myth: If outside in a thunderstorm, you should seek shelter under a tree to stay dry.
Fact: Being underneath a tree is the second leading cause of lightning casualties. Better to get wet than fried!

Myth: If you are in a house, you are 100% safe from lightning.
Fact: A house is a safe place to be during a thunderstorm as long as you avoid anything that conducts electricity. This means staying off corded phones, electrical appliances, wires, TV cables, computers, plumbing, metal doors and windows. Windows are hazardous for two reasons: wind generated during a thunderstorm can blow objects into the window, breaking it and causing glass to shatter and second, in older homes, in rare instances, lightning can come in cracks in the sides of windows.

Myth: If thunderstorms threaten while you are outside playing a game, it is okay to finish it before seeking shelter.
Fact: Many lightning casualties occur because people do not seek shelter soon enough. No game is worth death or life-long injuries. Seek proper shelter immediately if you hear thunder. Adults are responsible for the safety of children.

Myth: Structures with metal, or metal on the body (jewelry, cell phones,Mp3 players, watches, etc), attract lightning.
Fact: Height, pointy shape, and isolation are the dominant factors controlling where a lightning bolt will strike. The presence of metal makes absolutely no difference on where lightning strikes. Mountains are made of stone but get struck by lightning many times a year. When lightning threatens, take proper protective action immediately by seeking a safe shelter â€“ don’t waste time removing metal. While metal does not attract lightning, it does conduct it so stay away from metal fences, railing, bleachers, etc.

Myth: If trapped outside and lightning is about to strike, I should lie flat on the ground.
Fact: Lying flat increases your chance of being affected by potentially deadly ground current. If you are caught outside in a thunderstorm, you keep moving toward a safe shelter.

Myth: lightning flashes are 3-4 km apart
Fact: Old data said successive flashes were on the order of 3-4 km apart. New data shows half the flashes are about 9 km apart. The National Severe Storms Laboratory report concludes: "It appears the safety rules need to be modified to increase the distance from a previous flash which can be considered to be relatively safe, to at least 10 to 13 km (6 to 8 miles). In the past, 3 to 5 km (2-3 miles) was as used in lightning safety education." Source: Separation Between Successive Lightning Flashes in Different Storms Systems: 1998, Lopez & Holle, from Proceedings 1998 Intl Lightning Detection Conference, Tucson AZ, November 1998.

Myth: A High Percentage of Lightning Flashes Are Forked.
Fact: Many cloud-to-ground lightning flashes have forked or multiple attachment points to earth. Tests carried out in the US and Japan verify this finding in at least half of negative flashes and more than 70% of positive flashes. Many lightning detectors cannot acquire accurate information about these multiple ground lightning attachments. Source: Termination of Multiple Stroke Flashes Observed by Electro- Magnetic Field: 1998, Ishii, et al. Proceedings 1998 Int'l Lightning Protection Conference, Birmingham UK, Sept. 1998.

Myth: Lightning Can Spread out Some 60 Feet After Striking Earth.
Fact: Radial horizontal arcing has been measured at least 20 m. from the point where lightning hits ground. Depending on soils characteristics, safe conditions for people and equipment near lightning termination points (ground rods) may need to be re-evaluated. Source: 1993 Triggered Lightning Test Program: Environments Within 20 meters of the Lightning Channel and Small Are Temporary Protection Concepts: 1993, SAND94-0311, Sandia Natl Lab, Albuquerque NM.

Qs people asked me on science and my replies to them - part 199

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