The d in Modern English thunder (from earlier Old English þunor) is epenthetic, and is now found as well in Modern Dutch donder (cf. Middle Dutch donre; also Old Norse þorr, Old Frisian þuner, Old High German donar, all ultimately descended from Proto-Germanic *þunraz). In Latin the term was tonare "to thunder". The name of the Nordic god Thor comes from the Old Norse word for thunder.
The cause of thunder has been the subject of centuries of speculation and scientific inquiry. Early thinking was that it was made by deities, but the ancient Greek philosophers attributed it to natural causes, such as wind striking clouds (Anaximander, Aristotle) and movement of air within clouds (Democritus).[8] The Roman philosopher Lucretius held it was from the sound of hail colliding within clouds.
In the mid 19th century, the accepted theory was that lightning produced a vacuum and that the collapse of that vacuum produced what is known as thunder.
In the 20th century a consensus evolved that thunder must begin with a shock wave in the air due to the sudden thermal expansion of the plasma in the lightning channel. The temperature inside the lightning channel, measured by spectral analysis, varies during its 50 μs existence, rising sharply from an initial temperature of about 20,000 K to about 30,000 K, then dropping away gradually to about 10,000 K. The average is about 20,400 K (20,100 °C; 36,300 °F). This heating causes a rapid outward expansion, impacting the surrounding cooler air at a speed faster than sound would otherwise travel. The resultant outward-moving pulse is a shock wave, similar in principle to the shock wave formed by an explosion, or at the front of a supersonic aircraft. In close proximity to the source, the sound pressure level of thunder is usually 165–180dB, but can exceed 200 dB in some cases.
Experimental studies of simulated lightning have produced results largely consistent with this model, though there is continued debate about the precise physical mechanisms of the process. Other causes have also been proposed, relying on electrodynamic effects of the enormous current acting on the plasma in the bolt of lightning.
The shock wave in thunder is sufficient to cause property damage and injury, such as internal contusion, to individuals nearby. Thunder can rupture the eardrums of people nearby, leading to permanently impaired hearing. Even if not, it can lead to temporary deafness.
Vavrek et al. (n.d.) reported that the sounds of thunder fall into categories based on loudness, duration, and pitch. Claps are loud sounds lasting 0.2 to 2 seconds and containing higher pitches. Peals are sounds changing in loudness and pitch. Rolls are irregular mixtures of loudness and pitches. Rumbles are less loud, last for longer (up to more than 30 seconds), and of low pitch.
Inversion thunder results when lightning strikes between cloud and ground occur during a temperature inversion; the resulting thunder sounds have significantly greater acoustic energy than from the same distance in a non-inversion condition. In an inversion, the air near the ground is cooler than the higher air; inversions often occur when warm moist air passes above a cold front. Within a temperature inversion, the sound energy is prevented from dispersing vertically as it would in a non-inversion and is thus concentrated in the near-ground layer.
Cloud-to-ground lightning (CG) typically consists of two or more return strokes, from ground to cloud. Later return strokes have greater acoustic energy than the first.
The most noticeable aspect of lightning and thunder is that the lightning is seen before the thunder is heard. This is a consequence of the speed of light being much greater than the speed of sound. The speed of sound in dry air is approximately 343 m/s (1,130 ft/s) or 1,236 km (768 mi) at 20 °C (68 °F; 293 K). This translates to 3 s/km (4.8 s/mi); saying "one thousand and one... one thousand and two..." is a useful method of counting the seconds from the perception of a given lightning flash to the perception of its thunder (which can be used to gauge the proximity of lightning for the sake of safety).
A very bright flash of lightning and an almost simultaneous sharp "crack" of thunder, a thundercrack, therefore indicates that the lightning strike was very near.
Close-in lightning has been described first as a clicking or cloth-tearing sound, then a cannon shot sound or loud crack/snap, followed by continuous rumbling. The early sounds are from the leader parts of lightning, then the near parts of the return stroke, then the distant parts of the return stroke.
Need a fresh new idea for a go-along salad this season? Our Broccoli and Cheese Salad recipe fits the bill! This broccoli salad is sort of like a vegetarian antipasto, loaded with veggies and cheeses and topped off with an unforgettable, light and creamy dressing.
- 2 heads broccoli, cut into small florets
- 1 cup cherry tomatoes, cut in half
- 1/2 red onion, cut into 1/2-inch chunks
- 1 (6-ounce dr. wt.) can whole black olives, drained
- 1/2 pound Monterey Jack cheese, cut into 1/2-inch chunks
- 1/2 pound sharp Cheddar cheese, cut into 1/2-inch chunks
- 1 cup plain Greek yogurt
- 1 cup mayonnaise
- 3 tablespoons honey
- 1 teaspoon garlic powder
- 1 teaspoon salt
- 1/2 teaspoon black pepper
- 1/2 cup cooked crumbled bacon (optional)
- In a large bowl, combine broccoli, tomatoes, onion, olives, Monterrey Jack, and Cheddar cheeses.
- In a medium bowl, whisk together yogurt, mayonnaise, honey, garlic powder, salt, and pepper. Pour over vegetables and toss until evenly coated. Cover and chill until ready to serve. Sprinkle with bacon, if desired, just before serving.
Ah, spuds. On August 19th each year, the humble potato takes center stage. In truth, though, doesn’t it steal the show at nearly every meal?
Whether baked, fried or mashed, these taters bring on the flavor. They are a staple of many meals, too. Filling a void for appetizer dishes and working double duty at suppertime, these versatile root veggies satisfy and fill us up.
According to the International Potato Center, more than 4,000 varieties of potatoes grow around the world. Not only that, but they also come in a variety of beautiful colors and sizes. This starchy carbohydrate comes with no fat or cholesterol and is loaded with Vitamin C and potassium. Depending on your dietary needs and how you prepare your potatoes, this vegetable offers what many are looking for. However, with 26 grams of carbohydrates, it’s a no-no in a low-carb lifestyle.
When it comes to the health specs of a potato, we tend to tank the benefits when we prepare them. We fry them and load them with toppings like cheese, sour cream, and butter. Who doesn’t love a loaded baked potato? Ok, ok. You can all put your hands down, now.
HOW TO OBSERVE NATIONAL POTATO DAY
With so many ways to savor a potato, it shouldn’t be too hard to find a way. However, we do have a few tateriffic ways to get you started:
- Host a baked potato buffet. Line up all the best toppings such as cheese, jalapenos, bacon, chopped onions, chili, grilled chicken or ranch.
- Tried French fries dipped in soft, vanilla ice cream. If you’ve never had it before, you will be surprised.
- Swap out your corn chips with French fries and build a new kind of nacho. Think beer brats, sauerkraut, Swiss cheese and sour cream for German flair. Aim for a bit of Irish celebration by using corned beef.
- Share your favorite recipes. You know, the ones you always go to when you’re craving potatoes. Or, try a new recipe and give it a review.
- Make a delicious potato soup. With so many different recipes, one of them is sure to satisfy!
- Visit your favorite restaurant and pile on the potatoes. Whether it’s an entree or an appetizer, be sure to give the eatery a shout-out!
- Check out this Home Fries recipe.
NATIONAL POTATO DAY HISTORY
The nation’s comfort food has been celebrated since at least 2006. Before that National Potato Day celebrations had been cropping up throughout the year all across the country.
Potato FAQ
Q. Which is healthier, the white potato or the sweet potato?
A. The sweet potato edges out the white potato thanks to fiber and vitamins. However, both are quite nutritious. How we prepare these root vegetables makes a bigger impact on our diet than the vegetables themselves. Frying vs. baking, toppings and more will tip the scales on nutrition quickly.
Q. Are there other potato holidays?
A. You bet your sweet potato there is! November is Sweet Potato Awareness Month. In February, we celebrate National Eat a Sweet Potato Day and in March we celebrate National Tater Day. And we can’t forget National French Fry Day in July.
Q. How are potatoes prepared?
A. Potatoes can be prepared in a number of ways. Besides baking, boiling, roasting and frying, potatoes are also used to make bread, pasta, hash browns, salads, pancakes, soup, croquettes, among other preparations.
Q. What country produces the most potatoes?
A. In 2016, China produced the most potatoes at more than 99 million tonnes. The United States comes in 5th behind India, Russia, and Ukraine.
