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These are the world’s longest straight lines
Researchers use algorithms to find the longest straight-line distances on land and at sea
- What links a small town in Portugal and a huge port city in China?
- The answer may surprise even inhabitants of both places: the world's longest straight line over land
- That line and its maritime equivalent were determined not by exploration but by calculation
What connects the Chinese port of Quanzhou with Sagres, a tiny parish in southern Portugal? No, it's not the New Silk Route, the Sino-European rail link inaugurated in 2017 (1). The answer is so arcane that it will surprise most inhabitants of either place: they are the extreme points of the world's longest straight line over land (2).
Following the course of that line would require directional rectitude of the highest degree. Travellers would have to forgo the relative comfort of well-worn roads and mountain passes and traverse daunting peaks and inhospitable deserts – not to mention innumerable private houses and public buildings.
Longest sailable straight line on Earth, as suggested by Reddit user kepleronlyknows.
They would cross 15 countries; skirting Madrid and Switzerland's alpine highlands; cutting off a corner of Austria and passing just north of Auschwitz in Poland; barely touching Ukraine and slicing through Belarus; travelling through Russia and Kazakhstan before hitting China and reaching the Formosa Strait; but not before dipping into Mongolia twice.
Because the globe is round and this map is not, the world's longest straight line over land – like all others long enough – looks like a bendy one on this image. For anyone walking the line, though, it would have been straight as a ruler, and, at the end of that trip, close to 20,000 miles long.
Threading the needle
Algorithmically correct: the world's longest sailable straight line goes from Pakistan to Kamchatka
Image: Chabukswar & Mukherjee
The world's longest straight line on land was calculated by researchers Rohan Chabukswar of the United Technologies Research Centre (UTRC) in Cork (Ireland) and Kushal Mukherjee at IBM's Research Laboratory in New Delhi (India).
In a paper published earlier this year (and last updated on 25 December), they set out their solution to the question of finding the world's longest straight lines over land and at sea. That question sounds simple enough, but isn't: "This is an optimisation problem, rendered chaotic by the presence of islands and lakes, and indeed the fractal nature of the coasts".
They were prompted by a map that had raised a lot of discussion since its first publication on Reddit in 2012. Posted by user kepleronlyknows, it purports to show the longest possible straight-line sailing route in the world: from Pakistan to Kamchatka, threading the needle twice – through the Mozambique Strait separating Madagascar from the African mainland, and via the Drake Passage between South America and Antarctica.
Walk this way
A long walk indeed, but a straight one: Portugal to China
Image: Chabukswar & Mukherjee
Commenters have since sought to prove or disprove the longest straight-line sea route, and the analogous route over land. Suggested but disproved longer routes include two nautical ones: from Norway to Antarctica – a valid route, but not in fact as long as the Pakistan to Kamchatka one; and from Québec to British Columbia, which turns out not to be a perfectly straight line.
One suggested longer overland route leads from from Wenling in China to Greenville in Liberia. But this line crosses the Dead Sea and if, as the authors say, that qualifies as a 'major body of water', it disqualifies the route as being entirely over land.
Strangely enough, the direction from Portugal to China is due northeast
Image: Google Earth
So Messrs. Chabukswar and Mukherjee decided to put the issue through a scientific wrangler. Instead of conducting an exhaustive search of all possible routes – more than 233 million great circles (3), as the authors suggest - they calculated the two paths using a so-called branch-and-bound algorithm.
They found that the original poster on Reddit was right: the longest sailable straight-line path does connect Pakistan to Kamchatka. To be precise, it links Sonmiani (25°17′ N, 66°40′ E), a coastal town (4) approximately 90 miles (145 km) northwest of Karachi, with an unnamed location in the Karaginsky District (58°37′ N, 162°14′ E), a virtually uninhabited part in the north of the Kamchatka peninsula. The path is almost 20,000 miles long (to be precise: 19,939.8 miles, or 32,090 km).
Steppe by steppe...
Image: Google Earth
The same algorithm was let loose on the dry-land variety of the straight-line question. Here, the answer links a point near Sagres (37°2′ N 8°55′ W) to a point in the south of the greater Quanzhou metro area (24◦33′ N, 118◦38′ E). The distance covered is much smaller than the longest straight line at sea: just short of 7,000 miles (6,984.8 miles, or 11,241 km).
The researchers formulate a few theoretical caveats to their result, and one practical one: "The problem was approached as a purely mathematical exercise. The authors do not recommend sailing or driving along the found paths".
There is hope, however, for whoever had their heart set on long straight-line travels. Here are a few of the world's longest straight-line roads (5):
1. Highway 10 (Saudi Arabia): 159 miles (256 km)
There is little remarkable about either Haradh or Al Batha, two dusty towns in Saudi Arabia's Rub-al-Khali desert, or the featureless distance between them. Except that almost that entire stretch is traversed by a dead-straight road. Leaving the oil town of Haradh in the interior of the country, Saudi Highway 10 heads due east in a curveless line for 159 miles (256 km), bending slightly before entering Al Batha, near the Gulf coast and the Saudi border with the United Arab Emirates. That makes Highway 10 the longest straight stretch of road in the world.
2. US-54 (United States): 108 miles (173 km)
In its entirety, US Route 54 runs from Griggsville, Illinois to El Paso, Texas, covering 1,197 miles (2,115 km). For 108 miles, from Liberal, Kansas to Dalhart, Texas, US-54 runs in a virtually straight line (passing through Oklahoma as well). There are a few slight kinks in over the course of 54's 'straight' trajectory, though.
3. Eyre Highway, Australia (90 miles, 145.6 km)
The entire Eyre Highway is 1,030 miles (1,660 km) long, linking Norseman in Western Australia to Port Augusta in South Australia across the deserted Nullarbor Plain. It is part of Highway 1 that connects Perth to Adelaide, and the only 'sealed' road between both states. Between Balladonia and Caiguna, the road is completely straight for 90 miles – the longest stretch of straight road in Australia, commonly known as '90 Mile Straight'.
Strange Maps #954
Got a strange map? Let me know at email@example.com.
(1) A 7,500-mile (12,000-km) China Railway cargo service from Yiwu, calling on Hamburg, London and Madrid. The service could become part of China's wider Belt and Road Initiative: a massive infrastructure project connecting Chinese manufacturing to its markets in Europe and elsewhere.
(2) Perhaps the 1,000-odd inhabitants of Sagres, the westernmost point on the European road network, will be less surprised. Sagres also is a terminus of the longest (non-straight) driveable distance between two points on earth. The other one is Khasan, a Russian city on the North Korean border, and the eastern terminus of that country's road network. The route connecting both places is 8,726 miles (14,043 km) long.
(3) A great circle or orthodrome is the largest circle that can be drawn on a spherical object.
(4) Sonmiani is also notable as the northernmost point of the Arabian Sea, a seaside resort for Karachiites and a launch site for the Pakistani space agency.
(5) Most so-called straight roads have slight curves, hence the many differing lists.
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A new study finds that dogs fed fresh human-grade food don't need to eat—or do their business—as much.
- Most dogs eat a diet that's primarily kibble.
- When fed a fresh-food diet, however, they don't need to consume as much.
- Dogs on fresh-food diets have healthier gut biomes.
Four diets were tested<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTU5ODI1MS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY1NjY0NjIxMn0._w0k-qFOC86AqmtPHJBK_i-9F5oVyVYsYtUrdvfUxWQ/img.jpg?width=980" id="1b1e4" class="rm-shortcode" data-rm-shortcode-id="87937436a81c700a8ab3b1d763354843" data-rm-shortcode-name="rebelmouse-image" data-width="1440" data-height="960" />
Credit: AntonioDiaz/Adobe Stock<p>The researchers tested refrigerated and fresh human-grade foods against kibble, the food most dogs live on. The <a href="https://frontierpets.com.au/blogs/news/how-kibble-or-dry-dog-food-is-made" target="_blank">ingredients</a> of kibble are mashed into a dough and then extruded, forced through a die of some kind into the desired shape — think a <a href="https://en.wikipedia.org/wiki/Food_extrusion" target="_blank">pasta maker</a>. The resulting pellets are sprayed with additional flavor and color.</p><p>For four weeks, researchers fed 12 beagles one of four diets:</p><ol><li>a extruded diet — Blue Buffalo Chicken and Brown Rice Recipe</li><li>a fresh refrigerated diet — Freshpet Roasted Meals Tender Chicken Recipe</li><li>a fresh diet — JustFoodforDogs Beef & Russet Potato Recipe</li><li>another fresh diet — JustFoodforDogs Chicken & White Rice Recipe.</li></ol><p>The two fresh diets contained minimally processed beef, chicken, broccoli, rice, carrots, and various food chunks in a canine casserole of sorts. </p><p>(One can't help but think how hard it would be to get finicky cats to test new diets. As if.)</p><p>Senior author <a href="https://ansc.illinois.edu/directory/ksswanso" target="_blank" rel="noopener noreferrer">Kelly S. Swanson</a> of U of I's Department of Animal Sciences and the Division of Nutritional Sciences, was a bit surprised at how much better dogs did on people food than even refrigerated dog chow. "Based on past research we've conducted I'm not surprised with the results when feeding human-grade compared to an extruded dry diet," he <a href="https://aces.illinois.edu/news/feed-fido-fresh-human-grade-dog-food-scoop-less-poop" target="_blank">says</a>, adding, "However, I did not expect to see how well the human-grade fresh food performed, even compared to a fresh commercial processed brand."</p>
Tracking the effect of each diet<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTU5ODI1OC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY3NjY1NTgyOX0.AdyMb8OEcjCD6iWYnXjToDmcnjfTSn-0-dfG96SIpUA/img.jpg?width=980" id="da892" class="rm-shortcode" data-rm-shortcode-id="880d952420679aeccd1eaf32b5339810" data-rm-shortcode-name="rebelmouse-image" data-width="1440" data-height="960" />
Credit: Patryk Kosmider/Adobe Stock<p>The researchers tracked the dogs' weights and analyzed the microbiota in their fecal matter.</p><p>It turned out that the dogs on kibble had to eat more to maintain their body weight. This resulted in their producing 1.5 to 2.9 times the amount of poop produced by dogs on the fresh diets.</p><p>Says Swanson, "This is consistent with a 2019 National Institute of Health study in humans that found people eating a fresh whole food diet consumed on average 500 less calories per day, and reported being more satisfied, than people eating a more processed diet."</p><p>Maybe even more interesting was the effect of fresh food on the gut biome. Though there remains much we don't yet know about microbiota, it was nonetheless the case that the microbial communities found in fresh-food poo was different.</p><p>"Because a healthy gut means a healthy mutt," says Swanson, "fecal microbial and metabolite profiles are important readouts of diet assessment. As we have shown in <a href="https://academic.oup.com/jas/article/92/9/3781/4702209#110855647" target="_blank">previous studies</a>, the fecal microbial communities of healthy dogs fed fresh diets were different than those fed kibble. These unique microbial profiles were likely due to differences in diet processing, ingredient source, and the concentration and type of dietary fibers, proteins, and fats that are known to influence what is digested by the dog and what reaches the colon for fermentation."</p>
How did kibble take over canine diets?<p>Historically, dogs ate scraps left over by humans. It has only been <a href="https://www.thefarmersdog.com/digest/the-history-of-commercial-pet-food-a-great-american-marketing-story/" target="_blank">since 1870</a>, with the arrival of the luxe Spratt's Meat Fibrine Dog Cakes—made from "the dried unsalted gelatinous parts of Prairie Beef", mmm—that commercial dog food began to take hold. Dog bone-shaped biscuits first appeared in 1907. Ken-L Ration dates from 1922. Kibble was first extruded in 1956. Pet food had become a great way to turn <a href="https://www.dogfoodadvisor.com/choosing-dog-food/animal-by-products/" target="_blank">human-food waste</a> into profit.</p><p>Commercial dog food became the norm for most household canines only after a massive marketing campaign led by a group of dog-food industry lobbyists called the Pet Food Institute in 1964. Over time, for most households, dog food was what dogs ate — what else? Human food? These days more than half of U.S. dogs are <a href="https://www.nytimes.com/2014/08/03/magazine/who-made-that-dog-biscuit.html" target="_blank">overweight or obese</a>, and certainly their diet is a factor.<span></span></p><p>We're not so special among animals after all. If something's healthy for us to eat—we're <em>not</em> looking at you, chocolate—maybe we should remember to share with our canine compatriots. Not from the table, though.</p>
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Eating veggies is good for you. Now we can stop debating how much we should eat.
- A massive new study confirms that five servings of fruit and veggies a day can lower the risk of death.
- The maximum benefit is found at two servings of fruit and three of veggies—anything more offers no extra benefit according to the researchers.
- Not all fruits and veggies are equal. Leafy greens are better for you than starchy corn and potatoes.