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Could You Really Dig a Hole to China?

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In theory, yes. In practice, your journey through the planet might be hampered by the planet’s molten core.

There’s also the matter of finding a spot for all you’re digging through to make your tunnel. Let’s not rule out the possibility of mole people, dinosaurs and graboids living down there, either. Keep in mind, too, that you would need to build some sort of DIY digging contraption. Even the biggest and best digging operations in the world haven’t breached the Earth’s crust yet and to even get close, they had to start digging from the ocean floor. I’m going to guess you’re starting from your backyard, which means you don’t have a chance.

But we can dream, can’t we? And who am I to step on your dreams?

Let’s have a little fun and speculate, then, about what physicists say a trip through the planet might be like. To make your journey a little easier, we’ll assume certain ideal conditions:

1. You did your homework and know that if you dig a straight hole down in the United States, you’ll come out the other side not in China, but in the Indian Ocean. To avoid this very wet ending and get to China, you started digging in Argentina. Good for you.

2. You managed to actually dig a tunnel with your fancy homemade digging machine and found a place for all the rubble. You’re now standing there, peering into the hole and ready to jump in, passing Argentinians eyeing you warily.

3. The Earth’s core is not molten, so your digging machine did not melt and neither will you.

4. The Earth has the same density throughout. At the center, you have approximately equal amounts of mass on all sides of you, which cancel each other out and result in no net gravitational force acting on you.

5. The Earth isn’t rotating, which made it easier to dig your hole and will keep you from bouncing around in your tunnel and getting all bruised up.

6. There’s no friction, no air resistance, and no mole men.

update: some helpful readers have pointed out other conditions that I neglected in the original post...

7. Either Bernoulli’s principle doesn’t apply or you're wearing some sort of breathing apparatus and oxygen tank, that way your high travel speed won't affect your ability to breath.

8. The air pressure at your starting point, throughout your tunnel and at your end point is uniform, so you don't get squished into goo.

It’s a lot of concessions to make (and I'm sure we could even think of a few more), and we’re now on an Earth very much unlike the one we know and love. Whatever. It’s a small price to pay for the thrill ride you’re about to take.

So go on. Step into the hole. Or maybe dive in headfirst; you’ll have a better view. As you fall through your tunnel, gravity pulls you down towards the center, and you gain speed. As you get closer to the center, you’re closer to that balance of mass we assumed. Gravity doesn’t pull on you as much and while you’ll still gain speed, you won’t do it as fast. Once you hit the center of the Earth, you’ll be in zero gravity, but going at maximum speed (some 18,000 mph), you won’t even notice.

As you pass the center, gravity starts to work against you, pulling you back towards the core. You’ll start to decelerate at exactly the opposite rate that you accelerated during the first half of the trip. When you reach the opposite end of the tunnel (the trip would take you, appropriately, 42 minutes), you’ll come to a dead stop for an instant just as you pop out of the exit hole. Unless some considerate Chinese person happens to be near the hole and grabs you, all of Earth’s mass will pull you back towards the core and you’ll go back down (or up, as it were) the hole again.

If no one catches you at either end of the tunnel, you’ll spend the rest of your life oscillating back and forth, the human yo-yo at the center of the Earth.

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Live Smarter
Trying to Save Money? Avoid Shopping on a Smartphone
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Today, Americans do most of their shopping online—but as anyone who’s indulged in late-night retail therapy likely knows, this convenience often can come with an added cost. Trying to curb expenses, but don't want to swear off the convenience of ordering groceries in your PJs? New research shows that shopping on a desktop computer instead of a mobile phone may help you avoid making foolish purchases, according to Co. Design.

Ying Zhu, a marketing professor at the University of British Columbia-Okanagan, recently led a study to measure how touchscreen technology affects consumer behavior. Published in the Journal of Retailing and Consumer Services, her research found that people are more likely to make more frivolous, impulsive purchases if they’re shopping on their phones than if they’re facing a computer monitor.

Zhu, along with study co-author Jeffrey Meyer of Bowling Green State University, ran a series of lab experiments on student participants to observe how different electronic devices affected shoppers’ thinking styles and intentions. Their aim was to see if subjects' purchasing goals changed when it came to buying frivolous things, like chocolate or massages, or more practical things, like food or office supplies.

In one experiment, participants were randomly assigned to use a desktop or a touchscreen. Then, they were presented with an offer to purchase either a frivolous item (a $50 restaurant certificate for $30) or a useful one (a $50 grocery certificate for $30). These subjects used a three-point scale to gauge how likely they were to purchase the offer, and they also evaluated how practical or frivolous each item was. (Participants rated the restaurant certificate to be more indulgent than the grocery certificate.)

Sure enough, the researchers found that participants had "significantly higher" purchase intentions for hedonic (i.e. pleasurable) products when buying on touchscreens than on desktops, according to the study. On the flip side, participants had significantly higher purchase intentions for utilitarian (i.e. practical) products while using desktops instead of touchscreens.

"The playful and fun nature of the touchscreen enhances consumers' favor of hedonic products; while the logical and functional nature of a desktop endorses the consumers' preference for utilitarian products," Zhu explains in a press release.

The study also found that participants using touchscreen technology scored significantly higher on "experiential thinking" than subjects using desktop computers, whereas those with desktop computers demonstrated higher scores for rational thinking.

“When you’re in an experiential thinking mode, [you crave] excitement, a different experience,” Zhu explained to Co. Design. “When you’re on the desktop, with all the work emails, that interface puts you into a rational thinking style. While you’re in a rational thinking style, when you assess a product, you’ll look for something with functionality and specific uses.”

Zhu’s advice for consumers looking to conserve cash? Stow away the smartphone when you’re itching to splurge on a guilty pleasure.

[h/t Fast Company]

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Animals
Elusive Butterfly Sighted in Scotland for the First Time in 133 Years

Conditions weren’t looking too promising for the white-letter hairstreak, an elusive butterfly that’s native to the UK. Threatened by habitat loss, the butterfly's numbers have dwindled by 96 percent since the 1970s, and the insect hasn’t even been spotted in Scotland since 1884. So you can imagine the surprise lepidopterists felt when a white-letter hairstreak was seen feeding in a field in Berwickshire, Scotland earlier in August, according to The Guardian.

A man named Iain Cowe noticed the butterfly and managed to capture it on camera. “It is not every day that something as special as this is found when out and about on a regular butterfly foray,” Cowe said in a statement provided by the UK's Butterfly Conservation. “It was a very ragged and worn individual found feeding on ragwort in the grassy edge of an arable field.”

The white-letter hairstreak is a small brown butterfly with a white “W”-shaped streak on the underside of its wings and a small orange spot on its hindwings. It’s not easily sighted, as it tends to spend most of its life feeding and breeding in treetops.

The butterfly’s preferred habitat is the elm tree, but an outbreak of Dutch elm disease—first noted the 1970s—forced the white-letter hairstreak to find new homes and food sources as millions of Britain's elm trees died. The threatened species has slowly spread north, and experts are now hopeful that Scotland could be a good home for the insect. (Dutch elm disease does exist in Scotland, but the nation also has a good amount of disease-resistant Wych elms.)

If a breeding colony is confirmed, the white-letter hairstreak will bump Scotland’s number of butterfly species that live and breed in the country up to 34. “We don’t have many butterfly species in Scotland so one more is very nice to have,” Paul Kirkland, director of Butterfly Conservation Scotland, said in a statement.

Prior to 1884, the only confirmed sighting of a white-letter hairstreak in Scotland was in 1859. However, the insect’s newfound presence in Scotland comes at a cost: The UK’s butterflies are moving north due to climate change, and the white-letter hairstreak’s arrival is “almost certainly due to the warming climate,” Kirkland said.

[h/t The Guardian]

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