If the Moon is Gradually Moving Farther Away From Us, Will Its Gravitational Pull Ever Cease on Earth?

iStock.com/kyoshino
iStock.com/kyoshino

Robert Frost:

The Moon is receding from the Earth, but will not continue to do so forever. We have to consider why the Moon is moving away at around 1.5 inches (3.78 cm) per year—a force is necessary to cause that.

The Moon exerts a tidal force on the Earth, causing a bulge. But, because the Earth rotates, that bulge is not directly between the Earth and Moon. It is slightly in front. That bulge has a gravitational pull on the Moon, causing it to move forward, slightly faster.

Causing the Moon to move slightly faster results in it climbing very slowly to a higher orbit. The Moon climbs higher by about 3.78 cm per year. But, since we just said that the force is gravitational and we know that gravity decreases with distance, we know that the force will also decrease with distance.

That means the rate at which the Moon recedes will decrease with time. But there's more to it than that. A force acts upon both bodies. While the impact on the Moon is causing it to recede, the impact on the Earth is that it is being caused to slow its rotation. The day is getting longer.

Eventually, the length of the day will match the orbital period of the Moon. That means both bodies will be tidally locked—meaning the same part of the Earth will always face the same part of the Moon. And if that happens, there is no longer a leading bulge and thus no longer a force causing the Moon to move away.

This would happen when the orbital period of the Moon is about 47 days. That would put the Moon at a distance of about 550,000 km; less than half as far again as it is today. In other words, not very far.

However, it will take a long time for that to happen. In the meantime, the Sun will turn into a red giant and its outer layers will extend to where Mars is today, meaning Earth, the Moon, and every In-N-Out restaurant will have been swallowed up and turned into loose atoms.

This post originally appeared on Quora. Click here to view.

What’s the Difference Between Crocheting and Knitting?

djedzura/iStock via Getty Images
djedzura/iStock via Getty Images

With blustery days officially upon us, the most pressing question about your sweaters, scarves, hats, and mittens is probably: “Are these keeping me warm?” If you’re a DIY enthusiast, or just a detail-oriented person in general, your next question might be: “Were these knitted or crocheted?”

Knitting and crocheting are both calming crafts that involve yarn, produce cozy garments and other items, and can even boost your mental well-being. Having said that, they do have a few specific differences.

To knit, you need needles. The size, material, and number of those needles depends on the project; though most traditional garments are made using two needles, it’s also possible to knit with just one needle, or as many as five. But regardless of the other variables, one or both ends of your knitting needles will always be pointed.

While crocheting calls for a similar long, thin tool that varies in size and material, it has a hooked end—and you only ever need one. According to The Spruce Crafts, even if you hear people refer to the tool as a crochet needle, they’re really talking about a crochet hook.

crotchet hook and garment
jessicacasetorres/iStock via Getty Images

Part of the reason you only use one hook brings us to the next difference between crocheting and knitting: When crocheting, there’s only one “active loop” on your hook at any given time, whereas knitting entails lining up loops down the length of your needles and passing them between needles. The blog Darn Good Yarn explains that since each loop is attached to a long row of stitches, accidentally “dropping” one off the end of your needle might unravel the entire row.

Of course, you have a better chance of avoiding that type of manual error if you’re using a knitting machine or loom, which both exist. Crocheting, on the other hand, has to be done by hand. Since machines can create garments with extremely small stitches, some knit clothes can be much more lightweight or close-fitting than anything you’d be able to crochet—and knitted clothes can also be mass-produced.

When it comes to what the items actually look like, crochet stitches characteristically look more like knots, while knit stitches seem flatter and less bulky. However, materials and techniques have come a long way over the years, and now there’s more crossover between what you’re able to knit and crochet. According to The Spruce Crafts, socks and T-shirts—traditionally both garments that would be knitted—can now technically be crocheted.

knitting needles and garment
Sedan504/iStock via Getty Images

And, believe it or not, knitting and crocheting can even be used to depict complicated mathematical concepts: see what a crocheted hyperbolic plane, Lorenz manifold, and more look like here.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

What Happens to Leftover Campaign Funds When a Candidate Drops Out?

After nearly one year of campaigning for the Democratic presidential nomination, Kamala Harris has officially bowed out of the 2020 election. She's not the only would-be president to call it quits so far. So what happens to all the leftover campaign funds when a candidate drops out?

One thing's for sure: Upset candidates can't console themselves by putting the dough toward a new yacht and sailing off to recuperate. The Federal Election Commission has strict rules about what federal candidates can and can't do with leftover campaign money, and the biggest directive is that they can't pocket it for personal use.

Here's what a campaign committee is allowed to do with any lingering cash: it can donate the funds to charities or political parties; it can contribute $2000 per election to other candidates; and it can save the money in case the candidate chooses to run again. However, those regulations don't apply to the relatively new super PACs (Political Action Committees); this is only the third election where they have played a role, and there are currently no rules to stipulate what happens to that money beyond that it cannot go to fund another federal candidate. Much of that money tends to be returned to its original donors, used to wrap up the failed campaign, or donated to back a state-level candidate. The goal, however, is always to spend all of that money.

Running a campaign is an expensive proposition—Barack Obama spent nearly $750 million on his 2008 White House bid, and in 2012 he spent $985 million on reelection while challenger Mitt Romney spent $992 million—and insufficient cash is often a reason campaigns go belly up.

As for winning (or sometimes losing) politicians, they'll often put their leftover funds toward their next race. If they choose not to run, they have to abide by the same FEC rules. Wonder why this law is in effect? Until 1993, U.S. Representatives who took office before January 8, 1980, were allowed to keep any leftover campaign cash when they retired, but a study showed that a third of Congress kept and spent millions in campaign donations on personal items like clothing, jewelry, artwork, personal travel, and dry cleaning. Embarrassed, Congress passed a law negating this custom for the House; the Senate already had provisions in place so this wouldn't happen.

In reality though, officials can usually find a way to make that cash still work for them (and state laws differ from federal ones). After Chris Christie won reelection as New Jersey's governor in 2014, his campaign was granted permission to use some of its remaining war chest to cover the legal fees Christie incurred during the Bridgegate scandal. And this was well before he dropped $26.7 million on his failed 2016 presidential bid.

An earlier version of this article originally ran in 2012.

SECTIONS

arrow
LIVE SMARTER