If you’re in the market for a new mattress this Presidents Day weekend (the holiday is traditionally a big one for mattress retailers), one of the first decisions you’ll need to make is regarding size. Most people know a king mattress offers the most real estate, but the difference between a full-sized mattress and a queen-sized one provokes more curiosity. Is it strictly a matter of width, or are depth and length factors? Is there a recommended amount of space for each slumbering occupant?
Fortunately, mattress manufacturers have made things easier by adhering to a common set of dimensions, which are sized as follows:
Crib: 27 inches wide by 52 inches long
Twin: 38 inches wide by 75 inches long
Full: 53 inches wide by 75 inches long
Queen: 60 inches wide by 80 inches long
King: 76 inches wide by 80 inches long
Depth can vary across styles. And while you can find some outliers—there’s a twin XL, which adds 5 inches to the length of a standard twin, or a California king, which subtracts 4 inches from the width and adds it to the length—the four adult sizes listed above are typically the most common, with the queen being the most popular. It's 7 inches wider than a full (sometimes called a “double”) mattress and 5 inches longer.
In the 1940s, consumers didn’t have as many options. Most people bought either a twin or full mattress. But in the 1950s, a post-war economy boost and a growing average height for Americans contributed to an increasing demand for larger bedding.
Still, outsized beds were a novelty and took some time to fully catch on. Today, bigger is usually better. If your bed is intended for a co-sleeping arrangement with a partner, chances are you’ll be looking at a queen. A full mattress leaves each occupant only 26.5 inches of width, which is actually slightly narrower than a crib mattress intended for babies and toddlers. A queen offers 30 inches, which is more generous but still well below the space provided by a person sleeping alone in a twin or full. For maximum couple comfort, you might want to consider a king, which is essentially like two twin beds being pushed together.
Your preference could be limited by the size of your bedroom—you might not be able to fit a nightstand on each side of a wider bed, for example—and whether you’ll have an issue getting a larger mattress up stairs and/or around tricky corners. Your purchase will also come down to a laundry list of options like material and firmness, but knowing which size you want helps narrow down your choices.
One lingering mystery remains: Why do we tend to shop for mattresses on Presidents Day weekend? One reason could be time. The three-day weekend is one of the first extended breaks since the December holidays, giving people an opportunity to trial different mattress types and deliberate with a partner. Shopping Saturday and Sunday allows people to sleep on it before making a decision.
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Mission control personnel go through a lot more simulations than astronauts, as the flight controller needs to develop very specialized skills and knowledge. On the other hand, astronauts in general need to develop the appropriate depth of knowledge across many disciplines. So shorter classes targeted to their needs are used instead to make the best use of their limited time.
I was the robotics instructor for the EVA simulation (or sim) yesterday and the rig (the simulator system) was not behaving for me. Things were up and running quickly, but after I simulated the main robotics computer having a fatal software fault things went downhill. The team rebooted it to recover, as expected, but the rig did not cleanly handle the reboot.
Suddenly it would not accept any commands to the robot arm. The hand controllers were not communicating. And the astronauts' laptop would not connect.
Eventually, I ran out of troubleshooting options and had to tell my three robotics flight controllers in training that all this was unplanned and the sim was not going to go as expected for them. Other disciplines had "scripting priority," as there were controllers who were assigned to use this sim as an evaluation toward their certifications. I did not have the leverage to disrupt the sim by halting the rig to reset the robotics simulator.
Flight controllers go through so many sims partly because of days like this—where, for whatever reason, they don't get as much "content" as we'd like. I told my guys to greencard that the arm simulator was working as expected, which means that they had to pretend they were seeing all the telemetry indications that would normally happen for the arm supporting an EVA. Basically: Just follow along and pretend.
Each simulation is unique in terms of the coordination required with other disciplines, the malfunctions they get to work through, and the timing involved in planning. Throughout their training flow they need to display their ability to work through a broad enough variety of cases before we can call them "certified." How much they get out of each sim can be a roll of the dice.
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