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Why Aren't There Universal Sockets in Every Country?

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Why aren't there universal sockets in every country?

Balaji Viswanathan:

While the Americans developed the power delivery systems and the modern electric plug, other countries didn’t find the American standards—60 Hz, 110V, and their plug system—as efficient.

Thus, on their own, each country started improving on what they thought was an inefficient way to deliver electricity. Germans liked the 50Hz (which fit nicely with the metric system) and 220V (which provided more efficient power transmission) much better. Englishmen improved upon on the American plug with a much safer (and bulkier) plug.

Unfortunately for the Indians and Pakistanis, their innovation came after they left India in 1947, leaving the subcontinent in the older English standards and the English in newer plug standard. England and Europe don’t talk very much, and thus Europe didn’t adopt the English standard either.

Before that the world wars came in and pushed back all talks of standardization: "Oh you want to use the plug system of the Germans? No way."

Then there were the unique ways in which electricity was delivered and charged. For a long time, Italy had different systems for delivering electricity for bulbs versus non-illumination use. They just developed their own plug system to work with that requirement. Thus, each system of plugs had their own advantages suitable for their system and countries didn’t accept one system to be better than another.

Once you have picked one system of electric plugs, it is not easy to switch (no pun intended) to another. You need to rip apart all the wall sockets in every home, office, and factory, and also change stuff in your electrical appliance production. You need to do it all at once to prevent accidents and that will be very painful and expensive. That shock (again, no pun intended) and pain is not usually worth it. Most countries found that there weren't that many travelers who wanted to carry their electrical equipment around—why would you take your microwave oven or TV during your travels?—while there are easier workarounds for charging electronic equipment through USB standards. Thus, there is not really a push to accept the global standards (the Type N plug).

In summary, every country evolved its own system in parallel to replace what they thought was an inefficient American system and by the time they talked to each other there were two world wars, pushing out all talks of standardization. By the end of World War II, electricity was ubiquitous and it was very painful to switch to a common standard and there was very little demand for such a switch.

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

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Big Questions
How Are Speed Limits Set?
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When driving down a road where speed limits are oppressively low, or high enough to let drivers get away with reckless behavior, it's easy to blame the government for getting it wrong. But you and your fellow drivers play a bigger a role in determining speed limits than you might think.

Before cities can come up with speed limit figures, they first need to look at how fast motorists drive down certain roads when there are no limitations. According to The Sacramento Bee, officials conduct speed surveys on two types of roads: arterial roads (typically four-lane highways) and collector streets (two-lane roads connecting residential areas to arterials). Once the data has been collected, they toss out the fastest 15 percent of drivers. The thinking is that this group is probably going faster than what's safe and isn't representative of the average driver. The sweet spot, according to the state, is the 85th percentile: Drivers in this group are thought to occupy the Goldilocks zone of safety and efficiency.

Officials use whatever speed falls in the 85th percentile to set limits for that street, but they do have some wiggle room. If the average speed is 33 mph, for example, they’d normally round up to 35 or down to 30 to reach the nearest 5-mph increment. Whether they decide to make the number higher or lower depends on other information they know about that area. If there’s a risky turn, they might decide to round down and keep drivers on the slow side.

A road’s crash rate also comes into play: If the number of collisions per million miles traveled for that stretch of road is higher than average, officials might lower the speed limit regardless of the 85th percentile rule. Roads that have a history of accidents might also warrant a special signal or sign to reinforce the new speed limit.

For other types of roads, setting speed limits is more of a cut-and-dry process. Streets that run through school zones, business districts, and residential areas are all assigned standard speed limits that are much lower than what drivers might hit if given free rein.

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

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Big Questions
Do Bacteria Have Bacteria?
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Drew Smith:

Do bacteria have bacteria? Yes.

We know that bacteria range in size from 0.2 micrometers to nearly one millimeter. That’s more than a thousand-fold difference, easily enough to accommodate a small bacterium inside a larger one.

Nothing forbids bacteria from invading other bacteria, and in biology, that which is not forbidden is inevitable.

We have at least one example: Like many mealybugs, Planococcus citri has a bacterial endosymbiont, in this case the β-proteobacterium Tremblaya princeps. And this endosymbiont in turn has the γ-proteobacterium Moranella endobia living inside it. See for yourself:

Fluorescent In-Situ Hybridization confirming that intrabacterial symbionts reside inside Tremblaya cells in (A) M. hirsutus and (B) P. marginatus mealybugs. Tremblaya cells are in green, and γ-proteobacterial symbionts are in red. (Scale bar: 10 μm.)
Fluorescent In-Situ Hybridization confirming that intrabacterial symbionts reside inside Tremblaya cells in (A) M. hirsutus and (B) P. marginatus mealybugs. Tremblaya cells are in green, and γ-proteobacterial symbionts are in red. (Scale bar: 10 μm.)

I don’t know of examples of free-living bacteria hosting other bacteria within them, but that reflects either my ignorance or the likelihood that we haven’t looked hard enough for them. I’m sure they are out there.

Most (not all) scientists studying the origin of eukaryotic cells believe that they are descended from Archaea.

All scientists accept that the mitochondria which live inside eukaryotic cells are descendants of invasive alpha-proteobacteria. What’s not clear is whether archeal cells became eukaryotic in nature—that is, acquired internal membranes and transport systems—before or after acquiring mitochondria. The two scenarios can be sketched out like this:


The two hypotheses on the origin of eukaryotes:

(A) Archaezoan hypothesis.

(B) Symbiotic hypothesis.

The shapes within the eukaryotic cell denote the nucleus, the endomembrane system, and the cytoskeleton. The irregular gray shape denotes a putative wall-less archaeon that could have been the host of the alpha-proteobacterial endosymbiont, whereas the oblong red shape denotes a typical archaeon with a cell wall. A: archaea; B: bacteria; E: eukaryote; LUCA: last universal common ancestor of cellular life forms; LECA: last eukaryotic common ancestor; E-arch: putative archaezoan (primitive amitochondrial eukaryote); E-mit: primitive mitochondrial eukaryote; alpha:alpha-proteobacterium, ancestor of the mitochondrion.

The Archaezoan hypothesis has been given a bit of a boost by the discovery of Lokiarcheota. This complex Archaean has genes for phagocytosis, intracellular membrane formation and intracellular transport and signaling—hallmark activities of eukaryotic cells. The Lokiarcheotan genes are clearly related to eukaryotic genes, indicating a common origin.

Bacteria-within-bacteria is not only not a crazy idea, it probably accounts for the origin of Eucarya, and thus our own species.

We don’t know how common this arrangement is—we mostly study bacteria these days by sequencing their DNA. This is great for detecting uncultivatable species (which are 99 percent of them), but doesn’t tell us whether they are free-living or are some kind of symbiont. For that, someone would have to spend a lot of time prepping environmental samples for close examination by microscopic methods, a tedious project indeed. But one well worth doing, as it may shed more light on the history of life—which is often a history of conflict turned to cooperation. That’s a story which never gets old or stale.

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

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