CLOSE
Original image
ThinkStock

Why Don’t Cell Phones Have Dial Tones?

Original image
ThinkStock

Phones have come a long way since the old landline days. Our smartphones are light, fast, and have more computing power than NASA used to put a man on the moon.*  Some advances came not by adding things to the phone, but by taking things away. Noticeably missing for anyone of a certain age is the dial tone. What happened to it?  We don’t need it anymore. Or, at least the phones don’t.

Back in the early days of telephony, a switchboard operator would answer when you picked up the handset and connect you with whoever you were calling. When operators were replaced with an automated system that connected calls in the late 1940s, the dial tone was created so that callers would know that the phone was connected to the system, the system was live, and they could place their call.

For most people, this was helpful, but it threw President Dwight Eisenhower for a loop at first. Ike had never had to use a rotary telephone and had never heard a dial tone before (he had a dial-less phone in the White House that connected him to a switchboard). When he retired in 1961, he had to deal with both in an embarrassing incident witnessed by a Secret Service agent. According to the Eisenhower National Historic Site, “Upon lifting the receiver and being confronted with a dial tone, the President began to repeatedly press the dial tone button. When that achieved no results, he hung up and began turning the dial as though the phone were a safe. He finally gave up and turned to the agent for assistance.”

Ike eventually mastered the rotary phone, and decades later, Bell Laboratories was ready to move the telephone world forward another big step: supplementing, and, for some people, replacing, landlines with cellular mobile phone technology. Tech guy Dan Goldin was reading The Idea Factory: Bell Labs and the Great Age of American Innovation when he met the man who killed the dial tone. He quotes the book:

Meanwhile, Phil Porter, who had worked with [Richard] Frenkiel on the original system, came up with a permanent answer to an interesting question. Should a cellular phone have a dial tone? Porter made a radical suggestion that it shouldn't. A caller should dial a number and then push "send." That way, the mobile caller would be less rushed; also, the call would be connected for a shorter time, thus putting less strain on the network. That this idea—dial, then send—would later prove crucial to texting technology was not even considered.

The phone could do what it needed to without a dial tone, so why keep it around? That Porter’s dial-and-send idea, called “pre origination dialing,” and decision to leave the dial tone off the mobile network also did us the favor of paving the way for text messages is a nice bonus. Goldin wonders, “How many other technologies and businesses are built on top of SMS that wouldn’t have existed without this decision? I’m sure an SMS-like technology would have come along regardless of this decision but it still makes me wonder how significantly past technological decisions influence us in the present.”

For all the good its death did, some people still miss their old dial tone. The company Jitterbug capitalized on this with a  mobile phone and service—including a dial tone—that appeals to baby boomers and old folks. [Via Dan Goldin, via Gizmodo]

*I forget where I heard this or who first made the observation, and I wonder how accurate it is. That’s a post I should totally do, right guys?

Original image
arrow
Big Questions
Can You Really Go Blind Staring at a Solar Eclipse?
Original image

A total solar eclipse will cut a path of totality across the United States on August 21, and eclipse mania is gripping the country. Should the wide-eyed and unprotected hazard a peek at this rare phenomenon?

NASA doesn't advise it. The truth is, a quick glance at a solar eclipse won't leave you blind. But you're not doing your peepers any favors. As NASA explains, even when 99 percent of the sun's surface is covered, the 1 percent that sneaks out around the edges is enough to damage the rod and cone cells in your retinas. As this light and radiation flood into the eye, the retina becomes trapped in a sort of solar cooker that scorches its tissue. And because your retinas don't have any pain receptors, your eyes have no way of warning you to stop.

The good news for astronomy enthusiasts is that there are ways to safely view a solar eclipse. A pair of NASA-approved eclipse glasses will block the retina-frying rays, but sunglasses or any other kind of smoked lenses cannot. (The editors at MrEclipse.com, an eclipse watchers' fan site, put shades in the "eye suicide" category.) NASA also suggests watching the eclipse indirectly through a pinhole projector, or through binoculars or a telescope fitted with special solar filters.

While it's safe to take a quick, unfiltered peek at the sun in the brief totality of a total solar eclipse, doing so during the partial phases—when the Moon is not completely covering the Sun—is much riskier.

WOULDN'T IT BE EASIER TO JUST TELL YOUR KIDS THEY WILL GO BLIND?

NASA's website tackled this question. Their short answer: that could ruin their lives.

"A student who heeds warnings from teachers and other authorities not to view the eclipse because of the danger to vision, and learns later that other students did see it safely, may feel cheated out of the experience. Having now learned that the authority figure was wrong on one occasion, how is this student going to react when other health-related advice about drugs, alcohol, AIDS, or smoking is given[?]"

This story was originally published in 2012.

Original image
iStock
arrow
Big Questions
If Beer and Bread Use Almost the Exact Same Ingredients, Why Isn't Bread Alcoholic?
Original image
iStock

If beer and bread use almost the exact same ingredients (minus hops) why isn't bread alcoholic?

Josh Velson:

All yeast breads contain some amount of alcohol. Have you ever smelled a rising loaf of bread or, better yet, smelled the air underneath dough that has been covered while rising? It smells really boozy. And that sweet smell that fresh-baked bread has under the yeast and nutty Maillard reaction notes? Alcohol.

However, during the baking process, most of the alcohol in the dough evaporates into the atmosphere. This is basically the same thing that happens to much of the water in the dough as well. And it’s long been known that bread contains residual alcohol—up to 1.9 percent of it. In the 1920s, the American Chemical Society even had a set of experimenters report on it.

Anecdotally, I’ve also accidentally made really boozy bread by letting a white bread dough rise for too long. The end result was that not enough of the alcohol boiled off, and the darned thing tasted like alcohol. You can also taste alcohol in the doughy bits of underbaked white bread, which I categorically do not recommend you try making.

Putting on my industrial biochemistry hat here, many [people] claim that alcohol is only the product of a “starvation process” on yeast once they run out of oxygen. That’s wrong.

The most common brewers and bread yeasts, of the Saccharomyces genus (and some of the Brettanomyces genus, also used to produce beer), will produce alcohol in both a beer wort
and in bread dough immediately, regardless of aeration. This is actually a surprising result, as it runs counter to what is most efficient for the cell (and, incidentally, the simplistic version of yeast biology that is often taught to home brewers). The expectation would be that the cell would perform aerobic respiration (full conversion of sugar and oxygen to carbon dioxide and water) until oxygen runs out, and only then revert to alcoholic fermentation, which runs without oxygen but produces less energy.

Instead, if a Saccharomyces yeast finds itself in a high-sugar environment, regardless of the presence of air it will start producing ethanol, shunting sugar into the anaerobic respiration pathway while still running the aerobic process in parallel. This phenomenon is known as the Crabtree effect, and is speculated to be an adaptation to suppress competing organisms
in the high-sugar environment because ethanol has antiseptic properties that yeasts are tolerant to but competitors are not. It’s a quirk of Saccharomyces biology that you basically only learn about if you spent a long time doing way too much yeast cell culture … like me.

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

SECTIONS

arrow
LIVE SMARTER
More from mental floss studios