Wikipedia:Reference desk/Archives/Science/2014 June 18

Science desk
< June 17	<< May | June | Jul >>	June 19 >

Welcome to the Wikipedia Science Reference Desk Archives
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.

June 18

Contacting Google

Hi, so I have an idea that I would be interested in contacting Google (the corporate entity) with regards to. Obviously, everyone immediately thinks "crackpot inventor" who has some terrible invention that they think is amazing. Google obviously receives contact from people like this in the hundreds every day. What would be the best way to make someone with some semblance of decision making power aware of my idea? Email or post may not be an option as Google are famously un-contactable, however a social media campaign might work? Or contacting press to get notoriety? No legal advice please! 195.27.53.211 (talk) 10:01, 18 June 2014 (UTC)

Have you even tried? Obviously it has to be possible for people to contact them. There is a contact link here. I suggest you try that first.--Shantavira|^{feed me} 12:03, 18 June 2014 (UTC)

What is the idea? If you're considering using social media, then surely you could also tell us? My point is, if it matches up with some topic already being studied in Google's research labs, you might be able to contact that group directly. SemanticMantis (talk) 15:09, 18 June 2014 (UTC)

Many (perhaps most) tech companies go to some lengths to avoid even reading your suggestions! The reason for this is that they may be working on the same idea already - and if they talk to you about it - or even convey your message to those who create things - then you might be in a position to sue them for stealing your idea when it was really a case of parallel invention. In one company I worked for (a video game company), mail that came from unsolicited sources went to one specific staff member who would open it and dispose of anything that looked remotely like a suggestion for a new game or an improvement to an existing one. She never spoke to our engineers and other developers. We actively worked to AVOID taking suggestions from the public. I'm betting that Google are the same - they don't want your suggestions - they are just a pain in the butt to have to deal with!

So, if you have a world-beating idea, then work on it yourself - then run a Kickstarter project to raise some money to achieve it. SteveBaker (talk) 20:10, 18 June 2014 (UTC)

You may be right; I don't work at Google, or for a "tech" company (whatever that means :) But when I see people from e.g. Google Research or Microsoft Research at conferences, they are happy to present their work to us, and get feedback from their colleagues, etc. Of course, some of these people are more like academic research scientists than "normal" employees, so there is an expectation of sharing work via publishing, collaborating on projects across institutions, etc. SemanticMantis (talk) 20:54, 18 June 2014 (UTC)

A Google community relations manager (or somesuch) showed up at the Village Pump (if I remember right) when there were concerns about Google News changing in potentially negative ways. I think they had a Wikipedia account in order to make their comments. Someone like that might be a suitable contact. --Demiurge1000 (talk) 11:17, 22 June 2014 (UTC)

Silicon and the human body

This source says that there is no silicon in the human body. Is that accurate, or does it refer to the "living" parts only?

I.e. do the bones and/or teeth contain silicon? (The source doesn't look terribly reliable to me anyway. Lots of stupid little errors: "1026 watts" when it should read "10²⁶ watts" here, and even worse, H₂ when it should be H₂O here.) - ¡Ouch! (^{hurt me} / _{more pain}) 10:03, 18 June 2014 (UTC)

Composition of the human body does list a small amount of silicon. It has the unsourced claim that silicon is "probably needed by mammals also". -- Finlay McWalterᚠTalk 11:23, 18 June 2014 (UTC)

Well, there certainly will be some silicon in the digestive tract, although scientists consider this to be technically "outside" the body. Silicon dioxide is a common food additive: Silicon dioxide#Food and pharmaceutical applications. That's powdered quartz, BTW. StuRat (talk) 11:26, 18 June 2014 (UTC)

"Bartender, two quartz for Stu and me!" *COUGH*

Wow, thanks. I'd count that as outside, too. (Less than iron, too – I wouldn't have guessed that either!)

One more flaw of the source I was reading, I guess, not to mention the lines "Dimethyl borine (...) Soluble in organic solvents (ethanol, other[sic], etc.)" - ¡Ouch! (^{hurt me} / _{more pain}) 12:23, 18 June 2014 (UTC)

The answer is kind of hand-wavey. As near as I can tell, in humans it seems that silicon in various forms has some sort of beneficial effects on collagen and keratin(?) synthesis, but it's not clear that it is necessary. There is definitely evidence that it is present in the body, but it's not known if it is required. (See the footnotes for Silicon#Biological role, and Silicic acid#Silicic acid in health.) TenOfAllTrades(talk) 12:21, 18 June 2014 (UTC)

Disputed Identification

File:Artocarpus.odoratissimus1we.jpg

Tree with Disputed identification.

Any comments from the experts here? Sfan00 IMG (talk) 10:23, 18 June 2014 (UTC)

Any chance you know where in the world it was taken, or have any other photos of the leaves/flowers? I see the file is used at Artocarpus_odoratissimus, but the resolution is too low to even make out if the leaf margins are entire... SemanticMantis (talk) 15:07, 18 June 2014 (UTC)

It's sourced to a USGS image... I don't have much other information. :( Sfan00 IMG (talk) 18:03, 18 June 2014 (UTC)

Ok, who's disputing the ID, and where/why? I see a note on the file, but nothing on Talk:Artocarpus_odoratissimus. The source link on the file is broken, but I was able to re-find it here: [1]. Looks like these people are professional biologists, and have a ton of specific IDs for plants in Hawaii. The specific picture is tagged "Keanae Arboretum, Maui, August 07, 2003". Also, at the link above, we see there is a lot of variety in leaf shape of this species. So, together with the low resolution and the lack of specific reason to doubt, I'm inclined to use this as an expert ID and forget about it. SemanticMantis (talk) 19:48, 18 June 2014 (UTC)

What causes a radio to go off channel ?

I adjust a radio so the radio station comes in clearly, don't touch it after, yet the next day it is off station and needs to be readjusted. What causes this ? Is it temperature or humidity changes ? StuRat (talk) 11:19, 18 June 2014 (UTC)

Is it a digital, or analog control? IE, do you turn a knob to change the station, or press a button?Zzubnik (talk) 12:23, 18 June 2014 (UTC)

ObPersonal: having occasionally opened up old radios and radiograms to clean out decades of fluff accumulation, lubricate the parts, etc, I've noticed that some tuning mechanisms involve a length of cord between the tuner control wheel and the actual tuner. I assume that this might undergo slight changes of length due to both the factors you mention: tuning is often so sensitive that only a tiny change would have a noticeable effect, and my bathroom radio seems to require more retuning than most. {The poster formerly known as 87.81.230.195} 212.95.237.92 (talk) 13:52, 18 June 2014 (UTC)

(Not sure why you smalled your text, as this seems to be a direct answer.) Yes, it's an old analog clock radio. So, other than storing it in a hermetically sealed, temperature controlled vault, it sounds like there's no way to keep it on station. StuRat (talk) 17:49, 18 June 2014 (UTC)

That would have been a really cool magic trick back in the 50s or so. Have a cord with a good coefficient of thermal expansion near an ornamental hole where you could aim your breath into the radio. Ask the spirits to tune it in for you... if you could have done that without laying a hand on it, while your observers fail over and over again, even failing to see a reason after taking the radio apart... Wnt (talk) 16:54, 18 June 2014 (UTC)

• OR It heats up, the dial expands, and moves off channel. μηδείς (talk) 20:23, 18 June 2014 (UTC)

Most good FM radios have AFC (Automatic frequency control) with sufficient range to compensate for temperature or humidity changes to tuning. AFC can however allow a strong signal to pull the tuning away from a weak signal when the signal frequencies are close. For this reason some receivers have an AFC on/off switch. 84.209.89.214 (talk) 22:40, 18 June 2014 (UTC)

Interesting, thanks. Would e.g. a late 1970s radio have AFC? Our article seems to indicate that similar functionality can be had via a Frequency_synthesizer, and that sometime in the 1970s consumer radio devices might have switched over. As far as other signals, that reminds me of an idea I had on the topic (for I have very similar experience to Stu): could changes in other signals cause a radio to fall out of tune? In a city, there are any number of sources of interference. Of course devices are supposed to both not produce interfering signals, and to accept incoming interference without malfunction, but I always took that to mean an ideal, which doesn't always happen in the real world. So, if my radio stays tuned to one station for weeks, but on a certain day I have to re-tune, and sometimes find that same station very difficult to receive. Could changes in other broadcasts explain this? SemanticMantis (talk) 22:54, 18 June 2014 (UTC)

All FM (but not AM) receivers are subject to Capture effect which is a kind of AFC, not a welcome one when interfering signals are strong. 84.209.89.214 (talk) 23:30, 18 June 2014 (UTC)

StuRat, if your radio's old enough, tuning is a function of the capacitance between two sets of metal plates, one of which is turned by the dial on the front or side of your radio. Since the plates are fan-shaped, turning one set varies the surface area of the sets of plates that are close enough to each other for capacitive coupling between the plates to occur, thus changing the frequency at which the tuning circuit resonates. If the plates aren't sealed (or very well-sealed) both atmospheric pressure and humidity can change from day to day and alter the capacitance between the sets of plates in your tuner, thus changing the target frequency. loupgarous (talk) 01:01, 21 June 2014 (UTC)

Thanks. Are new, but inexpensive, radios still subject to going off channel like this ? StuRat (talk) 05:33, 21 June 2014 (UTC)

Natural units

Look up Planck length and Planck time. If my knowledge about these terms is correct, these are units that we can't have a fraction of; every measurement of length/time is these units times a whole number. This is clearly very wrong, however, for Planck temperature. What property does the Planck temperature have here?? Georgia guy (talk) 16:01, 18 June 2014 (UTC)

I think your conceptual understanding about the quantization of time and distance is a bit incorrect: there's nothing that forbids a distance or length or duration whose magnitude is smaller than one Planck unit. We simply don't know of any physical entity or process in which that distance is meaningful.

On the whole, when a physical system is quantized it means that whenever we observe it, we will find integer multiples of some fundamental unit. There are lots of systems that are quantized, including macroscopic systems: for example, a theoretically perfect, tightly stretched guitar string will only resonate at integer multiples of its fundamental frequency. In practice, we know this is untrue: we hear musical timbre because of the interplay of all the complex harmonics and non-harmonic motions of the string and its soundboard.

In microscopic physics, we have the same problem! Electron orbitals are quantized, and when we look at an atomic emission spectrum, we find perfectly harmonic integer multiples of a base energy level. ...Except when we don't. Just like the guitar string, the major components of the system follow a simple, quantized theoretical model; but as we zoom in closer and closer to the details, we sometimes find perturbations and other effects. When we zoom in really closely, we usually find that those other perturbations are also quantized, but with different parameters. (In fact, we can say the same about the guitar - its continuous acoustic spectrum can be decomposed into a Fourier series of individual vibrations - and by definition, a series is made of discrete (quantized) elements).

One of the ongoing quests in theoretical physics is to find the most fundamental particles - and therefore, the most fundamental scale of quantization. A century ago, we split the atom into its subatomic particles; and we developed a rigorous theory for how the energies of those particles were quantized. Decades later, we split the subatomic particles into even smaller particles - quarks - and we found that they too have certain properties that are quantized. To my knowledge, we have not yet found any physical entity whose energy scales are quantized in smaller increments than these subatomic particles. That is why, in common parlance, we say that we have found the fundamental particles.

But we should make it abundantly clear: it is a physical system whose properties follow quantization rules: it is not actually the units themselves which are quantized. We can easily define half a Planck length - or a whole 1.0 Planck lengths, for that matter - even if we can't find any physical system for which that length is important.

Nimur (talk) 16:14, 18 June 2014 (UTC)

Atomic energy levels are nowhere close to integer multiples of a base energy level. Protons have three valence quarks, but they don't divide into three discrete pieces, one per valence quark. The notion of the quest for the most fundamental scale of quantization sounds more like Greek atoms than modern physics to me. -- BenRG (talk) 21:10, 18 June 2014 (UTC)

Fascinating analogy about Greek atomic theory! So fascinating that CERN, arguably the world's preeminent research institution in the field of modern particle physics, uses the exact same analogy when describing their quest to break apart sub-sub-atomic particles! Nimur (talk) 01:38, 19 June 2014 (UTC)

The sound of a guitar string can be quantified by a Fourier series whose infinite series of terms can be truncated not due to any property of the string vibration but because listeners are oblivious to harmonic and non-harmonic energies above the upper limit of human hearing. The quantisation step between Fourier terms is dictated by the frequency resolution obtainable from a given observation time, which is chosen arbitrarily. It is that arbitrary choice that changes the true continuous acoustic spectrum to an approximate discrete series. 84.209.89.214 (talk) 22:19, 18 June 2014 (UTC)

...and why do you think that's any different for atomic scale systems? I think you've just restated the uncertainty principle, which expresses the relation between the maximum achievable resolution in one variable, and extent of measurement in a second non-commuting variable. In this case, your variables are bandwidth, Δf, and duration-of-measurement, Δt. Fascinating how that applies in a classical problem, and we didn't even need to resort to literary gimmickry! Nimur (talk) 01:33, 19 June 2014 (UTC)

I think there is a big difference between Fourier's classical world view where math would allow no limit to the frequency resolution Δf obtainable by extending the duration-of-measurement T (using my symbol) and Heisenberg's discovery of a real-world impossibility of simultaneously knowing exact values of both position and momentum of a particle. That uncertainty cannot be overcome by making the observation longer, nor somehow less intrusive (as was thought) but has the reality of a physical constant. Having to accept tradeoffs between precisions of different quantities is routine to engineers in many fields but the quantum mechanical notion that the Universe itself cannot be entirely accurate is the Paradigm shift that unseated Lord Kelvin's famous assurance in 1900 "There is nothing new to be discovered in physics now. All that remains is more and more precise measurement." 84.209.89.214 (talk) 12:15, 19 June 2014 (UTC)

According to the article, the Planck temperature is a maximum possible temperature. So it seems as if the inverse temperature were more fundamental somehow. But is there a quantization of temperature into fractions of the Planck temperature? I know in general I've read some strange things about negative temperature that is hotter than any positive temperature, etc. ... but nothing gets colder than absolute zero. Is this system telling us that we're looking at the inverse of the quantity that really matters? And if so... what does it mean? Wnt (talk) 17:49, 18 June 2014 (UTC)

The Planck units are the unique unit system in which c = ħ = G = 1. That's literally all that we know about them. Naively you would expect important quantities in a theory of quantum gravity to have values close to 1 in those units (this is called naturalness, or just dimensional analysis). That doesn't mean the values would be exactly 1, or would be constrained to integers. If, by some other argument, you could show that quantum gravity implied quantization of, say, inverse temperature, then the quantum of inverse temperature would probably be small in Planck units. The Planck units by themselves don't tell you anything about minimum or maximum values or quantization. -- BenRG (talk) 20:24, 18 June 2014 (UTC)

Unless something has changed since I took math in high school, presuming that these units are numbers, they can be divided by any other number [except 0] or multiplied by any other number. ←Baseball Bugs ^{What's up, Doc?} carrots→ 20:55, 18 June 2014 (UTC)

Well, to quote the article directly then, As for most of Planck units, a Planck temperature of 1 (unity) is a fundamental limit of quantum theory, in combination with gravitation, as presently understood. In other words, the wavelength of an object can be calculated by its temperature. If an object was to reach the temperature of 1.41 x 1032 Kelvin (TP), the radiation it would emit would have a wavelength of 1.616 x 10-26 nanometers (Planck length), past which quantum gravitational effects are irrelevant. At temperatures greater than or equal to TP, current physical theory breaks down because we lack a theory of quantum gravity.[2] Now my understanding, I should add, is that a photon with a wavelength around the Planck length has a mass around the Planck mass and is, in short, a black hole. There's something really weird about this math... Wnt (talk) 21:09, 18 June 2014 (UTC)

It works better if you try 10^–26 and 10³², or even better 10^–35 meters. (Although I have seen a "0.06 megapixel camera" once.) - ¡Ouch! (^{hurt me} / _{more pain}) 06:10, 23 June 2014 (UTC)

Abuse of ignition interlock device

Sometimes a person convicted of a DWI will be required to install an ignition interlock device in their vehicle. From what I understand, the idea is to make the person blow into the machine, which then calculates their blood alcohol content (BAC). If they have an acceptable BAC, the vehicle will start. If their BAC is unacceptable, the ignition of the vehicle will not start. The objective is to prevent the individual from driving drunk or driving while impaired. So, my question is this. If an impaired person wants to drive – and wants to beat the system – they can just have some other individual, such as a non-impaired friend, blow into the machine. Is there some way that the machine itself or law enforcement prevents this from happening? In other words, how do "they" (the machine, the law enforcement and criminal justice system, etc.) know that it is the correct person who is actually blowing into the machine? Thanks. Joseph A. Spadaro (talk) 21:20, 18 June 2014 (UTC)

The answer is in the second paragraph of the BAC article: It requires an additional sample at some random point in time. Meanwhile, if a sober passenger not only allows a drunken driver to take the wheel, but also helps him try to evade the test, that passenger sounds like a candidate for a Darwin Award. ←Baseball Bugs ^{What's up, Doc?} carrots→ 21:41, 18 June 2014 (UTC)

The answer is in the second paragraph of the ignition interlock device article. 84.209.89.214 (talk) 22:26, 18 June 2014 (UTC)

Oops! Too bad I don't have a designated typer. ←Baseball Bugs ^{What's up, Doc?} carrots→ 22:40, 18 June 2014 (UTC)

As described by the article this device sounds rather rudimentary, though I suppose someone very drunk might have difficulties. It doesn't even describe a CO2 sensor, just a need for air to be pushed in. People on this forum seemed to think that any source of minorly compressed air would work. Wnt (talk) 23:37, 18 June 2014 (UTC)

Thanks. Not sure how I missed that. I skipped over the lead and went directly into the article, where I found nothing. Nonetheless, that is their method of trying to prevent the wrong person from breathing into the machine? Wow. The article says that the machine will require a second sample at some random time, later on down the road. That doesn't seem like that would be particularly effective. I would think that, oftentimes, drunk people are relatively close to home, not that far away in distance (i.e., at the local bar). Plus, I am sure most drunks are not thinking rationally. So, it seems to me that the drunk would easily convince himself that "Oh, I will just drive for a few minutes until I get home; the machine won't ask for a sample so soon; I'm sure I will be home by then". No? Or, not to mention, when the machine is asking for a second sample, just ask a new "clean" person who happens to be in the vicinity. No? Joseph A. Spadaro (talk) 01:26, 19 June 2014 (UTC)

Like a padlock, even though it's basic and easy to "beat" by force, it's effective in "discouraging" the behaviour and making it impossible to deny the "intention" to commit the crime of drunk driving. That second person would be responsible and perhaps held liable in a criminal and civil courts, not to mention endangering their own lives. The devices themselves are generally low-tech and can be defeated even without the aid of a second person. Virtually all ignition interlock devices and breathalyzers for that matter can be fooled with a baloon filled by the person before drinking. Some basic devices also lack a carbon dioxide sensor and can be beaten by forced air from any source. — Preceding unsigned comment added by 24.100.220.34 (talk) 04:49, 19 June 2014 (UTC)

The "second person" does not necessarily have to get in the car and go for a ride as a passenger (thus, foolishly risking his own life by being driven by a drunk). The "second person" can just blow into the machine, exit the car, and his job is done. I expect that would happen a lot with "friends" trying to "help each other out". Joseph A. Spadaro (talk) 18:17, 19 June 2014 (UTC)

I'm sure there are plenty of ways to evade the device - but consider that doing so results in a crime of far greater magnitude than DWI being committed - so if this hypothetical person were to get stopped (eg for driving erratically) then it would be clear that the device had been tampered with or misused - and I would expect them to incur a considerably greater punishment as a result. Remember, the purpose of the device is to allow them the privilege of driving (when sober) for the purposes of going to work or something. Without that device, they'd be barred from driving completely.

Yes, but all of that is based on the premise of the driver thinking and acting rationally (i.e., weighing the cost/benefit and the consequences). A drunk who just wants to get in the car and go home is probably not thinking so rationally. He is probably convincing himself that "I only live just a few miles down the road; I am sure I can get there just fine". Joseph A. Spadaro (talk) 18:12, 19 June 2014 (UTC)

OK, so the corollary to the popular saying would be, "Friends DO let friends drive drunk, as long as they won't be in the car." ←Baseball Bugs ^{What's up, Doc?} carrots→ 18:56, 19 June 2014 (UTC)

These days, I'm rather surprised that the devices aren't equipped with a camera. It would be easy to capture a short video of the driver taking the test - and if they were required to present that for inspection (say once a month) that would be an almost certain way to ensure that they aren't cheating the machine. SteveBaker (talk) 04:58, 19 June 2014 (UTC)

Maybe someday. Technologies evolve. Think of the evolution of the seat belt and the air bag, for example. ←Baseball Bugs ^{What's up, Doc?} carrots→ 06:52, 19 June 2014 (UTC)

I had the same thought, although a snapshot should be sufficient. A flash might be needed, though, as presumably many of these drunks get in their cars at closing time at the bar, when it will be dark out. The car dome light might be disabled by the drunk to hide the identity of the person taking the breathalyzer test. Disabling the camera flash or covering the lens would be more obvious tampering. You could also refuse to start the ignition unless a certain level of light is detected by the camera. StuRat (talk) 15:50, 20 June 2014 (UTC)

It's worth remembering that while wikipedia may have an article on anything, they aren't always that good. This FAQ from a manufacturer of such devices suggests that

1) Some do have cameras.

2) They do have anti circumvention measures which try and stop you using any random source of compressed air (I don't know how well they work obviously).

3) The random retest is apparently at least partially to discourage getting someone else to provide a breath sample. This is what the LEDE says and wasn't disputed above but if you look at the talk page, someone claims the "official reason" is to prevent a driver drinking while driving. (Perhaps also a driver who drunk very recently, but long enough that mouth alcohol has largely dissipated.)

4) Several minutes are provided to take the retest so you can pull over if necessary. I guess this will nominally allow someone to attempt to cheat again (theoretically there could be a much smaller time frame once the car has pulled over but this require the device to have access to data it probably doesn't). But I was thinking there must be such an allowance otherwise you may end up with a hazardous situation if a person has to try and take the test ASAP in unsuitable driving conditions. That said, per that source and [2] it sounds like the devices are designed so you can take the test while driving rather than having to pull over or wait until you stop naturally at an intersection or whatever.

I didn't see any mention of a flash there but if you mean an ordinary one, it seems a bad idea, at least for the tests while driving (and the source did suggest the retests are also recorded). A better proposition would be to use an infrared light or flash. You just need enough details that the person is recognisable after all. (You could probably find out what they use with more searching.)

Nil Einne (talk) 17:38, 20 June 2014 (UTC)

Thanks, all. Joseph A. Spadaro (talk) 18:39, 21 June 2014 (UTC)