Wikipedia:Reference desk/Archives/Science/2012 February 27

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.

February 27

Time travel

I have heard it's possible to travel in time if we can somehow travel faster than light. It has been proven scientifically and mathematically. But i don't understand how it all works? Can someone explain it in the way that any ordinary people can understand it? Thanks!Pendragon5 (talk) 04:37, 27 February 2012 (UTC)

"Can someone explain it in the way that any ordinary people can understand it?" Probably not. Then again, it has also been "proven scientifically and mathematically" that we can't travel faster than the speed of light in the first place. Why do you think the universe should be understandable by "ordinary people"? It doesn't seem to make that much sense to those that spend their entire careers trying to understand it... ;-) AndyTheGrump (talk) 04:44, 27 February 2012 (UTC)

(edit conflict) It has not been proven scientificially, in the sense that science doesn't really "prove" anything, it provides evidence that it happens. Insofar as no experiment has ever been done to confirm time-travel, and so-far only one tenuous experiment has possibly confirmed FTL travel at all (the Faster-than-light neutrino anomaly) I would say that the empirical evidence of either faster-than-light travel or time travel is simply not there for it to be "scientifically proven" (again, for whatever you take "proven" to mean, which science doesn't really do). Mathematically, sure, there are all sorts of ways to manipulate equations to show that time travel is possible, if faster-than-light travel is possible, but empircal evidence for the latter condition is super tenuous, and the connection between FTL travel and time travel is unexplored (except mathematically), I would say that the jury is not just out on time travel, I'd say there hasn't even been an arraignment... --Jayron32 04:46, 27 February 2012 (UTC)

What do you mean by that science doesn't prove anything?? Science is always a tool for human to prove things, it's by far the most acceptable method around the world to prove stuffs.Pendragon5 (talk) 19:37, 27 February 2012 (UTC)

Strictly speaking, Jayron is correct. Science helps us develop models to predict the outcomes of experiments, but since there are always multiple models to explain any occurrence, nothing is strictly proven correct, although certain models will inevitably be disproven. Someguy1221 (talk) 10:22, 28 February 2012 (UTC)

Also (edit conflict). I'm not sure if you could say it's been "proven", it's probably safer to say that it fits certain interpretations using current models. We have an article which addresses what you are talking about Time_travel#Via_faster-than-light_.28FTL.29_travel Vespine (talk) 04:50, 27 February 2012 (UTC)

(edit conflict) It has never been proven, in that no one has actually done it. Mathematically and theoretically, it comes down to the relativity of simultaneity (you can also read Special_relativity#Causality_and_prohibition_of_motion_faster_than_light). Basically, as you'll surmise from the first article I linked, the order in which events appear to have occurred is not sacrosanct in special relativity (i.e. reality). There are situations in which the order that events occurred is different for different reference frames. But if you allow things to move faster than the speed of light, you can get some ridiculous observations, mainly effects occurring before their cause. My college special relativity text used the example of a projectile being sucked out of its target and back into the cannon that fired it. Such things can be interpreted as objects, such as that projectile, traveling backwards through time. Someguy1221 (talk) 04:51, 27 February 2012 (UTC)

It's not really true. The "proofs" you've seen start from unstated assumptions that are inconsistent with faster-than-light travel, and proceed to assume the existence of faster-than-light travel. From that, you can prove anything (ex falso quodlibet). The reason people write about amazing things that physics "proves" is the same reason they write about miracle diets and angel sightings. There's a market for it. It's not because of any scientific merit. -- BenRG (talk) 07:14, 27 February 2012 (UTC)

I don't think there's anything in the derivation of the tachyonic antitelephone that's logically inconsistent with faster-than-light travel. If there is, please enlighten me.

The assumptions may be inconsistent with faster-than-light travel plus currently understood physics, but that's quite a different matter. --Trovatore (talk) 02:13, 28 February 2012 (UTC)

Well, we have managed time travel! Ok, perhaps not quite, but this experiment was very interesting. http://en.wikipedia.org/wiki/Hafele%E2%80%93Keating_experiment They managed to get a clock to travel nearly 40 nanoseconds in to the past/future. Ok, it's not time travel as such... Zzubnik (talk) 10:48, 27 February 2012 (UTC)

That's "time travel into the future", aka the twin effect/paradox. It's a totally different beast from traveling to the past. -- BenRG (talk) 19:45, 27 February 2012 (UTC)

Hi BenRG. I'm aware of that. I thought it might be an interesting read to the OP. Personally, I think that time dilation like this is the closest that we will ever get to "travelling in time". — Preceding unsigned comment added by Zzubnik (talk • contribs) 10:17, 28 February 2012 (UTC)

If I'm playing snooker ball and move it back as it moves backward in time its an example . Thanks Water Nosfim — Preceding unsigned comment added by 81.218.91.170 (talk) 13:33, 27 February 2012 (UTC)

Here's a simple way of thinking about it. As you accelerate, time starts to slow down for you. At everyday speeds, this is entirely imperceptible, but once you get up near the speed of light, it ramps up and becomes noticeable (from your point of view, time will pass normally, though). As you go faster and faster, approaching the speed of light, time slows further still, and if you were able to travel at exactly the speed of light, time would stop completely. What this implies... is absurd, and just one of the many reasons why you cannot travel at the speed of light. But if you could then accelerate even more, time would begin to go backwards. The faster you went, the faster back through time you would go. Again, from your point of view, time would proceed normally. Goodbye Galaxy (talk) 15:21, 27 February 2012 (UTC)

I meant it has been proven scientifically and mathematically if we can somehow manage to travel faster than light. And yep as with our technology today, we are no where close to the speed of light. A lot of people today would say travel faster than time is impossible. But impossibilities always have changed over time, it is impossible right now doesn't mean it will be impossible in the future. A thousand years ago, there were a tons of stuffs that consider as impossible but we can do them with ease today. I'm not saying certainly time travel is possible but we don't know for sure it's impossible either. So basically theoritically it's possible if we can travel faster than light but practical is we will see in the future or our descendants will??Pendragon5 (talk) 19:37, 27 February 2012 (UTC)

@Goodbye galaxy: Why the faster you move = the slower than time is? I don't understand the concept that0 if you travel faster than light then why is it that time is running backward?Pendragon5 (talk) 19:37, 27 February 2012 (UTC)

Goodbye galaxy is wrong about that (see my reply below). As for the rest I don't know what to say except what I said above. -- BenRG (talk) 19:50, 27 February 2012 (UTC)

The time dilation factor is ${\sqrt {1-(v/c)^{2}}}$. This does go to zero as v → c, but it goes imaginary, not negative, when v > c. In fact, negative values of the factor correspond to speeds less than c; it's only by convention that the positive square root is used. Special relativity, without additional assumptions, has no concept of going "forward" or "backward" in time. -- BenRG (talk) 19:33, 27 February 2012 (UTC)

LOL then we just make an assumption that time connected to speed? I don't see how they connected, time has nothing to do with speed. Time is something always happening no matter what we do. As we travel faster and faster, how can it possible effect the flow of time? Time is just a concept that humans have came up with, it's arguable of what time actually is. As i can understand, we still have a poorly understand about time. We still have long way to go if time travel is possible. But the time travel concept many famous scientists have came up with really confused me.Pendragon5 (talk) 20:00, 27 February 2012 (UTC)

"As we travel faster and faster, how can it possible effect the flow of time?": Few if any people understand it completely, but it does. This is part of Einstein's theory and it has been confirmed by accurate clocks in spaceships. They travel at great speed, and their clocks go a little slower than clocks on earth. The theory of relativity is mind-boggling, but it does work. It makes accurate predictions. You are right that real time travel (i.e. backwards, because we always travel forwards anyway) is usually based on poor understanding of the theory. -- Lindert (talk) 20:21, 27 February 2012 (UTC)

Well the concept of the faster we go = the slower the time flows is just mind crunching, i don't think i can make any sense out of it. I see no connection between the two, no matter of faster you travel, it is only get you to one place to the other faster not travel in time. Even if we can travel faster than light, i don't see how it can possibly travel back in time. Perhaps there is something else is effecting it and we don't even have any knowledge about it yet, such as dark matter and a bunch of other predicting particles that scientists think it must be there so the whole thing can make sense. As i can see, we still have a lot of assumptions. I don't mean to say human race is stupid, we are the smartest species in the Earth indeed but i think we are still very stupid "compare" to the universe as the whole. I feel like as it is right now i only consider that we barely know anything about the universe yet, there are still a lot of things left unexplained or doesn't make sense to human's conscious. Plus what we think is right for now may be proven wrong in the future. It always have been like that, that's the natural of science. I wonder if there is an absolute truth that will forever never be proven wrong nor can it be improve one day.Pendragon5 (talk) 23:41, 27 February 2012 (UTC)

You're thinking about time in the wrong way. You're thinking of time (change) as more primitive than everything else in the world. That's why you don't understand how the laws of physics can "affect time". Actually, time is an aspect of the world on the same footing as distance. Clocks tick off the seconds, and people think and perceive the world and grow older, by means of physical interactions between their various parts. If you think of time in that way then there's nothing strange about special relativity at all. As someone who does understand it, I assure you that it's not nearly as amazing, or interesting, as it might seem at first. -- BenRG (talk) 01:34, 28 February 2012 (UTC)

Along that line, I used the phrase relativity is "a basic consequence of geometry" when a question came up a week or two back. If you work out the math to its logical conclusions, you'll see that there's no other way things could work - there'd be an inconsistency somewhere. That's why we have things like length contraction or time dilation. As far as physicists are concerned, conundrums like the barn door paradox are less inconsistent than the consequences if we did not make relativistic corrections. For example, if the speed of light were not constant, as observed from any reference frame, the natural consequence would be that some reference frame is the canonical one, and everyone else is wrong; the laws of physics would change from place to place and person to person. Not only is the idea of a canonical universal "correct" reference frame a profoundly unsettling concept for many physicists, it's also not what we measure. We use relativity (in both special and general forms) because it is internally consistent (the math all works out) and externally consistent (it matches our experiments). All the equations and the mathematical abstractions about relativity are simply tools to help us formally explore the consequences of our observations. Nimur (talk) 02:08, 28 February 2012 (UTC)

Hopefully these explanations have disabused the OP of any notion that the highly questionable (at best) nature of the concept of time travel is in any way comparable to the well understood and experimentally verified nature of the feature of our universe that is time dilation. The OP may wish to read Poul Anderson's classic hard science fiction novel Tau Zero, which prominently features, explains, and is titled after time dilation (to the extreme). If they have sufficient self-discipline, they should postpone reading our article until they have completed the novel; it is a good read. The OP may also find our Twin paradox article interesting. -- ToE 13:23, 28 February 2012 (UTC)

Don't really understand the concept at all. There could be some unknown factors that affect the clock to go slower but the time is not actually going slower. Humans made clocks to keep track of time so it may not totally define time. It's really hard to explain what i'm going to get at. I don't even sure of what i'm talking about, it's just something in my mind that... I think we, humans, have assumed that we know time enough but maybe we are not and we don't realize it. Every single concepts that we know are the products of our humans' conscious or imagination. We made up a lot of stuffs to explain things in our universe, what makes sense to us may not be in fact the truth. As we're getting more advance and more advance we started to realize many flaws we had in the past, it is keep improving over time. As it is right, i think we are no where close to perfect. We still have a long way to go, maybe 1 thousand more years or 1 million more years or we could be extinct one day? Anything be happen but i think if we have reached to the point where we understand the universe completely then we, human race or perhaps all individuals, will probably be immortal until the universe dies on its own. I seriously don't think we understand what time is yet, perhaps we think we have strong understand about it but doesn't mean it's 100% correct yet.Pendragon5 (talk) 19:44, 28 February 2012 (UTC)

With all due respect, your response comes across as simultaneously naive yet supremely arrogant for a high school sophomore who has expressed interest in becoming a professional astronomer (per previous discussions) to make. (Seriously, haven't you come across this concept before in popular science television shows? What have you thought relativity was all about?) This is a reference desk and we have provided references and have filled in the context explaining that this is a well established and scientifically understood field. Have you read our Special relativity, Time dilation, and Tests of special relativity articles? They are not overly heavy in math, but don't just stop if you run into a formula that doesn't make sense; push on, as there may be useful text further down the article. Once you have read those, you are welcome to come back and ask for more references. Perhaps someone here can recommend a popular physics book (as in a book targeting the non-mathematical populace) which addresses your questions. We understand that the concept seems counterintuitive to you, but that does not mean that it is not the way things are. Conversely, no one, particularly no scientist, is claiming that everything is known or that all scientific theories currently believed to be valid will hold for all time. Special relativity, however, so precisely predicts that which we observe experimentally that there is no strong motivation to replace it with anything else, and should experimental discrepancies ever be found that do force a change in our understanding of special relativity, that change will not be a whole-scale one, but will be a refinement, much as special relativity is a refinement of Newtonian mechanics, which itself does a good job explaining the laws of motion at speeds which are small compared to that of light. -- ToE 23:59, 28 February 2012 (UTC)

I'm not trying to be arrogant. The fact that i say human race is stupid compare to the universe is that in my opinion we still understand little about the universe. Let put it this way, the fact that i said human race is stupid doesn't make me smart. That only makes me even more stupid because there are a lot of smarter people than me. I never claim that i'm smart nor do i have understand everything yet. I never said that i'm correct nor am i proving any wrong. There is more likely that i could be wrong but well i still believe that we know little about time. Time travel is the very very interesting topic, which i spent around 50 hours reading about it before and of course i have watched countless of movies about time travel, the most interesting things are paradoxes. Well even though i have spent great amount of time reading about it throughout my life, i still understand little or nothing about it. And sorry that i'm too stupid to understand the relativity theory of Albert Einstein. The fact that we have done experiments that can prove speed related to time doesn't mean that we are correct. There could be other factors that mislead us like dark matter or a bunch of others we haven't even think about yet. That's just my belief. We, humans, can't be too sure that we have understand time enough until we can actually time travel.Pendragon5 (talk) 00:05, 1 March 2012 (UTC)

The truly strange thing is that the speed of light is the same for all observers, regardless of their velocities with respect to one another. Once this is accepted as experimentally proven, then length contraction and time dilation follow as natural consequences; it's the only way it all makes sense. If the OP does choose to major in astronomy at university, they will work simple special relativity problems in Freshmen-level Physics. A fuller understanding will come in their Junior year when they study classical electrodynamics. (The "classical" here distinguishes it from quantum electrodynamics.) Having mastered a text such a Griffiths', the student will understand the derivation of special relativity, and should be able to easily work most relativistic problems of motion, but it won't be until they study a graduate level text, such as Jackson's, that they will be in a position to work more complicated relativistic electrodynamic problems. General relativity is a much different story. Its consequences will be discussed in many an astronomy course, but its fundamental mathematics isn't really tackled until graduate level physics.

I'm no science historian, but I suspect that most physics graduate students will understand special relativity as well as Einstein, and those specializing in general relativity will likely understand it better than Einstein ever did. The profession marches on, and long past are the days when only a handful of people on Earth understood Einstein's work.

Finally, the OP should not assume that an undergraduate degree in astronomy is the best route towards graduate studies and a profession in that field. In my experience at university, I found that the astronomy majors were much less proficient at math than the physics majors. Both took the same Junior-level Classical Electrodynamics and Classical Mechanics classes, and grades were bimodal. I believe that the students who either double-majored or majored in physics and minored in astronomy had a much better chance of being accepted into a good graduate program, and those who were most interested in cosmology were often applying to physics departments, where that sort of work is mostly done. -- ToE 22:09, 27 February 2012 (UTC)

Just as an historical note: special relativity wasn't the one that required heavy mathematical work. That was the one where people just didn't like the conclusions. One of the main criticisms was that it was mathematically simplistic — a trick of algebra — as compared with, say, the kind of math you needed to calculate vortex stability in luminiferous ether flows. General relativity was the one that required some more mathematical ability than your average physicist had at the time, and was first embraced by heavily mathematical physicists in England primarily for this reason. (The British had a stronger mathematical physics tradition at the time; the Germans were mostly about very careful experiments.) Later generations of physicists would become increasingly mathematical and theoretical. (Even they didn't work on GR, though. GR more or less wasn't even taught from the 1920s through the 1970s, or something along those lines — I can't recall the exact dates. It wasn't a hip area of physics.) --Mr.98 (talk) 02:12, 28 February 2012 (UTC)

Anecdotally, I can confirm that my alma mater's physics department offered an undergraduate course in general relativity. I don't imagine that it was a large class, but there are at least a few undergrads each year who can handle GR. TenOfAllTrades(talk) 00:38, 29 February 2012 (UTC)

Many times the particle goes back and forth in time. When he starts moving faster, the average of time begins to run down, and see the parallel universes which is related only to the speed of C, what remained of the particles that move backward and forward in time remains to one parallel universe . Thanks Water Nosfim — Preceding unsigned comment added by 81.218.91.170 (talk) 05:39, 28 February 2012 (UTC)

I think that FTL is not sufficient by itself to achieve a true closed loop in time - it is necessary to achieve FTL in multiple frames of reference. FTL in one frame of reference appears as travel into the past from another; but provided the traveller does not move backward or sideways in time from one specific frame of reference, he can never return to his original spacetime coordinate. As most of the matter we see in the cosmos, and the microwave background radiation, exists at any given point within a fairly close range of velocity (usually under 0.1% c), I don't find the idea of an absolute frame of reference in which some sort of non-relativistic physics could occur (i.e. FTL) to be all that implausible. Wnt (talk) 00:03, 3 March 2012 (UTC)

nice but many frames as many worlds ' thanks Water

Binocular vision and microscopes

Is there a known condition whereby one cannot look through the microscope with both eyes simultaneously? How is this phenomenon called? What are the treatments if any? Thank you. Gidip (talk) 11:10, 27 February 2012 (UTC)

The same issues should apply to both microscopes and binoculars. Therefore, what you are looking for is the section Disorders of binocular vision in the binocular vision article. It lists several relevant disorders of the eye. As for treatment, the reference desk is not allowed to give medical advice. You would have to consult a professional Orthoptist. EverGreg (talk) 11:32, 27 February 2012 (UTC)

There are too many disorders listed there (I browsed this page before posting my question). I can't figure out which disorder is the relevant one. If someone can suggest one or a few specific disorders that would really help. Thanks. Gidip (talk) 11:57, 27 February 2012 (UTC)

Before we get into medical disorders, consider that it might just be improper setting of the microscope. The eyepieces have to be exactly the right distance apart or you have to move one way and the other to see through them. If you can't see through the microscope with both eyes at the same time, obviously you don't know that the current setting is correct. I'd say, keep trying. Wnt (talk) 12:53, 27 February 2012 (UTC)

He fathered seven point five children in one night and about Genghis Khan he only laughed

• http://www.youtube.com/watch?v=pzmI3vAIhbE

Er zeugte sieben Kinder in einer Nacht		He fathered seven children in one night
Und über seine Feinde hat er nur gelacht		And about his enemies he only laughed
Denn seiner Kraft konnt keiner widerstehn		Because nobody could resist his strength
Hu, ha...		Hu, ha...
		-- Dschinghis Khan by Dschinghis Khan

http://www.dailymail.co.uk/sciencetech/article-2106776/No-wonder-theres-violence-world-Hundreds-millions-people-related-despots-claims-study.html

... One historian believes that Yangdi, the 6th-century Sui dynasty emperor, for example, had children with 100,000 women.

The Emperor Yang of Sui (569-618) died when he was 49 years old. When he was 12, his father established the short-lived Sui Dynasty. So he was a prince when he was ready for having babies. He must have slept with at least 7.5 women each night for 37 years to father 100,000 kids. I mean from age 12 to age 49 and not a single miss.

Who is that historian?

Emperor Yang of Sui was 5 centuries before Genghis Khan. I guess he was unable to laugh at a man who could only father seven children each night. -- Toytoy (talk) 11:24, 27 February 2012 (UTC)

The Daily Mail references the anthropologist Laura Betzig. She mentions Yang in this article: "Yangdi, the Sui Dynasty emperor who built the Grand Canal and rebuilt the Great Wall, was credited by an official historian with 100,000 women in his palace at Yangzhou, alone, and when the Yuan dynasty founder, Kublai Khan, put up a capital at Beijing, he left a summer palace at Xanadu behind, with room in the excavations for another 100,000 (Wei, 2008)." So, he kept an enormous harem, but there is no claim that he had children or even slept with all of these women. --Wrongfilter (talk) 11:59, 27 February 2012 (UTC)

And it probably should be noted that estimates of population sizes (e.g. army sizes, harem sizes, city populations) by ancient historians are often off by an order of magnitude or so, either out of error or for dramatic/propagandistic effect. (Heck, we still do it today when estimating death tolls — the estimates before bodies have been counted in any systematic way, in either war or disaster, are often an order of magnitude off of the actual counts, in my anecdotal experience.) --Mr.98 (talk) 13:09, 27 February 2012 (UTC)

It is probably impossible to do that many women... to have many kids. I have read many Vietnamese and Chinese histories. Hundreds of children are typical for emperor but i never ever heard about any emperor has reached a thousand children mark yet. So 100,000 children = not even close to be possible. There were always some people who try to exaggerate stuffs about the kings so the king can favor them. Perhaps that emperor likes people to think he does a lot of woman. And as the emperor in any where of the world back there then they can basically say whatever they want and forced people to believe it. If you don't believe in it, the consequence will be really bad... Possibly deaths.Pendragon5 (talk) 19:44, 27 February 2012 (UTC)

Are you sure this is a literal description, rather than a gullibility of speech? After all, they say an emperor built a pyramid and nobody ever saw him hauling any bricks. Can't he have 100,000 children the same way? Wnt (talk) 00:57, 28 February 2012 (UTC)

I know nothing about 6th century Chinese medicine. But as to Chinese medical belief of early 20th century, I think many people, under Taoism influence, believed that one drop of semen equals to maybe 10 drops of blood or so. As a result, a playboy may be "sucked up dry" by women if he sleeps with too many of them for too many nights. I think many athletes still keep themselves from women before they are going have a big fight.

Sex is a very important subject in Chinese medicine and philosophy. Today's Taoists still practice a way to keep themselves from ejaculation during an orgasm. They trained not to "shoot" in order to enjoy sex and preserve their valuable bodily fluid. They did it to promote themselves to a higher degree of consciousness. An imaginary goal for some mysticism practioners is to "dominate" 100 women for a night without losing a drop of semen ("御百女而不洩"). I don't think there was feminism 1500 years ago, sorry.

There were very high ranked officials to decide who should sleep with the emperor each night. I don't think an emperor was allowed to waste his "dragon's essence" by sleeping with 100,000 women. If you play so much, you'll end up like a zombie! An emperor might have 100,000 women in his harem. However, the majority of these women were living in so-called "Cold Palace" ("冷宮"). They were not allowed to have sex with the emperor unless they were chosen. They end up marry an eunuch when they got too old to serve the emperor. The emperor could have several women with him each night. He was not allowed to ejaculate to all of them. On the other hand, if he ejaculated to the specially chosen woman, an eunuch outside was ordered to register the exact time of ejaculation in order to have the time reviewed by an astrologer. At least it was the practice of China's last Dynasty, Qing Dynasty.

Wang Zhaojun (50BC?-?) was a extremely beautiful lady-in-waiting of Han Dynasty. It is said that she refused to bribe a painter. As a result, she was painted as an ugly woman. The emperor did not know her before she was given to the Huns. ...... Well, the painter was sentenced death and she was sent far north .... Never been enjoyed by the emperor ......

I don't want to blame a scientist for her ignorance of Chinese history and philosophy, even though having 100,000 kids certainly is beyond science, logic and imagination. Not even a NBA basketball player could come even close without artificial insemination. I just want to know who's that historian? Ha! Ha! Ha! -- Toytoy (talk) 07:38, 28 February 2012 (UTC)

I don't think eunuch can have sex, their main sex organ is gone.Pendragon5 (talk) 19:15, 28 February 2012 (UTC)

No, they could not have sex. At least they could not have real sex. They still have fingers and tongues, though ...

The family formed by old concubines (gungnyeo) and eunuchs are called "cai4 hu4" ("菜戶") in Chinese. It means "vegetable family" literally. This family has no "meat"... -- Toytoy (talk) 11:14, 29 February 2012 (UTC)

While I agree that 100,000 children is beyond the realm of possibility, your numbers of 7.5 women a night for 37 years is off given that twin, triplets, etc. are also possible. 203.27.72.5 (talk) 01:41, 29 February 2012 (UTC)

It's probably off even more in the other direction, though. Only a third of sexual acts end in pregnancy under ideal circumstances (I'll admit its an iffy statistic, with so many variables at play), whereas the rate of twinning is typically 2%, and never more than 5% for any significant sample size. The rate of triplets is even lower at ~0.2%. And those are modern numbers probably tainted by fertility treatments. Someguy1221 (talk) 11:24, 29 February 2012 (UTC)

"Only a third of sexual acts end in pregnancy", Oh I thought that we could just assume he was always doing the one that does end in pregnancy :P. 203.27.72.5 (talk) 04:03, 1 March 2012 (UTC)

Can a Silicon atom get split into smaller atoms, like a carbon and oxygen atoms?

Hi, Is there any way to split a silicon atom (14) into a carbon atom (6) and an oxygen atom (8)?

Or is the fusion of lighter atoms (< 26) a one-way process towards iron (26) only?

Thanks --InverseSubstance (talk) 23:27, 27 February 2012 (UTC)

This kinda rings a bell. Have you been reading something like this:Biological transmutation. Neutron bombardment can transmute Si to phosphorous but as to the other theories I want to keep clear of them.--Aspro (talk) 23:51, 27 February 2012 (UTC)

Ah. Nothing sucks-seeds like a toothless biggie. With the aid of my dowsing pendulum I have found this... [1]. Well, it seems one learns something new every day ;-) --Aspro (talk) 00:06, 28 February 2012 (UTC)

Thanks - Not sure if the above is to be taken seriously? I not looking for a wacko nut job's outrageous claim. It seems physics basically says, once an atom has fused, it can never get defused.

Phosphorous (15) is higher than Silicon (14). I'm just wondering if light atoms can only ever become heavier atoms. That is, they can't ever migrate backwards towards lighter atoms. Just wondering. --InverseSubstance (talk) 00:21, 28 February 2012 (UTC)

Bombarding a nucleus with energetic particles (e.g. cosmic rays) can sometimes cause even relatively light nuclei to break apart. For example, the traces of Beryllium-10 found on Earth are mostly caused by cosmic rays breaking apart nitrogen or oxygen in the atmosphere. Dragons flight (talk) 00:42, 28 February 2012 (UTC)

For reference, the process is called Cosmic ray spallation Vespine (talk) 01:21, 28 February 2012 (UTC)

The Discovery_of_fission section of our Nuclear fission article alludes to "splittings" or fissioning of light elements achieved when the phenomenon was first investigated. Although Silicon is not explicitly mentioned, I can think of no reason why it should be any less fissionable than other light elements. {The poster formerly known as 87.81.230.195} 90.197.66.193 (talk) 02:09, 28 February 2012 (UTC)

All right! Thanks. Because now it seems possible to change sand into oil. Theoretically at least. I'll keep grinding away... --InverseSubstance (talk) 05:15, 28 February 2012 (UTC)

I don't think so. In theory, you can take any atom of your choice (eg silicon), and hit it with any atom or particle of choice (eg electron, gamma photon, thru to the largets atom possible). For each combination of traget atom and incident particle, you'll get smaller atom plus one or more particles and some energy radiated. Just what you get is governed by certain rules. More often than not, the smaller atom wil not be nuclear stable, and within microseconds to kiloyears, depending on the target and incident combination, decay into something else - this may continue several times. Problems: a) not all combinations have been tried, b) the technology to select and use the optimal combination may not exist, and c) we know enough to know what you get is seldom convenient. So, in practice transmuting silcon into carbon is not possible, and nor is the reverse. Ratbone124.178.178.1 (talk) 07:22, 28 February 2012 (UTC)

It's definitely possible to go from stable silicon to stable carbon, it just might not be possible to do directly. Regardless, the energy costs would be obscene compared to the energy you'd get from burning the resulting oil you plan on making. If you're already cool with the process being energy inefficient, you are much better off making oil out of carbon dioxide, which is easily doable. Someguy1221 (talk) 07:27, 28 February 2012 (UTC)

You can't make oil out of just carbon dioxide - you would need some hydrogen from somewhere. Water would be the obvious source. Then you're just doing the usual combustion reaction backwards. If combustion works, then combustion backwards should work, you just need to put enough energy into it (and somehow prevent the newly formed oil and oxygen from immeadiately combusting back into carbon dioxide and water - that would probably be the tricky bit). --Tango (talk) 12:34, 28 February 2012 (UTC)

The carbon and oxygen maybe radioactive depending on which isotopes are generated. The desired reaction pathway is also unlikely to be only one, so there may be other radioisotopes from side reactions present in the mix. For making oil, you don't just need the right element; the chemical state of the newly created carbon is also important. Transmutation of silicon sounds like a horrible choice of a carbon source to make synthetic oil. As mentioned above, why not just use carbon dioxide? 203.27.72.5 (talk) 02:01, 29 February 2012 (UTC)