Wikipedia:Reference desk/Archives/Science/2011 June 26

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June 26

Hotspot underneath Iceland is the same one that produced the Siberian Traps?

In this article, it is mentioned that the hotspot that produced the Siberian Traps may be underneath Iceland now. But do have have 250 million years of continuous volcanism from today in iceland to the formation of the Siberian Traps, 250 million years ago? Count Iblis (talk) 00:46, 26 June 2011 (UTC)

The article you cited did not claim that the plume that caused the Siberian trapps is now under Iceland. It said that a gigantic impact in Antarctica may have caused the Sib. trapp by antipodal disruption and incidentally may also have contributed to the Iceland plume. 190.148.136.161 (talk) 01:49, 26 June 2011 (UTC)

Prehistoric Scotland says that there was a lot of volcanic activity around the Scotland area in that same time period. The Icelandic plume is thought to have migrated N-W. from that area helping to open the North Atlantic.190.148.136.161 (talk) 02:07, 26 June 2011 (UTC)

It's a bit of a jump to get from the Siberian Traps to the Iceland plume, although in between there is the High Arctic LIP, which was mainly active in the middle to late Cretaceous (so about 100 to 80 million years ago), and the North Atlantic LIP which was active from the latest Cretaceous up to the end of the Paleocene (about 70 to 55 mya). The iceland plume reached its current location in the Mid-Atlantic Ridge by the Miocene (about 15 mya). Some people have suggested [1] following plate reconstruction that the siberian traps are located exactly where the North Atlantic LIP was to erupt some 180 my later, but I'm not sure that this is the view of everyone working on these things. Mikenorton (talk) 18:14, 26 June 2011 (UTC)

thanks! Count Iblis (talk) 15:13, 27 June 2011 (UTC)

crossing over

If I stood, or sat in my rowboat, at the east side of the international date line (somewhere in the Pacific), and then I stepped or rowed to the other side of the line. Would today now be tommorrow or yesterday? 190.148.136.161 (talk) 00:59, 26 June 2011 (UTC)

If it is midday on Tuesday on the east side of the line then it is midday on Wednesday on the west side of the line. See International Date Line for more information. --Tango (talk) 01:20, 26 June 2011 (UTC)

Of course, today is still today on either side of the line. It is simply that our time-keeping convention is to call today Tuesday on one side of the line, and to call today Wednesday on the other side of the line. It's just an arbitrary change of co-ordinates. Gandalf61 (talk) 08:12, 26 June 2011 (UTC)

It affects business in the South Pacific. When it is Monday morning in New Zealand and Australia it is Sunday morning on some Pacific Islands and the businesses there then suffer. Some Pacific Islands have decided to move one day ahead to deal with this problem. Count Iblis (talk) 17:07, 26 June 2011 (UTC)

The way to remember which is which is always to remember that as land moves to the east it moves later in time. (i.e. the Sun rises up over it) So the west edge of the date line is the furthest point east in the world, and so it's the latest time zone.

My suspicion is that there are many small and large ways (also road conventions, negotiating teams, human rights issues, Whale Wars) in which it looks like Australia is becoming more of a regional power over much of the South Pacific. Wnt (talk) 04:21, 27 June 2011 (UTC)

Constitutional walk [close to speed of light] on Einstein’s treadmill:

Although the stepping positions in space would remain same but would the moving clock on such a treadmill be slowed down? As air time is involved in RUNNING therefore WALK should be considered in the scenario - non-broken connection between walker and walk belt 68.147.41.231 (talk) 03:21, 26 June 2011 (UTC) Eccentric Khattak No.1

Yes, a clock attached to the treadmill belt would run slow, as observed in the racewalker's inertial frame of reference.

The footfalls all occur at the same location in space according to the racewalker's frame of reference (or really the same two locations, since the racewalker has two feet), but they do not all occur at the same location according to the belt's frame of reference. In the belt's frame of reference, the footfalls occur at the locations of the footprints left behind on the belt, which in the belt's frame of reference are stationary.

The two frames of reference do not necessarily agree as to whether the person is running or walking. The event of a front foot landing and the event at around the same time of a rear foot leaving the belt occur at two different locations, so there's relativity of simultaneity to deal with. I.e., the two frames of reference may disagree as to whether the rear foot has left the belt yet as of when the front foot lands. Red Act (talk) 12:06, 26 June 2011 (UTC)

Also, unless the belt is moving less than half the speed of light (in the racewalker's frame of reference), walking instead of running would be impossible, because walking would require the feet to move faster than the speed of light. Red Act (talk) 12:41, 26 June 2011 (UTC)

The person can be walking in their frame no matter how fast the treadmill is going, it just won't necessarily be walking in the treadmill frame. Rckrone (talk) 16:03, 26 June 2011 (UTC)

How do you define "their frame" for someone walking? Is that the frame of their head? I don't think it is possible to walk (on solid ground or a treadmill) faster than around 0.5c, since your feet need to move faster than your overall speed (in the lab frame) in a walking motion. The same is true of a vehicle travelling on wheels - the top of the wheel moves at twice the speed of the vehicle, so it can't go faster than 0.5c (in that case, it is exactly 0.5c, I'm not sure exactly what the top speed would be for a walker). --Tango (talk) 18:30, 26 June 2011 (UTC)

Yeah, I do mean their head. That seems like the only reasonable way to define "their frame". In that frame there's clearly no problem with having one leg moving at say 3c/4 in one direction and the other leg moving at 3c/4 in the other, and then at some regular interval both quickly switching direction (if you ignore the difficulty of accelerating a leg so much). Here I'm imagining the body and two legs as 3 separate objects. From the lab frame the person would be running, since the lift of the back foot would be well before the fall of the front one. The two leg speeds would be 0 and 24c/25, but clearly each leg would be spending the majority of the time moving forward since the average speed is still 3c/4. I can't think of any reason why c/2 would be any more of a barrier with wheels, but things get messy trying to describe "rigid" bodies rotating like that. Rckrone (talk) 05:07, 27 June 2011 (UTC)

In the lab frame, if a car is moving at c/2 then the top of its wheels are moving at c, hence the car cannot move at c/2 or faster (in reality, if you tried the wheels would spin - what we've found is a fundamental limit to friction between the wheel and the road). --Tango (talk) 11:52, 27 June 2011 (UTC)

In the frame of the wheeled vehicle, all we have is a rotating object that has a speed of c/2 at the edge. There's nothing impossible about that (besides holding an object together under so much force). In the lab frame the top of the wheel is not moving at a speed of c, it's going at 4c/5. From this perspective the wheel is pretty distorted, seeing as more of the outside edge of the wheel is on the top than on the bottom at any given time. You can think of the wheel case is basically like having a lot of feet. Rckrone (talk) 15:43, 27 June 2011 (UTC)

Yeah, that was another poorly worded sentence on my part. I should have put "(in the treadmill belt's frame of reference)" after the phrase "walking instead of running" in my post, because otherwise it sounds like the racewalker's frame of reference is being used to define walking vs. running, since that's the only frame of reference mentioned in that sentence.

I'll spell out and explain the c/2 limit in detail to make it clear to everybody (hopefully). In any reference frame used to define "running" vs. "walking", assuming the left and right footfalls are evenly spaced in terms of time and distance, "walking" means that each foot spends at least 50% of the time (in that reference frame) in contact with the treadmill belt, so that the other foot is in contact with the belt both when the given foot lands and leaves the belt. In the treadmill belt's frame of reference, let t₁ and t₂ be two consecutive times at which the left foot lands, and let x₁ and x₂ be the corresponding locations at which the left foot lands. If the belt is moving at speed v in the lab frame, then in the treadmill belt's frame, the person is moving at speed v, which implies that (x₂-x₁)/(t₂-t₁) = v. For the racewalker to be walking in the treadmill belt's frame of reference, the earliest the left foot can leave the belt during that cycle is at t₁+(t₂-t₁)/2. That means that during the second part of that cycle, the left foot only has at most a duration of (t₂-t₁)/2 in which to cover a distance of x₂-x₁, meaning its average velocity during that second part of the cycle must be at least (x₂-x₁)/[(t₂-t₁)/2] = 2(x₂-x₁)/(t₂-t₁) = 2v, which would be superluminal if v > c/2. Red Act (talk) 07:06, 27 June 2011 (UTC)

A clock attached to the treadmill would obviously run slow relative to a clock on the wall of the room (which I assume is the reference frame the OP is interested it), the fact that someone is running on it makes no difference at all. I don't think that was the question, though. I think the question was whether a clock attached to the runner would run slow compared to the wall clock. If it was attached to the runner's torso, then it wouldn't since the torso isn't moving significantly relative to the wall (that lots of other things are moving really quickly doesn't matter, you just look at the two clocks). If it were attached to one of the runner's legs, then it gets a lot more complicated because the legs are accelerating. At some points they will be moving backwards at relativistic speeds, at some points they will be stationary and at some points they will be moving forwards at relativistic speeds. That means the clock on the legs will run slow compared to the wall clock, but I can't immediately calculate by how much. --Tango (talk) 13:34, 26 June 2011 (UTC)

The other replies have effectively already said this, but let me emphasize: time dilation only depends on the motion of the clock relative to the lab. It never makes any difference how the clock is "attached" to the lab (via a pair of rapidly moving legs and a treadmill, in this case). Likewise, it makes no difference if it's not attached at all for some of the time (air time). In general relativity, the legs and the treadmill do technically matter, but only because they gravitate, not because they're attached to the clock. -- BenRG (talk) 16:47, 26 June 2011 (UTC)

To all - Sorry about the confusion!

By “Moving Clock”, I meant light clock [mini model] on the Runner’s head [fixed] not attached to the walk belt. As runner [walker] moves close to the speed of light and so the light clock therefore if time dilates then

Why a pulse doesn’t trace out longer path/ angled for stationary observer in Gym’s frame of reference?

Why same vertical bouncing of pulse between two mirrors for both moving [runner] and stationary observers? 68.147.41.231 (talk) 03:07, 27 June 2011 (UTC) Eccentric Khattak No.1

Let make it more simple – Let a person stands [on his Roll Skates] on aforementioned treadmill. Although a person seems stands still but the walk belt enable his wheels to roll on its smooth surface. 68.147.41.231 (talk)EEK No.1 —Preceding undated comment added 03:58, 27 June 2011 (UTC).

Just because a person is rolling along on a treadmill doesn't mean that he's moving. When you talk about something moving, you always have to specify what it is that the movement is relative to. In this case, the person, the treadmill, and the lab the treadmill is in all have the same comoving frame, i.e., none of them are moving relative to each other. In that lab frame, only the treadmill belt is moving (and the roller skate wheels). So as measured in the lab frame, the clock attached to the person's head does not exhibit time dilation, because its speed as measured in the lab frame is zero. However, that clock attached to the person's head would be running slow as measured in the belt's comoving frame, and a clock that moves along with the belt runs slow as measured in the lab frame. Red Act (talk) 04:24, 27 June 2011 (UTC)

If you're running on a treadmill, the only thing moving is the treadmill. And the treadmill is moving back and forth, just like the spaceship in the twins paradox, so it will end up with a different span of time like the accelerated twin. Wnt (talk) 04:26, 27 June 2011 (UTC)

When I said the treadmill wasn't moving relative to the lab frame, I meant the non-belt portion of the treadmill, not the belt. The belt is obviously moving relative to the lab frame, and moving relative to the non-belt part of the treadmill. I probably should have worded things differently. Red Act (talk) 04:36, 27 June 2011 (UTC)

"9,900 years hyperbolic orbit"?

At http://elenin.org/ we read that this comet "follows a 9,900 years hyperbolic orbit around our sun". That seems contradictory. To specify a number of years seems to imply periodicity. But "hyperbolic" seems to imply that it's not periodic. What is meant? Michael Hardy (talk) 04:34, 26 June 2011 (UTC)

At one Epoch the comet can be hyperbolic, while at another it can be a closed loop. The real orbit (or the best approximation to such) considers perturbations by all planets, a few of the larger asteroids, a few other physical usually small forces, and requires numerical integration. Comet Elenin's orbit will become closed because Jupiter's gravity will lower the eccentricity below 1 as Elenin is leaving the planetary region. -- Kheider (talk) 05:24, 26 June 2011 (UTC)

Confusion between orbit types is not the most surprising thing at http://elenin.org/. Further down the page, it speculates that Elenin is in fact a brown dwarf and that it will "preciptate major reactions within the Earth's core as well as on its surface that could very well lead to a global catastrophe". Apparently it is connected with the Nibiru collision theory and the whole 2012 "end of the world" thing. Gandalf61 (talk) 08:06, 26 June 2011 (UTC)

Diamond and Lonsdaleite

It is often said that Adamantane is the smallest molecule that technically, can be called a diamond. Is it really so, since it contains no carbon only moeities? I suggest a new basic diamondoid (SMILES): C1C2CC3CC1C14C5CC6CC(C5)C57C8CC9CC(C8)C3(C3CC1CC5C3)C47C269. A similiar case exists for Lonsdaleite, where its basic unit is bicyclo[2.2.2]octane. New basic Londsdaloid: C1C2CC3CC4CC5CC6CC7CC8CC9CC1C81CC8CC24C1(C57C8)C369. What are the major differences besides their size and mass? Plasmic Physics (talk) 04:41, 26 June 2011 (UTC)

I guess it depends on what you think the essential nature of diamond is. Is it being just carbon, or is it being a lattice of singly-bonded tetrahedral carbons? If you're single bonded tetrahedral carbon, you're going to have edge effects, where you cap the carbon with something else (like hydrogen). The question is how far in you allow the edge effects to penetrate. For example, for Adamantane, it's all edge. I would say that Adamatane *does* have a carbon-only moeity, which consists of the ten carbons bonded together. Yes, it's directly connected to hydrogens, but why should that matter? If you're just looking for an all-carbon moeity with tetrahedral structure, why doesn't neopentane count? Or 1-methyladamantane? -- 174.24.222.200 (talk) 18:20, 26 June 2011 (UTC)

Well, I didn't choose them, because neopentane is non-reprasentative of a singular allotrope; and I chose the ones I did because the central carbon forms closed hexagons with all four adjacent atoms, meaning at it contains five carbons which are only attatched to other carbons. That is what I meant by carbon only moeities, appologies for the confusion. Plasmic Physics (talk) 20:35, 26 June 2011 (UTC)

The simplest carbon-only moeties I can think of would be the fullerenes, but they have graphite-type bonding rather than diamond-type bonding. The problem is one of geometry; graphite- type bonding, with its planar 120 degree bonding, is relatively easy to bend back on itself and leave no open branches. With diamond-type bonding, being tetrahedral (three dimensional and 109.5 degrees), tends to create more branches the further and further you get from the "origin" as you branch out, it becomes impossible to cap it with only more carbons. Eventually, you need to cap it with some univalent atom to end the branching, so even a large diamond crystal (which is essentially a single molecule) has all of its branches terminated by hydrogen. If you are dealing with closed hexagons, you're back to fullerenes and graphite. --Jayron32 18:40, 27 June 2011 (UTC)

Yes, but only the central carbon forms closed hexagons in my examples. That is the key to my structures. According to my theory, the basic fullerene should be 1-dehydrophenalene: c1cc2cccc3cccc(c1)c23. Plasmic Physics (talk) 11:23, 30 June 2011 (UTC)

what is un-saturated polyester film

Dear Sir,

As per subject given up Kindly clearify my that what is diffrence between saturated and un-saturated polyester film . This question is asked because of in international harmonized code 3920-6310 of about polyester film which film shall applied for this code its not clear as fo as you are requested to please clerifiy me about diffrence between saturated and un-sturated polyester film and for which purpose these film shall be used.

Thanks and best regards usman hafeez -redacted-

LOL @ "un-sturated". StuRat (talk) 02:32, 27 June 2011 (UTC)

See Polyester and Polyester resin. Unsaturated polyesters are resins, generally used in structural applications (as "fibreglass"). I don't think it would be possible to make a _film_ from resin, so anything described as "polyester film" will almost certainly be made of a saturated polyester. Tevildo (talk) 11:27, 26 June 2011 (UTC)

Orbital speed and escape velocity

My book on physics says: "The higher the [circular] orbit of a satellite, the slower its speed and the longer its period." But it doesn't say anything about why this is so. My reasoning is that the escape speed farther from the earth is lower, so the speed of the satellite also needs to be lower, otherwise it won't stay in its orbit but escape. Is my reasoning correct? Lova Falk talk 09:50, 26 June 2011 (UTC)

Yes, it is. Plasmic Physics (talk) 10:21, 26 June 2011 (UTC)

Sort of. A better way to look at it is in terms of centripetal force. The centripetal force is the force that keeps the object on a circular path, in this case that is gravity. That article gives us a formula for centripetal force: F=mv²/r (r is distance from the centre of the orbit, m is the mass of the object and v is its velocity). If you equate that to Newton's Universal Law of Gravity, F=GMm/r² (M is the mass of whatever it is orbiting and G is the gravitational constant) and rearrange, you'll get v²=GM/r. That shows that as r increases, v decreases. That the orbital period will increase is obvious - it's travelling a longer distance at a slower speed, so it takes longer. --Tango (talk) 14:35, 26 June 2011 (UTC)

Looking for a good Scientific Paper

about the PRINCIPLES of the Imprinting phenomenon of Konrad Lorenz.

Many thanks. — Preceding unsigned comment added by 79.179.8.59 (talk) 12:45, 26 June 2011 (UTC)

I'm not sure what "principles" means, but in any case Google Scholar is often a good resource for digging up information of that sort. You can find a downloadable pdf of a 1958 Scientific American article here; or if you are looking for something more recent, this is a paper from 2011 that briefly describes the current state of the art. There is lots more available; the literature on that phenomenon is very extensive. Looie496 (talk) 17:11, 26 June 2011 (UTC)

Subterranean rivers

The concept of subterranean rivers somehow makes me feel as if I'm thinking about strange creatures from mythology, and I wonder if that's because I've found rather little information about them. Here we see one of a number of places in the Minneapolis/St. Paul area where such a stream emerges from underground at a point along the banks of the Mississippi River; at each such point there's a waterfall because the riverbanks in that vicinity are steep and high. From this map it looks as if this stream must flow under the campus of the University of St. Thomas. Obviously the locations of such things must be taken into account whenever a building is built on the land above it.

Where can I find maps of subterranean rivers in specified areas (Google Maps doesn't immediately give me those).

Leonardo da Vinci wrote that subterranean rivers flow from the Caspian Sea to the Black Sea. Is there any truth in that? Michael Hardy (talk) 19:38, 26 June 2011 (UTC)

If the mental picture you have is of an empty tube, filled with water, like a pipe or tunnel, that's extremely rare. Groundwater emerging from the terrain is almost always the outflow from an aquifer. Very occasionally, in the right circumstances, there can be flooded caves, but that's very rare. Anyone planning any building of reasonable size will perform a geotechnical survey which will determine the technical nature of the soil and the character of the water table (and other local hydrology) and will design the building's foundation accordingly. -- Finlay McWalter ☻ Talk 19:49, 26 June 2011 (UTC)

In cities it's not uncommon for natural rivers to be put into culverts and then built over, such that they become effectively subterranean rivers (see Subterranean rivers of London for some examples). It's mostly a matter of nomenclature whether these are really rivers or just drains. -- Finlay McWalter ☻ Talk 20:01, 26 June 2011 (UTC)

@Finlay: I don't think you would suspect that the stream in the map I linked to had been artificially put underground if you saw it close up.

Here's another one, maybe a mile and a half upstream from there. The stream flows out of the vertical face of a cliff maybe 30 feet below street level, and looking around you would see that the waterfall has been carved out over many centuries. Michael Hardy (talk) 22:11, 26 June 2011 (UTC)

Yes, but it could still be water flowing out of porous rocks, as opposed to a tube. If you fill a keg with sponges and water, then open the tap, water will flow out, but have you created a "river" ? StuRat (talk) 02:29, 27 June 2011 (UTC)

So if I want to find out whether a particular place where flowing water emerges from the ground is from a hollow channel or from porous rock, are there standard maps that I can find on the internet or in libraries that indicate that? Michael Hardy (talk) 20:34, 27 June 2011 (UTC)

The article on cave diving describes formations that are more river-ish in Florida and Yucatan (the first being karst limestone, the second cenotes where limestone has been impacted by the asteroid that killed the dinosaurs) I'm sure there must be many other good examples. Wnt (talk) 04:12, 27 June 2011 (UTC)

According to the internet one example of an underground river is in Battlefield Cavern, part of White Scar Caves in England. 92.29.127.234 (talk) 09:17, 27 June 2011 (UTC)

This site claims that a crypto-river has been tracked underneath the Nile. --TammyMoet (talk) 12:39, 27 June 2011 (UTC)

If people want to cite examples, there's Mammoth Cave in Kentucky, which IIRC was carved by a river flowing through it, under ground through most of its course. It's a tributary of the Ohio River. And in Bellefonte, Pennsylvania, a river emerges from the ground, which flows underground until it reaches that point and above ground downstream from there. Michael Hardy (talk) 17:32, 27 June 2011 (UTC)

Something else that relates is rivers that flow part-time. You may have a regular above-ground river at times, then perhaps it drops below the surface but continues to flow at other times, then stops entirely in the driest periods. Dotted lines are often used to show such intermittent rivers. StuRat (talk) 20:40, 27 June 2011 (UTC)

what is older?

A meteorite or gold? Or... were they formed at the same time? — Preceding unsigned comment added by 92.30.142.163 (talk) 21:16, 26 June 2011 (UTC)

Gold is a chemical element, so it will have been created in a supernova and will have been essentially unchanged ever since (gold rarely even bonds with other elements in compounds). Some of it may have come from the radioactive decay of other elements, but I believe that is a very small proportion. Meteorites, on the other hand, are lots of compounds stuck together. Meteorites will have formed during the early period of the formation of the solar system, which was some time (ie. millions, maybe billions of years) after the supernova that seeded the solar nebula with heavy elements. --Tango (talk) 21:27, 26 June 2011 (UTC)

(edit conflict)Your question really is asking to compare apples to oranges. A meteorite is defined as any extraterrestrial object, whether rock or metal, that has fallen to the Earth's surface. These have been falling to Earth since its formation, and many of the meteorites that fall are remnants from the early solar system before the earth was formed, but technically they are not meteorites until they land on Earth.

Gold, on the other hand, is an element; it is formed in the heaviest stars as they turn to supernovae. Gold we find on Earth was formed as stars exploded over and over during the billions of years before the formation of our solar system. Thus, in the strictest definition, you could say that gold is "older" than meteorites, but again, it is not really a good question to ask. Some meteorites may even contain gold. -RunningOnBrains^(talk) 21:36, 26 June 2011 (UTC)

I'd say almost all gold on Earth is older than meteorites on Earth, having been created by supernovae before the formation of our solar system (and thus before any meteorites here), but there could be some more recently created gold that drifted into our solar system and fell to Earth since it formed, and therefore could possibly be newer than some terrestrial meteorites. Also, gold can be created as the end product of radioactive decay, so there might be some newer gold from that source. As for the broader question of gold versus meteorites throughout the universe, that's a different story. I would think there were many meteorites prior to the first supernova, so they might win, in that case. StuRat (talk) 02:21, 27 June 2011 (UTC)

Meteorites need elements heavier than helium in order to form, so they must have come after the deaths of the first stars. The first stars are predicted to have been really large and would have gone supernova, producing gold. See Population III. Therefore gold existed in the universe before meteorites did (well, before meteors did - they weren't meteorites until there were planets from them to crash into!). --Tango (talk) 12:48, 27 June 2011 (UTC)

If the questioner is wondering about specific formations of gold, e.g. nuggets, veins, etc. Then it is worth noting that these are usually relatively recent geologic formations (e.g. 10s or 100s of million of years ago). The geologic processes that give rise to mineral veins are still ongoing, so a gold deposit could be of virtually any age. As discussed above, the gold atoms where created in supernova before the birth of our solar system, but specific gold deposits are likely to have been put in place much more recently. Dragons flight (talk) 17:46, 27 June 2011 (UTC)

Some meteorites are potentially over 10 billion years old. Solid gold requires it being expelled from Earth's interior. ~AH1 ^(discuss!) 01:35, 30 June 2011 (UTC)

Asperger's syndrome and stalking

Are there any empirical studies relating Asperger's syndrome and stalking? And what are the results..? --helohe (talk) 23:55, 26 June 2011 (UTC)

I don't know if there are, but I can tell you that I have definitely never stalked or considered doing so to anyone. Plasmic Physics (talk) 00:00, 27 June 2011 (UTC)

But, are you an aspie? — Preceding unsigned comment added by Wikiweek (talk • contribs) 13:17, 27 June 2011 (UTC)

Yes, I am. Plasmic Physics (talk) 11:26, 30 June 2011 (UTC)

Yes, this downloadable paper from 2007 directly addresses that question, and its introduction reviews earlier relevant literature. The results "show that the diagnosis of ASD is pertinent when individuals are prosecuted under stalking legislation in various jurisdictions". I will leave it to you to figure out what that means. Looie496 (talk) 02:06, 27 June 2011 (UTC)

I think the previous sentence from that paper is an even better one to quote here: "Individuals with [autistic spectrum disorders] were more likely to engage in inappropriate courting behaviours..., and were more likely to focus their attention upon celebrities, strangers, colleagues, and ex-partners ..., and to pursue their target longer than controls." Red Act (talk) 04:05, 27 June 2011 (UTC)