Wikipedia:Reference desk/Archives/Science/2015 April 23

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April 23

asperger's syndrome and autism: how do they relate to schizoid and schizotypal

Are people on the autism spectrum considered a subset of the people with schizoid personality and/or schizotypal personality? Thanks.144.35.45.65 (talk) 02:57, 23 April 2015 (UTC)

No. (That was an easy question!) SteveBaker (talk) 03:46, 23 April 2015 (UTC)

The articles autism spectrum and schizoid personality disorder may be helpful. As Steve says neither is a subset of the other, though they do have some overlapping characteristics. Dragons flight (talk) 03:56, 23 April 2015 (UTC)

The two are not subsets, but there is some genetic overlap. See [1] for example; there's a lot more on PubMed if you dig. To be sure, the roles of many of these genes are unknown, and I am tempted to speculate that traits like "trust of psychologists" and "failure to lie to make oneself look better" might be numbered among their disorders ... still, it's possible that there really are some underlying factors in common. What they tell us, mostly, is that the clinically recognized entities in psychology don't show up with as distinct of a basis on the genetic level as something like sickle cell anemia. Wnt (talk) 21:05, 23 April 2015 (UTC)

Superathlete

Lets say you constructed a giant centrifuge and had a house attached to it. An athlete would live in the house in twice the normal gravity. After a few months or year, would this person be a super athlete in normal gravity? — Preceding unsigned comment added by 88.115.38.169 (talk) 17:05, 23 April 2015 (UTC)

I think a continuous 2g would kill them. Specifically, the blood would pool in the low spots rather than circulate. But if you drop that down to 1.1 or 1.2g, then yes, they would probably get bigger muscles, but injuries would be more likely and more severe. Also, they might somewhat counter the benefits by becoming more sedentary. StuRat (talk) 17:15, 23 April 2015 (UTC)

, please. SemanticMantis (talk) 18:14, 23 April 2015 (UTC)

Possibly relevant: "Human subjects have been exposed to continuous high-G environment at most for seven days at 1.5 G. Although no immediate ill effects were found, extrapolation of the data to longer periods may be dangerously risky." [2] AndyTheGrump (talk) 18:22, 23 April 2015 (UTC)

Report on a proposed NASA experiment which intended to test subjects at 2 G for 22 hours. [3] I'll have a look later to see if I can find the results. AndyTheGrump (talk) 18:29, 23 April 2015 (UTC)

I've not been able to find any subsequent material on this proposed test, perhaps suggesting that it never went ahead. AndyTheGrump (talk) 21:39, 23 April 2015 (UTC)

A later article on the NASA experiment. [4] Sadly, it doesn't give any real data on the G levels actually tested, and I've not been able to find any reports of the conclusions. AndyTheGrump (talk) 21:55, 23 April 2015 (UTC)

Paper on how "Artificial gravity training improves orthostatic tolerance in ambulatory men and women". [5] 35 minutes per day at +1 to +2.5 G apparently has significant positive cardiovascular effects on "normal, ambulatory men and women" - I've only read the abstract though. One could probably extrapolate this to athletes, though there are simpler methods for exercising the cardiovascular system. AndyTheGrump (talk) 18:50, 23 April 2015 (UTC)

Of interest may be the book Great Mambo Chicken and the Transhuman Condition [stub] which discusses, amongst other things, experiments in which chickens were raised in high artificial gravity. Time magazine's 1960 article Science: High-G Life [paywall] discusses similar experiments on mice and hamsters. -- ToE 19:15, 23 April 2015 (UTC)

An excerpt from Great Mambo Chicken and some references can be found here. -- ToE 01:24, 24 April 2015 (UTC)

Yes, there seems to have been a fair bit of research done on long-term exposure to hypergravity in smaller animals and at the cellular level - see Google scholar: [6]. AndyTheGrump (talk) 21:46, 23 April 2015 (UTC)

Is it even possible to do it without making the subject incredibly dizzy? According to my understanding of centripetal force, $t={\sqrt {4\pi ^{2}s \over g}}$, or $s={{gt^{2}} \over {4pi^{2}}}$, where $g$ is the simulated gravity, $s$ the radius of the centrifuge, and $t$ is the period of revolution. A 1 km radius centrifuge, rotating once every 63 seconds will generate 1g. Then add the enginering effort required to build a centrifuge that can support a modest house. LongHairedFop (talk) 10:43, 24 April 2015 (UTC)

I'm not sure why you've decided to build him a whole spinning city. Cut it to 20 meters and let the floor curve a little. Why should he get dizzy? Do you get dizzy on the Tilt-a-Whirl? I don't. It just feels like being pressed into the structure. --Trovatore (talk) 19:13, 26 April 2015 (UTC)

Many people do get dizzy on the tilt-a-whirl, and the main difference there is that you don't get up and try to walk around while it is moving. That can be very disorienting, as out bodies are set up for a constant G-force, and any up-down movement changes the apparent G-forces you experience. And trying to sleep or eat under such disorienting conditions would be difficult. StuRat (talk) 19:32, 26 April 2015 (UTC)

Oh come on. With a 20-meter radius, moving up or down 2 meters would change the acceleration by just 20% 10%. I don't believe that would be disorienting to the extent that you wouldn't get used to it.

Of course you have to set it up sensibly. If you spun it around a horizontal axis, there would be 2g more at the bottom of the loop than at the top. So don't do that. Spin it around a vertical axis, and tilt the floor in such a way that the perceived gravitational force points perpendicular to the floor. --Trovatore (talk) 22:12, 26 April 2015 (UTC)

A 10% change in the G-force is quite noticeable. This is why NASA and other space agencies haven't built a rotating wheel design to simulate normal gravity. It would have to be impractically large to avoid causing nausea. (Of course, there are other problems, too, like making docking and positioning of antennas and solar panels difficult, necessitating a non-rotating portion of the ship, which in turn brings up problems with connecting to the rotating part.) StuRat (talk) 22:33, 26 April 2015 (UTC)

I didn't say it wasn't noticeable. I said I don't believe it would be disorienting or make you dizzy. As for that being the reason for what NASA has or hasn't done — evidence, please. --Trovatore (talk) 04:42, 27 April 2015 (UTC)

Since this is of interest even for cases with 1G or less, there's some discussion at Artificial gravity. You also find other discussions e.g. [7] [8] [9] [10]. Of course we are talking about speculations on speculations here since as the above highlights, the long term effects of living at 2G is unclear and so are the long term effects to simulated 1G or less via rotation. So the long term effects of 2G simulated via rotation doubly so. (When it comes to rotation, remember this includes how people adaptacclimatise, which may conversely mean they will have problems when reintroduced in to 1G environment as per the question.) However from my reading, the evidence that does exist suggests for 2G, a 1km radius will probably be close to being as fine as you can be at 2G. Most research is looking at far smaller radii (albeit for 1G or less), primarily because it's what we're likely to be able to achieve in space in the short term. BTW [11] may be useful to check calculations. Nil Einne (talk) 15:18, 24 April 2015 (UTC)

BTW, some athletes train wearing ankle weights, possibly supplemented with wrist or back/front pack weights. This increases the load on their muscles, and promotes their growth. It might be possible to wear them all the time; I don't know how much benefit this would give. LongHairedFop (talk) 11:20, 26 April 2015 (UTC)