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It seems to me that a large part of shame has to do with the fear of social rejection. So, one requirement may be that the organism needs to be able to predict the future or remember the past. Another requirement may be that the organism needs to fear social rejection. Another requirement may be recognition of the self. Ay, there seems to be so many factors that I wonder if humans are the only creatures that can experience shame. 50.4.236.254 ( talk) 02:24, 29 May 2017 (UTC)
Could an irradiator be an economically-viable alternative to a refrigerator? Would it require too much shielding? -- 78.148.98.254 ( talk) 12:43, 29 May 2017 (UTC)
Deinococcus radiodurans would have 37% viability after a 15,000 Gray dose. Then it would spoil the food. Edison ( talk) 17:59, 30 May 2017 (UTC)
Cobalt-60 is a poor choice for irradiating food at home. Better to use X-Rays. [1]
It isn't all that hard to build your own X-Ray source suitable for irradiating food.
You can easily cast a lead enclosure from lead salvaged from old car batteries. By placing your irradiation chamber inside a refrigerator or large freezer, you can have long exposure times, which allow for a weaker X-Ray source. -- Guy Macon ( talk) 20:16, 31 May 2017 (UTC)
I'm working on ice core, and have found a reference in Landais 2012 (p. 192) to a U-series dating method, cited to Aciego 2010. The latter is an appendix to the proceedings of a conference, without much discussion, but the reference in Landais, which just calls it "a promising study", makes it worth a one-sentence mention (and I've seen it cited elsewhere in introductions to journal articles on this topic). However, I don't understand the method and was hoping someone here could enlighten me -- I don't want to cite something I don't understand. It looks like Aciego et al are discussing U-series decay in dust that falls on the ice core, but what exactly are they measuring, and how does it determine age? Thanks for any help. Mike Christie ( talk - contribs - library) 14:17, 29 May 2017 (UTC)
The activity of 234U in the ice is due to (1) the recoil out of the dust plus (2) the decaying initial 234U dissolved in the precipitation plus (3) the accumulation from the decay of 238U dissolved in the precipitation. These three terms are functions of t, the time since deposition; she re-arranges to isolate t and calls t "the recoil age of the ice". I can see that if you can measure all three of those terms you can solve for t, but what is "the recoil out of the dust", and why does she call t "the recoil age"? Mike Christie ( talk - contribs - library) 21:36, 29 May 2017 (UTC)
Which plant is this?
-- Pyrophyt ( talk) 16:43, 29 May 2017 (UTC)
"Total solar eclipses are rare events. Although they occur somewhere on Earth every 18 months on average, it is estimated that they recur at any given place only once every 360 to 410 years, on average."
So, do we know whether there's a place in the inhabited part of the world that has historically experienced more solar eclipses (not necessarily total) than any other place? And what would explain this? Sorry if this has been asked before. -- Jack of Oz [pleasantries] 21:44, 29 May 2017 (UTC)
Attempting to answer the eclipses-in-Toronto question led me off onto yet another rabbit trail: solar eclipses in general. File:Central eclipses 2001-2020.png makes it clear that during this two-decade time, they're much more common in equatorial regions, decreasing with latitude increases, and they're virtually nonexistent at the poles. But maybe that's the result of a too-small sample (i.e. a time span of 200 years would show different results from this time period of 20 years), or maybe because it's a Mercator projection that simply doesn't show the poles well. Can all parts of the world experience a total eclipse, even the poles? Nyttend ( talk) 21:49, 29 May 2017 (UTC)
I'm thinking that at a zero-order approximation, the risk should be the same. I mean, every point on Earth is, on average, in the sun half the time, and on average, the risk of a moon shadow crossing the point is random at any given time and place. So if a polar area is bent away from the passing shadow and have less likelihood of being hit by any given pass, when a pass does hit its shadow should go a long way along the ground, like you're looking at your shadow at sunset. If you want to do a higher order simulation, you have to model the exact north-south distribution of the moon in its orbit, the exact reach of the cone of the umbra and how the Earth's curve away from it decreases the chance of totality and so on. That is a big project. There's also the wildcard of whether any kind of precise repetition could emerge at high level number crunching of the periodicities of eclipses - see [4] - so far as I know at the highest level it is just considered "secular variation" i.e. everything is hit eventually, but maybe there's some kind of NSA astrology you can do to show that there's no real randomness in the long run? It'd be funny if there turns out to be some spot in South America that never gets eclipsed because of a 9040:17337 resonance with Jupiter or something. ;) But I know of absolutely no such thing! Wnt ( talk) 18:41, 30 May 2017 (UTC)
The article on wormholes mentions that "In 1988, Morris, Thorne and Yurtsever worked out explicitly how to convert a wormhole traversing space into one traversing time by accelerating one of its two mouths". But would a causality violation occur if I merely used a wormhole traversing space as a data link?
Perhaps more succinctly, is traversing a wormhole inherently a form of time travel? What if didn't accelerate either end of the wormhole?-- Jasper Deng (talk) 22:19, 29 May 2017 (UTC)
Science desk | ||
---|---|---|
< May 28 | << Apr | May | Jun >> | May 30 > |
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. |
It seems to me that a large part of shame has to do with the fear of social rejection. So, one requirement may be that the organism needs to be able to predict the future or remember the past. Another requirement may be that the organism needs to fear social rejection. Another requirement may be recognition of the self. Ay, there seems to be so many factors that I wonder if humans are the only creatures that can experience shame. 50.4.236.254 ( talk) 02:24, 29 May 2017 (UTC)
Could an irradiator be an economically-viable alternative to a refrigerator? Would it require too much shielding? -- 78.148.98.254 ( talk) 12:43, 29 May 2017 (UTC)
Deinococcus radiodurans would have 37% viability after a 15,000 Gray dose. Then it would spoil the food. Edison ( talk) 17:59, 30 May 2017 (UTC)
Cobalt-60 is a poor choice for irradiating food at home. Better to use X-Rays. [1]
It isn't all that hard to build your own X-Ray source suitable for irradiating food.
You can easily cast a lead enclosure from lead salvaged from old car batteries. By placing your irradiation chamber inside a refrigerator or large freezer, you can have long exposure times, which allow for a weaker X-Ray source. -- Guy Macon ( talk) 20:16, 31 May 2017 (UTC)
I'm working on ice core, and have found a reference in Landais 2012 (p. 192) to a U-series dating method, cited to Aciego 2010. The latter is an appendix to the proceedings of a conference, without much discussion, but the reference in Landais, which just calls it "a promising study", makes it worth a one-sentence mention (and I've seen it cited elsewhere in introductions to journal articles on this topic). However, I don't understand the method and was hoping someone here could enlighten me -- I don't want to cite something I don't understand. It looks like Aciego et al are discussing U-series decay in dust that falls on the ice core, but what exactly are they measuring, and how does it determine age? Thanks for any help. Mike Christie ( talk - contribs - library) 14:17, 29 May 2017 (UTC)
The activity of 234U in the ice is due to (1) the recoil out of the dust plus (2) the decaying initial 234U dissolved in the precipitation plus (3) the accumulation from the decay of 238U dissolved in the precipitation. These three terms are functions of t, the time since deposition; she re-arranges to isolate t and calls t "the recoil age of the ice". I can see that if you can measure all three of those terms you can solve for t, but what is "the recoil out of the dust", and why does she call t "the recoil age"? Mike Christie ( talk - contribs - library) 21:36, 29 May 2017 (UTC)
Which plant is this?
-- Pyrophyt ( talk) 16:43, 29 May 2017 (UTC)
"Total solar eclipses are rare events. Although they occur somewhere on Earth every 18 months on average, it is estimated that they recur at any given place only once every 360 to 410 years, on average."
So, do we know whether there's a place in the inhabited part of the world that has historically experienced more solar eclipses (not necessarily total) than any other place? And what would explain this? Sorry if this has been asked before. -- Jack of Oz [pleasantries] 21:44, 29 May 2017 (UTC)
Attempting to answer the eclipses-in-Toronto question led me off onto yet another rabbit trail: solar eclipses in general. File:Central eclipses 2001-2020.png makes it clear that during this two-decade time, they're much more common in equatorial regions, decreasing with latitude increases, and they're virtually nonexistent at the poles. But maybe that's the result of a too-small sample (i.e. a time span of 200 years would show different results from this time period of 20 years), or maybe because it's a Mercator projection that simply doesn't show the poles well. Can all parts of the world experience a total eclipse, even the poles? Nyttend ( talk) 21:49, 29 May 2017 (UTC)
I'm thinking that at a zero-order approximation, the risk should be the same. I mean, every point on Earth is, on average, in the sun half the time, and on average, the risk of a moon shadow crossing the point is random at any given time and place. So if a polar area is bent away from the passing shadow and have less likelihood of being hit by any given pass, when a pass does hit its shadow should go a long way along the ground, like you're looking at your shadow at sunset. If you want to do a higher order simulation, you have to model the exact north-south distribution of the moon in its orbit, the exact reach of the cone of the umbra and how the Earth's curve away from it decreases the chance of totality and so on. That is a big project. There's also the wildcard of whether any kind of precise repetition could emerge at high level number crunching of the periodicities of eclipses - see [4] - so far as I know at the highest level it is just considered "secular variation" i.e. everything is hit eventually, but maybe there's some kind of NSA astrology you can do to show that there's no real randomness in the long run? It'd be funny if there turns out to be some spot in South America that never gets eclipsed because of a 9040:17337 resonance with Jupiter or something. ;) But I know of absolutely no such thing! Wnt ( talk) 18:41, 30 May 2017 (UTC)
The article on wormholes mentions that "In 1988, Morris, Thorne and Yurtsever worked out explicitly how to convert a wormhole traversing space into one traversing time by accelerating one of its two mouths". But would a causality violation occur if I merely used a wormhole traversing space as a data link?
Perhaps more succinctly, is traversing a wormhole inherently a form of time travel? What if didn't accelerate either end of the wormhole?-- Jasper Deng (talk) 22:19, 29 May 2017 (UTC)