I think gravity and light work the same on psych majors as it does physics and engineering students…
I kid.
So in biology I know e the Euler number is important. It is used in growth equations (from finance to physics as well).
Statistics is fucking huge in every field. That is how you measure uncertainty. Bell curves and the Five Numbers and all that stuff is how you analysis thousands of widgets coming off an assembly line, or measurements in the social sciences field.
Our [particle physicists’] problems and the way we approach them are quite different from some other fields of science, especially social science. As one example, I think I recall reading that you do not mind adding a parameter to your model, whereas adding (certain) parameters to our models means adding a new force of nature (!) and a Nobel Prize if true. As another example, a number of statistics papers talk about how silly it is to claim a 10^{⁻4} departure from 0.5 for a binomial parameter (ESP examples, etc), using it as a classic example of the difference between nominal (probably mismeasured) statistical significance and practical significance. In contrast, when I was a grad student, a famous experiment in our field measured a 10^{⁻4} departure from 0.5 with an uncertainty of 10% of itself, i.e., with an uncertainty of 10^{⁻5}. (Yes, the order or 10^10 Bernoulli trials—counting electrons being scattered left or right.) This led quickly to a Nobel Prize for Steven Weinberg et al., whose model (now “Standard”) had predicted the effect.
I replied:
This interests me in part because I am a former physicist myself. I have done work in physics and in statistics, and I think the principles of statistics that I have applied to social science, also apply to physical sciences. Regarding the discussion of Bem’s experiment, what I said was not that an effect of 0.0001 is unimportant, but rather that if you were to really believe Bem’s claims, there could be effects of +0.0001 in some settings, -0.002 in others, etc. If this is interesting, fine: I’m not a psychologist. One of the key mistakes of Bem and others like him is to suppose that, even if they happen to have discovered an effect in some scenario, there is no reason to suppose this represents some sort of universal truth. Humans differ from each other in a way that elementary particles to not.
And Cousins replied:
Indeed in the binomial experiment I mentioned, controlling unknown systematic effects to the level of 10^{-5}, so that what they were measuring (a constant of nature called the Weinberg angle, now called the weak mixing angle) was what they intended to measure, was a heroic effort by the experimentalists.
Seldon develops psychohistory, an algorithmic science that allows him to predict the future in probabilistic terms. On the basis of his psychohistory he is able to predict the eventual fall of the Galactic Empire and to develop a means to shorten the millennia of chaos to follow. The significance of his discoveries lies behind his nickname “Raven” Seldon.
I don’t have a source for it, but I recall hearing that yes, their eyes work at a different speed than ours, and that’s part of why cats and dogs are generally not so interested in TV. Unfortunately I don’t know what search terms might be useful here since I don’t know if this has a technical name, but something like “refresh rate” or “fps” might help in the search.
Sometimes my cats will be interested in TV, especially if there are really interesting birds. One cat in particular was very interested in Felix the Cat cartoons.
I am a biologist but I’m warning you up front that I’m going off of memory on this one, and animal vision was never my area of specialization (except in evolutionary models, which I can get into but which don’t apply to your specific question).
Cat vision, as I recall, is optimized around two things - seeing in low light conditions and seeing motion. Cats can have a harder time focusing on stationary objects and I don’t believe they have a particularly high level of processing for visual detail.
It’s important to remember - especially when we’re talking about trying to reverse engineer what another species sees - that the phenomenon we refer to generally as “vision” is an incredibly complex process. It involves multiple cell types, chemical and physical processes, and things like memory, taste, and smell. You’ve probably seen comments on nasty rooms where people say “I can smell this picture,” or caught a whiff of a cologne or perfume that evoked powerful memories including being able to visualize the person you associated it with, even though they’re not actually in front of you.
The visual parts of your brain can be activated absent any input from your eyes (something those with PTSD can know all too well), and your eyes take in a huge amount of information that never makes it to the visual processing layers of your brain, because you simply disregard it.
So when we look at the cells in a cat’s eye, we’re only seeing (so to speak) a very tiny part of the story. We learn more when we start to study how cats respond to visual stimuli - how they hunt, how they play, how they explore their worlds - but it’s all a blind men and the elephant kind of thing. Plus, I have to imagine it’s pretty hard to get that kind of research funded.
Anyway, I’d keep that in mind when you do start finding papers on cat vision, and I’d recommend more comprehensive works on cat behavior in general, from which you can infer things about vision but will provide a more full context like I’m talking about.
If you’re thinking about building Rube Goldberg type machines for keeping cats entertained, I think you should just go for it. Experiment. Do note that cats have a huge amount of variability in what they find interesting or fun. Some will watch tv, others will chase a laser pointer or a feather on a string. I had one that would just sit and stare at absolutely nothing all day long and couldn’t be bothered with anything but head scratches and the occasional piece of chicken.
One thing that seems to be pretty popular is having a ball or something that skitters around while under a blanket or towel, but do be aware that you’re basically training them to bite your toes really really hard while you’re trying to fall asleep. I speak from experience on that.
I think I read somewheres that you need 240Hz monitor to reach flicker-fusion with parrots?
It was either 120Hz or 240Hz.
I lost flicker-fusion one time in a movie theatre when an onscreen character pulled a knife, & suddenly the screen was AVALANCHING my mind with discrete-frames, & they were jumping around ( my eyes were jumping-around, but my perspective, within my brain, had been jarred ). That even seemed to have lasted about 1 second.
There is some video, journalism or documentary or something, on dragonflies, and the person with the knowledge was saying…
~ we know how long it takes for each layer in a brain ( neural-network ) to process its layer’s stuff, and we know from the short reaction-time of dragonflies that they’re using 3-neurons-deep brain for navigating/hunting/reacting.
We don’t know how. ~
I seem to remember that neural-signal in our biology runs at about … 300km/h?
Something like that.
So, with all the circuitry being shorter in an always-smaller kind of animal, it may have a predictably-shorter flicker-fusion rate?
( within kind, so no extrapolating from humans to birds, e.g. )
This says most of earth’s nitrogen was present when earth formed. The nitrogen cycle eventually leads to atmospheric nitrogen which can be stripped by solar winds except earth has a magnetosphere that shields us. So planets with no or a weak induced magnetosphere lose nitrogen. Earth does not.
I’m not a scientist, but one could argue that it’s likely that all three planets had nitrogen, but only Earth still has it.
I don’t know much about Venus, but I know that part of why we have way more atmosphere than Mars is due to Earth’s magnetic field. Earth has a much stronger magnetic field than Mars, and it does a pretty good job of shielding us from the solar wind; meanwhile Mars has been slowly trickling atmosphere into the void for ages because it lacks that shielding.
Given that CO2 is actually super heavy, it makes sense that Mars would lose almost everything else first. You mentioned H2, but it’s also almost twice as heavy as N2 - because of this, nitrogen would concentrate at higher altitudes, eventually becoming exposed to the solar wind as lighter gases were stripped away.
As for Venus… Again, I’m not an expert, but a quick search suggests that it has a weak magnetic field as well. With a primarily CO2 atmosphere and a weak magnetic field, one could infer that Venus is in a similar position to Mars, and any significant nitrogen that may have been in its atmosphere has simply been stripped away by the solar wind.
Sorry, I think my phrasing might have been kind of weird - I was referring to the weights of H2 and N2 relative to CO2, which weighs a whopping 44 grams per mol.
…Although, I just did some quick estimates last night, and “almost twice as heavy” was still pretty far off. CO2 is much closer to 1.5x the weight of N2 than double the weight of N2.
After some reading today, there isn’t much info on how cells form into specific shapes for arms, hands, organs, etc. (I am sure there is a ton of data, but I don’t know what subject to Google.)
Perhaps the term you’re looking for is morphogenesis.
Yes, thank you. That is exactly what I am looking for. I dunno what I expected, but I was hoping that I was going to avoid a ton of maths. Alas, everything seems to be math. /s
For those who are interested, this led me directly to these:
how cells form into specific shapes for arms, hands, organs, etc.
Not really qualified to answer, but Michael Levin have done some very interesting work on bioelectricity and growth of bodyparts. He is beginning to control the cell/formation of bodyparts, and other fascinating stuff. There’s some fine interviews on yt.
(Just for fun!)
Oh, just noticed that. Anyway, you seem interested in the subject, so you should check him out anyway ;)
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