Humans (Homo sapiens) are the most abundant and widespread species of primates, characterized by bipedality and large complex brains enabling the development of advanced tools, culture and language. Humans are highly social beings and tend to live in large complex social structures composed of many cooperating and competing groups, from families and kinship networks to political states. Social interactions between humans have established a wide variety of values, social norms, and rituals, which bolster human society. Curiosity and the human desire to understand and influence the environment and to explain and manipulate phenomena have motivated humanity's development of science, philosophy, mythology, religion, and other fields of knowledge.
Humans evolved from other hominins in Africa several million years ago. Although some scientists equate humans with all members of the genus Homo, in common usage it generally refers to Homo sapiens, the only extant member. H. sapiens emerged around 300,000 years ago, evolving from Homo erectus and migrating out of Africa, gradually replacing local populations of archaic humans. Early humans were hunter-gatherers, before settling in the Fertile Crescent and other parts of the Old World. Access to food surpluses led to the formation of permanent human settlements and the domestication of animals. As populations became larger and denser, forms of governance developed within and between communities and a number of civilizations rose and fell. Humans have continued to expand, with over 7.8 billion humans occupying almost all regions of the world in 2021.
Genes and the environment influence human biological variation in visible characteristics, physiology, disease susceptibility, mental abilities, body size and life span. Though humans vary in many traits (such as genetic predispositions and physical features), two humans on average are over 99% similar, with the most genetically diverse populations from Africa. The greatest degree of genetic variation exists between males and females. On average, men have greater body strength and women generally have a higher body fat percentage. Females undergo menopause and become infertile decades before the end of their lives. They also have a longer life span in almost every population around the world. The division into male and female gender roles has varied historically, and challenges to predominant gender norms have recurred in many societies.
Humans are omnivorous, capable of consuming a wide variety of plant and animal material, and have used fire to prepare and cook food since the time of H. erectus. They can survive for up to eight weeks without food, and three or four days without water. Humans are generally diurnal, sleeping on average seven to nine hours per day. Childbirth is dangerous, with a high risk of complications and death. Both the mother and the father provide care for human offspring who are helpless at birth.
Humans have a large and highly developed prefrontal cortex, the region of the brain associated with higher cognition. They are intelligent beings, capable of episodic memory, flexible facial expressions, self-awareness and a theory of mind. The human mind is capable of introspection, private thought, imagination, volition and forming views on existence. This has allowed great technological advancements and complex tool development possible through reason and the transmission of knowledge to future generations. Language, art and trade are defining characteristics of humans. Long-distance trade routes might have led to cultural explosions and resource distribution that gave humans an advantage over other similar species.
Daedalus 88 is a human powered aircraft built in 1988 by MIT students. I'm trying to find research papers describing the construction process but can't find anything.
So I'm asking here: what books should I be reading to start building this? I
My math skills are up to basic calculus. Last time...
Hello there! Who belongs anywhere; am i right? It’s a whole bag of worms. Or strings. Planks? Anyway, im not a student currently and on the rare occasions that i can afford to sign to sign up for a class or two I'm more of a liberal arts kinda guy.
As stated above i googled “Metaphysical...
I'm asking in order to understand if the only difference between the DNA of all living things is merely the arrangement or sequence of their letters. This is more of a curiosity question, not about sci-fi or current feasibility.
Could the letters of a human DNA be reordered so it's identical to...
Popular science:
https://www.livescience.com/health/genetics/1st-draft-of-a-human-pangenome-published-adding-millions-of-building-blocks-to-the-human-reference-genome
Nature (open access:)
https://www.nature.com/articles/s41586-023-05896-x
A pangenome is a genomic map using extant variable...
The human body is made up of mostly oxygen, hydrogen, nitrogen, carbon, calcium, and phosphorus. Less than 1% is sulfur, potassium, sodium, chlorine, and magnesium.
If a human body was teleported to the surface of the sun, what would happen to these elements? Which ones would cease to exist...
"The fossilized find, first uncovered two decades ago, suggests that early humans regularly walked on two feet some seven million years ago. This new analysis, published today in Nature, makes a strong case that Sahelanthropus tchadensis, a species that lived during the critical time when our...
There has been an explosion of discussion among experts about the evolving/growing dangers of AI and what to do about it. This debate has gone public, largely due to the recent success of generative AI, and the rapid pace of improvement. As an example, AI models which can generate images based...
Nikola Tesla, the prominent 20th century inventor, stated in his book "My Inventions" that all human movements appear to come from the will but are are actually generated from the outside. He goes on to say that this phenomenon is of incalculable vale to the human race and he urged further study...
my notebook says that we can rewrite the integral
$$\int {75\sin^3(x) \cos^2(x)dx}$$
as
$$\int {75 \cos^2(x)\sin(x)dx} - \int {75\sin(x)\cos^4(x)dx}$$
however, i have literally no idea how it got to this point, and i unfortunately can't really provide an "attempt at a solution" for this...
In another thread the concept of how many seconds in a year came up and it made me think of putting milestones of a human lifetime on a log scale. Units are seconds. Please feel free to amend or change or just make it better. Maybe an actual plot? What strikes me is most of life is in the last...
From my point of view:
1) survival
2) do something good to satisfy your inner soul and for others.
3) help to continue the race of human being
4) and die
What others think about life?
I recently read that there is enough hydrogen in the human body to lift 195 lbs off the ground. I know this sounds super-silly but if we ever develop nanites; could they manipulate the hydrogen and allow us to float?
Just the summary as written. My own impression WAS that Pepsi Cola was a little sweeter, and Coca Cola was spicier and slightly less sweet. I do not remember my impressions of other colas. I would be interested in other details which members may tell.
I'm interested in chemistry but it's all new for me and I'm just starting out. I tried to do some calculations but got stuck...
I was wondering, for example a supplement has the following values:
Molar mass: 306.247 g mol-1
Tmax 2-4 hours
Cmax 363.3 ng / ml
Half life: 11.21 hours
How do...
NY Times article here.
Paywalled Nature Human Behavior article here.
bioRxiv preprint here.
Sing-songy talk to babies has been observed in
Adults of any culture seem to be able to identify baby talk in any other language.
Many think that baby talk leads to more adult language development...
I was having trouble with a physics problem (string tension dynamics) In this case I have a model that simulates the phalanges of a human finger. Each phalanx is a block of mass m1, m2 or m3 respectively. And to simplify it, consider the 3 equal masses.
These phalanges are linked by joints that...
Hi,
How does a human eye classify any shape as a circle, square, triangle etc.?
Let's focus on a circular shape. Suppose we have a circle drawn in white on a black surface. The light falls on the retinal cells. I think the light falling on the retina will constitute a circular shape as well...
I'm sure this is a strange question, but I am really curious as to whether the human body can produce electromagnetic pulses. And particularly, whether an orgasm is a type of EMP.
Wikipedia says an orgasm is "a sudden discharge of accumulated sexual excitement". So is this discharge of...
Well since we count all possible posts , including those that have no syntax, no proper grammar or proper words, and no sensible meaning, all posts of length n are something like 100^n (I suppose we have 100 possible chars besides the letters of ordinary alphabet, including symbols like the...
Hi,
I often hear people saying that why and how that person could react in such a way , he or she is so intelligent, so educated etc. The statement implies that if a person is considered to be intelligent or educated, he or she could control their emotions such as anger, jealousy, depression...
do you think there are biological limits to our capacity to understand physics or mathematics?could it be that in the distant future, no scientific progress could be achieved using the human brain, and we have to depend on superhuman level ai to do the work for us?
Does the human eye see things at the correct size or is there such a thing? I know one of my eyes sees things slightly smaller than the other, but ideally should the eyes biologically not magnifying or shrink anything at all?
Summary:: Looking for a certain degree program
What kind of degree would be best if I really wanted to get into studying energy within and around the human body and interactions of it between electronic signals and things like that? I am really starting to believe that our understanding of...
I have been really curious about the possibility of simulate the human's communication hability using computer language/softwares. Most specifically, i have been thinking that the most difficult part of the simulation would be to "cofide" the level of randomness+logic that the human brain can...
Back in grade 10..,.( Oh my that was awhile back 😀 ) our electronics teacher passed around a multimeter and everyone measured their resistance ( a lead held in each hand, Fluke was set on infinite ).
All in the class measured between 700K and 800K approx. All except me that is. I measured 1.4M...
I just listened to a great podcast on the explosion of human genomic data about human migration, which ties in with the spread of ancient language groups, and reveals some of past cultural practices.
It is Sean Carroll's Mindscape podcast #179; David Reich on genetics and ancient humanity...
Summary:: How fast does a human sized object(or a human) need move so I won’t be able to see it at all if it passes right next to me?
Im trying to figure out something in regards to the Flash movies/Flash series but I’m super bad at calculations and math :(
Do you think that mach 2...
I was in doubt if this is the right chapter to place this thread, but it seems there are many talents just here.
"we were observing from a decent distance through optics. The weather was frosty, clear, calm. When хххххх appeared from under the arch of the house (he was хххххххх to walk to the...
Perhaps psychology is not exactly a "science" in a STEM sense, but understanding human irrationality is these days important more than ever before. To beat the pandemic or the climate changes, we have to cope not only with medical and environment issues, but also with human irrationality. Some...
When a Mars Simulation Goes Wrong
https://www.theatlantic.com/science/archive/2018/06/mars-simulation-hi-seas-nasa-hawaii/553532/
The article came across my desk (computer screen). Human behavior is complicated.
I'm more interested in the technical side of space travel, specifically the...
I gotten randomly hooked on this lecture series by Prof Sapolsky, I thought I'd share in case anybody felt like giving them a watch or discussing some things you found interesting
In competitive rowing, the more people in a boat, the faster it goes, but what is the ratio of additional human to speed, and what is the theoretical limit?
If I could fabricate a boat where each additional person added 100kilos, 100watts of power, and 1 meter of length to the wetted surface...
Hello,
I need to scale down a human model by 1:20
i.e,
i need a human model of 9 cm height scaled down.
Help me calculate the weight of the 9 cm scaled down human model.
Regards,
Viky
I know this is a hypothetical question, but we can still have a general idea for how we could do it in the future. I wonder how theoretically with good enough technology a human can achieve a super-human strength(or close to it) without large muscles or non-biological components attached to...
A six way, all out release of humanity's entire stockpile of "engineered criticality devices" and slag the planet.
The damned aliens were exterminating humanity anyway, why should they get what they want, while we go black?
I'd bet money neither the movie's writers nor the extraterrestrials...
I was wondering how many visible photons humans emit in a day. I did all the calculations with the Planck's Law (it's quite easy, because in the visible spectrum and for temperatures above 0 degrees the exponential term is much larger than one, and the "-1" can be taken out of the integral...
Two studies on human brain evolution/development.
FIRST
A new study is the first to identify how human brains grow much larger, with three times as many neurons, compared with chimpanzee and gorilla brains. The study identified a key molecular switch that can make ape brain organoids grow more...
Hello All
It seems to be accepted wisdom that the human appendix is gradually getting smaller, and eventually it will disappear altogether. Is there any evidence that this is true?
For the organ to get smaller generation by generation, wouldn't there have to be a selective advantage for...
I'm past middle age, and it seems I should have fewer questions about life and the universe than ever. I have more now. For some reason this past year or so I've been absolutely consumed with trying to grasp the immensity of the universe and distances. For whatever reason, I'm having more...
Hi,
Does the brain control the physical growth of a human baby?
I think if, for some unfortunate reason, the brain is absent, the growth would still take place normally but more like a vegetable. I don't think if the brain is absent, one can even blink the eye or move a finger. But the...
I was researching what the total electrical resistance of the human body was and got some quite far ranging values. It seems to range from 1, OOO to 1OO,OOO ohms. Some quite elaborate ways of testing it too.
Then I thought I'd just get the old multimeter out. I have two and both measured about...
Hi!
So my question is: how to human brains detect false irregularities in faces? With false irregularities in faces I mean aspects of for example deepfake faces or photoshopped faces which show irregularities that are not normal to appear in an observed human face (for example weird lines...
I want to do a project for my class on the obstetrical conundrum. Which is basically the antagonism of selective pressures on pelvic morphology. I need help to find literature. I want to know if over the course of history, if Human baby's fontanelles increased in size in order to compensate for...
I was reading this:
https://www.cnbc.com/2020/12/01/elon-musk-highly-confident-spacex-will-land-humans-on-mars-by-2026.html
It just seems that the Delta-V requirements - especially with a spacecraft that is stocked with supplies for a few years or for the Hohmann transfer helio-orbits - will...
The NY Times, on the 20th anniversary (on Halloween) of the ISS being continuously occupies, published an article (with lots of pictures and a really cool time line) showing what the inside of the ISS is like.
Duct tape on the ISS (didn't see any WD-40):
Galley:
Science stuff:
I thought of my experiences with night vision when I happened upon this essay (Into the Night).
To stay in best health, I do a two-hour, six mile walk every day. In the summer (when the days are hot) and the winter (when the days are very short), I often choose the night for this activity - and...
Hi, forgot to say a thanks for all the info provided in my previous thread to everyone who posted. So what is the answer or answers to this threads question or what works?
From the abstract. The findings, it is argued, likely represent the oldest securely dated evidence for Homo sapiens in Arabia. The paleoecological evidence indicates a well-watered semi-arid grassland setting during human movements into the Nefud Desert of Saudi Arabia. We conclude that...