Human Definition and 895 Threads

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.

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  1. anorlunda

    Pentagon plans 2024 F-16 dogfight between human pilot, AI

    Man oh man this sounds like a great stay-home-spectator-event. Better than a super bowl. But we'll have to wait until 2024. https://www.washingtontimes.com/news/2020/sep/10/pentagon-2024-fight-pilot-artificial-intelligence/
  2. Keth

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  3. Nathan M

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  4. Tony Hau

    B Can the human body affect a radio receiver?

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  5. Yashi234

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  6. J

    The Impact of EMR on Human Health: Exploring the Effects

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  7. ZapperZ

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  8. Spinnor

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  9. S

    How Can Music Videos Enhance Learning in High School Science Classes?

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  10. E

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  11. S

    Is the Timing of Heart Sounds Caused by the Opening and Closing of Valves?

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  12. P

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  13. F

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  14. Dr. Courtney

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    https://www.sciencedirect.com/science/article/pii/S0370269320301040#br0210 I need to give this more thought, but the ballistics section is pretty good, and I think their basic dE/dx argument is sound: If a collision at a ballistic rate transfers about the same kinetic energy to the human body...
  15. Piotrovskiy Yury

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  16. F

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  17. BillTre

    Plans for Human Germline Modification being Discussed

    Science news article: Denis Rebrikov of the Pirogov Russian National Research Medical University in Moscow has been discussing how he wants to modify the human germline to correct a genetically inherited hearing loss condition. He has been discussing this for a while, plans on seeking rigorous...
  18. N

    Can the face of others can be transplanted into another person?

    Last night I watched a very intriguing sci-fi movie about human farm where children were raised to serve as reservoir of human organs. in the movie it's the face that is removed from adolescents and transferred to elderly rich clients. I can't reveal the title or it would be a spoiler. I want...
  19. S

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  20. D

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  21. jaumzaum

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    Hello. Yesterday I was making some calculations, and I started to wonder the average number of alleles per gene the human specie have today. The best question would be how many mutations per base or how many alleles in an average 1000 base gene, as genes vary in size. What made me wonder this...
  22. BillTre

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  23. Graeme M

    B The Human Eye as a Detector in Double-Slit Experiment

    Trying to wrap my head around what the double-slit experiment is illustrating, it occurred to me that one could replace a mechanical detector with the human eye. I found that this was tested with what seems an elaborate test setup in 2016, and the result suggests that while an interference...
  24. T

    Are additives and preservatives in food bad for the human body?

    Hi I would like to know the facts about this
  25. F

    I Human eye and its focal length range....

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  26. mfb

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  27. S

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  28. chasrob

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  29. Auto-Didact

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  30. A

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    In a discussion between Sam Harris and Brian Greene, at this point, Brian stated that even if we return the brain and all the environment to its previous state, we "WON'T MAKE THE SAME NOISES"; I know that for example, indeterminacy in determining the precise time of decay of an atom (and the...
  31. P

    Why Doesn't Hydrogen Bonding Occur Through Skin Contact?

    if the human skin consists of hydrogen, then why does not happen hydrogen bond through contact with something or with another person?
  32. barryj

    How is DNA arranged in a human cell?

    I have read many sources on DNA and still have a few questions. Let me start with this one, and depending on the answers I will ask more. Question 1. f I were to look into a human cell how would I see the DNA? Is there a single very long copy of the DNA string or are there two copies. Question...
  33. Ygggdrasil

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    https://apnews.com/4997bb7aa36c45449b488e19ac83e86d As detailed in the AP news story, most scientists believe the work to be unethical as the safety of the CRISPR gene editing technique used has not yet been fully established. See also...
  34. maxd23

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    Homework Statement While unrealistic, we will examine the forces on a leg when one falls from a height by approximating the leg as a uniform cylinder of bone with a diameter of 2.3 cm and ignoring any shear forces. Human bone can be compressed with approximately 1.7 × 10^8 N/m2 before...
  35. X

    The Mystery of Human Luminosity: A Comparison to Daily Energy Intake

    Homework Statement If we assume that a human radiates like a black body, calculate the luminosity in watts, then compare it to the daily energy a human gets from eating. (The area of a human A=1.3 m2) The Attempt at a Solution The temperature of a human is 310K so L=AσT4 =...
  36. NTL2009

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    I was surprised to see this in a 'pop science' article a few years ago ("Ask Marilyn"), but quickly found the source, which appeared reputable (to me). But I have not seen any follow up. I finally got back to it. https://www.nature.com/articles/ngeo1476 To stay within forum guidelines, please...
  37. José Ricardo

    (Biophysiscs) Failures of the human body

    https://translate.google.com.br/translate?sl=pt&tl=en&js=y&prev=_t&hl=pt-BR&ie=UTF-8&u=https%3A%2F%2Fmisteriosdomundo.org%2Fessas-sao-as-7-falhas-que-o-corpo-humano-possui-em-sua-estrutura%2F&edit-text=&act=url What do you guys think about this article? Is there some error? Or the article is...
  38. José Ricardo

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    How much time the machine can overcome the human? I was thinking about around 50 years? But I am not sure. I would like that you guys can take me this doubt.
  39. curiousman

    Electrical current through the Human Body

    Hi lads, I couldn't find this info on Google... Are the Heart and Brain the only organs which physiological functions are based on electrical impulses? What happens if we apply electrical current through other organs? Thanks
  40. S

    Insect Endocrinology: How Similar are Insect and Human Nerve Cells?

    It's easy to find descriptions of how the nervous systems of species differ in the organization of nerves, but are there any important differences in the individual cells? For example, are the individual nerve cells of insects similar to individual nerve cells of humans?
  41. R

    If light speed (not in a vacuum) was about human walking speed ....

    If light speed (not in a vacuum) was about human walking speed ... Did any sci fi writer try that?
  42. jim mcnamara

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    https://www.cell.com/trends/ecology-evolution/fulltext/S0169-5347(18)30117-4The authors do not seem to use the term bushy to describe the non-linear evolution of Homo sapiens, but other authors have used it. They use 'African multiregionalism' instead. And also they exclude panmyxia (free for...
  43. José Ricardo

    B Human Eyes vs Cameras: Exploring the Limits of Perception

    When the camera can oversee the human eyes?
  44. T

    Is the human body a heat engine?

    If this is a valid enough definition of a heat engine: All heat engines transfer heat energy from higher to lower temperatures, and do work in the process. ... then is the human body a heat engine?
  45. jedishrfu

    The Far Reaching Effects of AI - Mimicking the Human Voice

    This Bloomberg article profiles the Lyrebird startup where AI can mimic your voice or any voice given a snippet of spoken words. and an earlier Verge article on the technology https://www.theverge.com/2017/4/24/15406882/ai-voice-synthesis-copy-human-speech-lyrebird
  46. DrChinese

    I Big Bell Test Collaboration: Challenging Local Realism with Human Choices

    Not sure if this reference has been posted yet, but I just saw it come through and thought I'd share. This is the "Big Bell Test Collaboration" using measurement choices provided by persons (as opposed to computer generated "random" choices). (The authors are a virtual who's who in the world...
  47. F

    Medical Heating of the Human Body and Radiation Wavelengths

    Hello Everyone, Sunlight is composed of UV, visible and infrared (IR) over a wavelength range from ~290nm to ~2500nm. When we are exposed to sunlight and feel hot, is it because of the absorption of energy at the visible wavelengths and FIR, i.e . infrared wavelength much larger than 2500nm? I...
  48. BMR

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    This is my first post here, so pardon if forum guidelines/criteria require this to be designated elsewhere. I am designing a clamp mechanism utilizing lever mechanics, and I am getting conflicting info regarding Mechanical Advantage and the Law of 1st Class Levers. Regarding MA, knowing that...
  49. C

    Postdoctoral Work Stress and the Human Cost

    A friend shared this article with me recently and I thought I might post it here for discussion. The Human Cost of the Pressures of Postdoctoral Research While I'm not sure that academic journals are the right venue for such statements, I agree that as a community it's important for us to have...
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