What is Death: Definition and 333 Discussions

Death is the permanent, irreversible cessation of all biological functions that sustain a living organism. Brain death is sometimes used as a legal definition of death. The remains of a previously living organism normally begin to decompose shortly after death. Death is an inevitable, universal process that eventually occurs in all living organisms.
Death is generally applied to whole organisms; the similar process seen in individual components of a living organism, such as cells or tissues, is necrosis. Something that is not considered a living organism, such as a virus, can be physically destroyed but is not said to die.
As of the early 21st century, over 150,000 humans die each day.Many cultures and religions have the idea of an afterlife, and also may hold the idea of judgement of good and bad deeds in one's life (Heaven, Hell, Karma).

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  1. jack action

    News Death of astrophysicist Hubert Reeves at 91

    We lost a great man today - originally from my part of the World - with the death of astrophysicist Hubert Reeves at 91.
  2. N

    Well of Death: Physics behind it

    While studying motion of car on banked curve, I was wondering, what will be the vmax when theta is equal to 90 degrees or is close to 90 degrees as it happens in a well of death which is organised in a village fair. On a banked road with friction present, vmax is given by: if we put theta = 90...
  3. S

    I Avoiding heat death in an accelerated expanding universe?

    https://en.m.wikipedia.org/wiki/Heat_death_of_the_universe Is the heat death of the universe completely unavoidable in an universe with an accelerated expansion dominated by dark energy like ours? Or can there be any way to avoid it according to current knowledge, observations and experiments...
  4. jim mcnamara

    Apparent death from supplement overdose: news analysis

    A non-technical opinion piece that claims there are many fatal and near-fatal events, ~23000 total, in the US every year -- with regard to supplement consumption/abuse. Additionally, it explains US labeling requirements and available remediation for problems related to supplement usage. Which...
  5. nomadreid

    Medical Brain Death: Tests & Secondary Reactions

    Looking at the site https://emcrit.org/ibcc/brain-death/ and similar sites, I see that there are a series of tests of secondary reactions for brain death. Isn't the lack of brain activity sufficient?
  6. TimeSkip

    Would you cryogenically freeze yourself?

    There are companies that specialize in cryogenically freezing a person as to treat ailments in the future that aren't yet treatable today. I know there are some preppers here; but, no neologism for cryogenic freezing really exists, maybe cryogenics? Would you ever cryogenically freeze...
  7. A

    Black Death pandemic in medieval Europe -- prevention?

    We are told that the Black Death, pandemic that ravaged Europe between 1347 and 1351 was caused by the bacterium Yersinia pestis with rats as the main vehicle of transmission and transmitted to human by the bites of fleas. At those time there were no vaccines, of course. So, what would have been...
  8. jack action

    Determining the Cause of Death: A Scientific Perspective

    There is an old local politician who died today. He was 85 years-old. He caught Covid in his nursing home, it rapidly escalated and he died of complications (in around 24h). Here's the thing: he already had a pulmonary condition (the reporter did not specified). He was an avid smoker all of his...
  9. D

    Determining the time of death of victims of poisoning

    Hi everyone I'm writing a murder mystery in which someone is poisoned at work at around midnight. The killer wants it to seem like the victim died around 8 am the next morning. They leave the body in a room with the heating running to keep the body warm. Would an autopsy be able to...
  10. M

    B Low entropy early Universe and the heat death musings

    I came upon a realization recently. The early universe is always described to have begun in a state of extremely low entropy and it's been increasing ever since. But the same amount of stuff exists now as it did back then. Only thing that's changed is how big the universe is now vs then. So...
  11. E

    CV19 infection rates are increasing, but death rates are decreasing?

    CV19 infection numbers are increasing substantially throughout the world, but deaths from the virus are steadily decreasing, why is this? Does this mean that the virus is becoming less virulent?
  12. K

    Coronavirus death toll estimations

    I was looking for projections on how many will die from the new virus. Unfortunately I found only this site https://www.vox.com/2020/3/5/21165973/coronavirus-death-rate-explained but it is outdated as you can see. Perhaps it is because I'm not in the US? So that makes Google hide me a lot of...
  13. R

    What are animal reactions to death?

    This might be a little unsettling for some and I don't know exactly where to post this but here we go... What would the reaction of say a mother cat be in the moment if you where to take one of it's baby and kill it in front of them? Would they attack you? Would they show some signs of sadness...
  14. L

    I Birth and death process and Little's law

    Assume that an individual only has two possible states: susceptible (S) and infected (I). Further, assume that the individuals in the population are independent, and that for each susceptible individual the time until the next infection follows an exponential distribution with expected value 1/λ...
  15. L

    Can a Death Star weapon actually be built?

    Star Wars revolved around the Death Star that could wipe out an entire planet. Another movie is coming up soon so we can start to reflect on it. Can a Death Star weapon actually be built? What could power it? In nature, gamma ray burst can also wipe out a planet...
  16. BWV

    Livestream AI Generated Death Metal

  17. BWV

    Want to relax and be happy? Listen to Death Metal

  18. Wrichik Basu

    Automotive Death of a car battery and related issues

    We have a Toyota Etios Liva, four years old, petrol variant. Today, my father took it for annual servicing at the authorised service centre, where the service personnel declared that the battery was "dead". Our car is not used much. Usually on an average, it is driven for around 14km per month...
  19. P

    Motherboard sudden death in 1-week old phones?

    What accounts for sudden death failures in 1-week old smartphones, given mass production? If one fails, surely the rest should follow suit, assuming user usage is fairly equal? And what accounts for those in which the motherboard died after 1 year? This indicates proper implementation given...
  20. bbbl67

    I Red Dwarfs: Is 100% Hydrogen Conversion Practically True?

    Now, it's been said that red dwarfs are completely convective, therefore they can convert 100% of their hydrogen supply into helium. However, is this really practically true? One would think that at some point in its lifespan that there simply won't be enough hydrogen left to sustain a practical...
  21. P

    T-Cell Loss and Mortality: A Critical Examination

    Can a percentage of total and immediate (hypothetical sub 1 second) T-Cell loss cause death to a typical adult? What percentage of hypothetical immediate loss would yield rapid death under 1 minute? What would the most likely cause of death be? What size is a typical T-Cell in µM^3 ? Is...
  22. Fervent Freyja

    Death in Elderly: The Chainlike Phenomenon?

    Has anyone heard of a particular phenomenon where elderly living together begin dying in a chainlike reaction close together? 4 months ago I lost a constant in my life. I found her dead in her bed. It was one of the most gruesome and shocking events in my life. One of my daughter's biggest...
  23. caters

    MHB What is the maximum death rate I should allow?

    With 44000 people on a generation ship for genetic diversity reasons, it is inevitable that some will be ill. However, if I were to go through a list of every infectious illness and decide whether or not it is allowed, should I have a death rate limit? Is there a point at which pregnancy rate...
  24. benorin

    B Probability and Death Sentences

    Originally posted by Galileo in the thread I started called Bad Math Jokes on top of pg. 4: _____________________________________________________________________________________________________________________ Not so much a joke as a brainteaser. Three prisoners, strangers to each other, were...
  25. R

    I Heat death of the universe and the 3rd law of thermodynamics

    If the universe keeps expanding and eventually ends in a "big freeze" or heat death, does this contradict the third law of thermodynamics? The third law of thermodynamics states that a crystal at absolute zero has zero entropy. Since the entropy of the universe can never decrease, as the age...
  26. Posty McPostface

    Death toll from radiation exposure wrt. Chernobyl?

    Hi, I've been trying to de-misinform myself about the Chernobyl disaster in relation to radiation exposure. I found this study on the WHO website that states, Main points I would like to bring up: Source. Now, it seems that the source of my confusion is due to some apparent shortcomings...
  27. scottdave

    Death by light saber - YouTube video

    I came across this YouTube video describing some of the "science" behind light sabers, and what it would be like to be hit with one. I thought it was worth sharing.
  28. russ_watters

    Fox Sports Ends Print -- the Death of Sports Reporting?

    Interesting little development in [sports] media: Fox Sports, which was my go-to for sports reporting has fired all 20 of its writers (seems like a really small number...) to focus entirely on video. I noticed this a week ago when I went looking for commentary on the NBA draft (Philly had a...
  29. Daniel Petka

    B GRB vs Death Star: Could Gamma Rays Destroy Planets?

    A gamma ray burst radiates an enormous amount of energy. Could it blow up planets like, let's say a Death Star can if they were close enough? I can imagine that, since grbs are able do destroy an atmosphere while being light years away.
  30. durant35

    I Can a finite universe end in heat death?

    Hello guys, I was reading some models about the topology and size of the universe (always a controversial topic), then a question came to my mind. It is predicted that our universe will expand until it reaches heat death. Can a closed, finite universe also reach heat death and be described by...
  31. RooksAndBooks

    Carrie Fisher, Actress of Princess Leia, Dies at 60

    More at http://www.rollingstone.com/movies/news/carrie-fisher-princess-leia-in-star-wars-dead-at-60-w457713 You will be missed, Carrie Fisher.
  32. V

    B Entropy change during the formation and death of stars

    The stars formation decreases the entropy but the radiations given out increases the overall entropy i am said ...but once the fusion processes are over the star no longer gives out radiations...and still the volume in which the matter particles of the star can be becomes less as the star...
  33. G

    I Would Heat Death overcome Strong Nuclear Force?

    Hi, layman here. As I understand, the theoretical Heat Death of the universe would imply that the accelerating space expansion reaches an expansion rate so big that it takes bodies and eventually even fundamental particles apart, leaving them alone up to an ultimate point in which no particle...
  34. RooksAndBooks

    British Actor Kenny Baker, Known for R2-D2 Role, Dies at 81 - CNN

    http://www.cnn.com/2016/08/13/entertainment/actor-kenny-baker-dies/ R2-D2 was perhaps my favorite droid in the Star Wars universe. R2-D2 appeared in every Star Wars movie. RIP, Kenny Baker.
  35. zoobyshoe

    Death of a Condenser (with Autopsy)

    So, a few days ago I was beetling down the road, and out of nowhere, the engine started all kinds of unacceptable tomfoolery: spluttering, loss of power, misfiring, hesitation, refusal to accelerate. I pulled over and fiddled with various things for an hour or so, and ended up with it running...
  36. L

    Death of 3 Dogs After Drinking Water from Kent Lake: Investigation Begins

    https://uk.news.yahoo.com/three-dogs-die-drinking-kent-lake-011715191.html Have you seen this one? Does the green-blue algae hypotesis fit with the nearly instantaneous death of the dogs that drank the water?
  37. jedishrfu

    Cautionary story: Death by GPS

    This recent article from Ars Technica tells the story of the dangers of relying on GPS for directions: http://arstechnica.com/cars/2016/05/death-by-gps/ Please be careful out there!
  38. Kelsey Clifton

    Questions regarding the condition of a buried body

    Hello everyone! I'm new to this site, and I'm looking for some help regarding a short story that I'm writing, specifically about the condition of bones (and the remains of a brain) that have been buried for about 5-7 months. I've seen a similar thread, but it didn't really answer my questions...
  39. Greg Bernhardt

    Who is donating body parts to science after death?

    I've been hearing of many athletes coming forward to donate their brains to science when they die. Curious with most of us being involved in science and its progress has anyone here made plans to donate their body or an organ to science after they die? Why not? Let's do it!
  40. wolram

    B Final Temperature of the Universe: Effects of Dark Energy and Spatial Curvature

    I know there are a few ways the universe can end, if it ever does, but at what temperature would the universe be in after heat death?
  41. C

    Should physician-assisted death be legalized in all countries?

    Where do you stand on the issue of physician-assisted death? In Canada this issue has been a leading news story over the last year or so. See for example: Alberta Doctors Prepare for 'Culture-Shift' Created by Physician Assisted Death. Physician-assisted death is where a competent person...
  42. G

    I Heat Death of the Universe, Total or Not?

    Let's assume that the universe will evolve over time to resemble the one predicted by heat death theorists. We're also assuming that the Big Bounce, Crunch, Rip etc. don't occur. Is it possible that while it resembles a heat death scenario, the heat death will never be total? That means: is it...
  43. mgkii

    B Maximum Radius for Wall of Death

    Hi - Can anyone help me out with a question. The answer seems obvious, but maybe so obvious that I'm jumping to wrong conclusions! Just been reading Guy Martin's book "When your dead, your dead" (good read by the way) and one of his stories is about breaking the world speed record for a wall of...
  44. J

    Birth and death process -- Total time spent in state i

    Homework Statement Let X(t) be a birth-death process with parameters $$\lambda_n = \lambda > 0 , \mu_n = \mu > 0,$$ where $$\lambda > \mu , X(0) = 0$$ Show that the total time T_i spent in state i is $$exp(\lambda−\mu)-distributed$$ 3. Solution I have a hard time understanding this...
  45. E

    Can We Engineer Our Own Stars to Prevent the Heat Death of the Universe?

    Assuming the law of thermodynamics holds true throughout the entirety of the universe, is it theoretically possible to engineer our own stars and solar systems, and would doing so prevent the proposed eventual "Dark Age" of the universe? We understand how stars are formed, so what's stopping us...
  46. goat-on-a-stick

    How can quantum tunneling create Big Bang after heat death?

    Wikipedia states that, after he heat death of the universe: "Random quantum fluctuations or quantum tunneling can produce another Big Bang in years." How would this work?
  47. T

    Is Vaporising Someone Considered Murder?

    1. Considering that not too many people have been vaporised, would you say it is murder?2. Because they are not alive anymore, does that necessarily mean they are dead? Forgetting religion, would you say having every single atom in your body separated would be death? Or Inanimation? I don't want...
  48. Stephanus

    The End of the Universe: Heat Death and the Fate of Matter

    Dear PF Forum Can I ask something quoted from a closed thread? In a closed thread: https://www.physicsforums.com/threads/predicted-heat-death-of-the-universe.824652/ This quote was presented by a Brian Cox. A scientist? And if he is, I'd like to ask this question. Is it technically possible...
  49. Tony Stark

    News What is the Legacy of Dr. APJ Abdul Kalam?

    It is with deep personal regret that I want to inform the members of PF society that Dr. APJ Abdul Kalam has left for heavenly abode yesterday. Dr. APJ Abdul Kalam was India's finest scientist and also the President of India. He was very famous for his zeal to re-inculcate lost imagination in...
  50. J

    Predicted Heat Death of the Universe

    Predicted Heat Death of the Universe In his thought provoking documentary “Wonder of the universe” ( ) Professor Brian Cox explains the thinking behind current predictions for the “Heat death of the universe”. He explains the predictions through the effect of the second law of thermodynamics...