(Sep 26, 2018 06:23 AM)Magical Realist Wrote: [ -> ]Quote:Something that was dead suddenly coming to life.
Patients do it all the time--dying and coming back to life.
No, they actually don't. You can only defibrillate a fibrillating (arrhythmically
beating) heart...not a completely stopped one.
Myth: Shocking someone who has flat-lined can get their heart started again.
It never fails. You’re watching television and someone is circling the drain, in the toilet that is their life. The noise from the heart monitor affirms they’re still alive, with its consistent, rhythmic beeps. All of the sudden, alarms start going off. On the monitor- the dreaded “flat-line”.
...
The problem is that, in real life, you’ll be accomplishing nothing by shocking a “flat-line”. Unless you like your meat well done that is.
Medically, a “flat-line” is known as asystole, meaning no (heart) contraction. It might seem common sense that if there is no contraction you might want to contract it with a shock. The truth about why this will never “restart” the heart lies in how the heart creates its life giving beat. In the end, it all comes down to electrolytes.
- https://gizmodo.com/why-shocking-a-flat-...1376053985
Arrhythmia is a heart beat that is too chaotic to circulate blood, which is why people do chest compressions to maintain some blood flow/oxygen to vital organs. Shocking it can restore a regular rhythm and circulation.
Quote:FYI the brain of the fetus isn't dead. It's alive and growing. It's just not functioning yet. That's what is meant by brain dead.
brain death
irreversible brain damage causing the end of independent respiration, regarded as indicative of death.
A developing brain is not damaged, nor has there been any activity to cease. Again:
death
the end of the life of a person or organism.
the permanent ending of vital processes in a cell or tissue.
So brain death presumes a vital brain process existed then ended, and permanently.
Quote:All the cells in your body die and get replaced by new generations of cells.Did you know your tissues start dying the moment you are conceived? Death is just a stage in the process of life. It's called regeneration.
And? Living cells divide into more living cells, to replace themselves,
before they die (just like humans can't reproduce after death). A dead cell doesn't magically come to life or produce a living cell. Again, you're conflating widely disparate things. Aging is not actually dying, and cellular regeneration is not organism death.
I'm having a hard time believing that anyone can actually be this ignorant of basic science.
(Sep 26, 2018 03:22 PM)Yazata Wrote: [ -> ]Introductory biology classes usually begin with some definition of life, if only to define the subject matter of the class. Unfortunately, despite a couple of thousand years of biology, extending all the way back to Aristotle if not before, there still isn't any universally accepted definition of "life".
Wikipedia tried this:
"The definition of life is controversial. The current definition is that organisms are open systems that maintain homeostasis, are composed of cells, have a life cycle, undergo metabolism, can grow, adapt to their environment, respond to stimuli, reproduce and evolve. However, several other biological definitions have been proposed, and there are some borderline cases of life, such as viruses or viroids."
https://en.wikipedia.org/wiki/Life
Maybe try a better source than Wikipedia:
Life
(1) A distinctive characteristic of a living organism from dead organism or non-living thing, as specifically distinguished by the capacity to grow, metabolize, respond (to stimuli), adapt, and reproduce
- https://www.biology-online.org/dictionary/Life
Sounds pretty definite and universally accepted to me. Like many things, life is defined by both what it is and what it is not.
Quote:My feeling is that if totally alien "life" is ever discovered in outer space, 'life' with a a totally different origin, then our definition of 'life' will probably undergo a dramatic revision. My expectation is that it will move away from a descriptive approach based on what we see with Earth life, towards a functional approach based on the functions that anything worthy of the name 'life' would have to perform. Metabolism (which may differ dramatically from ours), homeostasis (more or less, life can't be totally static and unchanging), abillity to make more of itself (growth and/or reproduction) and the ability to evolve. The 'borderline cases' will almost certainly multiply, which will necessitate more flexible definitions.
So..the same definition as the one I've given.
Differing or not, if a thing does not take in energy (metabolize) it either cannot be alive or it is violating the second law of thermodynamics.