CULTURAL QA 12202410
TOPIC- SCIENCE BASE QUORA QA
Q1 Why can't we run engines off of water? Can't science easily
convert H20 to Hydrogen? And I thought we had lots of hydrogen engines
already. Is is too complex or energy intensive to convert? Always wondered,
thanks.
KR: BETTER ANSWER FROM QUORA FROM A REALLY LEARNED QUOTED BY SCIENCE:
“Christopher VanLang's answer is a great overview of the scientific aspects
of photocatalysis. I wanted to add some perspective from electrolytic water
splitting combined with solar too because it's another area of intense
research. There are also a lot of engineering challenges to touch on.
1. The good catalysts are expensive.
We actually can make pretty decent catalysts with long-term stability in
acidic environments for the oxygen and hydrogen half reactions. All you do
is stick a pair of metals in water, apply a small voltage, and you can
generate hydrogen and oxygen. You can even buy your own water splitter for
home experiments that can be powered by a cheap solar panel (we use it for
demos at the Cambridge Science Festival). This is essentially what plants
do: they have one part that converts sunlight into electrical energy, then
transports it to another part that uses that energy to split water.
But these commercial catalysts are precious metals like platinum and
ruthenium/iridium oxides, all of which are ridiculously expensive and low
abundance making them hard to scale. Alloying platinum with other elements
to reduce costs is a major target for the DOE to realize fuel cells and
water splitters.
2. Cheaper catalysts lead to other problems.
The good ones often have poor long-term stability. Cheaper catalysts also
require moving from acidic solutions to basic (aka alkaline) solutions.
Acidic environments are nice because protons are the charge-carriers in
solution, which can easily transport through polymer membranes because
they're small. Alkaline solutions use OH- as charge carriers, which are
much larger and therefore harder to transport through membranes. The
membrane is essential for separating the oxygen and hydrogen products and
becomes the greatest source of losses in alkaline systems.
3. We need a lot of hydrogen.
If you want to bring it to industrial scales to replace hydrogen generation
in ammonia production facilities or oil refineries, you need to generate
tonnes of hydrogen. Literally tonnes. As in 300 tonnes per day in any
modern ammonia production plant. These plants use steam reforming, which is
dirt cheap (< $1/kg H2), coproduces 10 to 100 MW of electricity, and
operates at around 65% efficiency. Modern chemical plants are also capable
of carbon sequestration with around 95% efficiencies, so they leave a much
smaller carbon footprint.
Compare this to water splitters, which today cost at best $5/kg H2 and at
worst $25/kg H2, require roughly 1 GWh/day of energy to operate, and have
similar device efficiencies.
4. Solar water splitters are capital-intensive.
For every H2 atom you create, you need to consume 2 electrons. So if you
create 300 tonnes of H2 per day (a metric tonne is 1000 kg), this is
roughly using 3400 mol electrons per second, or 10^8 A. This is a huge
current -- most electrolyzers operate in the 100 mA/cm^2 so it would
require an enormous amount of operating area to achieve those currents.
These could have some sort of stacked configuration but more importantly it
leads to large capital cost.
In addition, with catalysts as they are now it takes a few GWh/day of
electrical energy minimum. The large amount of electrical energy needed is
a big contributor to the cost, even when coming from the grid at industrial
rates (about $3.00/kg H2). Practically, If you want that to come from
solar, in the sunniest parts of the US this means you'd need around
1,000,000 m^2 of solar panels, which is roughly the size of the Pentagon.
Solar farms are typically about 10 to 100 times smaller.
More efficient catalysts (much better than even the best catalysts today)
could bring this down about an order of magnitude, so it would only require
about the base area of the Great Pyramid of Giza, which is roughly that of
a standard solar farm. Keep in mind though that this would need a solar
farm for every ammonia production facility, oil refinery, or any other
large-scale hydrogen production plant.
5. Photocatalysts are hard. Really hard.
This goes back to Christopher VanLang's answer. Catalyzing water splitting
has some good candidates if you simply want to supply an electric current.
But if you want to integrate that with photovoltaics in a single device
(using photoanodes and photocathodes) to minimize losses and mitigate
capital costs, you run into an incredibly challenging materials design
problem.
So yes, water splitting is hard. It's hard science. It's hard engineering.
And energy is a really hard market.
Note: All of the above are back-of-the-envelope calculations. Let me know
if you catch anything that feels way off -- edit suggestions are always
welcome.
Correction: I originally had the price of electricity estimated around
$0.40/kg because of a silly arithmetic error. More accurately, the cost is
around $3.00/kg at relatively good efficiencies (which makes a lot more
sense given the electricity usage), and this has been corrected in the
text. It's the bulk of the cost at large-scale generation and a non-trivial
one for small distributed generation. You can read more here: Page on
nrel.gov
KR IRS 271224----------------------------
Q2 Are there examples where evolution went wrong?
(G) MY NOTE- It is the personal opinion of a scientist. Many need not agree
to it.
KR: It is short term memory loss repeated again.
II Where evolution went wrong is pre-determined erroneously phrased
question of an atheist.
The phrase "evolution went wrong" is an interesting one and suggests a
perspective
that might be looking at some aspect of evolutionary history or the current
state of life on Earth and questioning whether things could have turned out
differently. However, from a scientific standpoint, evolution doesn't have
a fixed direction or goal—it's a process of change driven by natural
selection, genetic drift, mutations, and other mechanisms, often responding
to the environment and random events rather than aiming for a particular
outcome.
Here are a few angles where people might feel like "evolution went wrong":
1. Human Impact on the Environment
Many people see the rise of industrialization, climate change, and
biodiversity loss as a sign that our species may be an unintended
evolutionary "error." The way humans have shaped the environment often
seems out of balance with the rest of the ecosystem, and the consequences
can feel like a misstep.
However, from an evolutionary standpoint, humans are just another species
responding to their environment. Evolution isn't inherently good or bad;
it's just change over time.
2. Design Flaws in the Human Body
Some people point to apparent "flaws" in human biology, such as our back
pain due to an upright posture, or the vulnerability of our knees and hips,
as evidence that evolution "made mistakes." But these are often the result
of trade-offs in evolutionary design. For example, our bipedalism (walking
on two legs) is a huge advantage, but it comes with structural challenges
that can lead to problems over time.
Evolution works with what’s available—it's not about perfect design but
what works in a given environment.
3. The "Survival of the Fittest" Misconception
The idea that evolution is about creating the "best" organisms can
sometimes lead to the notion that evolution is flawed if something doesn't
seem to be perfect. But "fitness" in evolutionary terms refers to an
organism's ability to survive and reproduce in its environment—not
necessarily to be the strongest or most intelligent.
4. Mental Health and Modern Life
The rise of mental health issues, such as anxiety, depression, and stress,
might be seen as a failure of evolution in the modern world. Our brains
evolved for survival in environments that are vastly different from the
modern world, leading to mismatches between our evolved psychology and
contemporary life.
However, evolution isn't about creating a perfect life—it's about adapting
to an environment. In today’s world, some of those ancient instincts (e.g.,
fear of threats) are not always as adaptive, given our new circumstances.
5. Extinctions and Species Loss
Evolution also leads to the extinction of many species. When you consider
how many species have come and gone throughout history, it can sometimes
seem like evolution has "failed" for certain lineages. But in a larger
sense, extinction is part of the process, making way for new forms of life.
In conclusion, it's not that evolution "went wrong"—it's just that it's a
continual, ongoing process with no ultimate "right" or "wrong." It's shaped
by chance, natural forces, and adaptations to ever-changing environments.
What seems like a flaw may just be a trade-off or a byproduct of
evolutionary pressures.
K Rajaram IRS 271224
Q3 Why does fission create a mass deficit? It seems like two
halves of a broken brick would have the same mass as the whole brick.
KR: Yes, fission can reduce the mass of the system. This is a key
aspect of how nuclear fission works and is described by Einstein's
mass-energy equivalence principle, which states that mass and energy are
interchangeable. The equation that describes this is:
𝐸=𝑚𝑐2 Where: E is energy, m is mass, c is the speed of light (a very
large number).
How Mass is Reduced in Fission:
In a nuclear fission reaction, a heavy atomic nucleus (like uranium-235 or
plutonium-239) splits into smaller nuclei (called fission fragments) along
with a few neutrons and energy. The total mass of the fission fragments,
the released neutrons, and the energy released is less than the mass of the
original nucleus.
The difference in mass is known as the mass defect, and this missing mass
is released in the form of energy, primarily in the form of kinetic energy
of the fission fragments and radiation (like gamma rays).
Example:
Uranium-235 Fission: When a uranium-235 nucleus absorbs a neutron and
undergoes fission, it typically splits into two smaller nuclei (like
barium-141 and krypton-92, along with a few neutrons). The total mass of
these products is slightly less than the mass of the original uranium-235
nucleus.
Energy Released: This difference in mass is converted into energy, which is
what powers nuclear reactors or atomic bombs.
In practical terms, this mass-energy conversion is why nuclear reactors can
release such enormous amounts of energy from a small amount of fuel, even
though the mass loss seems small in each individual fission event. However,
on a large scale, this energy can be significant.
Why Does Mass Decrease in Fission?
The mass decreases because the binding energy of the fission fragments is
greater than that of the original nucleus. Binding energy is the energy
required to hold the protons and neutrons together in the nucleus. When a
large nucleus fission, the resulting smaller nuclei are more tightly bound,
meaning they are lower in energy and, therefore, have less mass. The energy
difference is released as radiation and kinetic energy.
No, when bricks break, fission does not occur, and their mass is not
noticeably reduced. Fission is a nuclear reaction in which the nucleus of
an atom splits into smaller nuclei, typically releasing a significant
amount of energy. This process is most often associated with heavy elements
like uranium or plutonium, and it occurs under specific conditions, such as
in nuclear reactors or atomic bombs.
When a brick breaks, it undergoes a physical process of fracturing or
crumbling into smaller pieces, but the total mass of the brick (and its
fragments) remains virtually unchanged. The breaking of the brick is a
mechanical process, not a nuclear one, and no significant mass loss is
associated with it.
The mass might appear to decrease very slightly due to the release of
energy in the form of heat or sound, but this loss is negligible, in
accordance with Einstein's mass-energy equivalence (E=mc²), where the
amount of energy released would be so small that the corresponding mass
loss is imperceptible.
K RAJARAM IRS 271224
Q4 Gravity is a theory. It’s observed. Evolution is also a
theory, but there hasn’t been a pig turning into a chicken or any real
example of evolution. Why do people still believe in evolution?
KR Is there any relevance in the question Gravity, Evolution and
theory?
KR The theory is a well-substantiated explanation of some aspect
of the natural world that has been repeatedly tested and confirmed through
observation and experimentation. In scientific terms, a theory is not just
a guess or hypothesis, but a comprehensive framework that provides an
understanding of a broad range of phenomena.
Hypothesis: A proposed explanation for a phenomenon that can be
tested. It is usually more specific and narrower than a theory.
Theory: A broad explanation of phenomena, supported by evidence,
that can generate multiple hypotheses and guide future research.
Law: A statement that describes a consistent relationship
observed in nature, often expressed mathematically (e.g., Newton's Laws of
Motion).
In everyday language, "theory" might be used to describe a guess or an
idea, but in science, it has a much stronger meaning—it’s a
well-established and tested framework for understanding how the world works.
In science, a theory is not considered "truth" in an absolute or
final sense, but rather a highly reliable explanation based on the best
available evidence at the time. Science does not claim to discover ultimate
"truths" in the philosophical sense, but instead seeks models and
explanations that can best account for observed phenomena and make accurate
predictions. Here’s a breakdown of how theories fit into the scientific
process and why they aren’t considered absolute "truths":
Science doesn’t deal with “truth” in the philosophical sense (i.e.,
something that is eternally unchangeable or absolute). Instead, science
aims to achieve accuracy and reliability:
A scientific theory is true enough to make useful predictions and explain
observed data with a high degree of certainty. Over time, theories may
become more refined, more accurate, or even replaced as new evidence comes
to light.
Example: Theory of Evolution
The Theory of Evolution is a good example. It has been supported by an
overwhelming amount of evidence from a variety of fields (genetics,
palaeontology, embryology, etc.). It is not considered absolute truth in a
metaphysical sense, but it is a well-supported, robust scientific
explanation for the diversity of life on Earth. As new discoveries are
made, certain aspects of the theory might be adjusted (e.g., understanding
of genetic mechanisms), but the overall framework remains foundational to
biology.
K Rajaram IRS 271224
Q5 If Brahma created Manu the first person, why do we say that
humans evolved from monkeys?
KR Its wrong to say Brahma created Manu first as ADAM and EVE in
Christianity. It is wrong to compare the science in one language AND PERIOD
TO ANOTHER SCIENCE RELEVANT TO EARLIER PERIOD AND Its LANGUAGE. WHO SAID
MAN FROM MONKEY? WHAT IS THAT “WE” VAGUE STATEMENTS DO NOT MAKE A SCIENCE
OR VEDIC. I SHALL WRITE TOMORROW SEPARATELY ‘
K RAJARAM IRS 271224
---------- Forwarded message ---------
From: Gopala Krishnan <[email protected]>
Date: Fri, 27 Dec 2024 at 19:14
Subject: [iyer123] CULTURAL QA 12-2024-10
To: <[email protected]>
CULTURAL QA 12-2024-10
TOPIC- SCIENCE BASE QUORA QA
Q1 Why can't we run engines off of water? Can't science easily
convert H20 to Hydrogen? And I thought we had lots of hydrogen engines
already. Is is too complex or energy intensive to convert? Always wondered,
thanks.
A1 Steve Baker, Senior Software Engineer (2013–present)Sun
You know when you burn something - coal, wood, paper, whatever - you end up
with some ashes and some CO2. If you burned pure carbon - then there would
be no ashes - just CO2.
What you did was to extract energy from a high energy state material and
the result is a low energy state material.
That’s why you can’t burn the ashes from a fireplace - and you can’t burn
things in CO2 (which is why CO2 fire extinguishers work.)
OK - so if you take hydrogen gas and burn that - the “ashes” left over is
the water it generates.
*So just as you can’t burn ashes and you can’t burn CO2 because the energy
has already been extracted - so you can’t burn water because the energy has
already been extracted.*
So there isn’t any chemical energy left in water to extract.
Hence any and all efforts to run an engine on water are 100% guaranteed to
fail.
We CAN convert water into hydrogen - using electrolysis, for example - but
that takes energy.
In fact it takes more energy to extract the hydrogen from water than you
get from burning hydrogen to make water…typically about three times more!
But the process isn’t complicated - if you take a 9v battery (**NOT** a
lithium battery!!!) and drop it into water (to which you’ve added a little
salt to make it conduct electricity) - then you can actually see the
bubbles of hydrogen coming off of one terminal and oxygen coming off of the
other.
https://youtube.com/shorts/azSdq-SXiYA?si=dydsGK1sjBJh0xpy
https://youtube.com/shorts/azSdq-SXiYA?si=dydsGK1sjBJh0xpy
https://youtube.com/shorts/N0O4I4jBTYw?si=SspXGfWEVYXOp5aW
https://youtube.com/shorts/N0O4I4jBTYw?si=SspXGfWEVYXOp5aW
Since hydrogen is a tad explosive - you might want to do that out in the
open air!
*Hydrogen engines are not a great idea - I’ve written extensively on this
subject - but the bottom line is that hydrogen is a TERRIBLE fuel for
things like cars.*
Q2 Are there examples where evolution went wrong?
A2 Kitty Juniper, Lives in Victoria, Australia Thu
There’s plenty of suggestions here already, but here’s one that’s
particularly bad for humans: We’re placental mammals.
This means when we have a baby, it grows inside our body until it’s big
enough to survive outside, and then it has to be born. This isn’t only a
problem for humans, of course – calves and lambs and kid goats and foals
and many other babies can also get stuck during birth, leading to their own
death and often causing catastrophic injury or death to their mother as
well. But *humans’ upright gait has made the problem a whole lot worse by
pushing us to have a narrower pelvis, and therefore a smaller pelvic
opening*.
Human childbirth is so desperately dangerous that until the advent of
modern medical care, childbirth was the most common natural cause of death
of adult women worldwide. Millions more women who have survived giving
birth still have catastrophic injuries, causing infertility, incontinence,
and chronic severe pain for the rest of their lives.
But do you know which animals never die in childbirth? Marsupials!
In the entire history of mammalia, no marsupial ever has had her baby get
stuck in the birth canal. This is because they give birth to a tiny embryo,
which then crawls along a path through the mother’s fur that she has licked
smooth to guide it, into the pouch on the front of her belly where the
embryo will find a teat and settle in to suckle.
That’s where it does its ‘gestation’ – and when it’s big enough to
discover the world outside the pouch, it can climb out to look around, but
go back to the pouch to sleep, or when the mother wants to travel faster
than what the baby can keep up with. The opening to the pouch isn’t
constrained by bones at all, it’s literally on the front of the belly, so
the only limit on the baby climbing back in to the pouch is when the mother
decides the baby is too big for that.
Different species of marsupial handle weaning differently. Koalas have
thick fur and strong claws, and a bulging pouch makes it hard to climb
around in a tree, so they prefer to carry their older babies clinging to
their back rather than in the pouch. Kangaroos’ claws and fur aren’t suited
to that and they travel very fast, so their babies need to be a lot closer
to adult size before they can be banned from the pouch and expected to keep
up with the mob on their own feet.
If humans had been descended from kangaroos instead of apes, no human would
ever have died or even been injured in childbirth. Also, for all the
anti-abortionists out there, it would actually be possible to adopt someone
else’s pregnancy – just transfer that embryo from one person’s pouch to
another! Carrying a baby would still be work, of course; they’re physically
heavy, they demand a lot of nutrients from the body of the person carrying
them, they’re tiring, and they restrict what activities you can do. The
pouch doesn’t seal, because the baby has to be able to breathe, which means
if the mother is forced to swim very far the baby may drown. But having a
baby in the pouch is only actually life-threatening when the mother is
being chased by a predator such as a pack of dogs, and humans sorted out
our relationship with dogs a long time ago.
Make humans descended from kangaroos. They already use their front paws
like hands, so if they had opposable thumbs as well they’d be unstoppable.
They travel so fast on their own feet we may never have bothered
domesticating the horse. Make them omnivores so they’d have access to more
food options than just grass, and give them intelligence .. a lot of
intelligence, because as they stand they’re as thick as two planks
sideways. That skull is built for aerodynamics, not thinking! But with
enough intelligence to choose to limit their own fertility they wouldn’t
breed up in unsustainable numbers every good season and then need to be
culled en masse at the start of every drought to stop them eating every
last blade of grass in the country and then starving, because it turns out
their only natural predators are humans and dogs, and the occasional
crocodile or shark if they stray into crocodile or shark territory.
Being descended from an omnivorous, intelligent kangaroo, with opposable
thumbs, would just be better for us all. We might never have developed the
fancy brachiating shoulder we have, that enables us to throw things like
spears, but with a kangaroo’s top speed we wouldn’t need it – we could run
down any prey we wanted, and kill them with a hand-held spear instead of
throwing it. We’d probably struggle with stairs, and spend a lot more money
on shoes. But no baby and no mother would ever die in childbirth or suffer
the catastrophic and life-changing injuries that are still unconscionably
common even today. No child would have to grow up without the mother who
died in childbirth with their younger sibling, or live with the knowledge
that their mother died birthing them.
Evolution did us dirty. We should have been descended from kangaroos.
MY NOTE- It is the personal opinion of a scientist. Many need not agree to
it.
Q3 Why does fission create a mass deficit? It seems like two
halves of a broken brick would have the same mass as the whole brick.
A3 Silk Road - The Second Act,Studied Physics23h
You are not just breaking a uranium atom cleanly like a brick when you do
this—You are severing the bonds keeping those nuclear particles together—We
call these bonds binding energy; they have mass of their own. Real
mass—like the weight of a bullet in your hand.
Part of that binding energy releases itself when the atom splits. It
follows Einstein's—E=mc² and transforms from mass to pure energy. Not lost
like a card from a deck is the mass "missing" following fission. It has
become raw energy.
Say you have two strong men arm-wrestling. Their grips show the binding
energy. Suddenly separating them releases that tension—that energy of their
grip.
*That released binding energy in an atom has actual mass; when it turns to
energy, that mass vanishes from your measurements.*
Unlike nuclear fission, your brick example is held together by
electromagnetic forces, which lack sufficient mass to be noticeable.
But nuclear bonds are different animals entirely; they pack enough mass
that you could scale what is lost when they break.
Q4 Gravity is a theory. It’s observed. Evolution is also a
theory, but there hasn’t been a pig turning into a chicken or any real
example of evolution. Why do people still believe in evolution?
A4 Patrick,JD from Northwestern University Dec 21
A pig turning into a chicken would disprove evolution. Evolutionary science
does not posit or predict that.
I’m reminded of the comment ascribed to J.B.S. Haldane when asked what
would disprove evolution to him. He said fossilized bunny rabbits from the
Precambrian.
Evolutionary science does make predictions. For example, it predicts that
populations of animals showing the transition between fish and amphibian
existed around the Late Devonian (circa 375 million years ago). Only a tiny
fraction of organisms fossilize, but if fossils of such animals exist, they
would be in strata from that time period.
Behold Tiktaalik. Scientists went looking in Canada, in far-northern
Nunavut, where strata from that period are exposed. After a few years of
looking, they found what they predicted they could find: three intact
fossilized specimens of Tiktaalik.No magic required.
Q5 If Brahma created Manu the first person, why do we say that
humans evolved from monkeys?
A5 Jeevan, Studied at University of Kerala Dec 21
This apparent contradiction arises from differing frameworks: the
mythological and philosophical narratives of Hinduism versus the scientific
theory of evolution. Each has its own purpose and context.
1. The Hindu Philosophical Perspective:
According to Hindu cosmology, Brahma, the creative aspect of the Absolute
Consciousness, created Manu, the progenitor of humanity. "Manu" is both a
specific being and a symbolic archetype representing the origin and
sustenance of human civilization. The word "Manu" is etymologically linked
to "manas" (mind), signifying humans as beings endowed with reflective
consciousness.
Manu is often seen as a metaphysical symbol rather than a historical or
physical figure. The story emphasizes the idea that human life is rooted in
divine will and endowed with the ability to reason and grow spiritually.
2. The Scientific Perspective:
The theory of evolution, as understood in modern biology, posits that *humans
evolved over millions of years through gradual changes in species, with
modern humans (Homo sapiens) sharing a common ancestor with primates like
monkeys and apes*. This is a purely materialistic explanation based on physical
evidence like fossils and genetic studies.
Reconciling the Two Perspectives:
Symbolism in Creation Myths: Hindu cosmological narratives often use
symbolic and allegorical language. The story of Manu can be interpreted as
addressing the emergence of higher consciousness in human beings rather
than detailing the biological origin of humanity.
Different Layers of Reality: Hindu philosophy acknowledges multiple
levels of truth—Vyavaharika (empirical) and Paramarthika (absolute). The
evolutionary narrative belongs to the empirical domain (dealing with
physical reality), while the story of Manu belongs to the spiritual and
metaphysical domains (exploring consciousness and dharma).
Non-Contradiction: If interpreted non-literally, Hindu philosophy does
not necessarily conflict with the theory of evolution. It can be argued
that the "creation" of Manu represents the divine spark of consciousness
emerging within evolved biological forms.
Bridging the Gap:
In essence, the myth of Manu describes humanity's spiritual essence and
purpose, while evolution explains humanity's biological development. The
two frameworks address distinct aspects of human existence and need not be
viewed as mutually exclusive
Gopalakrishnan 27-12-2024
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