He was an uber nerd of the
first order (I say this as a complement)
StarTalk: Neil deGrasse Tyson reminds us why we celebrate Earth Day
Learn how "a NASA selfie in 1968" and "a moon-landing in 1969" triggered the creation of the EPA
(Environmental Protection Agency) and NOAA
(National Oceanic and Atmospheric Administration) in 1970 to protect our air and water.
quote: we journeyed to discover the moon but then we discovered the Earth
Laying the ground-work: Winner of 8 awards, Rachel Carson's 1962 book "Silent
Spring" is the history making bestseller that stunned the world with its terrifying revelation about our contaminated
planet. No science-fiction nightmare can equal the power of this authentic and chilling portrait of the unseen destroyers
which have already begun to change the shape of life as we know it. "Silent Spring" is a devastating attack on human
carelessness , greed and irresponsibility. It should be read by every American who does not want it to be the epitaph of a
world not very far beyond us in time.”
When I was a teenager in the 1960s, many people (except medical and legal
professionals) aspired to be scientists, engineers, technologists or technicians. It seemed that everyone was reading
magazines like Scientific American, Popular Science and Popular Mechanics. A real "can do" attitude existed everywhere in our
society. For example, when President John F Kennedy announced
America's intention to visit the Moon before the end of the decade, naysayers complained that the goal was impossible because
the technology did not exist. Meanwhile, once funding was in place, other "can do" engineers and scientists simply created the
technology. Both the internet and "personal computers" are two spin-off technologies which were never dreamed of by anyone
when Kennedy publicly gave his moon shot speech in
1962 but by the mid 1970s it appeared that everyone was building computer kits (like the Altair
8800 or the Heathkit H8) or were buying personal computers
(like the Apple-2 or the Radio Shack TRS-80).
Within 5 years it seemed that everyone was reading Byte magazine
and/or attending nightly college courses to learn computer programming and/or digital electronics. Life today is much
different. It appears to me that life this side of 1995 is considerably different with many people aspiring to be
politicians, political advisors, political aids, or just political pundits with a YouTube channel. The "can do" attitude has
been replaced with a "can't do" political divisiveness with wannabe millionaires calling for taxes cuts and austerity (why
should I be expected to pay for that?). Just at a time when humanity has become dependent upon science and technology, western
civilization has decided to replace scientific facts with political opinion.
Now watch this video: https://www.youtube.com/watch?v=D99qI42KGB0
Science is Bigger Than Politics. Neil deGrasse Tyson on The rise (and fall?) of America (from
Abraham Lincoln's founding of the National Academy of Sciences in 1863, to the US currently leading the world in the Nobel
Prize count (a third of which we owe to immigrants), America was built on science. What happens when we doubt and defund it? Transcript: I have to chuckle a
little bit when I'm approached by anybody, but in particular journalists, and say, “Are scientist worried that the public is
in denial of science or is cherry-picking it?” And I chuckle not because it's funny but because they're coming to me as a
scientist when they should be going to everyone. Everyone should be concerned by this, not just scientists. In fact,
scientists will just continue as they're doing. You might withdraw funding, but then there isn't any science done—okay. You
are transforming your civilization if you choose to either stand in denial of science or withdraw science funding from those
who are actually doing the research. Everything we care deeply about that defines modern civilization pivots on innovations in
science, technology, engineering and the math that is the foundational language for it all. Everything: transportation, your
health, your communication through smart phones that talk to GPS satellites to find out where Grandma is. To make a left turn
to find her address or the nearest Starbucks. Whatever is your need, whatever is your want, the emergent innovations in
science and technology are not only enabling it, they are creating for you solutions to challenges you always lived with but
never thought that they could be solved. The message is clear: if you do not understand what science is and how and why it
works—by the way, I'm not even blaming you. I look back as an educator, I look back to K through 12, kindergarten through 12th
grade, and I say there's something missing there. If you, as an educated adult, can say, "This is what these scientists agree
to, but I don't agree with them." If that sentence even comes out of your mouth it's like: oh my gosh. Okay, well, we live in
a free country, you can say and think what you want. I'm not even going to stop you. But if you rise to power and have
influence over legislation and that legislation references what you think science is but is not, that is a recipe for the
unraveling of an informed democracy. So I'm not even going to blame you. It's not your fault. Click here
to read more
George Clooney speaks against Rampant DUMBF**KERY on ABC's Jimmy Kimmel Live!
while promoting UDUMASS (United to Defeat Untruthful Misinformation And Support Science)
Can You Say Why America is the Greatest Country in the World?
This fictional interview was first shown on the HBO program The Newsroom back in 2014. The answer was scripted by American writers and everyone you see here is an
actor, but it speaks a truth that many modern Americans are unable to see.
Will: It’s not the greatest country in the world, professor. That’s my answer.
Moderator: You’re saying…
Moderator: Let’s talk about…
Will: Fine. [Turns to Sharon] Sharon, the NEA is a loser. Yeah, it accounts for a penny out of our paycheck, but he
[gestures to Lewis] gets to hit you with it anytime he wants. It doesn’t cost money, it costs votes. It costs airtime and
column inches. You know why people don’t like liberals? Cause they lose. If liberals are so fucking smart, how come they
lose so god damn always?
Will: [Turns to Louis] And with a straight face, you’re gonna tell students that America is so star-spangled awesome
that we’re the only ones in the world who have freedom? Canada has freedom. Japan has freedom. The UK. France. Italy.
Germany. Spain. Australia… Belgium! has freedom… 207 sovereign states in the world, like 180 of ’em have freedom.
Will: [Looks at Jenny] And, yeah, you… sorority girl. Just in case you accidentally wander into a voting booth one day,
there are some things you should know. One of them is: There is absolutely no evidence to support the statement that we’re
the greatest country in the world. We’re 7th in literacy, 27th in math, 22nd in science, 49th in life expectancy, 178th in
infant mortality, 3rd in median household income, number 4 in labor force and number 4 in exports. We lead the world in
only three categories: number of incarcerated citizens per capita, number of adults who believe angels are real and
defense spending – where we spend more than the next 26 countries combined, 25 of whom are allies. Now, none of this is
the fault of a 20-year-old college student, but you, nonetheless, are without a doubt a member of the worst period
generation period ever period, so when you ask what makes us the greatest country in the world, I don’t know what the FUCK
you’re talking about!… Yosemite? [Stunned silence]
Will: … It sure used to be. We stood up for what was right. We fought for moral reasons. We passed laws, struck down
laws – for moral reasons. We waged wars on poverty, not on poor people. We sacrificed, we cared about our neighbors, we
put our money where our mouths were and we never beat our chest. We built great, big things, made ungodly technological
advanced, explored the universe, cured diseases and we cultivated the world’s greatest artists AND the world’s greatest
economy. We reached for the stars, acted like men. We aspired to intelligence, we didn’t belittle it. It didn’t make us
feel inferior. We didn’t identify ourselves by who we voted for in the last election and we didn’t scare so easy. We were
able to be all these things and do all these things because we were informed… by great men, men who were revered. First
step in solving any problem is recognizing there is one. America is not the greatest country in the world anymore.
I just heard this on the CBC radio program IDEAS
which I publish as food-for-thought: Reclaiming Marxism in an Age of Meaningless Work https://www.cbc.ca/radio/ideas/reclaiming-marxism-in-an-age-of-meaningless-work-1.5175707 comment: While it is true that Marx published some wacky stuff (the communist manifesto first springs
to mind), Marx's description of how capitalism failed Europeans of the 1840s (after the promises by Adam Smith in the
middle to late 1700s) sounds very familiar to how extreme capitalism is failing most people today, except the very rich. In
Marx's time, he worried that the very rich "didn't ever think about the rest of humanity" and I fear the same is true today.
Listen to the program at least once even if you don't agree with everything that is presented. At least you might get a handle
on some of the ideas of the economic theory known as Marxism.
This includes: stir-sticks, drinking straws, cutlery, soft-drink containers, and shopping bags.
They stated: if something isn't done now, then by 2050 there would be more plastic in the ocean than
Canada announced it
will follow Europe's lead and also ban single-use plastics by 2021.
Comments: Most rational people agree that using petroleum (a non-renewable resource) to create
single-use plastic products (drinking straws, knives, forks, spoons, coffee cup lids, and cream containers) is wasteful as
well as stupid. This is made worse by the fact that less than 9% of all plastic is recycled with the remaining amount going
to land fills or, eventually, the ocean. Did you know that those resin
identification codes imprinted upon plastic products is almost useless? Numbers "1" and "2" can be easily recycled
while numbers "3" through "7" can only be recycled with great difficulty so
are usually shipped elsewhere or discarded. So why did those numbers ever get printed? It is all a part of a huge
marketing scam to maximize profit - but the misguided souls who made the decision had no idea that their short sighted
decision would produce this mess. Now they expect the rest of us to clean it up. Let's start by having the laws changed so
that the polluter pays. This generally means "the manufacturer" but until then consumers should just stop buying
items vended in plastic.
Everyone who has ever been concerned with both good nutrition and exercise will be familiar with powdered protein
supplements sold in thick plastic bottles.
Now take a close look at the protein container pictured to the right. This is not a plastic bottle.
It is a much lighter, crushable cardboard container employing a thin plastic bag to protect the product inside (too bad
they have not yet ditched the plastic lid). Although the protein is from Bodylogix,
the container was manufactured by Ecologic Brands. Click
here to learn more.
Question: What's wrong with these pictures of two competing toothpaste products? Answer:
the second product employs more waste plastic in the lid which YOU pay for then discard. Suggestion:
always buy the product with the smallest ecological foot print.
Note: I am not taking a jab at any one company or brand here. They ALL sell products in containers
with high levels of plastic waste. The plastic waste associated with roll-on deodorants is much worse (where did all the
balls float to?)
More Insanity: Many people drink multiple cups of coffee each day then throw in several
creamers each time without giving it any thought. Now you have really got to think about this one: an inexpensive
biologically replaceable resource (cow's milk) is served up in a one-time use plastic made from a non-renewable resource
(petroleum). Suggestion: until dairy producers move their product into cardboard containers, we
must reduce or eliminate the use of plastic creamers.
Children born now could live to see the oceans rise
well over 1 m (3.2 ft) by 2100. Even conservative forecasts of sea level by 2100 are now rising above the meter mark for high
emission scenarios. The last report from the Intergovernmental Panel on Climate Change in 2013 concluded that sea level could
rise between 0.3 and 1 meter by 2100 depending on how much carbon dioxide we emit. Now a study by
Tamsin Edwards of King’s College London has added 0.2 meters to the IPCC report. “Our likely range is
about 20 centimeters higher” says Edwards. Other studies have come to similar conclusions. In fact, the IPCC is set to up its
projections: according to a leaked version of an upcoming IPCC report, sea level will rise by as much as 1.3 meters by 2100.
In the US alone, a 0.9 meter rise in
sea level rise would displace 13 million people. Global average sea level has
already risen around 22-cm (9-in) since 1880. There are three key questions about what happens next: How much higher
will the sea rise for a given amount of warming? How fast will it rise? And will
the loss of some ice sheets become unstoppable once set in motion, as several recent studies suggest? The only way to
find out is by looking at the past and using computer models. But our knowledge of past sea level changes is poor, and
computer models of ice sheets are relatively new and crude, so there are huge uncertainties. The 2013 IPCC estimate of up to 1
meter assumes hardly any
contribution from Antarctica. However, as the report itself acknowledged, many researchers think the unstable West
Antarctic sheet could start to lose a lot of ice long before 2100.
according to tide gauges by sea-faring nations,
sea level increased by 22 cm (~ 9 in) between 1880 and 2004 which equates to 1.77 mm per year. Radar measurements
by weather satellites show the new value as 3.3 mm per year which is double; and this rate appears to be
increasing. So even if you do not accept the fact that the rate-of-rise is accelerating, sea level is absolutely
guaranteed to rise an additional 33 cm (~ 13 in) in the next 100 years but remember that this rise is vertical.
Beaches are sloped which means that tide-surges will make things a lot worse much sooner.
Ice ages come and go based when CO2 levels naturally bounce between 180 ppm (ice age) vs. 280 ppm
(inter-glacial). But humanity's
industrial age has pushed CO2 levels more than 140 units past 280 which is pushing "the melting of ice"
to a totally new place. Had we known this earlier, then none of us would have built large cities so close to the coast. I
fear that Venice Italy stands as a symbol for American cities like New York, San Francisco and Miami to only name three of
In his latest book titled Light
of the Stars, astronomer Adam Frank presents convincing information that variable 'L' in the Drake
Equation should be changed from " self destruction through nuclear war" to " self
destruction though climate change". He argues that even if some extraterrestrial civilizations had never developed
nuclear weapons (as humanity did), all would eventually grow to a size where their collective actions would change their
climates, and possibly outstrip their natural resources. This is an extrapolation of the predator-prey model (described in the
book) which was previously used to model the collapse of various civilizations where local people outstripped their resources
Easter Island, The Mayans, etc.)
comment-1: What does this say about what humanity is currently doing to planet Earth? In the era of mutually assured destruction (MAD), a large number of
western citizens advocated for nuclear deescalation because the thought of an accidental conflict seemed too great. Today,
many people seem to think that a healthy economy is more important than a healthy biosphere. In fact, many people with
financial ties to the old economy are actively working to speed the collapse by denying that the climate is warming or that is
is human induced. comment-2: Many climate deniers do not believe it is possible for modern humans to change Earth's
atmosphere. And yet, it was the action of microscopic
stromatolites (cyanobacteria) that added oxygen to Earth's atmosphere ~ 3.5 billion years ago.
Computers speak a simple language known as binary. The
lexicon is built from digital 0s and 1s, so the 'C' letter at the start of this box would be represented as an elaborate code:
'01000011'. The dominance of binary is partly due to computers being built from transistors, electrical switches that either
allow current to flow or not, and nothing in between. These two well-defined states stand in neatly for 0 and 1. But there’s a
newer electrical component on the scene called a memristor (see main
story). These devices are becoming more and more useful in computers built to mimic the brain, and they are plenty more
versatile than the transistor. Rather than being simply on or off, they can adopt several different states of resistance. Last
year, researchers led by Vikas Rana at the Peter Grünberg Institute in Jülich, Germany, got a set of memristors successfully performing calculations in a ternary language,
which uses the digital equivalent of 0s, 1s and 2s. This means memristors could allow computers to compute much more
efficiently. And it doesn’t have to stop at base 3; memristors can reliably adopt at least seven, and
possibly more, resistive states.
Comment: quantum computing (as opposed to quantum communications) is the focus of much research because
(entanglement aside) it primarily moves from two digital states (0+1) to three (0-middle-1) but most punters overlook the huge
liquid nitrogen cooling tanks. It seems to me that memristor-based technology (with 7 or more states) might be a better
candidate for certain applications like neural nets and artificial intelligence. Sci-fi author, Isaac Asimov, employed the
phrase "positronic brain" as at literary device meaning "fill in the blank". I wonder if memristor technology could fill this
Size differences in two brain structures, the amygdala (larger in conservatives) and the
anterior cingulate (larger in liberals), bias human perspective of the world. Therefore ...
Conservatives see most issues as "black and white" while liberals see "shades of gray"
Conservatives play politics as a team sport so will almost always "vote their party" while Liberals will split their
vote choosing alternate parties (now you know how Trump got in)
Conservatives (larger amygdala) are more fearful of others so are more easily encouraged to vote for POPULIST issues
like "building the wall" or BREXIT (funny point: Britain had the lowest number of Syrian immigrants but apparently the
highest political reaction against them)
Since conservatives only see things as black and white, they try (and sometimes succeed) in converting liberals over to
their way of voting. It seems to me that the reverse never happens
Every citizen today should read this story paying special attention to the reactions of his opponent, John Hampden, who
believed data from Wallace's experiment proved the Earth was flat. Wallace was declared the winner and so won 500 pounds but
lost it all in court costs when Hampden would not stop personal attacks while refusing to acknowledge the
evidence. Why would the courts allow this? Remember that this occurred in Victorian England at a time where many
respectable people were seance-attending spiritualists. I find it difficult to understand that this could happen in the
country of Isaac Newton approximately 150 years after Newton's death. The point I am trying to make is this: today's climate
change deniers claim to be on the side of Galileo but they are really Flat
is a cult of ignorance in the United States, and there always has been. The strain of anti-intellectualism has been a
constant thread winding its way through our political and cultural life, nurtured by the false notion that democracy means
that "my ignorance is just as good as your knowledge."
-- Isaac Asimov (Column in Newsweek, 21 January 1980)
Excerpt from Wikipedia:Isaac Asimov was an
atheist, a humanist, and a rationalist. He did not oppose religious conviction in others, but he frequently railed against superstitious and pseudoscientific
beliefs that tried to pass themselves off as genuine science. During his childhood, his father and mother observed Orthodox
Jewish traditions, though not as stringently as they had in Petrovichi,
Smolensk Oblast, Russia; they did not, however, force their beliefs upon young Isaac. Thus he grew up without strong
religious influences, coming to believe: "that the Torah represented Hebrew mythology in the same way
that the Iliad recorded Greek mythology". So when he was age 13, he chose not to have a bar mitzvah. As some of his
books (which include: Treasury of Humor and Asimov Laughs Again) record, Asimov was willing to tell jokes
involving: God, Satan, the Garden of Eden, Jerusalem, and other religious topics, expressing the viewpoint that a good joke
can do more to provoke thought than hours of philosophical discussion.
comment: I wished Christians (like my parents) shared the same perspective.
the Sun rises in the morning then sets in the evening
Hypothesis (hypo-thesis literally means 'below thesis') is a proposed
explanation; here are three of many:
the Sun moves around the Earth (jump to step 3a) in circles
the Earth moves around the Sun (jump to step 3b) in circles
all planets, including the Earth, move around the Sun in elliptical orbits (although they all have different
Theory is the result of an experimentally tested Hypothesis; at this point a scientist will write, then
publish, a thesis
experimental test of hypothesis 2a...
passes (until the era of precision measurements) so jump to step 4 to build models (mathematical, mechanical,
fails during the era of precision measurements (Tycho Brahe)
so go back to step 2 to develop hypothesis 2b
experimental test of hypothesis 2b...
passes for a time (we have a theoretical understanding of the issue) so jump to step 4
fails during the era of evermore precise measurements so jump to hypothesis 2c
Law is a detailed mathematical description
develop a model to test the hypothesis with greater precision (early physical models were machines; modern models
many times, a successful theory produces yet-unobserved predictions (eg. Atomic Theory, Quantum, Theory of
improved observations (new facts) through newer instrumentation may force us back to step 2 (eg. General Relativity
morphs into General Relativity)
A.I. has been shifting from an "engineering discipline" (expert
systems was the most visible practical success before IBM's
Watson) to a "cognitive science" discipline for a while now. This shift has forced researchers to view the human mind
from a different perspective. One proposal by Daniel Kahneman
separates the human mind into two abstractly labeled modules colloquially referred to as system-1 and system-2
(abbreviated: S1 and S2). S1 is a high-speed parallel processor evolved for avoiding
hungry lions but also handles wrote intelligence ( what is "2 plus 2"?) while S2 is a serial processor which
deals with higher level procedural intelligence ( what is "19 times 21"?).
S2 requires more energy and concentration (not something you want to be doing while being chased by a lion) so idles until
activated by S1.
"S1 immediately engages S2 but fails to pass accurate information to S2 (causing S2 to make an error)"
"S1 will answer incorrectly without ever engaging S2"
"S1 immediately engages S2; S2 employs a little algebra to compute the answer then notifies S1; S1 doesn't believe
S2 so requests S2 to double-check; S2 repeats the solution then notifies S1; S1 still doesn't believe S2 so requests
S2 to perform a detailed rationalization of where S1 had gone wrong"
"S1 will do a preliminary scan of the facts then will usually give up as soon as it notices one facts is missing;
Sometimes S1 will defer to S2 which may dig deeper then make the same mistake; However, sometimes experienced
"logicians" or "digital circuit designers" will notice that "since two of three facts were provided" that a possible
solution might exist. So those people will reengage S2 to produce the correct answer.
This graphical algebra problem employs picture symbols rather than x, y and z. (answer) step-1:
"Apple = 7"; step-2: "Pear = (7+5) = 12"; step-3: "Three Bananas = (7-1) = 6"; therefore: One Banana = 2; step-4: "2 +
12 + 7 = 21";
"All flowers need water. All roses need water. Therefore, all roses are flowers". Is this logically true? (answer) S1 usually
answers "yes" but this is logcially false as many things require water
A bat and a ball cost $1.10 in total. The bat costs $1 more than the ball. How much does the ball cost? (answer) S1 usually
answers 10 cents but the correct answer is 5 cents (Proof: 1.05 + 0.05 = 1.10)
If it takes 5 machines 5 minutes to make 5 widgets, how long would it take 100 machines to make 100 widgets? (answer) S1 usaully
answers 100 but the correct answer is 5
A lily is placed in a lake. Every day the lilies doubles in number. If it takes 48 days for the lily patch to cover the
entire lake, how long would it take for the patch to cover half of it? (answer) S1 usually
answers 24 but the correct answer is 47
Three people check into a hotel room. The clerk says the bill is $30, so each guest pays $10. Later the clerk realizes
the bill should only be $25. To rectify this, he gives the bellhop $5 to return to the guests. On the way to the room, the
bellhop realizes that he cannot divide the money equally. As the guests didn't know the total of the revised bill, the
bellhop decides to just give each guest $1 and keep $2 as a tip for himself. Each guest got $1 back: so now each guest
only paid $9; bringing the total paid to $27. The bellhop has $2. And $27 + $2 = $29 so, if the guests originally handed
over $30, what happened to the remaining $1? (answer)
misdirection in this riddle is at the end of the description, where a bunch of unrelated totals are added together, and
the listener assumes these numbers should add to 30 (should be 27 after the 1 dollar refund)
Jack is looking at Anne but Anne is looking at George. Jack is married but George is not. Is a married person looking at
an unmarried person? Possible answers are: "yes", "no", and "cannot be determined" (answer) At first
their appears to be insufficient information. But let's assume that Anne is unmarried. In this case the question would
be true. Now let's assume that Anne is married. Once again, the question is true. This reducation in the size of logic
happens all the time when digital engineers employ "boolean algebra"
A little math proves the current human population is already too large at
7.57 billion (this is a real-time counter BTW). Anything higher (caveat: humanity adds 1 billion every 12 years) is
certainly out of the question. Why?
Higher temperatures reduce the efficiency of photosynthesis resulting in a loss of agricultural productivity (biologists
estimate a 10% drop for every degree increase). This is a shift in the direction of famine, disease (due to compromised
immune systems), war (due to food and water shortages), and death. Since photosynthesis is required to replenish atmospheric
O 2 (oxygen), then we can expect O 2 to drop as well. So I guess it should be no surprise that...
Atmospheric oxygen levels have been dropping ever since
measurements began in 1990. While CCS (Carbon Capture and Storage) technologies promise to limit some CO2
releases, any burning of fuel will continue to consume atmospheric oxygen. So when calculating the optimum human population
we also need to include the number of large internal combustion engines. (for now, just think about the number of
ocean-going boats, jet airplanes, locomotive engines, and one billion functional automobiles). Now for one additional
Many people mistakenly believe higher CO2 levels "are good for plants" and "will trigger plant growth" (some
people call CO2 the gas of life). First off, atmospheric CO2 levels have risen
from 315 to 405 ppm (an increase of 28.5%) ever since direct annual measurement began in 1958 but humanity has not
noticed any explosion of plant life to compensate for the increase (if we did, we might not have seen an increase in CO2
levels). Secondly, this schematic diagram of photosynthesis shows the first stage involves the photolysis
of water by sunlight (this is the only place where oxygen is released to the atmosphere). This diagram is proof
that sunlight (input 1) and H2O (input 2) are more important than CO2 (input 3) but each ingredient is
considered a limiting factor to maximum photosynthetic productivity (it goes without saying that there is no release of
oxygen on short days, cloudy days, or at night). The majority of plant life acquires water through roots rather than the
atmosphere. Higher temperatures will evaporate a greater volume of water into the atmosphere making it bio-unavailable to
plants. While more evaporation usually translates into more rain fall, higher temperatures will send it back into the
In 1873, while investigating infrared radiation and the element thallium, the
eminent Victorian experimenter Sir William Crookes developed a special kind of radiometer,
an instrument for measuring radiant energy of heat and light. Crookes's Radiometer is today marketed as a
conversation piece called a light-mill or solar engine. It consists of four vanes each of
which is blackened on one side and silvered on the other. These are attached to the arms of a rotor which is balanced on a
vertical support in such a way that it can turn with very little friction. The mechanism is encased inside a clear glass bulb
where the air has been pumped out to partial vacuum.
When sunlight falls on the light-mill, the vanes turn with the black surfaces apparently being pushed away by the light
(is photon momentum being absorbed?)
In 1901, with a better vacuum pump, Pyotr Lebedev showed that the radiometer only works when there is
low pressure gas in the bulb but the vanes stay motionless in a hard vacuum. This is proof that the thermal
properties of the low pressure gas are responsible for the motion, not the direct action of photons. Climate-Warming
Food-for-thought:too much gas traps too much heat causing the machine to stop working.
The radiometer can also be made to rotate backwards in a refrigerator.
Other mistaken explanations for the radiometer: Since the black side of each vane would absorb heat from infrared
radiation more than the silver side, then this would cause the rarefied gas to be heated on the black side. In that
case, the obvious explanation is that the pressure of the gas on the darker side increases with its temperature, creating
a higher force on the dark side of the vane which thus pushes the rotor around. Maxwell analyzed this theory
carefully and discovered that, in fact, the warmer gas would simply expand in such a way that there would be no net force
from this effect, just a steady flow of heat across the vanes. So this explanation in terms of warm gas is wrong,
but even the Encyclopedia Britannica gives this false explanation today. A variation on this theme is that the
motion of the hot molecules on the black side of the vane provide the push. Again this is not correct, and could
only work if the mean free path between molecular collisions were as large as the container, instead of its actual value
of typically less than a millimeter.
The correct solution to the problem was provided qualitatively by Osborne Reynolds in 1879 in a paper to the Royal
Society in which he considered what he called "thermal transpiration". To explain the radiometer, therefore,
one must focus attention not on the faces of the vanes, but on their edges. The faster molecules from the warmer
side strike the edges obliquely and impart a higher force than the colder molecules. Again, these are the same
thermo-molecular forces responsible for Reynolds' thermal transpiration. The effect is also known as thermal creep,
since it causes gases to creep along a surface that has a temperature gradient. The net movement of the vane due to
the tangential forces around the edges is away from the warmer gas and towards the cooler gas, with the gas passing around
the edge in the opposite direction. The behavior is just as if there were a greater force on the blackened side of
the vane (which as Maxwell showed is not the case); but the explanation must be in terms of what happens not at the faces
of the vanes, but near their edges.
He was known for his radical views on religion and politics. As a young man, he was banned by his own religious community
for his scandalous ideas. He made his living by grinding precision lens for scientists. He died young, at the age of 44,
presumably from inhaling glass dust. Spinoza did not believe that God created the heavens and earth per se. For Spinoza, God
was equivalent to all of nature. He believed that "false religion" created superstition. A "true religion," on the other
hand, was liberating because it allowed freedom of thought. The Europe of 17th century was a place of stifling religious
orthodoxies, strife and war. Spinoza believed in freedom of thought and the principle of religious tolerance. Spinoza also
had radical ideas about the nature of politics. He believed in democracy. He is credited with helping to shape the
revolution in human thought known as The
Enlightenment. This program is an introduction to Spinoza's life and thought.
many people continued the enlightenment efforts of Spinoza including John Locke (1632-1704) and David
Hume (1711-1776), Thomas Paine (1737-1809)
is the name most citizens might recognize today. He wrote many things including "the importance of the separation between
church and state" and "racial equality" (he proposed "abolishing slavery 100 years before Lincoln"). The following three book
are a "must read" for all modern citizens: