Listing /Science ...
#1190864 SIG HEADER: /Science SIG-Op: Odo Created: 11-AUG-99 20:34
SIG Topic: The World Of Science :)
SCIENCE SCIENCE SCIENCE SCIENCE SCIENCE SCIENCE SCIENCE SCIENCE :)
It took a long time to get here, but it's finally here!!!!!!
This SIG is for any messages related to any of the Technical Sciences
that exist! Some examples are Physics, Chemistry, Medical Science,
Biology, Geology, Material Science, Engineering, Electronics, Astronomy,
or even Chinese Herbal Medicine :)
Some of the topics covered will be things like quantum mechanics, aliens,
pyrotechnics, relativity, medical drugs, time travel, black holes, DNA,
Schrdinger's Cat :), Electronics, Origin of Life/Universe, etc.
Basically, any of the Technical Sciences. The more technical you want
to get, the better. The stranger the concept you want to put forth and
discuss, the better. As you know, with Science, *nothing* can be
proven, but everything can be discussed :)
Cheers,
...NickZ <this sig isn't for the weak minded :)>
Thoughts of the Day:
๚ We're being watched ๚
Public Msg #1200800 *Science* 13:11 15-OCT-99 *EXEMPT*
From: Odo (Awarded 2000 Credits)
To: ** ALL **
FILE: 1999 Nobel Prize in Chemistry
The 1999 Nobel Prize in Chemistry was awarded a few days ago
(12/10/1999) to Ahmed Zewail who is a Professor in both Chemistry and
Physics.
The award was for his research in a very new field of Chemistry -
Femtochemistry. This is the study of what happens in Chemical Reactions
in real time (femtoseconds).
A femtosecond is 0.000000000000001 of a second, and femtochemistry
allows observations to be made on this time scale. :)
The first part of this press release is relatively basic, so its worth a
read, tho the document gets a bit more technical in the second half.
Source: http://www2.laboratorynetwork.com/welcome/ngck
The site contains graphics that may help in understanding part II of the
document.
John
Public Msg #1209178 *Science* 07:14 09-DEC-99 *EXEMPT*
From: Nickz
To: ** ALL **
FILE: * NASA's Repulsion Physics Selections *
Attached to this message is an interest news release from NASA, dated
August 1999, on 6 experiments to be performed by NASA to test suggested
far fetched (but possible) theories, including gravity shielding and
changes of inertia of matter, all of which are being studied for the
purposes of long distance space travel.
So if you're interest in new sci-fi type experiments which NASA are
conducting, then have a brief read of the attached file.
...NickZ <ascii download>
Public Msg #1209322 *Science* 20:36 10-DEC-99 *EXEMPT*
From: Nickz
To: ** ALL **
FILE: Physics.txt
Ok, last night I found the most amazing file on Physics, which
explains everything, including special and general relativity, quantum
mechanics, uncertainties, time asymmetry, entropy, big bang, various
philosophies, consciousness, superstring theory, all to a very indepth
degree.
I don't expect anyone to read this entire file, but I am upload and
exempting it as a reference for future discussions. It covers just
about every area of physics you can imagine. You may even want to just
browse various sections on specific topics when Active's empty and
you're bored.
...NickZ.
Public Msg #1212607 *Science* 18:34 29-DEC-99 *EXEMPT*
From: Odo (Awarded 500 Credits)
To: ** ALL **
FILE: Albert Einstein
Albert Einstien, has been named as the person of the century.
What better fitting tribute is there to him...than to present an archive
of him explaining his famous equation.
The attached ZIP file contains a .wav file and .jpg of him. If you don't
have a standalone sound player, use netscape to view/play these files.
The sound is a bit crackly..so here is the transcript of what he is
saying.
"It followed from the special theory of relativity that mass and energy
are both but different manifestations of the same thing -- a somewhat
unfamilar conception for the average mind. Furthermore, the equation E
is equal to m c-squared, in which energy is put equal to mass,
multiplied by the square of the velocity of light, showed that ver small
amounts of mass may be converted into a very large amount of energy and
vice versa. The mass and energy were in fact equivalent, according to
the formula mentioned before. This was demonstrated by Cockcroft and
Walton in 1932, experimentally."
Source: www.aip.org:history/einstein/
๚๙odo๙๚
Public Msg #1214223 *Science* 18:44 09-JAN-00 *EXEMPT*
From: Odo (Awarded 5000 Credits)
To: ** ALL **
Subj: Weird Science
I've had these pinned up on my room for ages..I think they are from the
Guinness book of Records..but I'm not sure.
Strangest Substance:
Scientifically speaking, water is the world's strangest substance. Where
most substances shrink when they are cooled, water expands, and unlike
most substances, water is less dense as a solid than as a liquid (ice
floats). It needs 10 times as much energy to heat as solid iron and
dissolves almost anything.
Saltiest Water:
The lower layer of the Dead Sea has a salinity of 332 parts per 1,000,
making it the world's saltiest water. The dry heat of the Middle East
has caused much of the sea to evaporate over the centuries, and as it
has shrunk, its saline content has increased.
Most Vital Substance:
Oxygen exists as molecules in the Earth's atmosphere, and all living
things would die without it. Invisible, odourless, and tasteless, it
makes up 21% of the atmosphere.
Most Absorbent Substance:
'H-span' or Super Slurper (which is 50% starch derivative and 25% each
of acrylamide and acrylic acid) can, when treated with iron,retains
water at 1,300 times its own weight.
Smallest Ever Test-tubes:
The smallest ever test tubes for containing a chemical reaction were
made at the Ecole Polytechnique de Fderale de lusanne in Switzerland in
1996. Each is 1 micron (1 millionth of a metre) long and has an internal
diameter of less than 10 nanometres (10 billionths of a metre). The
carbon nanotubes contained silver nitrate, which was heated until it
formed chains of tiny silver beads.
Most Heat-Resistant Substance:
NFAAR, or Ultra Hightech Starlite, is able to temporarily resist plasma
temperatures (10,000๘).
Smelliest Substances:
Ethyl mercaptan (C2H5SH) and butyl seleno-mercaptan (C4H9SeH) are among
the most evil of the 17,000 smells classified to date. Each smells like
a combination of rotting cabbage, garlic, onions, burnt toast and sewer
gas.
Bitterest Substances:
The world's bitterest substances are based on the denatonium cation and
have been produced commerically as benzoate and saccharide. Taste
detection levels are as low as one part in 500 million, and a dilution
of one part in 100 million will leave a lingering taste in the mouth.
Sweetest Substance:
Talin obtained from arils (appendages found on certain seeds) of the
katemfe plant, which was discovered in West Africa, is 6,150 times as
sweet as a 1% sucrose solution.
Deadliest Artifical Chemical:
The compound 2,3,7,8-tetrachlorodibenzo-p-dioxin, or TCDD, is 150,000
times more deadly than cyanide.
Most Carcinogenic Chemical:
The most carcinogenic substance ever tested is the compound
3-nitrobnzathrone, found in the exhaust fumes of diesel machine. In Oct
1997 it produced the highest score ever in an Ames test, a standard
measure of the cancer-causing potential of toxic chemicals, carried out
at Kyoto University, Tokyo, Japan.
Most Chemically-Complex Food:
Choclate, which was invented by the Maya 2,000 years ago, contains
approximately 300 chemicals, including caffiene, phenylethylamine and
N-acetylthanolamines, which mimic the effects of some drugs.
Most Aphrodisiac Chemical:
Inhabitants of the central African state of Cameroon discovered long ago
that the bark of the yohimbine tree is a powerful aphrodisiac - just
10mg is enough to have an effect. Chemists has since proved that this is
due to its chemical content.
Most Harmful Radiation:
Gamma rays, the msot harmful form of radiation, can only be stopped by
thick lead of concerete. They travel at the speed of light.
More Physics type stuff in next message!
๚๙odo๙๚
Public Msg #1214226 *Science* 18:59 09-JAN-00 *EXEMPT*
From: Odo (Awarded 5000 Credits)
To: ** ALL **
Subj: Weird Science 2/2
Least Harmful Radiation:
Alpha radiation, a stream of positively charged particles consisting of
two protons, and two neutrons, is the least harmful form of radiation.
Its particles cannot pass through a piece of paper, and alpha rays can
only travel at 10% the speed of light.
Strongest Superacid:
A 50% solution of antimony-pentafluoride in hydrofluoric acid is a
record 10^18 times stronger than concentrated sulfuric acid.
Strongest Natural Fibre:
Silk, the only major fibre obtained from an insect, is the strongest
natural fibre. About 10,000 silk worms are needed to make a garment. To
prevent larva emerging as moths and breaking the cocoon filament, they
are steamed alive.
Strongest Plastic:
Kevlar, which was discovered in 1965, is the strongest plastic substance
in the world. Fire resistant, flexible and light, it is extremely strong
(5X stronger than steel) and becomes even stronger when it is spun into
fibre and heat-treated. Kevlar is used in the manufacture of
bullet-proof vests, body armour, spacesuits, and formula 1 racing cars.
Most Ductile Element:
One gram of fold, can be drawn to a distance of 2.4km.
Most Reactive Element:
Fluorine, which is used in the production of Teflon (the nondestructible
material used in space vehicles, proective clothing, and non-stick
cooking utensils), is the most reactive of all the elements - steel wool
bursts into flames in Fluorine.
Shorest-Lived Element:
Only a few atoms of seaborgium element 106, have ever been produced, and
none of them lasted more than half a minute. They were produced by
bombarding Californium in a Cyclotron. (Odos note: Some of the new
elements produced have lives even lower than this).
Highest Artifical Temperature:
The highest ever artifical temperature was 510 million ๘C - 30 times
hotter than the centre of the Sun. It was created using
deuterium-tritium plasma mix at the Tokamak Fusion Test Reactor at the
Princeton Plasma physics laboratory, New Jersey, USA, on 27 May 1994.
Lowest Temperature:
Absolute zero (0K on the Kelvin scale) corresponds to -273.15๘C, a point
when all atomic and molecular thermal motion ceases. The lowest
temperature ever reached is 280 pikoKelvin. (280 trillionths of a
degree), in a nuclear demagnetization device at the Low Temperature
Laboratory of the Helsinky University of Technoloy, Finland. It was
announced in 1993.
Hottest Flame:
At one atmosphere presure, carbon subnitride (C4N2) can generate a flame
calculated to reach 4,988๘C.
Most Dense Material:
A pinhead-sized piece of a neutron star weighs 1 million tonnes. The
geninga star, at 20-30km across, weighs more than the Sun.
Most Accurate Natural Thermometer:
Crocus flowers are the most accurate natural thermometers in the world.
The spring blooms can react to temperature differences as little as 0.5๘C
by opening and closing as the temperature rises and falls. The
seed-producing element of spring crocuses is under the ground to protect
it from the cold. Crocuses ahve been cultivated since the 16th Century,
and the flowers were used by the Romans to scent theatres and public
places.
๚๙odo๙๚
Public Msg #1215195 *Science* 18:57 14-JAN-00 *EXEMPT*
From: Rex (Awarded 2000 Credits)
To: ** ALL **
FILE: TWIN MONKEYS?!?!? OMOGAWD!!!
Ok!!
Here's that stuff on that cute little banana eating twin bald arse
monkey Tetra...
Enjoy!!!
[Ascii Download (1) to view it]
R e x . . .
Rex...
ReX...
Public Msg #1216635 *Science* 17:48 21-JAN-00 *EXEMPT*
From: Rex (1 Reply) (Awarded 10000 Credits)
To: ** ALL **
Subj: Quantum Shenanigans...
ษอออออออออออออออออออออออออป
บ Quantum Paradox Refined บ
ศอออออออออออออออออออออออออผ
...Atoms Moved Between Normal, Quantum Worlds...
By Alex Dominguez
The Associated Press
Jan. 19: Physicists say they have managed to nudge atoms back
and forth between our everyday world and the strange quantum
realm where objects can paradoxically be in two places at the
same time.
If physicists can further refine their control over
this realm, it could result in incredibly fast quantum computers
able to crack even the toughest encryption codes used by
conventional computers today.
Quantum theory was developed and elaborated on in the
first third of the 20th century by such figures as Max Planck,
Albert Einstein, Niels Bohr and Werner Heisenberg. It radically
changed how scientists considered the behavior of matter and
energy.
Quantum theory holds that energy, light and matter
sometimes behave more like particles than waves. According to
quantum theory, objects on the atomic level can simultaneously
be in two places, have two colors and travel in two directions.
...Precision Gets Better...
Scientists have achieved quantum states. But in an
experiment reported in Thursdays issue of the journal "Nature",
they were able to move atoms into and out of quantum states with
more precision than before.
That kind of control is necessary if scientists are to
come up with practical devices that employ quantum principles.
For example, a quantum computer could store information
in the quantum states of atoms or molecules instead of in silicon
chips. But for such a computer to work, scientists would have to
be able to block the outside forces that can cause a quantum state
to collapse.
David Wineland and fellow researchers at the National
Institute of Standards and Technology in Boulder, Colo., coaxed a
beryllium atom in a vacuum to be in two places at the same time,
the paradoxical "Schroedinger's cat" state. The researchers then
caused the system to collapse by introducing contact to the outside
world.
...Wanted: Dead or Alive...
Austrian physicist Erwin Schroedinger proposed the cat
paradox in the early 20th century. He described the hypothetical
situation of a cat in a box with vial of cyanide gas capped by a
decaying radioactive atom, which would release the poison once
it decayed. Under quantum theory, the atom could be in both
states, meaning the cat could be both dead and alive.
Cats, however, are too big for the quantum effect to
remain in place for very long.
The NIST researchers said they were able to keep a
beryllium ion in a Schrodinger's cat-like state for as long as
as 100 millionths of a second.
...Atom Cooled, Isolated...
To do that, the beryllium atom was cooled to close to
absolute zero (minus 459 degrees) and isolated from all types of
radiation, radio waves and other energy sources.
The researchers then used lasers to force the atom's
single electron into two states of spin, which also forced the
atom to be in two places at the same time.
The researchers then caused the situation to break down
by deliberately introducing contact to the outside world via an
electrical field. Then, in some cases, they reversed the process.
The experiments helped the scientists determine what
causes a quantum state to collapse.
Simply observing a quantum system can also cause it to
revert to a classical, or everyday state. The answer to how to get
around that problem still evades Wineland and others
R e x . . .
Rex...
ReX..
Public Msg #1217102 *Science* 16:43 24-JAN-00 *EXEMPT*
From: Pengo (Awarded 5000 Credits)
To: Nickz
Subj: Rates!
Reply to #1214817, Reply to #121481*
> > well according to mr einstein places that are far away from eachother
> > have a certain amount of "fuzziness" in their relative times. umm. yeah.
> > or something.
>
> ?? I've never heard this before. I'm not doubting it, I'm just
let me try to find a quote from Martin Gardner
...
To explain his special theory in a non-technical way, Einstein once
introduced the following famous thought experiment. Imagine, he said, an
observer M who is standing beside a railroad track. At a certain
distance down the track is spot A. At the same distance up the track is
a spot called B. Lightning happens to strike simultaneously at points A
and B. The observer knows these events are simultaneous, because he sees
the two flashes at the same instant. Since he is midway between them,
and since light travels at a constant speed, he calculates that the
lightning struck simultaneously in the two spots.
Now assume that when the lightning strikes, a train is moving at a great
speed along the track in the direction from A to B. At the instant the
two flashes occur, an observer o the train--we call him M'-- is exactly
opposite observer M on the track. Since M' is moving toward on flash and
away from the other, he will see the flash at B before he sees the flash
at A. Knowing that he is in motion, he will make allowances for the
speed of light; he, too, will calculate that the two flashes occurred
siultaneously.
All well and good. But according to the two fundamental postulates of
the special theory (and confirmed by the Michel-Morley test), we have
just as much right to assume that the train is at rest while the ground
moves rapidly backward under the train's wheels. From _this_ point of
view, M', the observer on the train, will conclude that the flash at B
actually did occur ahead of the flash at A, just as he observed them. He
knows that he is midway between the two flashes and, since he regards
himself at rest, he is forced to conclude that the flash he saw first
must have occurred before the flash he saw second.
M, the observer on the ground, is forced to agree. True, he sees the
flashes as simultaneous, but now _he_ is the one who is assumed to be
moving. When he makes allowances for the speed of light and the fact
that he is moving toward the flash at A and away from the flash at B, he
will calculate that the flash at B must have taken place first.
We are driven to conclude, therefore, that the question of whether the
flashes are simultaneous cannot be answered in any absolute way. The
answer depends on the choice of reference. Of course, if two events
occur simultaneously _at the same spot_, it can be said absolutely that
they are simultaneous. When two airplanes collide in midair, there is no
frame of reference from which the smashing of both planes will not be
simultaneous. But the greater the distance between two events, the
greater the difficulty of deciding about simultaneity. It is important
to understand that this not just a question of being unable to learn the
truth of the matter. _There is no actual truth of the matter_. There is
no absolute time throughout the universe by which absolute simultaneity
can be measured. Absolute simultaneity of distant events is a
meaningless concept.
...
There ya go. Thanks to Martin Gardner.
Pengo
Public Msg #1225257 *Science* 19:10 04-APR-00 *EXEMPT*
From: Jedd (Awarded 400 Credits)
To: Mikez
Subj: Microwave Ovens
Reply to #1224403, Reply to #122065*
> Ummm...please explain? At sea level you can't heat water any hotter
> than 100 degrees C and keep it liquid. You can blast it with all you
Okay. I'll explain. Though it'll sound a lot like my
original suggestion to Nick when he first posed the
question some time ago . . . don't be alarmed by this.
Firstly I should explain .. like Slartibartfast, I'd much
rather be happy than right, any day - normally my existence
is blessed with a good dose of both, but at the moment, I'm
content to just extract some degree of the former from the
latter (which is, after all, both a renewable resource and,
all evidence suggests so far, an almost inexhaustable one).
Last week I was swimming around, bothering the wildlife,
and pointing rudely at white-tipped reef sharks, in water
up to 20 metres deep. At 20 metres, of course, you
experience a pressure roughly equivalent to three atmospheres.
I mention this for no good reason other than to get a reference
to white-tipped reef sharks into this message. At a few km's
under the surface of the sea, down in the vicinity of where
life most likely started, water can (and is) heated (by naturally
occuring means) to 350 degrees celsius.
And I mention *that* for no good reason other than to savour the
up-coming moment. Oh, and also it's an interesting fact unto
itself, IMHO.
Of course, your average microwave oven operates at about
one atmosphere, roughly around sea level, and usually in
the complete absence of white-tipped reef sharks. You and
Nick both, though, seem to believe it's impossible for water
in that situation to exist (in liquid form) above 100 degrees,
if even only slightly above, and if even only a small portion
of the total volume of the water you're heating.
This would appear to be an incorrect assumption.
Since no one believed me, though, I went to a slightly higher
(well, I like to think of it as a side-ways step, but let's
not trifle over semantics) authority . . New Scientist. I'm
not sure if you've ever read one - but they have a terribly
interesting section, each week, on the last page, called, quite
sensibly, The Last Word. Therein are contained questions from
readers about 'ordinary every day things', with responses in
the following weeks from all kinds of dreadfully well-informed
people. Most of whom show all the classic symptons of people
lacking anything remotely resembling a social life. But we
appear to be digressing.
Anyway, after a few minutes wandering around their archives,
I found an article that inspired a profound sense of deja vu.
The question had been posed thusly :
] q. A colleague of mine is in the habit of heating
] bottled water for his tea in a mug in a microwave
] oven. When the water is up to temperature he removes
] the mug.
]
] On several occasions, the water has started to bubble
] violently after he has added a tea bag. On one occasion,
] the boiling started when he was removing the mug. It was
] so violent that it blew 90 per cent of the water from the
] mug--which is obviously quite dangerous. What is happening?
Obviously I've crapped on somewhat chronically in this
message - in no small part due to the woeful results on the
ASX today, but, undeniably also because, in the same way
familiarity breeds, it's well documented that smugness
induces verbosity rarely seen amonst the non-cognoscente.
Anyway, the point is you'll have to read the next message.
<Jedd>
Public Msg #1225265 *Science* 19:17 04-APR-00 *EXEMPT*
From: Jedd (1 Reply) (Awarded 1500 Credits)
To: Mikez
Subj: Microwave Ovens
Reply to #1224403, Reply to #122065*
To continue . . .
There were two responses - I provide them here, verbatim.
] a. A portion of the water in the cup is becoming
] superheated--the liquid temperature is actually
] slightly above the boiling point, where it would
] normally form a gas. In this case, the boiling is
] hindered by a lack of nucleation sites needed to
] form the bubbles.
]
] This never occurs when boiling a kettle, for example,
] because the presence of the rough surface of the
] element, as well as the convective stirring from
] rising hot water, are sufficient to produce proper
] boiling. Turbulence in liquids is known to provide
] enhanced nucleation in other cases: when you pour
] a cola drink, for example.
]
] In your colleague's case, the addition of a tea bag
] (and, in the other case, simple movement) sufficed
] to allow bubble formation. Even with a large proportion
] of the water superheated, only a little will convert to
] steam, as the amount of latent heat required for this
] phase change is very large. I imagine that by keeping
] the cup still and microwaving for a long time, one could
] blow the entire contents of the cup into the interior of
] the microwave as soon as you introduced any nucleation
] sites. It is this sometimes explosive rate of steam
] production that means you should take great care when
] using a microwave oven.
]
] RICHARD BARTON
] Guildford
] Surrey
]
]
] a. Superheated liquid can boil explosively if something
] is added, as in the examples given by your previous
] correspondents, or if the vessel is moved. I have seen a
] spectacular explosion of a bottle of liquid which had just
] been removed from a microwave in a laboratory--glass and
] hot liquid were thrown across the room. This can be avoided
] by leaving any liquid that has been heated in a microwave
] to stand for at least a minute before touching it or opening
] the door. This allows for slight cooling and for the heat to
] become more evenly distributed. I recommend that everyone
] does this when heating liquids in a microwave, even to make
] a cup of tea.
]
] DIANE WARNE
] Cambridge
Cheers,
Jedd.
Public Msg #1231831 *Science* 19:31 08-JUN-00 *EXEMPT*
From: Cheshire (1 Reply) (Awarded 3000 Credits)
To: ** ALL **
FILE: Speed of Light
SCIENTISTS claim they have broken the ultimate speed barrier: the
speed of light.
In research carried out in the United States, particle physicists
have shown that light pulses can be accelerated to up to 300 times
their normal velocity of 186,000 miles per second.
<full article in ASCII format attached>
Public Msg #1241911 *Science* 18:42 13-OCT-00 *EXEMPT*
From: Cheshire (Awarded 1000 Credits)
To: ** ALL **
Subj: Life On Mars (1 of 2)
Mars' First Colonists: Roaches?
by Leander Kahney
3:00 a.m. Oct. 12, 2000 PDT
MOUNTAIN VIEW, California -- Turning Mars into a habitable planet is a
difficult but doable problem with today's technology, said scientists
at the Physics and Biology of Making Mars Habitable conference.
Making the uninhabitable planet habitable, a process known as
terraforming, begins with raising its temperature, which is perhaps
the easiest step.
Scientists at the conference suggested it could be accomplished within
a century by pumping the atmosphere full of super-greenhouse gases.
The greenhouse gases would form a warming blanket around Mars, which
would melt the planet's abundant supply of frozen carbon dioxide.
Itself a greenhouse gas, the carbon dioxide would promote further
warming while forming the basis of a pressurized atmosphere.
Chris McKay, an astrobiologist at NASA's Ames Research Center,
estimated the surface of Mars could thaw in 100 years, and the whole
planet in about 700.
While thawing, microbial and plant life could be introduced. However
at this stage, early life faces the problem of finding enough nitrogen
to support life. Nitrogen is a key component of photosynthesis and
essential for plant life.
McKay told the conference that while preliminary analyses suggest
there may be enough nitrogen in Mars' atmosphere and soil to support a
biosphere, it may be not be in high-enough concentrations to be
absorbed and metabolized by microorganisms.
McKay said the temperature of Mars has to be raised only a few degrees
to make it hospitable to the hardiest of Earth's microorganisms, which
are species of lichens and algae found in Antarctica. He also
suggested special microbes may have to be genetically engineered.
Julian Hiscox, a microbiologist at Reading University in England, said
it is possible to genetically engineer microbes to withstand low
pressure, cold and high levels of radiation, but it would be much more
difficult to engineer an organism to deal with very low levels of
nitrogen.
The problem, Hiscox said, is that nitrogen-fixing is controlled by at
least 15 separate genes and there may be hosts of other genes also
involved.
"Nitrogen fixation isn't a show-stopper," he said, "but it's going to
be very difficult."
The biggest milestone in making Mars suitable for humans will be
establishing trees on the red planet. Over tens of thousands of years
trees would pump enough oxygen into the atmosphere to make it
breathable, scientists said.
Martin Heath, an Earth scientist at Greenwich Community College in
London, said Mars had enough sunlight and probably enough carbon to
support Earth-like forests, but he remained skeptical they could be
established.
"The problem is you've got to change Mars dramatically to support
trees," he said.
<end of part one>
Public Msg #1241912 *Science* 18:44 13-OCT-00 *EXEMPT*
From: Cheshire (1 Reply) (Awarded 1000 Credits)
To: ** ALL **
Subj: Life On Mars (2 of 2)
One of the first animals introduced to Mars may be the one astronauts
would most like to leave behind: cockroaches. Charles Cockell, a
microbiologist with the British Antarctic Survey, said cockroaches
would make ideal biological maids for cleaning up after human
colonists.
"Cockroaches are an excellent way (to) biologically control detritus,"
he said. "The earlier they are introduced, the better." Cockell said
other insects would also be necessary to pollinate plants and spread
microorganisms like algae over the planet. They are also an excellent
source of food.
"Insects are very high in protein," he said.
In a series of experiments, Cockell found insects can survive ultra
low pressures -- the kind of atmosphere that might be found on an
early terraformed Mars.
Cockell and his colleagues put about a dozen different species of
insects, including roaches and ants, in a large vacuum box and sucked
the air out.
The scientists found that most insects still function at about 50
millibars, the equivalent pressure of about 70,000 feet in the air.
The roaches' body doubles in size and the insect starts active
breathing, Cockell said, but it still moves about and lays eggs.
"Insects could be introduced at the early stages," he said. At about
20 millibars "the mobility of the insect decreases and they expire."
"The extraordinary thing about these pressures is that they are
extremely low," he said.
A big problem for life on Mars is the planet's lack of a tectonic
system of shifting continental plates to recycle essential nutrients
through the biosphere.
Penny Bishop, a microbiologist at the University of New Mexico,
suggested rock-eating bacteria may play a role in distributing
essential nutrients to plant and animal life.
"Tectonic processes are essential for recycling nutrients on Earth,"
she said. "Tectonic processes are critical. You can't have a biosphere
without recycling."
Instead of relying on volcanoes and earthquakes to distribute minerals
and nutrients, Bishop suggested unique, rock-eating bacteria could be
injected into the ground.
Bishop said the rock-eating bacteria are so vociferous, they could
easily churn the Martian soil.
"They are so rapid you can walk through passages and rocks are raining
down from above," she said. "It would produce the same benefits as
tectonics, without tectonics."
<end>
Public Msg #1250314 *Science* 17:45 15-APR-01 *EXEMPT*
From: Nickz (2 Replies) (Awarded 500 Credits)
To: ** ALL **
FILE: ** 20 Years Apart **
Several years ago, in fact in Feb 98, I was discussing time travel
with several users. One of which was Elysium.
We were discussing what would happen if you went back in time and
killed your grandfather.
Anyway, to help create a scenario, I created a little story for
Elysium to perhaps help answer the question, or perhaps to make the
question a little clearer. Personally, I think I wrote it for my own
enjoyment :)
Anyway, I just found this message captured, dated 22nd Jan 98, so I
thought I'd attach it to this message.
I think it was originally posted in /Psyche!
...NickZ <READ THE CAPTURE!!! :)>
Public Msg #1250733 *Science* 17:41 21-APR-01 *EXEMPT*
From: Nickz (Awarded 1000 Credits)
To: Snoopen
Subj: ** 20 Years Apart **
Reply to #1250684, Reply to #125050*
Personally, I don't think you can just instantaneously jump to another
time period, just like you can't instantaneously jump 8 km's to the
right.
However, I do think that you can change your direction in time to
travel backward.. Just as time slows to a rate of 0 as you approach C,
going beyond C would start pushing it backward <but it our frame of
reference, you wouldn't necessarily be travelling faster than C, just
travelling backward at near C>.
But yes.. then the question is whether <when viewing the world as a 4D
block, with time being the same as all other dimensions> whether this
4D block is dynamic and never changes <ie, can't change the past or
future>, or static.
If it's static <ie, if you can modify the past to change the future>
then this implies that there's a 5th dimension of time, such that the 4D
space can have a different structure now compared to later if you went
back in time.
Soooo.. for it to be static <changeable>, then there has to be a 5th
dimension. if you apply that to 5 dimensions, then for THAT to be
changeable, you need a 6th dimension, as so forth :)
Sooooooooooo... I think either there's 4 <x, y, z, t> and you can't
change the past <but rather if you went back there, then the events you
create were events that already happened, and it's all balanced>, OR,
there's infinite dimensions :)
...NickZ.
Public Msg #1250734 *Science* 17:56 21-APR-01 *EXEMPT*
From: Nickz (1 Reply) (Awarded 1000 Credits)
To: Snoopen
Subj: Net Material Reverses Snell's Law
Reply to #1250685, Reply to #125050*
> If the light hits the surface perpendicular to the surface normal then
> it doesnt matter what refraction index the material has, the light isnt
> going to bend. Its only when the light is entering at an angle that
> there is any refraction. Unless, it has a negative refraction index. In
> which case the light will just bounce back.
No no!! a negative refractive index just means it bends in the
opposite direction to the perpendicular of the glass surface. If the
light approaches perpendicular tho, then neither positive or negative
refractive index <n> would cause any change at all.
The reason they say that a flat slab could focus light is because a
pinpoint of light striking a flat glass would be spreading out as it
approached the glass, hence striking it "not quite perpendicular" as it
struck it further from the straight line.. a negative refractive index
would mean that it could bend it back beyond the "perpendicular", hence
making the light come to a focus again on the other side of the flat
slab of glass. ie. a perfectly flat lens.
A diagram is in order :) Two upright slabs of glass, each being air
on left side of line, glass on right side. The diagram on the left is
for normal glass, and the diagram on the right is for glass with a
negative refractive index. The horizontal line is just a perpendicular
line drawn in, and doesn't represent any physical objects. The dots '.'
are the path of the light from left to right.
> . Air|Glass . Air|Glass ...
> . | N > 1 . | N < -1 ...
> . | . | ...
> . | . | ...
> _ _ _ _ .| _ _ _ _ _ _ _ _ _ _ _ _.|..._ _ _ _ _ _ _ _ _ _ _ _ _
> |... | perpendicular
> | ... | line
> | ... |
> Air|Glass ... Air|Glass
As you can see, with normal glass, the light pends closer to the
perpendicular. But with negative refractive index, it bends beyond the
perpendicular.
> A vacume has a refraction index of 1 and, as far as im concerned, a
> vacume is nothing. So the speed of light taveling in a vacume will
> always be constant. Hence proving that it's highly unlikely that any
> material could have a refraction index between -1 and 1.
Nods... HOWEVER, they did make pulses of light recently travel faster
than the speed of light through some gass :) Apparently... such an
effect would be like having a refractive index between 0 and 1 :)
However, that's a completely different thread altogether :)
...NickZ.