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January 23, 2007
Science Funding for 2007
Anyone who believes that funding scientific research is a worthy and
important goal of our government should be concerned that, to this point,
Congress has done nothing except continue funding at 2006 levels. If
increases are not passed and funding is left at 2006 levels, the following
consequences may arise:
- There will be a significant reduction in operations or a complete
shutdown at some key national user facilities that academic and
industrial researchers from around the country rely on. (See
this DOE analysis
for a more detailed discussion of the DOE situation.)
- Scientific and technical staffing at the national laboratories may
suffer reductions in force, since the FY06 funding levels do not
account for salary-adjusted inflation.
- University grants will be notably reduced
- At NSF, there will be a 10% reduction in the number of new research
grants, a loss of 40 planned Graduate Fellowships and $439 million in
missed opportunities for scientific discoveries. (See
this report for a more
detailed list of the effects that will be felt by NSF)
- At DOE, university grants could be cut by 10% or more. Due to the
significant cut in funding of the Office of Science in FY06, DOE has
been operating below FY05 levels. The proposed Continuing Resolution
would extend these difficult levels through October 2007.
To do something, write or email your US Represenative and Senators. The
following link allows you to send a form letter to them. You don't have to
personalize the letter (other than putting your address so that the letter
goes to your represenatives). The more people that raise this issue with
their representatives then the more likely it is to come to a positive
resolution.
Congress Web.
December 21, 2006
December 07, 2006
December 05, 2006
Does 1 = 0.999...?
Here's a video I made in the wee hours while in the lab last night. It
explores the question of whether or not 1 = 0.999..., where there are an
infinite number of 9s following the decimal point, by demonstrating three
proofs.
Does 1 = 0.999. .
.? - video powered by Metacafe
As to whether you accept the proof depends your intuition and beliefs about
real numbers. Can you operate on integers the same way you operation on
fractions? This problem arises from applying mathematical operations to an
infinite series (0.999 = 9/10 + 9/100 + 9/1000 . . .). The best counter
argument I've heard against the demonstrated proofs is that there should be
an infinite number of points between 0.999... and 1. The debate is by no
means settled, and as a amateur mathematician I certainly can't provide
much more insight than I already have.
August 03, 2006
Inflating your tires with Nitrogen?
A story about people filling their tires with pure
nitrogen, supposedly to get better gas mileage, made me exclaim, out
loud, alone in my apartment, "What?!"
I had to read the story. You see, air, which most people use when filling
their tires, is about 78% nitrogen. The bulk of the rest is oxygen and
water vapor. I can understand the arguments about reduced oxidation on the
inside of the tire, but the other arguments seem a bit bogus.
The first of these arguments is that nitrogen molecules are larger than
oxygen molecules, and so nitrogen leaks out of the tire slower. This
argument is incorrect. The molar volume of nitrogen is 13.54 x 10-6
m3/mol, while for oxygen it is 17.36 x 10-6
m3/mol. In other words, if you had enough nitrogen molecules to
fill a 10 ft. x 10 ft. x 10 ft. room, you would need 10.86 ft. x 10.86 ft.
x 10.86 ft. room for the same number of oxygen molecules. Nitrogen molecules are not
bigger than oxygen molecules. Without going into details, the difference
between the size of oxygen and nitrogen is neglible given the material
(vulcanized rubber) through which they leak. You may also read about
kinetic diameters, and for some materials the kinetic diameter of nitrogen
is smaller than oxygen. But for some materials, water has a smaller kinetic
diameter than hydrogen! I do not know if this is true for vulcanized
rubber, but my guess is the difference is neglible. Very specialized
materials are produced when making molecular sieves that are based on
kinetic radii, and I know of none that rely on vulcanized rubber.
The last argument is that water inside the tire can cause the pressure to
be less stable than with pure nitrogen. This might be true, but the higher
pressue inside the tire means that less water actually remains as vapor.
So while this argument is technically correct, the most
one might expect the pressure to fluctuate is 0.5 psi.
The reason most people likely see an immediate improvement when they switch
to nitrogen is that they finally have their tires inflated to the proper
pressue. In short, the best way to improve your gas mileage via tire
inflation is just to make sure you have your tires properly inflated. Also,
your tires will likely need to be replaced because of outside treadwear
before inside-out oxidation is a problem. The additional cost of nitrogen is
not
justified by the very limited benefits it provides.
June 02, 2006
Leonardo da Vinci and Mona Lisa break their centuries long silence
A Japanese scientist has attempted to create what Mona Lisa may have
sounded like when she spoke. The geek in me thinks that's just plain
cool.
You'll just need to click the button under their portraits to hear them. Unfortunately, you will need to use Internet Explorer to hear her speak,
but here's the link.
Hear
Mona Lisa and Leonardo da Vinci speak for the first time in centuries!
May 12, 2006
Final Theory: A book review
Today while checking on my website I saw an ad that caught my eye. It may
even still be there. It was advertising a book, "The Final Theory" by Mark
McCutcheon with the claim "The best selling book our scientists hope you
never read. Find out why!" As a scientist myself, I had to check this
out.
And as a scientist, I do hope you never read this book, at least not before
you gain a solid understanding of current scientific theory. While I
haven't read the entire book, I did begin reading the first chapter
(available for free if you click on the ad). I didn't get very far before I
realized the author does not have a deep understanding of the laws he's
trying to critique.
In the first chapter, McCutcheon makes the claim that Newton's theory of
gravity violates a fundamental law of physics. He also claims that Newton's
theory simply models gravity, but does not explain it. This claim is valid,
but the claim that it violates other physical laws is untrue.
The physical law that Newton's theory of gravity supposedly violates is the
"Law of Conservation of Energy". McCutcheon claims that the moon "would fly
past the Earth and off into space if not forcefully constrained by gravity
to circle the Earth, according to Newton's theory. Yet, this tremendous
continual effort expended by Earth's gravitational field is not considered
to diminish the strength of this field at all, millennium after
millennium." I'm not exactly sure where to begin, but the statements in the book
are misleading. I will offer a brief explanation that McCutcheon either
does not comprehend or has intentionally left out of his book.
The Earth does create a gravitional field that pulls the moon toward it.
Likewise, the moon creates a gravitional field that pulls the Earth toward
it. The force between the objects is proportional to both masses. As
McCutcheon stated, Newton did not explain the source of gravity, simply
that it exists and the force is proportional to mass and distance. The
modern explanation that mass bends the space around it does offer a source
for gravity. This explanation requires no continous expenditure of energy.
However, this does not yet get to the key flaw in his argument.
McCutcheon used a car analogy to claim that the Law of Conservation of
Energy must be violated in Newton's theory of gravity. When a car increases
its speed, it is accelerating. The engine is converting the potential
energy of its fuel into kinetic energy, thus the Law of Conservation of
Energy is obeyed. Now, if the vehicle is turned in a circle there is a
force acting to change it's intial direction, and the car is undergoing centripetal acceleration.
However, there is no energy required to maintain this constant diversion.
Imagine twirling a yo-yo around your head. In the absence of friction and
air resistance, the yo-yo would forever twirl. Gravity can be viewed as the
string that ties the moon to the Earth. Adding friction and and air
resistance simply causes the yo-yo (and Earth) to slow.
To put it another way, gravity is a force, energy is force through a
distance.
Imagine pushing on a wall with all your might. You push and push,
but the wall does not give. You have exerted alot of force and your body
converted alot of energy. However, the wall pushed back, but did not
convert any energy. The force it exerted was due to the potential energy
inherit in its structure. Potential energy does not change unless converted
to another form. This view is the proper one to describe the moon revolving
around the Earth. The potential energy is what keeps the moon orbiting,
potential energy created by gravity. No constant source supplying energy to
the system is necessary as the potential energy remains stored in it.
The biggest mistake McCutcheon made was in assuming that all types of
acceleration require an energy conversion. However, such a basic
misunderstanding of scientific principles serves to discredit his entire
book, in the first chapter nonetheless. If you'd like to see some of the
mistakes people can make when they only think they fully understand
something,
then go for this book. If you'd like to learn some science, though,
find a more credible source.
April 27, 2006
Not So Smart Science Writing from a 'Physics Phobe'
A recent piece from NPR, 'Smart Science Writing from a 'Physics Phobe'' highlights
a work by Jennifer Ouellette, "Black Bodies and Quantum Cats". The title is
a reference to black body radiation and Schroedinger's cat, but I won't go
into detail about those. My issue here is that the her writing demonstrates
only a superficial understanding of the science, basic high school level
science at that.
In the piece, an excerpt is included. In this excerpt, she gives an
interesting if brief history of roller coasters along with an anecdote
about the maiden run of 'Apollo's Chariot' in Maryland. However, that's
where the credibility ends. In attempting to explain the phenomenon
involved she refers to potential and kinetic energies. She states that the
roller coaster is "always shifting between potential (stored) and kinetic
(released) energy". A body does not shift between types of energies. It can
gain or lose the different types of energy, so it can be said that the body
is having its total energy converted between the two types. We will igore
energy losses due to friction.
The coaster train is initially pulled up the first hill, giving it more and
more potential energy as it rises. The potential energy is a function of
height and mass (PE=mgh, where m=mass, g=Earth gravitational constant, 9.8 m/s^2,
and h=height). Once at the top of the first hill, the train has all the energy it
will have for the duration of the ride. The total energy is a sum of
potential and kinetic energies, E=KE+PE. At the top of the hill, KE=0, such that
total energy, E, is equal to the potential energy. As it rolls down the hill, it
begins losing potential energy and gaining kinetic energy. Kinetic energy
is a function of mass and
speed (KE=0.5*mv^2, v=speed). If the train
goes all the way down such that its height is zero, all of the
potential energy has been converted to kinetic energy and the train is traveling
as fast as it possibly can travel. At
h=0, PE=0 and E=KE. Once the train begins
going up the next hill, it slows because kinetic energy is being lost and
potential energy gained. The take home message is that if you know your
height, you can always calculate your speed. The highest speed the train
can travel is dependent upon the height of the first hill.
Roller coasters simply don't go up and down hills, though. The tracks twist
and turn, causing the train and passengers to experience a range of forces
pushing them around. These are sometimes mistakenly referred (as Ouellette
did) to as "g-forces". A g-force is simply a convenient unit to measure the
magnitude of the force experienced, with one unit of g-force being equal to
that of the Earth pulling you toward it. In her description, she attempts
to explain the difference between weight and mass. She is correct that
weight is mass multiplied by the acceleration due to gravity. However, mass
is not "how many atoms make up our body". Different atoms have different
masses. For example, carbon is 12 times as massive as hydrogen. Mass is the
amount of matter in a body. If you could count the number of atoms in your
body, you still wouldn't know your mass without knowing the mass of the
individual atoms. By counting the number of different types of atoms, you
could then work out your mass.
This review wasn't meant to go into alot of detailed explanation, although
there is a fair amount. Ultimately, I just wanted to state that the book by
Jennifer Ouellette oversimplifies some concepts as wall as makes some
statements that are only partially correct. If someone claims to have
avoided science writing and physics in particular for 25 years, don't
expect them to suddenly be able to offer lucid explanations. Based on the excerpt, I would
not recommend this to anyone wishing to understand physics. Instead, look
for something written by Richard
Feynmann .
April 07, 2006
Smart as a Crow
This story
about bird intelligence is pretty amazing. Crows in Japan and
California have learned a very clever way to crack nuts: they put them in
front
cars to be run over. However, just putting them in the road and waiting for
a car presents a dangerous task in retrieval. So, the
crows actually learned to put them in front of cars at a red light. When
the cars have stopped, they put the nuts in the road and then fly off and
wait for the cars to move again, running over the nuts and cracking them
open. If the nuts didn't get run over, the crows put them in a
different spot in the road. Is that not amazing? I known people with
college degrees less clever than these crows.
March 28, 2006
How does an astronaut feel?
Ever wonder what it's like in space? A study in the March issue of the Journal of Applied
Physiology (J Appl Physiol 100: 951-957, 2006) showed that all you have to do is lie down
and recline your head at a 6-degree angle below your feet for a few days. So, that's your
ticket to ride into space!
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