What we Still dont know

What we Still dont know
http://www.livephysics.com/physics-v...dont-know.html
There is a fundamental chasm in our understanding of ourselves, the
universe, and everything. To solve this, Sir Martin takes us on a mind-
boggling journey through multiple universes to post-biological life.
On the way we learn of the disturbing possibility that we could be the
product of someone else experiment.

Easy Graphical Multiplication Trick
http://www.livephysics.com/physics-v...ion-trick.html
It's not a way to make mental multiplications easier, it's just a
funny way to resolve graphically a multiplication. It's only meant to
be a little trick to show to friends and kids who hate maths. It's NOT
meant to be efficient as some seems to think. You can do any kind of
multiplication with it but yes it's boring to draw numbers like 8 or
9.

Bitwise Operation
http://www.livephysics.com/ptools/bitwise-operation.php
In computer programming, a bitwise operation operates on one or two
bit patterns or binary numerals at the level of their individual bits.
On many computers, bitwise operations are slightly faster than
addition and subtraction operations and significantly faster than
multiplication and division operations.

Eros Global Rotation
http://www.livephysics.com/physics-v...-rotation.html
On March 22, 2000, while in orbit 124 miles (200 kilometers) from
Eros, the NEAR Shoemaker spacecraft captured this rotation movie of
the asteroid's northern hemisphere. The movie features three of Eros'
major morphologic features under dynamically changing lighting
conditions.

Multi Touch Computer Screen
http://www.livephysics.com/physics-v...er-screen.html
Perceptive Pixel is a startup founded by Jeff Han. Working all but
alone from his hardware-strewn office, Jeff Han is about to change the
face of computing. Not even the big boys are likely to catch him. Jeff
Han and Phil Davidson shows how a multi-touch computer screen will
change the way we work.

Superconducting Magnetic Levitation Model Train
http://www.livephysics.com/physics-v...del-train.html
Superconducting Magnetic Levitation Model Train from the IFW Dresden,
Germany. Magnetic levitation, maglev, or magnetic suspension is a
method by which an object is suspended above another object with no
support other than magnetic fields. The electromagnetic force is used
to counteract the effects of the gravitational force.

Time Fountain - Optical Illusion
http://www.livephysics.com/physics-v...-illusion.html
This device creates the illusion that a simple stream of water
droplets can defy the known laws of physics. By controlling a set of
flickering LEDs, the dripping water can appear to slow down, freeze in
mid-air, and even reverse in direction.

On Apr 17, 6:59 pm, LivePhysics wrote:
What we Still dont knowhttp://www.livephysics.com/physics-videos/documentary/what-we-still-d...
There is a fundamental chasm in our understanding of ourselves, the
universe, and everything. To solve this, Sir Martin takes us on a mind-
boggling journey through multiple universes to post-biological life.
On the way we learn of the disturbing possibility that we could be the
product of someone else experiment.


What you now know is that when you build concepts on an obvious
mistake made by John Flamsteed* you end up centuries later talking
about multiple universes and disturbing experiments.Perhaps a decade
ago you would have people rapt with attention but not today.

The era of the mathematical theorist running amok with astronomy is
drawing to an end and while there is plenty of room for dynamicists to
consider celestial dynamics perhaps something closer to home is best
for that group at the moment.

When men start taking the motions of the Earth into account,and
properly,then astronomy can resume.







* "... our clocks kept so good a correspondence with the Heavens that
I
doubt it not but they would prove the revolutions of the Earth to be
isochronical... " Flamsteed






Easy Graphical Multiplication Trickhttp://www.livephysics.com/physics-videos/tools/easy-graphical-multip...
It's not a way to make mental multiplications easier, it's just a
funny way to resolve graphically a multiplication. It's only meant to
be a little trick to show to friends and kids who hate maths. It's NOT
meant to be efficient as some seems to think. You can do any kind of
multiplication with it but yes it's boring to draw numbers like 8 or
9.

Bitwise Operationhttp://www.livephysics.com/ptools/bitwise-operation.php
In computer programming, a bitwise operation operates on one or two
bit patterns or binary numerals at the level of their individual bits.
On many computers, bitwise operations are slightly faster than
addition and subtraction operations and significantly faster than
multiplication and division operations.

Eros Global Rotationhttp://www.livephysics.com/physics-videos/technology/eros-global-rota...
On March 22, 2000, while in orbit 124 miles (200 kilometers) from
Eros, the NEAR Shoemaker spacecraft captured this rotation movie of
the asteroid's northern hemisphere. The movie features three of Eros'
major morphologic features under dynamically changing lighting
conditions.

Multi Touch Computer Screenhttp://www.livephysics.com/physics-videos/technology/multi-touch-comp...
Perceptive Pixel is a startup founded by Jeff Han. Working all but
alone from his hardware-strewn office, Jeff Han is about to change the
face of computing. Not even the big boys are likely to catch him. Jeff
Han and Phil Davidson shows how a multi-touch computer screen will
change the way we work.

Superconducting Magnetic Levitation Model Trainhttp://www.livephysics.com/physics-videos/technology/superconducting-...
Superconducting Magnetic Levitation Model Train from the IFW Dresden,
Germany. Magnetic levitation, maglev, or magnetic suspension is a
method by which an object is suspended above another object with no
support other than magnetic fields. The electromagnetic force is used
to counteract the effects of the gravitational force.

Time Fountain - Optical Illusionhttp://www.livephysics.com/physics-videos/tools/time-fountain-optical...
This device creates the illusion that a simple stream of water
droplets can defy the known laws of physics. By controlling a set of
flickering LEDs, the dripping water can appear to slow down, freeze in
mid-air, and even reverse in direction.

On Apr 17, 11:59 am, LivePhysics wrote:
Bitwise Operationhttp://www.livephysics.com/ptools/bitwise-operation.php
In computer programming, a bitwise operation operates on one or two
bit patterns or binary numerals at the level of their individual bits.
On many computers, bitwise operations are slightly faster than
addition and subtraction operations and significantly faster than
multiplication and division operations.

On many computers ?!?!

As far as bitwise operations being faster than addition and
subtraction;
there are no current mainframes, nor any computers used in PCs or MACs
since the mid 1980s that have this characteristic. Nor do any of the
RICS
machines (present or past) have this characteristic.

What, pray tell, denotes 'many':: a) 5 dozen computers world wide
still
in operation, b) 1%, c) 5%, d) 50% ?

On 18 Apr 2007 18:50:18 -0700, MitchAlsup wrote:

On many computers ?!?!

As far as bitwise operations being faster than addition and
subtraction;
there are no current mainframes, nor any computers used in PCs or MACs
since the mid 1980s that have this characteristic. Nor do any of the
RICS
machines (present or past) have this characteristic.

Well, the vast majority of computers in the world are not mainframes,
but are living in things like your microwave oven or electric
toothbrush. Some of these require an extra cycle for addition and
subtraction (although more and more microcontrollers are able to use a
single cycle for nearly all their instructions). I think the statement
is fair. I also think it's not very original:
http://en.wikipedia.org/wiki/Bitwise_operation

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

MitchAlsup wrote:
As far as bitwise operations being faster than addition and
subtraction;
there are no current mainframes, nor any computers used in PCs or MACs
since the mid 1980s that have this characteristic. Nor do any of the

RISC

machines (present or past) have this characteristic.

Bitwise operations _are_ intrinsically faster.

Even with a Sklansky adder, you're going to have more gate delays,
because of carry propagation, for addition than in even the slowest
bitwise operation, XOR.

Now, it's true, that because of the overhead introduced by buffer
stages saving intermediate results in a pipeline, usually a fairly
large number of gate delays equal one clock cycle, and so one or more
add times is often taken as the clock cycle. So the intrinsically
shorter time to do a bitwise operation *in the ALU hardware* ends up
getting lost in *instruction timings* in a CPU.

So while an XOR may not be faster than an add if you are writing a
program even in assembly language, it certainly is if you're designing
special-purpose hardware at the gate level.

John Savard