dawned on me.
Let us
move on from this now and see
if some ideas
come out of the Fibonnacci
numbers that can make the design of the universe more natural
and less of a mystery. There are those who find any idea that logic lies
behind the wonders of creation and the glories of art and beauty as in
some way
diminishing. I can't say I share this view. The unknown is always
exciting and is to all intents endless, but invention means finding and
dis-covery means just that.
Many people have tried to find a principle or theory behind nature. We
see that there has been physical and chemical and biological evolution
because while we experience the passage of time we are able to look
back into the past. We have more than our personal memories and more
than the collected memories of others in the form of written history.
We can dig into the past on the surface of this planet. We can bore
into trees, But even more remarkably we can look back an examine every
stage of the evolution of the universe because due to its size and rate
of expansion and the finite speed of light, the images and even the
effects of the past are preserved in exemplar form. While any
particular object can only be observed in the sate it was at the moment
the information reaching us left it, we know that the elemental
structural nature of the universe is the same in different places. So
by choosing the distance of the observed object we can select the date.
The same is true of drilling down to layers of strata or an ice-cap
which has been built up by continual accretion on the surface.
Based on our examination of the history of the universe, the solar
system, the planet earth, organic life and human life, various theories
have been developed. Physicists search for a 'Theory of everything'
that coordinates all the physical laws they know. Such a theory does
not necessarily explain existence, just how existing energy and matter
behaves and why. Biological evolution has seen the development theories
of natural selection (incontestable) and of random mutation as the
basis of the variations on which this selection acts. It is now
accepted that while there may be random mutations there are also
evolutionary trends and developments that are very far from random as
the complexity of organisms prescribes the possibilities in some ways
as it enlarges them in others. At the cutting edge, geometry and
arithmetic decides the probabilities and, as we have seen in our brief
examinations above, the mathematics are not as random as we might
suppose.
There are many theories that can be set up as ways of looking at and
explaining evolution at the organic biological level. The Selfish Gene
theory of Richard Dawkins no doubt has something to tell us about one
aspect of the survival techniques of species. But it is possible to
propose many such theories, some reductionist, some
holistic. They may not be mutually exclusive. Here is one I invented
this morning based the Fibonacci sequence and the Golden Ratio. I have
called it Predator Theory. I
imagine it must have already been invented by others. All inventions
are possibilities sitting there waiting to be expressed.
In Predator theory, we start with energy emanating from a singularity,
and suppose a minimal pattern imposed on it in space-time, - an initial
frequency, like a musical note, a 'word'. It has no meaning other than
that as a result, space-time is no longer utterly bland . This
corresponds with conventional thinking about the universe we observe,
and we can call the energy 'dark energy' just as we do now for our
universe. The pattern causes the universal expansive force which is
otherwise infinitely entropic to cause relative compression in some
places and this is the start of the gravitational effect, whereby, when
matter is formed out the energy, it exaggerates the differential and
very gradually the overall repulsive force causes a corresponding
coalescent effect .
For our theory, we will ignore all of the physics and chemistry so far
discovered, the business of matter and anti-matter, and stipulate only
the possibility that any matter that comes into being then has the
possibility to associate with any other matter brought within its
reach, by any force or combination of forces that can act in the
circumstances. We shall ignore all qualities and consider only
quantities. We shall assume that initially matter is formed in units of
ONE, whatever this matter may be e,g, quark, proton, neutron, electron,
molecules, anything at all and will then associate according to what is
available.
Units will first find other units, combining to form a combination with
value 2. Those with value 2 will be most easily able to influence the
dynamic trajectory of remaining adjacent units, becoming 3. Matter with
value 3 will find and predate available 2s, making 5s. The nearest
available meal for 5s will be the remaining 3s. In this way there will
be a tendency to favour any assemblage by capture in a way that is
statistically less than random. Now it is a long time before we get to
the formation from gas clouds to the first stars, which overgrow and
massively implode as their huge mass condenses into violent quasars and
other beasts of the early universe. Every sort of excess is formed and
self-destructs, perhaps returning first through time via black holes to
the origin, then bursting out in clouds of dust containing the elements
formed in their giant furnaces which will form the next generation of
stars in the forming galaxies. But all through this process there will
be a bias against randomization, a bias that depends on absolutely
nothing except the building on what is there.
Abstraction is overruled as soon as real events take place, and in that
reality the Fibonacci sequence will automatically be favoured, for the
same reason that men climbed Mount Everest: because it is there! As
soon as some units have combined, you have two types, the ones and the
twos. These make 3s. 2s and 2s make 5s, 5s and 3s make 7s. As we get to
complex substances and large volumes, the Golden Ratio will tend
to feature. Where it does, there will be harmonies and resonances that
will cause other values to harmonise trancendantly. So, when we arrive
at a solar
system where this is a dominant feature (see http://goldennumber.net/solarsys.htm
) it is not hard to reason that many of the attributes that make life
possible on earth could be the result of Phi resonance which, in
the anti-entropic environment which systems subject to the reflexive
attractive gravitational force provide, can assemble mutually
supportive proportions and provide planets at appropriate distances
from appropriate suns with appropriate moons.
The Golden Mean then features in all life forms and as life develops to
conscious and self-conscious minds we reach the point where we choose
the proportions knowingly, as the basis of both practicality and
beauty. Phi is the very means by which reductionist theories and
holistic theories interact, for it demonstrates how the whole causes the
parts just as much as the parts cause the whole, in any
arrangement of
nature.
APRIL 24th 2006
The previous paragraphs should help to explain to the reader why Oscar
Wilde, though no mathematician, puts the following words into the mouth
of Vivian in the Plato-istic dialogue "The decay of lying"
"The third doctrine is that Life imitates Art far more than Art
imitates
Life. This results not merely from Life's imitative instinct, but from
the fact that the selfconscious aim of Life is to find expression, and
that Art offers it certain beautiful forms through which it may realize
that energy. It is a theory that has never been put forward before, but
it is extremely fruitful, and throws an entirely new light upon the
history of Art."
[Addendum
Nov
2006]
I realise that
at this point I should not have been tempted to move on to a discussion
of Relativity, before finishing this section with a discussion of the
Pentatonic scale in music. This scale is common to all cutures and is
naturally 'hard-wired' into the human brain. Songs were written and
performed using the notes of the pentatonic scale long before the
different modes, intervals, scales and final merging of these in the
'equal temperament' compromise that permits all 'keys' to be used and
all instruments to play together. The pentatonic scale, like the
pentangel and pentagon, eixists as an apparently complete, finite
presentation but, upon examination and use, forces us to explore the
spaces and transcend.its limitations. There is no doubt a relationship
between the self-forming properties of the Fibonnaci sequence and
Golden Ratio, and the hard-wired pentatonic scale in the human brain.
MAY
22nd
2006
E=mc2
We will now move
on to explaining some of the other mathematical theories that are never
explained to the general public by either mathematicians or scientists.
The reason they are not explained is that these worthy men and women do
not understand them themselves. They understand how to use them and get
results, but you will see from the following they do NOT know how
to explain them. Here are some scientists trying to explain E=mc2 - Einstein's famous
equation.When you have read their 'explanations' you will have gained a
small amount of knowledge from one or two of them and no understanding
whatsoever. But read it carefully. Then you can read the explanation
from me.
NOVA |
Einstein's Big Idea | E = mc2 Explained (text version) | PBS
OK, if you have read that, here is the proper explanation of E=mc2.
First we will define mass, which is the m in the equation. Mass is the
property of matter which gives it inertia.
That
is
the measure of the
resistance of an observable object to acceleration.
Acceleration is the alteration of velocity (speed in a given
direction). For an object at rest relative to an observer to acquire
relative velocity by acceleration, a force has to act on it. When that
has been applied, the object will have acquired energy. We call this
energy, now represented by its motion, kinetic
energy. It is measured therefore according to the velocity
relative to an
observer and the resistance it exhibited in changing its velocity
(which
we have defined as its mass). Velocity could be measured in metres per
second. Acceleration (change of velocity could be measured in metres
per second added per second, which we call metres
per second squared [m/s2].
Now this kinetic energy is relative. The kinetic energy of a speeding
bullet is very small compared to another bullet fired just before from
the same automatic machine-gun, but very high compared to a stationary
target. So the initial kinetic energy is proportional to an initial
velocity of zero and its muzzle velocity before it starts to slow due
to air friction. The acceleration takes place over time in the
barrel of the gun. If we assume for the sake of argument this is a
uniform acceleration we can take the average speed, which is half the muzzle
velocity,
You can see how confused modern students are by this page http://www.newton.dep.anl.gov/askasci/phy99/phy99032.htm
Newton and Leibnitz together settled on a formula of E=½mv2 [though
this
does
not, I am told, appear in Principia Mathematica] as the way
to calculate the kinetic energy of an object relative to an observer at
relative rest with respect to the object before it was accelerated.
Now, when matter is released from its local inertial cage and scoots
off
as radiation, there is no acceleration over time as there is no longer
a mass to
accelerate. The change is total and
instant into 100% kinetic energy. There
is
no
average to be taken. We
can dump the ½. We
can just use the final velocity to give the value, as it is the start
value as well and we know that
electromagnetic radiation travels at the speed of light which we write
as 'c'. You can therefore assume E=mc2
the moment you accept that mass can be converted into energy. It could
not be otherwise.
The strange thing is that this was not worked out centuries ago. Any
time you sit in from of a warm coal fire you are witnessing an
electrical phenomenon in which some mass is converted into energy.
Admittedly it is a small amount of mass. A lot of Oxygen has been added
to the combustible material. But If you collect all the Carbon
Dioxide and other gases and the ashes and clinker, you will find a
small difference. But that's the point. It only needs a tiny amount and
a coal fire does not give off radiation at wavelengths that damage us
unless we are so close as to be burned. We are not dealing here with
smashing the nuclei of atoms, releasing energy at wavelengths shorter
than X-rays, just setting up a great game of musical
chairs with the electrons till some of them can't sit down. We end up
with elements that have less mass and less energy when at theoretical
rest than the ones we started with.
Now of course not all the heat from
a coal fire is radiation by the time it emerges. A lot of hot gas goes
up the chimney but that is radiating as well. Nor is the radiant heat
from the fire in the most part the direct result of matter being
converted into energy, but the change in energy level of electrons
which results from the chemical reactions in the fire. This cviolent
hemical reaction causes the minute transfer via kinetic energy of
charged particles (protons and electrons) which generate the
electromagnetic waves of light and heat. Because there are billions of
them, the overall effect is significant. Nevertheless, E=mc2
rules in the overall equation of a coal fire.
In due course, when I have moment, I will explain the paradoxes which
you will have had to swallow in the explanation of the speed of light
being the same for different observers even when they travel past each
other at speed in the opposite direction. And I will explain what
happens as you approach the speed of light which of course, according
to that scenario, you could not do. Yes folks, the fact is your
teachers do not understand it either or, when they do, cannot explain
it properly. The same is true of religion, which is not understood by
many
Archbishops, Rabbis or Mullahs. They learned what they were taught. They learned how to
make it work for them and the best make it work for others. In fact the
same goes for all human knowledge that I have looked at so far. Some
amazing brains have been employed producing amazing results, but they
don't understand it really. As they get close to understanding these
things they realise that there are problems in their world-view. Ask
anyone developing quantum computing. If they are truthful...
Since writing the above I have listened to a news report triggered by
the appearance in the sale room of some of Einstein's papers. The point
is made that his big contribution was as a physicist and a visionary of
the big picture rather than a mathematician. This is true. He took his
maths from existing formulae developed by others. The 'squared' in
c-squared was suggested by a woman whose name I forget many decades
earlier and the formulae for General Relativity (which makes sense out
of Special Relativity) come from a Frenchman in the 1700s whose name I
have also forgotten - Eloi somebody. That in no way diminishes
Einstein's work. There is a
pile of maths knocking about looking for a home. It's a language
developed from observation of Nature, just like English. It can
be fiction or realised in fact. We are often quoting Shakespeare to
describe reality.
SUMMARY SO FAR:
If
in Newtonian physics E=½mv2 is true (which has
been
accepted for centuries)
and
If matter in any amount at all can be released or
forced from its
inertial bonds as radiant energy,
then
It follows that E=mc2 must be true with or
without any Theory of Relativity
MAY 24th 2006
Now that we have seen why the formula for the equivalence of mass and
energy is indeed E=mc2, and that this is a Newtonian
construct, we can have a look at Special Relativity. By using the
symbol c for the speed of
light we have avoided giving it a value. But clearly to get a numerical
output from the formula, on the supposition that we have a value for
the mass, we need to choose a
value for c.
Here I am greatly
relieved to find today that true understanding has permeated the
international
community and been set before the public now at no charge in Wikipedia. I
don't know who wrote that page, but I am unspeakably grateful to them.
I wish I had known them in 1983 when I was despairing of the failure of
science journalism or textbooks to explain Einsteinian rather than
Newtonian relativity. Happily, in 1983 a fundamental change was made to
the system of SI Units (metres, seconds, grams etc.). Before
October 21st 1983 the speed of light was a measurement, arrived at by
experiment, in metres per second. Since that date c has been accepted as a
mathematical constant on which metres and seconds depend.
One metre is now
defined as the distance light travels in a vacuum in 1/299,792,458 of a
second. Only when this is accepted and understood can any discussion of
Special Relativity make the slightest sense. [Note: There is a lot mre
to Special Relativity than E=mc2, but later...]
The reason why
it is not 1/300,000,000 of a second is that the metre had already been
established, as had the second, in relation to other realities of
global science and commerce. The metre was meant to be one
ten-millionth of the distance from the equator to the north pole, which
was then formalized in 1889 as the International
Prototype Metre as the distance
between two lines on a standard bar, kept in Sevres, of an alloy of
ninety percent platinum and ten percent iridium, measured at the
melting point of ice. In 1893 this distance was measured with an
interferometer using light. Had we started with the current method of
defining length in terms of the distance light travels in a time, we
could have chosen 1/300,000,000 seconds as the time, but changing it
now is too
complex and would have repercussions.
But I digress.
Although E=mc2 is, as I have emphasized, a Newtonian
construct, it contains in c a
function of electromagnetic waves, which we call (to keep it simple)
light. Therefore it has to be reconciled with the formulae of James
Clerk-Maxwell which describe the mathematics of electromagnetic
phenomena. Newton and Clerk-Maxwell's formulae are irreconcilable in a
context where time, distance and the speed of light are all constants
regardless of the motion of objects and observers Something has to
give! This is where Albert Einstein (a) appreciated the problem and (b)
imagined the solution.
MAY 25th 2006
Now, before I go on, I just have to clear the decks with the
professionals. Those who know me well understand that I have spent my
life torn between exasperation with orthodox interpretations of the
world and the 'cooking' professionals who are stuck with these, and
admiration for those professionals whose mastery of their subject and
control of their thinking is what has produced the miracles of
technology and art that form the civilisation on which we all depend.
It never occurred to me (silly, I know) to look up this subject in
Wikipedia before starting on it. Having now done so I am deeply moved
by the care taken on http://en.wikipedia.org/wiki/Mass
to get to grips with the subject. I started off this file on
Mathematics by deploring the failure of professionals and teachers to
explain things even when they understood them, which often they did
not. I have to admit that the guys writing this stuff in Wikipedia are
really with it. However I am going to take issue with one important
point. I am including here a couple of paragraphs from the page I have
just refrenced. I am goig to take issue with the last sentence of each
paragraph.
Wikipedia Extract:
For a macroscopic object, the rest energy mc2 includes the thermal energy, which depends on the temperature
of the object, and is related to the random motion of the atoms or molecules
of which the object is composed. This contribution is usually much
smaller than the total rest energy, but often bigger than the kinetic
energy. For example, if two objects stick together after a collision
between them, the total kinetic energy of the objects is not conserved,
and a significant part of it is transformed into thermal energy, so their mass increases by
a tiny amount. Similarly, metabolism,
fire and
other exothermic chemical processes convert mass to
energy, however the mass change is usually negligible.
My
comment:
small
it may be, negligeable it is not. Ignoring it is
why E=mc2 was thought to be something new, to do with
Relativity and Atomic Bombs, instead of Newtonian logic. It is only
when we decide that c is a
constant that Relativity raises its head, and nuclear fission does not
prove Relativity.
Wikipedia extract:
More significant changes of the rest energy occur in processes that
split or combine subatomic particles. The reason is
that mass, as we have defined it, is not conserved during such
processes. The simplest example is the process of electron-positron annihilation,
in
which
an electron
and a positron
annihilate each other to produce a pair of photons: the electron and
positron both have non-zero mass, but the photons are massless. Other
examples include nuclear fusion and nuclear fission.
Energy, unlike mass, is always conserved in special relativity, so,
roughly speaking, what is happening in these reactions is that the rest
energy of the reactants is being transformed into the kinetic energy of
the reaction products. The fact that rest energy can be liberated in
this way is one of the most important predictions of special relativity.
My
comment:
I
do not see Special Relativity as predicting that
energy can be liberated in this way. Energy always was and is liberated
in this way. The formula is inevitable, as I have shown. Special
Relativity deals with the theoretical problems that arise as a
consequence of understanding this and in certain practical applications
involving extremes of accuracy, velocity and distance measurement.
Another point I
wish to make at this stage is that the definition of mass that I used
at the start [May 22nd] is the definition of Inertial Mass. Wikipedia
has very correctly stated that there are definitions of Gravitational
Mass (active and passive), and that no experiment has ever detected a
difference - which leads us to General Relativity later. However, for
the moment the definition I have used is what I meant to use.
Finally (for today)
I want to take the opportunity to note that while Donald G. Shead
54
Chaplin St, Chaplin CT 06235 suggested a definition of MASS as:
(a) "the mutual resistance of two particles, bodies or masses of
material matter from simultaneously occupying and/ or passing throught
the exact same place" and/or (b) "the mutual resistance of the
penetration of a body resting on a planet's terra firma surface." -
that is a definition of MATTER, and quite a good one. The (a) option
has always been the one I favoured. It is not (for me) a definition of
MASS, as opposed to MATTER, even though there may be circumstances when
one implies or infers
the other.
JUNE 28th 2006
I am sorry about the delay in completing the explanation of Special
Relativity and General Relativity but I have to be in the mood in order
to hit the spot and clear up the misunderstandings. It is no good just
spouting stuff. Today's double
page
spread
in The
Independent has some attempted explanations of Gravity Waves
but does not really give the right picture. It does not help that they
are wrongly named - they should be called INERTIAL WAVES, but Einstein
was trying to keep it simple knowing most people had heard of gravity.
MARCH 17th 2007
Before getting back to General Relativity it is time to pay tribute to
a programme trilogy on UK BBC 2 called The Trap. The fundamental issue
examined in The Trap concerns
the need to advance from the basic Game-Theory of John Nash and the
Selfish-Gene theories of Dawkins and others. Nash is alive and
well and in a state of enlightenment, realising his theory is (a)
inadequate in relation to the complex human beings it aims to include
in its behavioural models and (b) subject to the universal law of all
theories of this kind: they contain the seeds of their own destruction
which will germinate if application is taken close the extreme.
Dawkins, although he still fails to understand his selfish gene theory
has no effect whatsoever on arguments for or against atheism, has
learned a lot more than he knew when he first got so excited about it.
It's extraordinary how people burst into print and lecturing before
finding out what othrs have already discovered many times over the past
few thousand years, but there you go..
The Trap
is not without a few
misperceptions of its own. In its effort to show that the chasing of
numerical targets by hospital managers, targets set according to
game-theory rules to incentivise those responsible, it found fault with
classifying a trolley with wheels removed as a bed, or a corridor
converetd ito a ward as a ward. Why? A bed is a trolley without wheels
and a large corridor full of beds is a ward. If beds and wards were
needed, that was how to add them quickly and speed was what was
requested. In fact the NHS invested far too much as it is, which is why
it spent locally beyond its means and s now introuble because of that.
Putting off complicated operations to get the quick ones off
the waiting list may or may not be cheating with harmful side effects
but more detail needs to be shown to establish that. Nevertheless on
the whole The Trap is
intelligent and thought provoking.
MARCH
25th
2007
Well that was
easy. The third episode of The Trap finished with an indicated
conclusion: that Isaiah Berlin was wrong when he said that liberty had
to be limited to what he defined as 'Negative Liberty' (because, if it
were
given a collective aim or vision, this would end as tyranny). If that
is indeed the conclusion of the author I can
confirm without doubt that this conclusion is correct, and that a
philosophy of liberty such as Berlin's, necessary and valid as it was
to enable us to defeat that of Marx, is nevertheless useless as a
formula for existence, just as was the mathematical basis for it
proposed by Nash.
So what, you may
ask, is the positive aim that we should encourage the world's citizens
to strive for in both their own and the collective interest, not
because they are forced to but willingly?.Very
simple: it is the one that Nature shows us - the management of this
planet. That means managing our immediate personal environment and
relationships, our local and our global environment and relationships.
By facing us with a crisis, Nature has supplied us with the answer. Now
that we know that the negative freedom of Isaiah Berlin or the
Positive Freedom of Marx will both lead to disaster, we can perhaps
begin to see that we can serve ourselves best by serving others.
Neither formulae from Nash or Philosophy from Berlin or Marx can
obsolve us each and every one from our personal responsiblity. That is
to inform ourselves and educate our children. We have millennia of
works to choose from, so I suggest a sensible way to proceed is to look
first at what informed some of those whose lives we most admire. A lot
of stuff is free on the web and we have an Open University and the
Bible (Auhorized version) and Shakespeare, and all the works of
philosophy and science; but first of all we much
teach people to listen, speak, read and write in at leat one or two
established modern languages. English is a good one.
APRIL
17th
Getting back
into Special and General Reativity, I am pasting here an
important news item which I will use to deal with Einstein's Relativity
in due course. It concerns what we call 'the fabric of space-time' and
its interaction with concentrations of energy (such as significant
mass).
Einstein
was right, probe shows
Early results from a Nasa mission designed to test two key
predictions
of Albert Einstein show the great man was right about at least one of
them.
It will take another eight
months to determine whether he got the other correct say scientists
analysing data from Nasa's Gravity Probe B satellite.
The spacecraft was launched into orbit from California, US, on 20
April 2004.
The mission's chief scientist presented details at a physics
meeting in Jacksonville, Florida.
Gravity Probe B uses four ultra-precise gyroscopes to measure two
effects of Einstein's general relativity theory.
|
A scientist starts with a
bulldozer, follows with a shovel, and then
finally uses dental picks and toothbrushes to clear the dust away from
the treasure. We are passing out the toothbrushes now
William Bencze,
Stanford University |
One of these effects is called the geodetic effect, the other is
called
frame dragging. A common analogy is that of placing a heavy bowling
ball on to a rubber sheet.
The bowling ball will sit in a dip, distorting the
rubber sheet around itself in much the way a massive object such as the
Earth distorts space and time around itself.
Minute measurements
In the analogy, the geodetic effect is similar to the shape of the
dip created when the ball is placed on to the rubber sheet.
If the bowling ball is then rotated, it will start to drag the
rubber
sheet around with it. In a similar way, the Earth drags local space and
time around with it - ever so slightly - as it rotates.
Over the course of a year, these effects would cause the angle of
spin of the gyroscopes to shift by minute amounts.
The mission's principal investigator, Professor Francis Everitt,
from
Stanford University, discussed preliminary results at the American
Physical Society meeting in Jacksonville at the weekend.
The data from Gravity Probe B's gyroscopes clearly confirm
Einstein's geodetic effect to a precision of better than 1%.
The scientists from Stanford are still trying to extract its
signature of frame-dragging from the data.
They plan to announce the final results of the experiment in
December 2007, following eight more months of data analysis.
Larger puzzle
Professor Tim Sumner, a physicist at Imperial College London, told
BBC
News: "Having an announcement at this stage, on the way to the final
result, is very encouraging. I'm very pleased to see that the result
has now been released.
|
There is an expectation that at
some level we will expose a departure
from pure general relativity as envisaged by Einstein
Professor Tim Sumner,
Imperial College London |
"Most individual measurements are part of a larger puzzle. But
general
relativity is one of the big branches of physics and it is poorly
tested at the moment because of the relative weakness of gravity as a
force."
"I would see this as a piece of solid verification to underpin
general relativity, which occupies a special place in physics."
William Bencze, Gravity Probe B programme manager at Stanford
University in California, said: "Understanding the details of this
science data is a bit like an archaeological dig.
"A scientist starts with a bulldozer, follows with a
shovel, and then finally uses dental picks and toothbrushes to clear
the dust away from the treasure. We are passing out the toothbrushes
now."
Unified theory
Tim Sumner said few physicists were expecting to see a deviation
from Albert Einstein's predictions in this experiment.
But he said that other tests could start to reveal cracks in
general relativity, suggesting where modifications might be made.
Physicists have been unable to incorporate gravity into a unified
theory to describe all that is known about the fundamental forces
between elementary particles in nature.
Modifications to general relativity could be important steps
towards a unified theory.
"There is an expectation that at some level we will expose a
departure
from pure general relativity as envisaged by Einstein," Professor
Sumner said.
"One of the areas of general relativity that is less
well founded is when you get into very intense gravitational field
interactions. Some astrophysical objects will be in very high field
situations such as pairs of massive black holes orbiting one another."
A joint mission between Nasa and the European Space
Agency called Lisa (Laser Interferometer Space Antenna) will study
gravitational waves coming from binary systems such as these.
General relativity is not expected to break down in
these situations. But Lisa should help scientists understand how the
theory works in "high field" gravitational regimes such as pairs of
massive black holes.
Other experiments are due to test the equivalence
principle, one of the foundation stones of general relativity. This
principle stems from the observation that when two objects are dropped,
they will accelerate at the same rate.
"Here there is a theoretical framework where one might
expect to see a departure from the equivalence principle," said
Professor Sumner. "This might give us pointers as to the way forward."
The Imperial College physicist is involved in two
mission concepts to test the equivalence principle. One is the
Satellite Test of the Equivalence Principle (Step), which has been
proposed by some of the same scientists involved in the Gravity Probe B
mission. Another is the GrAnd Unification and Gravity Explorer (Gauge).
Gravity Probe B was launched from Vandenburg Air Force
Base in California on 20 April 2004. It transmitted its data for
exactly 50 weeks, from August 2004 to August 2005.