What is time? Does time has a start? Can we travel through time? What is the nature of time?

I believe that time started when humans started to notice time....It is also mental concept for we possibly created time and its like tool to navigate the universe with and with it we have been able to invent equations in physics and math....And can we travel through time? Well I guess only time will tell....

Hi yi ching master,

Those are very good questions, and unfortunately there is no real answer to most of them yet.

What is time ? Perhaps the best definition I have heard so far is that "time is what prevents everything from happening at once". In most (and I would like to say "all") theories we have the moment, time is just treated as a parameter that can have any real value.

Does time have a start ? According to the Big Bang hypothesis, the fabric of spacetime was created when the big bang occured. Hence, under that hypothesis, time started at the big bang.

Can we travel through time? That depends on how you want to define time-travel. Can you go to the future ? Yes, Einstein's theory of relativity predicts that if you get in a spaceship and take a flight through the solar system at a high enough speed, you can travel any time you like into the earth's future almost instantly (as long as you go fast enough). Going backwards in time is not possible according to Einstein's theory of relativity, and you are probably well aware of the many paradoxes that can arise by traveling backwards in time (e.g. the grandfather paradox). There is no theory or evidence yet, but most physicists assume that travelling backwards in time is not possible.

What is the nature of time? The answer to that question will bring you fame, fortune, and a Nobel prize or two... Be sure to drop me a note when you have the answer ;).

Bye!

Crisp

-time alone does not exist. it is a measurement relative to space, hence "time-space".
-this being said, it starts when we choose. much like a timeline, we decide a beginning, end and increments according to our purpose. we measure a year as one revolution of the earth around the sun. if we lived on jupiter our years would be longer, yet our physical progression wouldn't be affected.
-as far as travelling through time, we do every day as we continue to measure its' progression. :D
travelling through time is like retracing energy back from its source. as your energy has passed a given point, you would be unable to fold back upon yourself so you would not have to worry about the time-space continuum. you may be able to travel through others' pasts since your relative perception of their energy has not yet been established. a ray from the sun cannot reverse its course, but it can reflect back upon the course of other rays.
-webster's defines nature as "the inherent character or basic constitution" time is incremental. it is also subjective. who is to say when a year begins or when it ends. the traditional chinese differ from what is generally accepted today. i have used "progression" above because it is the true master of time. we use time to mark points in our existence, and our place in history. we use time to measure our cells' finite number of reproductions due to degradation in mitochondrial dna. when mitochondria stop producing energy, the cell ceases to function, as do we. that is our internal clock, our basis and need for time. the "inherent character" is as a measurement. the "basic constitution" is perception. other types of measurements, length as a foot or a meter, are a matter of acceptance. so is time in that it tracks different progressions and allows us to structure an otherwise unmanagable future.

We know that American gained independence "before"French build their Republic. So what is before Big Bang?

A theory called `membrane theory` supposes that two membranes floating in 5 dimensional space collided to form the Big-bang.
The collision perhaps gave the energy to create all the matter and space.
There was not really a `before` ( as in time) because technically time was created at the BB.

Time itself may be a quantum unit, there may be `bits` of time, like frames in a movie-film.
And created by constructive/destructive temporal waves that propagate from individual events. These waves called retarded and advancing waves travel (instantaneously) through time (one forward and one back-wards) and interfere with itself.
The boundary conditions (BB & end) of the universe impose the direction of time (the arrow of time)
.

Hope this helps.

The mind invented the concept of time to represent the changes which happen in real world.

Every thing changes. To give the changes a name (symbol), human created this concept (time)
Since, changes happen in different rate, human invented tools (clocks) to measure and compare speed of these changes (flow of time).

Human discovered rules of change for many phenomena.

Now can we reverse the direction of changes (the direction of time)?

Physics laws do not say it is impossible to reverse the direction of time.

In fact, theoretically, it is possible to reverse.

However, human are not capable yet of converting this dream into reality.

Einstein proved that time does not have the same flow rate over the entire universe.

Each location in the universe has its own clock, which is correlated to the geometry of gravity in that place. The greater the gravity, the slower the time .

And since gravity is caused by mater, can we say the ani-mater can creat a negative gravity and then reverse the direction of time.?

God knows

Thanks

-some hold that all the galaxies within our known universe are indeed coming together towards the center of which may be a great amount of dark matter. when all has been consumed into infinitely dense mass (black hole) this will then explode into the next big bang. if that theory is correct, which i'm not sure it is, then before the big bang was time as perceived by the current residents of that universe.
-another way of looking at it is similar to western civilization's time line. big bang = 0, prior to BB = BC, time since BB = AD
-as i stated before, time is a subjective measurement we use to our own ends.

Yes it is true that there is a <b>great attractor</b> that is pulling our local cluster of galaxies to-wards the direction of Sagittarius.

But the latest findings of the(<i>now renamed</i>) WMAP probe show that there will <b>not</b> be a big crunch...
It seems that the universe will sail on, forever expanding (<i> not including the big rip</i>)

@skyline
Not to detract from what you were saying, but, it is the `<i>reality</i>` of time that we should discuss here, ( or move it to the philosophy section), it is true that we as humans have evolved to perceive time with our own unique view-points .
We should perhaps be discussing how we may learn more (<i>experimentally</i>) about the nature of time.
(Anybody know about electron resistance in free-space?)

As I've said in another thread, it's just our conceit that makes us measure time the way that we do, to conform to the way we have been perceiving its passage during our extremely short stay here. That system of measurement creates the appearance of a lower bound.

Graph time on a log scale. That will help with two problems.

1. It will do away with the hypothetical lower bound.

2. It will make everything that appears to have happened so quickly near that illusion of a lower bound appear to have happened at much more normal speeds.

It seems to me that if time did not exist before the BB then neither did cause and effect. This seems to make the idea of membranes colliding, or anything at all happening, before the BB rather counter-intuitive. If time did not exist prior to the BB then surely the BB must have been causeless, at least in our normal sense of 'cause'.

Being that time is another dimension of space...space-time... is it possible there can be found an equivalence relationship between the second and the meter (or any time and length unit).

If so, some things start to get weird. v = dx/dt if tey have the same units then v has no real unit at all. It simply becomes a slope.

Is any of this possible? Or should we just always and forever seperate time and space units.

-AntonK

Supposedly, there is a smallest unit of time and of distance - something like 10^-23 seconds and 10^-33 meters or something. The smallest unit of distance comes from Planck's constant, and the smallest unit of time is the time it takes for light to travel that distance. In that sense, distance and time ARE related, and the conversion factor is the speed of light.
Aaron

Originally posted by synergy
Supposedly, there is a smallest unit of time and of distance - something like 10^-23 seconds and 10^-33 meters or something. The smallest unit of distance comes from Planck's constant, and the smallest unit of time is the time it takes for light to travel that distance. In that sense, distance and time ARE related, and the conversion factor is the speed of light.
Aaron

then what happens if the speed of light can change?

synergy,

a small correction. the Planck's distance is 1.61 x 10^-35 meters and Planck's time is 5.36 x 10^-44 seconds. they r not the smallest. they r the minimum possible 'seeable/observable' units of distance and time. after all the planck's time is, as u said, the time required by light to travel 1.61 x 10^-35 m (planck's distance). Distance and time are continuous not quantized by these units. in short, continuum of space-time is not quantized.

Wait a second.
I read somewhere that the speed of light, is slowing down. Forgive me for not knowing the details, I read this awhile ago, and didn't fully understand it. But does anyone else know what I'm talking about?

Another thing:
Time travel, SHOULDN'T be possible. It would complicate the universe.

~Nivao
Ghost of Mirkwood

Time is not something you can examine.
Here is event flow.
Future -> Present -> Past -> past
Time here is in the flow.

I was talking about the SPEED OF LIGHT slowing down, not time. Wait... was it time? I forget. I was hoping someone could refresh my memory.

I'll let time "flow on."

Namarie

~Nivao
Ghost of Mirkwood

@everneo

Hum, it seem to me that string theory predicts that particles and space/time are made of tiny strings.
These units are the basic quanta of space/time.

And as for the velocity of light changing then it is possible that it could have.

Time is the way the human mind percieves entropy.

@ Xev
i imagine it possible to perceive time with a mechanical mind, or a alien mind. The perceptions may be different,but the underlying `reality` is the same( imho).

As an update to my previous post....
Using two HST images, astronomers from Italy and Germany looked for but did not find evidence supporting a prevailing scientific theory that says time, space and gravity are composed of tiny quantum bits.
http://www.spacedaily.com/news/cosmology-03i.html

By inverting Albert Einstein's theory of relativity (E=mc2 becomes m=E/c2), physicists could calculate how much mass should be added to a photon as it gains energy. Using that, they calculated a theoretical limit to how much energy a photon might contain before gaining so much mass it would collapse into a photon-sized black hole.
That theoretical upper limit was then used to set theoretical limits on time. One cycle of a photon carrying that much energy would last 5 x 10-44 seconds, an interval called Planck time. As the shortest potentially-measurable interval of time, theorists speculated that time moves is Planck time-sized quantum bits.
Since the expected blurring "signature" of quantum space time isn't seen, however, it might mean that time isn't made of quantum bits, and neither are space or gravity.

This goes against all current thinking (along the ideas of membrane theory), and contrary to findings from a previous study published a few months ago...

Time is the property of the universe that allows change. It may be the resultant, on some quantum level... of change. For instance if a quantum state exists in an isolated system, then for some reason the state collapses, time ensues because change has occured (at least I wildly theorize).... I'm saying this while imagining the "quantum foam" that I've heard theorized that must have exists before the big bang or "great expansion". Once the ball is rolling though, it cannot be stopped because it's basically the beginning of a chain reaction of ever changing states...

A note about the psychology of time: An important realization in our understanding of time is that the human mind can not percieve an individual moment in time but instead percieves a slice of moments in time. Psychologicly speaking that is what time is along with your memorys.
As for what time is concerning physics, we can say it is part of space. "time" as the word is used in physics is one dimension of space (the 4th) that energy passes through. A note of importance is that sense we do not have a complete understanding of everything then we may not have a complete understanding of time because time is part of everything. Time-Space as it should be reffered to in physics is a mathmatical model that is used to express our understanding of reality. One hypothesis is that Time-Space is unifide with matter/energy so that the all the pieces of the universe is actually one whole thing that we understand with a mathmatical model. So we can say that the energy that is moving through time is actually part of time and time is actually part of space as well if this hypothesis turns out to be correct. When we get to that understanding of unification or have another final theory we will be able to deffinitly say what time is; part of our model(s) of reality.

According to the theory of interaction /1/ what we see as time is created from interactions that occur at the scales of the interaction that builds the observation. Thus we see changes perceived as time. Similarly larger sources of interaction create what we see as space.

Time is what occurs at the scales of perception /2/.

The universe is made of self-reproducing and that is why similar sources of interaction /1/.

1. http://www.eugenesavov.com

2. Savov, E., Theory of Interaction, Geones Books, 2002

Cybermorphic - Nice post. In particular:

"A note of importance is that sense (as?) we do not have a complete understanding of everything then we may not have a complete understanding of time because time is part of everything"

We have a bad habit of forgetting this in almost every circumstance. Science will have no foundation until we sort out metaphysics.

time is a measurement of an abstract concept that a only small number of universe organisms care about. that is all. :)

what you really should be asking is: do you wear a watch? if so, why? as a measure of conformity? so you can say "it will be done by 3pm" ?

ask a child what time is.. he wont have much of an answer, as the concept doesnt have much of a meaning to them.. they play out till they cant see, they sleep till they arent tired.. how much of a better world it is when man stops imposing limits and measures

@cjard

Yes i agree with you.

Our concepts influence on how we understand how <b>time</b> fits into the GUTs theories or string theories...

BUT we do need to find out the true relationship that time has to gravity and matter and the 10 dimensional space that we may inhabit...

We may have to forget our concepts , and perhaps create new mathematical tools to describe time...
The bounded membranes , <i>before the big-bang</i>, were in a `timeless` 5 dimensional space... !!!

We don`t have a concept for that!
But when they collided they created (the big-bang) our `normal`, and conceptualised space/time framework...


;)

Originally posted by blobrana
[BThe bounded membranes , <i>before the big-bang</i>, were in a `timeless` 5 dimensional space... !!!
;) [/B]
Well that's settled then.

Originally posted by blobrana
@cjard



We may have to ... create new mathematical tools to describe time...


i find that the Casio tool my mum bought me for christmas, does quite well. but even when i dont have a watch, i dont really care.. the current time has never been something that i've really wanted to know

time reltes to gravity? nah.. time isnt even linear.. only the aspect that we choose to interpret is.. trying to relate it to gravity is like trying to relate an engine bolt to the road.. the bolt is part of a bigger picture that has little bearing on the external factor, when considered as a part, rather than a whole.. stop worrying about it :)

In one of his books or perhaps in an essay for laymen, Einstein talked about time. He said something like the following.When an individual thinks about the events in his life, he is able to order them using the criteria of before and after. He can assign numbers to the events in such a manner that events with smaller numbers occurred before events with larger numbers.

It is convenient to use a device called a clock to provide the numbers assigned to events. It is also convenient to use a variable called time in many of the formulae of physics.

It is reasonable to believe that the time variable of physics is related to the concept involved in the ordering of events in the life of an individual.

The concept of time cannot be analyzed further.I encountered the above when trying to make sense out of many chapters in a book assigned by a philosophy professor. After rereading the book, I decided that it really said nothing meaningful, but the Einstein view was as good a description as I was likely to find.

I recently read an article which objected to the concept of time flowing from past through the present to the future. That article said it was best to think of time as a measurement analogous to distance. which seems similar to what Einstein said. When one measures distances along a line, there is no thought of distance flowing from one point on the line to another.

One merely says that point X is so many meters from some starting point. Similarly, one says that event X happened so many seconds after some starting instant.

It is the events and processes that have meaning, not the time or distance variables used in the formulae of physics.

@Dinosaur
I found this unfinished article on my computer...( i was looking for a reference to the Einstein/wheeler/Feynman theory of time...

Where the direction is created by the interfering action of retarding and advancing waves, and by the boundary conditions of the universe. The BB is closed , and bounces the waves back to the open end (that can`t reflect the waves)...thus a direction is formed...

The Second Law of Thermodynamics

Thermodynamics is the branch of theoretical physics which deals with the laws of heat motion, and the conversion of heat into other types of energy.

1) The first principle is the law of the conservation (it can never be created or destroyed )of energy, which assumes the form of the law of the equivalence of heat and work.

2) The second principle states that heat cannot of itself pass from a cooler body to a hotter body without changes in any other bodies. This states that "entropy" (i.e., the ratio of a body’s energy to its temperature) always increases in any transformation of energy.

Entropy is generally understood to signify an inherent tendency to-wards disorganisation. Everything tends to pass from a state of order to disorder, there appears to be a general tendency to-wards chaos. According to the second law, atoms, when left to themselves, will mix and randomise themselves as much as possible. The fast moving atoms collide with the slower moving atoms and transfer their energy to them.

This law was redefined by Ludwig Boltzmann. His version, derived from the atomic theory of matter, entropy appears as a function of the probability of a given state of matter: the more probable the state, the higher its entropy. In this version, all systems tend towards a state of equilibrium (a state in which there is no net flow of energy).

Boltzmann was the first one to deal with the problems of the transition from the microscopic (small-scale) to the macroscopic (large-scale) level in physics. He attempted to reconcile the new theories of thermodynamics with the classical physics of trajectories.
Following Maxwell’s example, he tried to resolve the problems through the theory of probability. This represented a radical break with the old Newtonian methods of mechanistic determinism.
Boltzmann realised that the irreversible increase in entropy could be seen as the expression of a growing molecular disorder. His principle of order implies that the more probable state available to a system is one in which a multiplicity of events taking place simultaneously within the system cancel each other out statistically. While molecules can move randomly, on average, at any given moment, the same number will be moving in one direction as in another.

There is a contradiction between energy and entropy. The unstable equilibrium between the two is determined by temperature. At low temperatures, energy dominates and we see the emergence of ordered (weak-entropy) and low energy states, as in crystals, where molecules are locked in a certain position relative to other molecules. However, at high temperature, entropy prevails, and is expressed in molecular disorder. The structure of the crystal is disrupted, and we get the transition, first to a liquid, then to a gaseous state.

The second law states that the entropy of an isolated system always increases, and that when two systems are joined together, the entropy of the combined system is greater than the sum of the entropies of the individual systems.

We may however get order out of Chaos , with biological systems...nature is complexity and ordered in sharp contrast to the rest of the inanimate universe...

But it is an illusion...

life is only a small sub-system of the greater (closed) system...

It seems to me that entropy is only a product of the `action` created by the retarding /advancing waves...

In an empty universe , there would still be time/space...



"This is the way the world ends
Not with a bang but a whimper." (T. S. Eliot)

Wheeler's comment was that time is what stops everything from happening at the same time.

The entropy thing is OK but its a funny way of looking at it. Usually people say something like - It's easy to break your coffee mug by accident but there's no way the pieces are going to jump back together again. There are too many ways it couldn't happen. Entropy has thus increased and in this way the arrow of time is defined.

However this seems to completely ignore the problem of how the unbroken mug came into existence in the first place, and the infinite number of ways that it might not of done. I don't know why this is always ignored. Is there some scientific reason I don't know about? Entropy seems a muddled idea in some ways.

Canute: The point they try to make with the mug breaking is that this process is not reversible. It took intelligence and energy to create the mug, but that intelligence and energy could not remake the mug by reversing the accidental breakup process.

I always thought that the evaporating perfume was a better example of entropy increasing.

I don't think this makes sense. The making of the mug is even more irreversible than the breaking of it. After all at least all the bits are in roughly the same location. Don't forget that it also took energy to break the mug.

I agree that the perfume example is better, but the same objection applies. By what incredible, irreversible and strictly deterministic process did the perfume get in the bottle in the first place? It probably took energy to put it there, thus an increase in disorder, but then it also took energy to release it.

To get away from perfume and mugs - was the universe at the BB the most ordered state of its energy or the least?

At the time of the Big Bang, the universe was in its most ordered state. It has all been downhill since then.

It takes energy to get all the perfume in the bottle and/or to manufacture the mug. The efforts & energy required result in entropy increase elsewhere. The order represented by the perfume/mug is paid for with overhead by increased disorder elsewhere.

Ignoring entropy and disorder, it is interesting to consider the requirements for reversing classical world processes.

Consider dropping a steel ball bearing into a conical container partially filled with water. Assume it was dropped in the center. High speed photos by Edgerton show that a very symmetric pillar of water with a round drop on top appears momentarily just after impact. Concentric circular waves move outward on the surface toward the perimeter of the tank. Some concentric shock waves move outward as the ball bearing displaces water while on its way to the bottom of the tank. There are small energy exchanges between water and the material comprising the container.

Every quantum world interaction involved in the above is reversible. In theory, applying precise amounts of energy using some very rigid time table would cause the entire process to reverse. The ball bearing would rise like a buoyant object and leap above the surface of the water. The interesting pillar and ball of water would be reformed.

Another thot about reversibility.

Imagine a motion picture of the manufacture of a mug or of its accidental destruction in a fall. Either movie played backwards would be recognized as being a time reversal of the actual events.

Even a SciFi creature formed of pure energy metabolizing star light to maintain itself, would be able to figure out which way to play such movies. Our knowledge of which way to play the movies is not due to our experience with mugs. It is more fundamental than that.

BTW: A reversal of the Big Bang movie would be accepted as okay if it did not provide enough detail to show the life cycle of stars from condensing dust cloud to black hole, neutron star, white dwarf, or dead cinder.

Technically, there should be a <b>perfect</b> reversal of time (<i>with the old newtonian ideas</i>) , and it would just be a case of <b>probability</b>...


but there is the <b>CPT</b> reactions that put a stop to that idea...

http://www.spacedaily.com/news/physics-03d.html

I don't believe you could sensibly construct a realistic arrow of time based on Feynman-Wheeler transactional theory. If there was reflection of advanced (backward propagating) waves at the initial boundary condition, then one would expect that reflection to either reinforce or destroy the incident wave (ie interfere constructively or destructively). If the interference is destructive, the postulate is only a theoretical exercise - there will be nothing to detect. If the interference is constructive, why don't we already detect echoes?


To the original question:

Most physical theories use time as an operator or placemarker to define rates of change. The theory which doesn't have time playing a background arena role is relativity. In relativity time is a single dimension in a four dimensional geometry called "space-time". Time is then just intervals along a given coordinate dimension.

It's important to realise that nowhere in modern physics is there a notion of the "passing" of time. This particular concept seems to be a peculiarity of humans. I have read a convincing anthropological argument which suggests that our notion of time passing stems from the way we catalogue and order memories, which in itself is tied to our development of recording of history. With these comes our understanding of the distinction between "future" and "past", and the constant storage of experience as memory (ie turning "present" into "past") makes us think time is passing. However physics (and by extension the greater universe) can be completely understood by treating time as a series of coordinate references and intervals. No passing. Just events here and there which we might order by reference to Arrows of Time.

An arrow of time distinguishes unambiguously for us between "future" and "past". This might at first sound trivial, however much of physics is symmetrical under time reversals. Stephen Hawking in his "Brief History of Time" identifies three Arrows of Time:
i) The thermodynamic arrow - given two snapshots of the universe, the one with the greater entropy happened later
ii) The cosmological arrow - given two snapshots of the universe, the one with the expansion happened later
iii) The psychological arrow - people seem to be able to differentiate between future and past

Imo iii) is a manifestation of our ability to recognise i) in action. ii) is only the case in our particular universe at this period. In a contracting universe this arrow would reverse. Which just leaves us with i).


Hope this helps!
The Chicken

With respect , i think that the theory is the best that has been put forward, todate..

The influence of the wave (constructive/destructive ) depends on the universe being open...obviously the open end (boundary condition) does not reflect the advancing wave, where as the Big-bang `end` reflects the retarded wave...

This also ,however, raises the question of the possible creation of a universe without a `arrow of time`...

It seems to me that to have this particular universe (with omega =1) requires that it <b>has</b> a direction arrow...

<puzzled>Any thoughts?</puzzled>

What if galaxies, stars and planets are like enormous gigantic "atoms", which interaction creates what we see as space, while the coupling of the real atoms in one's brain is percieved as time.

Then time will be incorporated in every body from the interaction, the change, created from its interacting parts.

The interaction unfolds its finite sources, thus creating the unique moments of time (see the free downloads at [Advertisement removed by moderator])

What?

Are you saying that the planets and Galaxy's could be made of atoms?
And that atoms (or the creation of reality) are produced by the conscious <b>mind</b> of an observer?

Or that at every event (<i>even at the quantum scale</i>) the universe `divides` into separate temporal lines...?


<question>?</question>

the Big-bang `end` reflects the retarded wave...

Why don't we see echoes then?

It seems to me that to have this particular universe (with omega =1) requires that it has a direction arrow...

Why? Why does <font face=symbol>W</font> = 1 require an arrow of time?

Hum,

http://www.npl.washington.edu/npl/int_rep/dtime/node2.html

The theory of "advanced" waves,
are mathematically permissible by Maxwell's equations (time-reversibility ) ; they travel back-wards/for-wards in time... and allow the effect of this `radiation` to be felt <b>instantaneously</b> by an electron/particle (no delay for the reflection/effects to travel ).

The electrons, Of course, are constantly emitting particles
("photons") , AND space is always filled with these particles.
Basically all particles emit radiation <i>equally<b>/symmetrically</b></i> into the past and future.

"The observed properties of an electric charge, that it radiates energy and suffers damping of its motion can be explained in terms of an "absorber theory of radiation". They used the Schwarzschild- Tetrode-Fokker equation for a flat space and found that they had to postulate both "advanced" (future) and "retarded" (past) fields; the divisions of time seemed to be "inextricably mixed". ..."

If the radiation is confined to an opaque enclosure, so that all of it is absorbed, the waves striking (or not) the `ends` will cause the charged particles therein to radiate likewise into both the past and the future.

(BTW, The `reflection` is in the `time` dimention...) ;)

If the universe is fully opaque or open at one end, ( As in omega equals or is greater than one), ,,,,the advanced waves emitted by the `ends` will just cancel those from the source particle and through <i>construction/destruction</i> and only the retarded waves will be left. ... (thus arrow of time)

http://www.lns.cornell.edu/spr/2002-05/msg0041858.html

When the comet hit jupiter in July 10, 1994,
my deja vu began...did the massive explosion
warped space and time and affected time...
it affected mine....

Jacquie:

There are processes far more explosive than the comet hitting Jupiter happening all the time in the sun. I'm surprised the sun didn't trigger your deja vu long before 1994.

Let's just say it may have affected me prior to that but as far as consciously I was totally aware of the effect right after 7/10/04..perhaps it took that type of explosive energy to trigger
time warp instead of the sun's energy...the sun is hollow...
the comet hit jupiter the explosion was the size of the earth...
any ways....it is my theory based on my reality...

<i>...the sun is hollow...</i>

Do you have any evidence for that?

Originally posted by James R
[BDo you have any evidence for that? [/B]
Admirable restraint I must say.