|© Our Universe & what we know of it.
© Ron Lebar, Author. Edited: 27-9-9. Loaded:
Creation of the Universe.
It is generally thought the Universe was created around thirteen thousand seven hundred million years ago. Man has been around for less than one million of those years.
At the point when it all started, the laws of physics were already in place. There are probably many more than we know. All that has happened, all that will happen, is governed by them.
The hydrogen atom is the key. Its elegant simplicity is the basis of all matter & energy. A single positive electro-magnetic wave, with a matching negative wave in orbit.
The "age" of the Universe.
Data received from NASA's WMAP vehicle has been used to 'accurately' date the Universe. It seems it is thirteen thousand-seven hundred million years old, with an error margin of two hundered million years. Careful thinking shows an obvious & dramatic error in that age. Click here for an explanation.
Nothing is 'known' about the beginning of the Universe, not a lot is known for certain about its current state. There are many theories however, probably as many as there are people thinking seriously about it.
The 'Big Bang' theory is still favourite among those competing for its origin. This explains many things discovered during astronomical observations, it also opens up many more questions than answers.
It is postulated that a large explosion started everything off, debris flew off in all directions at high speed. Later some coalesced due to gravitational attraction, eventually forming stars, planets & galaxies etc.
Whatever caused the explosion in the first place is an open question, did someone light the fuse? Certainly the theory is not convincing regarding the 'pre-bang' situation. One suggestion is that the bang is a time reversed collapse into a singularity, this is attractive for many reasons & will be described further.
Some scientists accept that a creator is theoretically possible.
The speed of light in a vacuum has long been considered a constant. Much effort has been expended, over the centuries, in measuring it, using increasingly sophisticated techniques. It is now generally considered that its value is known, to a high degree of precision.
There are anomalies, in many areas of study, that bring current knowledge & values into doubt.
My solution to many of these problems is simple. The speed of light is not a constant, it is a variable. The only thing constant about it is that it is constantly varying. The principle of Ockham's Razor is that unnecesary complication should be avoided. If a number of possible explanations fit the facts, the simplest is more likely to be correct.
Improvements in telescopes over the years have enabled astronomers to see stars further away. It was discovered that the light from the most distant is shifted towards the red end of the spectrum. The most likely cause is Doppler shift due to motion away from us, the concept of the expanding Universe was born.
The 'big bang' theory for the origin of the Universe has much to commend it, it explains many observed phenomena. Some predictions resulting from it have since been verified. This is not proof, incorrect theories have, in the past, spawned correct predictions. It will probably do, until its turn comes to be verified or disproven.
More recently, with further optical improvements, an apparent anomaly was discovered. Light from even more distant stars was more red shifted than those previously found. It seems that the oldest stars we can see are moving away faster than those nearer. The Universal expansion is apparently accelerating.
Many theories have been put forward in an attempt to explain this observation. Some form of Universe wide repulsive force has been proposed, pushing the matter in the Universe apart.
This so called 'dark energy' works in the opposite way to all known energy & matter. Pushing galaxies & stars apart at ever increasing rates. This is probably another myth, like the aether.
It seems that physicists & astronomers are caught up in their own cleverness. They can't see an obvious explanation if it's about to bite them. The basic laws of mechanics may play a part. An explosion starts with rapid acceleration, then slows down, finally stopping. In the absence of other influences it then collapses back (implodes) due to mutual attraction. All the energy released during the first phase is returned.
Two possible outcomes. If velocity due to kinetic energy exceeds that required to escape from the gravitational pull of total mass, expansion will continue unchecked. If not, everything will eventually collapse towards the centre. Astromomers use the letter Omega for this ratio. It is theorised that an Omega of unity (1) will result in a stable fixed size. This can only occur (for a limited time) if part of the outward motion is circular. <Return to beginning>
If this model is used for the universe a number of simple explanations for red shift are possible. The most obvious is that the outer stars are further away. The light we see from them is from a time when they were moving faster, as were the nearer stars. By now they may be much slower, even stopped altogether or heading back towards us.
Another, more fundamental, explanation is that c was faster when the light from those stars started out. Since then light has been slowing, together with the frequency of that light. Hence the red shift, which will be greater with increased distance. So the Universe may no longer be expanding, for all we know it may be contracting.
It is probable that, at the time of the 'Big Bang' light travelled much faster, possibly by an astronomical ratio, & has been slowing asymptotically since. This will provide, in conjunction with red shift, another way of estimating the Universe's age.
In any case stars further away than those yet discovered may be more red shifted. Possibly into the infra-red or even radio frequencies. Radio telescopes are difficult to focus with sufficient accuracy to pick out individual stars, but this problem needs to be addressed, in order to find them. <Return to beginning>
Yet another possibility is that the Universe is static in size. The red shift being solely due to the gradual slowing of light. In this case it will presumably continue slowing, eventually reaching a speed that we would not be able to distinguish from stationary. I do not give this one much credence.
It is likely that estimates for the age of the universe based on red shift need to be revised. The premise of expansion on which they are founded being wrong. The Hubble measure, based on white dwarf's decay, is not affected. Its accuracy is open to debate though.
Much is said in astronomical circles about this strange postulated ratio, Omega. It is defined as the ratio of the Universe's total mass to a certain 'critical mass'. If Omega is less than one the Universe will continue to expand, without limit. If it is greater than one the Universe will ultimately collapse in on itself, with all that that entails.
I specify Omega more simply, as the ratio of mass to kinetic energy. If the kinetic energy of the matter in the Universe is sufficient, it will escape. If it isn't, it won't.
There is no mystery, it is a simple engineering requirement. Take an example a little closer to home. If we propel an object vertically upwards from this planet's surface, one of two things will happen. If it initially travels fast enough it will escape the pull of gravity & continue into space. If only slightly slower than a certain figure it will fall back to earth.
The critical figure is called escape velocity & is set by the downwards acceleration, or upwards deceleration due to gravity. For Earth it is around 25,000 miles per hour, not allowing for air friction, for a more massive planet it will be higher. As the object moves away from the planet, it is slowed by gravity, at the same time gravitational pull weakens & the required escape velocity lessens.According to astrophysicist's theory, there is one exact starting velocity at which the object will rise, slowing to an eventual halt & remain in geo-stationary orbit. At any other speed it will escape or fall back. The same applies to the Universe, but is complicated by the existence of more than one object and more than one planet. Any matter that is travelling fast enough will escape. Any that isn't will collapse back towards the centre. It is not possible for an Omega of one to result in a static Universe, this would defy logic & natural laws. <Return to beginning>
As energy, including light, travels from place to place it is doing work. work done equals energy transferred, resulting in a reduction of velocity. All of space is filled with a gravitational field, from the matter bounding & pervading it. As Albert Einstein proved, when light crosses a gravitational field it slows, losing energy. All of the energy in the Universe has probably traversed it many times, during its lifetime.
With this in mind there is no need for the Universe to be expanding, therefore the 'Big Bang' may not have happened. For a static or 'flat' Universe the outer galaxies must circle, so that centrifugal force counters gravitational attraction. There is evidence for this, that circling also does work, so will tend to slow. So it is unlikely that the Universe is truly static. Will it all stop one day?
As c slows the total energy available for work reduces. Albert Einstein gave us the simple equation E=mc2. E is energy, m is mass & c is the velocity of light. So the energy available in a body is equal to its mass multiplied by the velocity of light squared. This amount of energy is huge, even for small amounts of matter, but can only be obtained by complete conversion into energy.
Chemical processes, such as burning, only release some of the energy in molecular bonds, a minute fraction of the available energy. Nuclear fission processes, as used in nuclear power stations, release some of the energy in matter's atomic bonds. They are inefficient, none of the matter itself becomes energy, merely its form changes.
A uranium 235 atom, split by a single neutrom impact, the same mechanism as used in the first atom bomb, gives two new smaller nuclei, plus 2 neutrons. The total mass obtained is 99.9% of the original nuclear mass. So 0.1% of the original mass is converted to energy.
Leaving noxious by-products, with lower energy yield & nuclear decay times of Centuries or Millennia.
The equation shows the relationship betwee energy & light speed. If we assume that light reduces to half its present speed, what will happen? If only the c2 part is considered, it seems that the energy available will be one quarter of its previous value. But is it as simple as that?
What happens to the mass in this case? Try a little transposition from E=mc2. Dividing both sides by m leaves E/m=c2. Taking the reciprocal of both sides gives m/E=1/c2. Multiplying both sides by E gives the answer m=E(1/c2). If c has halved then E is one quarter of its previous value, c2 is a quarter of its previous value, thus quadrupling its reciprocal. So despite having one quarter of the energy, mass is unchanged.
The implications for us.
Assume that current theory is right, in some respects at least. The speed of light is distance travelled divided by time taken, c=d/t. Distance is measured in metres & time is measured in seconds. The metre is specified in the S.I. system as the distance travelled by light in one second, divided by 299,792,458. So the measure of distance is proportional to light speed.
The most accurate short term means of time measurement available to us is a hydrogen maser clock, using the spin rate of an atom's electron. This has an angular velocity of c/137, so the measure of time is proportional to light speed.
The SI standard for one second is the duration of 9,192,631,770 cycles of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom. So this standard is proportional to light speed.
If light slows to half its current speed, then the metre will become shorter, by the same amount. This will cause everything to measure twice as large, with eight times the volume, for the same mass.
Time will slow to half its present rate, thus the second will be twice as long. This will exactly cancel the change in linear measurement, thus restoring the status quo. So everything will actually seem unchanged in size & density.
So basing our system of measurement on the speed of light means that we will remain unable to measure changes in that 'constant'. The reduction in available energy, proportional to the square of c's change, will be real & measurable or will it?.Surely, if everything is actually occupying only one quarter of the volume, only one quarter of the energy is needed? So everything will appear to be just as it was or will it? The nature of mass is still a problem for current theory, as is the nature and speed of gravity. So have we got anywhere in the last one hundred years?
Thousands of millions of years will pass, before c halves. So we have no need to worry, just yet. But it will be nice to have some idea of what that future may hold in store.
To be continued...
Using data from the Wilkinson Microwave Anisotropy Probe (WMAP), the age of the Universe has been calculated as 13.7 X 109 years, give or take 200 million. The furthest stars that we can see appear to be 13.5 X 109 light years away, therefore they must be that old for light to have managed to reach us.
The first stars seem to have formed a mere two hundred million years after the 'big bang'. Adding these two figures gives the age of the Universe.
There is an obvious error in this reasoning, if the farthest stars are that far away, how did they get there?
Assuming that they travelled as energy, then somehow converted into matter, they would take 13.5 X 109 years to reach the point when the light we see started back. Add the return journey plus 200 million years to form into stars, this comes to 27.2 X 109 years as the minimum possible age for the Universe.
The only way out of this difference is to assume the distant stars, along with everything else, were instantly created where & as we see them now. This of course totally negates the 'big bang' theory.
This alternative does not fit most astronomical observations. Assuming that it is not acceptable leaves unresolved issues. It is unlikely that energy would travel that distance, then stop & condense into matter.
The more likely answer is that matter travelled at a more sedate pace than c, on the way condensing into stars & galaxies. This makes the Universe considerably older than 27.2 thousand million years. If the average outward travel speed was half current light speed, then 40.7 thousand million years is the minimum possible age. There seems no way out, either instantaneous creation or a very old Universe.
None of these alternatives allow for future improvements in optical sensitivity showing us even more distant stars. The fact remains, as it always has, that we do not know the age or extent of the Universe. It is unlikely to be infinite, bur it is almost certain to be larger than we can ever know.
There is a lot of talk about possible sizes for space, is it finite or infinite? Is it static, expanding or contracting? The truth is, space has no size, of itself it does not exist. What we call space is merely the gaps between physical entities, including energy.
As for the Universe, a lot is said about various models for its existence. Is it open or closed? Is it expanding, static or contracting? There is no possibility of a static Universe, it can only expand & has been doing so since its creation. The speed of that expansion can only be the speed of light (c).
The matter in the Universe may expand or collapse, it can not stay still. Its radiated energy is forever travelling outwards & is lost. So the whole thing will slow & cool down. The cyclic Universe is a possibility, but each time it recycles it will probably have less total energy, although possibly retaining the same mass.
All theories are conjecture, nothing more, no matter how authoritative they seem. They are no more cast in stone than the old beliefs, such as the planets & stars being drawn around the heavens by horses.
This latter is unlikely, since some-one would have to be out there, to feed them.
All opinions on this subject are exactly that, opinions, including mine. For an alternative theory on the age of earth, together with reasoned argument, click on this link.
Whatever we choose to call it, science, philosophy, religion, much remains a matter of faith.
We Wish ALL the Universe Peace, Justice, Equality, Prosperity & an End to Fanaticism.