It is not a formal theory. It is an assumption that we logically "predict" to have happened back in time. It stemmed with Hubble's observation of the recession of galaxies (Hubble law 1929) : the farther galaxies are the quicker they recede. So, there should have been a starting point (first interpretation by Lemaître in 1927, who was aware of Hubble's first results for a piece of 40 galaxies).
Big bang theory is a speculation based on Space-time Singularity theorems. However, the singularity theorems are based on assumptions, Which are now proven invalid. Also the interpretation of the Hubble's law as supporting evidence is actually invalid.
So, the big bang theory is a groundless speculation only.
....... The 1927 article of Lemaître was in French (copy enclosed). Sir Arthur Eddington translated it into English in 1931, but without the part on the piece of 40 galaxies (42 exactly).... On request of Lemaître himself as it seems : see link below !
http://www.nature.com/nature/journal/v479/n7372/full/479150a.html
Hi, we observe that objects in space generally move away from us. as there is no reason to assume we have a special positon in the universe, expansion of space itself would explain that observation. the ratio of that expansion to the distance is called the hubble constant and can be messured as here: http://ned.ipac.caltech.edu/level5/Sept01/Freedman/Figures/figure1.jpg
if you do the math than, you will get roughly 13 billion years for the time passed since the distance was... Zero! (see file attatched)
though, the assumption made here is a constant value for the hubble "constant", which is not sure.
Hope this helps :)
best
Patrick
Dear Mahmoud,
Observations of an expanding universe (redshift of light emitted by distant galaxies) indicate that at some point in the past, the universe was compressed into a point of infinitesimal volume. Therefore, it is a theory based on astronomical observations, i.e., phenomenological.
Ales,
When I speak of infinitesimal, I am not referring to an infinitely small size, only to a very small volume, similar to the dimensions of the known atoms.
Ales,
The primeval atom is an hypothesis of Lemaître : see link below. To my knowledge, there are no (and probably there won't be before long time ...) observational data leading to such an "atomic" smallness of the universe in the beginning !
Historically, Fred Hoyle made fun of the idea calling it "Big Bang" (in a radio program in the years 1940 if I remember well). But with time going the "Big Bang" idea was well accepted by the community of physicists (of course with the reservations made in the post of Robert J. Low putting guard against "oversimplification").
https://books.google.be/books?id=N3l4Rngj4B0C&pg=PA202&lpg=PA202&dq=%22primitive+atom%22%2B%22lemaitre%22&source=bl&ots=M5osUvK9Ad&sig=KqGxa7YMuIKaRenon93wut0_FUY&hl=fr&sa=X&ved=0ahUKEwig75yh09TLAhUCcBoKHaMNCc4Q6AEIHjAA#v=onepage&q=%22primitive%20atom%22%2B%22lemaitre%22&f=false
Ales:
We can make a calculation without much difficulty as follows:
1. According to: The "Magnitudes of Physics", published by The Physics Teacher, the radius of the universe is ~ 1x10 ^ 28 m.
2. The age of the universe is ~ 13,800,000,000 years.
3. If we go back to the time of Planck (10 ^ -43 seconds) before of the inflationary period.
4. We can calculate that the diameter of the universe was ~ 4.6 x 10 ^ -33 m, which is smaller than an average atom.
I think it is a good approximation.
In Euclidean spaces with the number of spatial dimensions of a large three the Lorentz transformations are obtained elementarily, if the proper time of an elementary particle assumed to be proportional to the path traversed by it in the extra space, supplementing the observed three-dimensional space until a Multi-dimensional space, provided that the elementary particles like photons, moving at the speed of light in the whole space. All areas of the universe larger than 300 million light years have the same properties. The universe is a three-dimensional sphere, expanding in the space of a higher dimension. Elementary treatment of a spin, isotopic spin, Heisenberg relations as well the magnetic moment of the electron all require 6 spatial dimensions. Therefore, cosmology must also take into account the 6 spatial dimensions of a complete space.
Six-dimensional interpretation of the expanding universe is built on the principle of simplicity. The simplest geometric object of finite size in the 6D Euclidean space is a 5D sphere. Therefore, the simplest 6D interpretation of the expanding 3D sphere is its representation as the intersections of three 5D spheres expanding in the 6D Euclidean space − three 5D spherical frontiers of disturbances propagating in this space. Thus it is assumed that these perturbations occurred as a result of three separate ‘explosions’ in the centers of these 5D spheres. Point of first contact of the three 5D spheres corresponds to the location of the center of the three-dimensional universe in the 6D space. The intersections of three -dimensional spheres are three -dimensional spheres, which, in turn, intersecting to form three -dimensional sphere, etc.
The theory contains 5 free parameters. For the chosen parameters in the case N = 5, the many results of the theory and observations are compared. By this, the radius of the Universe is 7100 Mpc, the Metagalaxy radius is 3980 Mpc. The speed of light on our three-dimensional sphere and the speed of its radial expanding of this sphere are connected by Pythagorean’s theorem. Sum of the squares of the two speeds is assumed constant according to the principle of simplicity. By this the velocity of light was equal to zero when the radius of the Universe was less than 18 percent of the current one in the case N = 5 . From this point the speed of light is constantly increasing, asymptotically tending to a constant limit. Increase the speed of light leads to increasing of proper energy of elementary particles and thermal energy of stars and planets.
See
I. A. Urusovskii, Multidimensional Treatment of the Expanding Universe,
Physical Science International Journal, 4(8): 1110-1144, 2014.
I. A. Urusovskii
Ales and all others,
Thank you for your words of sympathy. What have we done indeed ? Why do humans commit suicide to kill as many as possible other peaceful humans ? Why do educated modern people want to foster terror and to induce the feeling of an ubiquitous world fight against democratic values ? Brussels airport .... And metro station Maelbeek which is at 3' walk from the European Parliament, 2' walk from the European Commission buildings (and 1' walk from Belgian Prime Minister's office).
The big bang theory is theoretically based on the singularity theorems, and the interpretation of the Hubble's law as supporting evidence of an expending universe. However, the singularity theorems have been found to be irrelevant to physics because its energy conditions cannot be satisfied. Moreover, the interpretation of Hubble's law as an expanding universe is also found to be invalid. So, the big bang theory is only a groundless speculation without adequate supports.
A Scale Expanding Cosmos where the universe expands in the scale of spacetime four-dimensionally has no beginning or end. This model agrees with all observations and explains both the Dark Energy and the Dark Matter. See further my book on Amazon or my technical monograph published by the Russian Academy of Sciences. The West is missing the boat due to its dogmatic ideas of creation.
When a gas (petrol) tank explodes, if you go back in time to evaluate the initial conditions, you find that the things were pretty cool at the beginning. A person could even swim comfortably in the petrol tank. Such conditions could not be ruled out in case of big bang either. Another point is the idea of infinite energy density at a single point of origin. Little analysis shows that this is not feasible. At planck time, the size of the universe had a planck length which could not hold more energy than the planck energy (~10^19 GeV). Where as the total energy of the universe is about ~10^81 GeV. More discussion in following article.
Article Periodic quantum gravity and cosmology
First of all, big bang is a misnomer. No bang or explosion happened. Space-time remains continuous from the earlier epoch, except that spatial extent becomes comparable to the Plank's length before starting to expand again. Every possible classical information is lost in that squeezed form and the universe starts afresh, may be due to excessive pressure. So we may say it is an oscillating Universe rather than an ever expanding universe.
Recent findings indicate may be the present phase of the Universe is not just expanding, it is also accelerating. For that various types of counter-intuitive equation of states (negative pressure) are invoked. It is doubtful is the interpretation is at all correct.
The time "t" is just a parameter in the equations. If Einstein had not derived the field equations of GR from a brilliant insight into the relationship of gravity to differential geometry, astronomers would only be recording gigantic increases in heat and density, with no notion of there being any "singularity". This is feature of the equations, not the universe. To take a familiar example: our birth is a singularity, a discontinuous disruptionn in causation. Were we "somewhere else" before we were born; many many schools of philosophjy are based on the possible viewpoints. But th "field equations" of our life start at a time t=0.
The mathematical singularity in the Einstein equation at time t=0 is not physical, physics does not have singularities. Extrapolating backwards in tiime until the Planck time, the Einstein equation ceases to be a valid description of the physics, one also needs quantum mechanics. But we don't have a quantum theory of relativity so there is no prediction of what happened at t=0, whether even quantum mechanics permits such a time.
The big bang in classical general relativity involves a space-time singularity, a point of zero volume, infinite density, and infinite space-time curvature. This involves the interesting topic of how to handle infinite values in physical theories as well as the limits of applicability of theories.
In most areas of physics the appearance of a singularity or an infinite value of an experimentally measurable physical quantity can be taken a a sign that we have reached the limits of applicability of the theory. One example is the ultraviolet catastrophe where applying equipartition of energy to the normal modes of the electromagnetic field emitted by a blackbody (a perfect absorber and emitter of radiation) in thermal equilibrium results in an infinite amount of energy at short wavelengths (so we should be blasted by an infinite amount of energy while sitting in front of our fireplace). This was solved by Planck with quantization of the emission and absorption of electromagnetic energy.
In some cases an infinite value is considered "benign" and removed by a procedure such as renormalization or regularization. The value of the "bare" charge of an electron in QED (quantum electrodynamics) is infinite but this is not the value which results from a laboratory measurement of the charge. This apparent infinity is removed by renormalization which takes virtual higher order effects into account to produce a finite value corresponding to what is actually measured.
General relativity has sometimes been described as the only area of physics that takes its singularities seriously or literally, whether it is the initial singularity at the big bang or the singularity at the center of a black hole. There are even singularity theorems which specify the conditions under which singularities occur. This takes place in a classical space-time with no quantum gravitational effects. Once again the occurrence of a singularity is really a sign that our theory is breaking down and that a new theory, in this case a theory of quantum gravity, is required. It is generally believed that this occurs at a finite but very small scale which for distance is referred to as the Planck length, approximately 10^-33 cm, beyond which classical general relativity no longer applies (Technically it is the space time curvature which is important here. When the curvature is of the order of one over the square of the Planck length then quantum gravitation effects are expected to be important). This length scale is extremely small and is approximately 10^-20 times the diameter of a proton.
Thus while extrapolating backwards in standard cosmology appears to lead to a singularity of zero volume, infinite density and infinite space-time curvature, classical general relativity is no longer applicable at a stage before the singularity occurs when all relevant quantities are still finite. Until a full theory of quantum gravity is available we can only make limited and speculative statements about what may happen at smaller scales (greater space-time curvatures).
As a final note, for completeness I should point out that there exist alternate theories of gravitation and alternate cosmologies that find various ways to get around this problem. Three examples are John Moffat's MOG or modified gravity, Roger Penrose's Conformal Cyclic Cosmology and QSSC or Quasi-Steady State Cosmology of Hoyle, Burbidge and Narlikar. In general there are far fewer people working on these theories compared to standard general relativity and cosmology and thus far fewer resulting publications. It should also be pointed out that these alternative theories are generally not accepted by the (vast) majority of relativists and cosmologists.
Zero and infinity are poorly defined in mathematics and physics. I don't think there is absolute zero. To me zero means infinitesimally small value which can be ignored and infinity means something which cannot be explained with a finite number. I define infinity as one without a second. In other words, infinity does not have a boundary that you can define second something beyond that boundary. This is absolute infinity. When someone divide a finite number by zero, they get a very large number which is a pseudo infinity. There are so many pseudo infinities in physics and mathematics.
In the following theory Gravity is the tendency of the energies to unite so that the particles can acquire Planck energy level in order to unmanifest. A particle having planck energy at planck length cannot hold any more energy. When it acquires more energy the particle wave collapses and becomes flat and perfectly motionless. This unmanifested state does not have any mass gap like the zero point energy. More about the unmanifest in following article.
Article Unified field of consciousness
Is a very hot, dense big-bang consistent with a low entropy initial state that is desired, since entropy increases with time? When everything is jam-packed like in a blackhole, how can we say that it was a very hot initial state? When all degree of freedom have almost frozen where can the kinetic energy be that will lead to heat or temperature. It seems inconsistent. It can be a big bang, it can be highly dense, but it cannot be very hot, certainly.
Inflation would cool the universe but we know it was at least hot enough to create helium. BB nucleosynthesis is fairly well understood (other than the "Lithium Problem"). Reheating after inflation is a current area of study.
We can make a calculation without much difficulty as follows:
1. According to: The "Magnitudes of Physics", published by The Physics Teacher, the radius of the universe is ~ 1x10 ^ 28 m.
2. The age of the universe is ~ 13,800,000,000 years.
3. If we go back to the time of Planck (10 ^ -43 seconds) before of the inflationary period.
4. We can calculate that the diameter of the universe was ~ 4.6 x 10 ^ -33 m, which is smaller than an average atom.
5. So if we go back to the time t = 0, we'll find a point whose volume tends to minus infinity, i.e., if t tends to 0, then the volume tends to (- infinity).
I think it is a good approximation.
Juan,
Don't speak about the radius of the universe when in fact you mean the radial distance to the event horizon.
If you go back to the time of Planck using classical physics your result for the radius of the event horizon might be wrong, it depends on your model for the inlation.
Latest at Planvk time your calculation breaks down, you need quantum gravity. It is not sure whether the time t = 0 is physically meaningful then.
.
Matts,
My calculations are based on widely known physical parameters, my calculation is only an approximation, i.e., is not a result 100% accurate, no one knows exactly what happened in the singularity of the Big Bang, whitout to mention the dark epoch, after inflation. Therefore, although my calculation can be very wrong, in the final numbers, there is a high probability that the singularity at the Big Bang, possesses an extremely small measure of volume, besides, the uncertainty principle of Heisenberg prohibits any type of measurement at that moment zero of the universe. The theories are only an indirect method of measurement.
In standard big bang model there is very little kinetic energy (electromagnetic radiation) at the beginning. And the Helium is formed 3 minutes after the big bang. In my model the entire energy of the universe (~10^81 GeV) is in the form of pure kinetic energy like cold fuel. This primal kinetic energy is made up of electronuclear force. The gravity has just separated. The friction within this primal kinetic energy causes the big bang explosion.
JE: if t tends to 0, then the volume tends to (- infinity).
The scale factor in the radiation dominated era is prortional to the square root of the age so as t tends to zero, so does the volume.
George,
Ok, I meant the following:
if t tends to 0, then the volumen tends to 10^(-infinity), therefore, the volumen tends to 0.
Thanks for the suggestion.
I am glad to meet this discussion place. My main studies are waveform inversion
for petroleum seismology, numerical modeling of any wave equation and seismic migration. I happend to submit my paper to phisycal societies including high lanked
journals to low ranked journal. I get rejected all the times without having any comments
on my paper. Any one can help me to flaws of my paper. Attached is my paers's pdf file. Looking forward to mercy Sicerely yours Changsoo Shin, Professor of Geophysics, Department of energy resources engineering, college of engineering,
Seoul National University.
To get your paper published, you would have to remove any references to religious beliefs, these are considered to be independent of science and inappropriate in scientific publications.
In my opinion,Universe is a combination of several space times. It is in steady state only. But the whole physics is defined for a particular space time and all other space timed are viewed as different forces or interaction with reference to that particular space time. We are in that particular space time. So Big bang is physically correct for our physics. But as a whole it is a partial truth.means 'Big bang is a part of Steady state' An appropriate Grand Unification theory can explain it perfectly.
prior to the initial singularity/physical matter there was no such thing as time.
Just the conception of time by our One common designer/creator.
What if current physics is incomplete? It is likely that the universe expands by increasing the scale of both space and TIME. When the meter expands the second gets longer. This would imply perpetual existence. The energy needed to sustain this world would be induced by the expansion of time.
This new theory is developed in my book:
http://www.amazon.com/Progression-Time-expansion-powers-universe-ebook/dp/B00D52WWSS/ref=asap_bc?ie=UTF8
I have also authored a book published in the Russian language by the Russian Academy of Sciences. This book has now been distributed to universities, libraries and book stores across Russia. Is the West missing the boat due to ancient, religious, ideas of divine creation?
Dear Lo,
Can you please tell me what are those invalid assumptions which are not related to physics? Please take it in a positive manner...
I think physics has already explained space and time in its own way(with in some limitations)
If we can extend the limits we can extend with in the scope of physics.
Thank you.
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