On my constant quest for knowledge, determining the actual orgins of the Universe has been one of the most difficult. This of course due to the current impossibility of definitive proof. After researching several points of view, my critical thinking path leans toward the old Big Bang Aroo.
It's not surprising that many folk just don’t like the Big Bang Theory for some reason or other. Of course most all religious types have their minds made up without even looking at the evidence. It somehow offends their preconceived notions of how earth, man and indeed the entire universe came to be.
Many try to articulate arguments against the Big Bang by either trying to poke holes in it or by inventing their own alternative cosmologies that seem to make more sense to them, in a biblical sorta way. Most of those who won't even try to back up their ideas with evidence. The bible explains everything, period.
The anti-Big Bang crowd has never really jived with mainstream science. (surprise surprise). Needless to say, they are confused by even the concept, as are many other folk who either aren’t aware of how strong the foundations of the Big Bang Theory are, or how weak the foundations of the alternative theories are.
So Uncle PooBah is going to attempt to enlighten and answer in simplistic terms the age old question; How did we get here? What are the origins of the Big Bang Theory and why is it so widely accepted by scientists?
1915 -- Einstein publishes his General Theory of Relativity. In its original form it predicts an expanding universe. Astronomers say the universe is not expanding, so Einstein adds a “fudge factor” called the Cosmological Constant to relativity to make it predict a steady state universe in accordance with the best astronomical data of the time. The idea that the universe could be expanding though is the first inkling of a Big-Bang origin for the universe.
1924 -- Edwin Hubble discovers that the universe is much larger than previously thought. He discovers that the so-called spiral nebulae are made of stars and are very far away. Up till then, these nebulae were thought to be part of the Milky Way Galaxy, and that the Milky Way was thought to constitute the entire universe. After 1924 it is known that the Milky Way is only one Galaxy among billions in an unimaginably huge universe.
1929 -- Edwin Hubble (among others) notices that the light from distant galaxies is redshifted and that the more distant the galaxy, the more the redshift. Since a redshift implies motion away, and everything seems to be moving away from everything else, Hubble proposes that this is the result of the universe expanding. Here is the true birth of what would eventually be called the Big Bang theory.
1948 -- Physicists Ralph Alper and George Gamow work out the timeline of events that must have taken place during the Big Bang. Modern Big Bang Theory is born. Their theory makes testable predictions about the properties of a universe born out of a Big Bang. One of those predictions is a Cosmic Background Radiation permeating the universe. However, the technology does not exist in 1948 to look for this radiation. Validation of the theory will have to wait until some future date.
1949 -- Fred Hoyle coins the term “Big Bang Theory” for the first time, as he mockingly refers to the new theory in a BBC interview. The name sticks. Hoyle does not believe in the Big Bang. He is an advocate of a Steady State universe.
1964 -- Hoyle & Tayler in "The Mystery of the Cosmic Helium Abundance" showed that most of the helium in the Universe could not have been produced in stars. This effectively killed off the various Steady State models of the day since none of them could account for the Helium except by producing it in stars. However, The Big Bang could account for it. The irony here is that Hoyle does not believe in the Big Bang but his work helps validate it. Still rejecting the Big Bang, he goes on to try to rework the Steady State theory to try to salvage it in some form.
1965 -- Arno Penzias and Robert Wilson, two radio astronomers using an ultra-sensitive radio telescope at Bell Labs in Holmdel, New Jersey, unexpectedly detect the Cosmic Background Radiation predicted by Alper and Gamow in 1948. This put the final nail in the steady state coffin. Since steady state theories cannot account for the radiation.
After 1965 -- The Big Bang Theory is considered totally validated and from that point forward is accepted by nearly all cosmologists. Okay, that seems simple enough. So what’s the beef then? What are some of the main issues some people have with the Big Bang and what arguments and evidence do they offer? Lets look at a few.
Argument: Good evidence is lacking that supports the Big Bang Theory and discredits alternative theories.
Counter: Actually there is a lot of good evidence. Here is a partial list. The universe almost certainly had a beginning (though some people may dispute that) The universe is expanding. So it must have been smaller in the past. Keep going back in time and you must reach a point where the universe reaches zero size. The we have the Cosmic Background Radiation. The abundance of the "light elements" Hydrogen, Helium and Lithium found in the observable universe.
Argument: Big Bang assumes that the Doppler Effect is the cause of the observed Redshift but what if it is not? Why assume an effect originally observed in sound waves also applies to electromagnetic radiation from distant quasars?
Counter: The Doppler Effect is demonstrably real and the only known agent that could cause the observed redshifts. The Doppler Effect is seen in electromagnetic radiation, and all other forms of waves.
Argument: The Big Bang depends too much on interpretation of quasar redshifts. Quasars could be made of some sort of exotic matter that has far different properties than ordinary matter and this could explain their redshifts.
Counter: Emission and absorption lines in quasar spectra show they are made of normal matter. Deep images of quasars show them to be embedded in ordinary galaxies. There is no evidence of anything exotic about quasars.
Argument: Quasars are too often seen “close” to nearby galaxies, more often than chance would allow, and so they are more likely to be nearby objects that have been ejected from those nearby galaxies.
Counter: Over 50 examples of quasar lensing by foreground galaxies disprove theory that chance alignments are rare. The laws of chance actually require there to be many more “close” alignments than exact alignments, so such “close” alignments are expected and aren’t proof of anything. Also, gravitational lensing only works if there is a vast difference in distances between the observer and the foreground and background objects. So quasars are indeed very far away. Also, all surveys done to date show quasars are distributed randomly across the sky, and not clustered around nearby galaxies as some alternative cosmology backers claim.
Argument: General Relativity could be wrong, and then all the assumptions about the Big Bang based on Relativity would be wrong too.
Counter: General Relativity is the most thoroughly tested and validated theory in the history of physics. No theory for the origin of the universe will be taken seriously if it does not work within the confines of General Relativity.
Argument: Fully formed galaxies and galaxy clusters appeared “too early” if the universe is as young as the Big Bang theory claims.
Counter: How early is “too early?” When the universe was younger, matter was closer together and gravitational attraction was stronger, allowing much of the large-scale structure of the universe to form in only the first few billion years after the Big Bang. One wouldn’t expect many new galaxies or galaxy clusters to be forming now that the universe has expanded and matter has thinned out.
Argument: Too many holes and unknowns in the Big Bang theory.
Counter: Nobody ever claimed it was complete. It hangs together better than any of the alternatives though. Arguing that the Big Bang Theory is invalid because it is incomplete is like arguing against evolution because of holes in the fossil record. The record is still there, even if we can’t quite see all of the details, the big picture is pretty obvious.
Argument: Big Bang theory is constantly being tweaked and modified to fit new discoveries, like epicyles being added to the old Earth-centered universe cosmology.
Counter: Big bang is more flexible than other theories which totally fall apart and must be discarded when new discoveries are made that can’t be integrated into them. The Big Bang Theory has many adjustable parameters and variables. New discoveries and concepts like Dark Matter and Dark Energy can not only be integrated into the Big Bang Theory, but even help explain some of the unanswered questions.
Alternative cosmologies like Steady State and Quasi-Steady State fall apart because they have rigid rules and make absolute predictions about the nature of the universe that just don’t pan out in observation.
Argument: Alternative cosmology proponents have been blacklisted and there is a conspiracy to silence critics, suppress the truth and protect the status quo.
Counter: The various alternative cosmologies all seem to be “junk science” at their cores. People who waste limited resources (like telescope time) on bad science do sometimes get blacklisted, and rightly so.
Truth can’t be easily suppressed in science because science works the same everywhere. Proliferation of the A-bomb and H-bomb are good examples of this. There are lots of telescopes on every continent. A conspiracy to suppress alternative cosmologies would have to be world-wide and involve cooperation between rival nations and rival scientists all trying to be the first to announce the next big discovery. Not a likely scenario.
To sum it up, there's a large body of observational evidence supporting the Big Bang Theory which puts it on a very firm foundation compared to any other alternative theories i've researched. It makes predictions which are validated by repeated observation.
The alternatives lack supporting evidence. They make predictions that are not confirmed, and sometimes even refuted by observation. They resort to assuming exotic forms of matter, dowop physics or even biblical babble are at work to try to make their case.
It’s not hard to see why the Big Bang is accepted and the alternatives can’t seem to gain any traction with scientists. All one has to do is open ones eyes. One might even be amazed at what one might see. :)