1. The "Big Bang"
It has been known for about 70 years, that the galaxies of the universe are moving apart and away from each other, in similar fashion to raisins moving apart and away from each other in an expanding lump of dough. In 1929, astronomer Edwin Hubble's measurements on more than 40 galaxies established that the galaxies of the universe are indeed receding away from each other at several hundred miles per second, as an explosion would propel exploded pieces from each other. That "explosion"-event is now popularly called the "Big Bang" --- and this event is evidenced by left-over heat (or "background radiation") throughout the universe which (along with much other evidence) leaves little doubt that this hot explosive event occurred.
In addition, recent research, such as data from the "BOOMERANG experiment" (short for "Balloon Observations of Millimetric Extragalactic Radiation and Geophysics") have determined that the geometry and ""shape" of the universe," is "flat" (as opposed to having "curved" space). A "flat" universe means that Euclydian geometry applies throughout space, and every "straight" line (as people normally think of straightness) in the universe does not curve with the fabric of space --even over a very long distance. It doesn't matter that gravity causes light to curve --the geometry of space is still flat. This means that there is an approximate "center" to the material universe (since there is a finite number of galaxies).
One of the implications of the universe being "flat" is that it will expand forever --and in fact, there is experimental confirmation that the universe is actually accelerating in its expansion rate. All of this means that the expansion will never reverse and bring the universe back together into a "Big Crunch," because there's not enough gravity in the mass of the universe to stop the expansion. -- Therefore, we know that the universe has not been on an endless cycle of bang, crunch, bang, crunch, etc. And because of this, we know that the universe is not an eternal entity.
In the following video, Dr. William Lane Craig discusses this current cosmological evidence:
The Evidence of Cosmology
Astrophysicists (such as Stephen Hawking) determined that the evident starting point just before the Big Bang involved something called a "singularity," which is: all the cosmos's potential mass (matter), energy, and dimensions --and time-- reduced down to an infinitely small point of zero volume. ---Thus, matter, 3-dimensional space, and time virtually did not exist before the Big Bang.
The expanding universe is an important discovery, because if we "reverse the film" of that expansion, then we arrive back at a starting-point for its beginning ...and if there is a beginning, there must logically be a "beginner" to initiate the Big Bang. The beginner of the Bang precedes and is outside of (transcends) all matter, dimensions and time. In light of this, the thoughts of many people go to the first verse of the Bible, which states, "In the beginning God created the heavens and the earth" (Gen. 1:1).
This powerful evidence contradicts worldviews and religions that posit an eternally existing universe (such as older materialism), ... or views which posit the idea of cosmic "reincarnation" with an oscillating universe that eternally expands and contracts (such as Hinduism, Buddhism, & New Age philosophies); ---but instead, --the Big Bang would support the biblical view of a transcendent God; that "the universe was formed at God's command, so that what is seen was not made out of what was visible" - Hebrews 11:3. In addition, ---unlike any other supposedly "holy writings"--- the Bible alone says that there was a "beginning of time" (2Tim. 1:9 & Titus 1:2), ---and God was causing effects before that beginning (John 17:5 & Colos. 1:16-17).
The Balance of the Bang: In order for life to be possible in the universe, the explosive power of the Big Bang needed to be extremely closely matched to the amount of mass and balanced with the force of gravity, so that the expansion-speed is very precise. This very exact expansion-speed of the universe, is called the "Cosmological Constant." If the force of the bang was slightly too weak, the expanding matter would have collapsed back in on itself before any planets suitable for life (or stars) had a chance to form, ---but if the bang was slightly too strong, the resultant matter would have been only hydrogen gas that was so diffuse and expanding so fast, that no stars or planets could have formed at all.
Science writer Gregg Easterbrook explains the required explosive power-balance of the Big Bang, saying that, "Researchers have calculated that, if the ratio of matter and energy to the volume of space ...had not been within about one-quadrillionth of one percent of ideal at the moment of the Big Bang, the incipient universe would have collapsed back on itself or suffered runaway relativity effects" (My emphasis.) (ref. G.Easterbrook, "Science Sees the Light", The New Republic, Oct.12, 1998, p.26).
In terms of the expansion rate of the universe as a result of the Big Bang: "What's even more amazing is how delicately balanced that expansion rate must be for life to exist. It cannot differ by more than one part in 1055 from the actual rate." (My emphasis.) (Ref: H.Ross, 1995, as cited above, p.116). (Note: 1055 is the number 1 with 55 zeros after it ---and 1055 is about the number of atoms that make up planet earth).
THE PROBABILITY: The chances we can conservatively assign to this: It was about one chance out of 1021 that the force of the Big Bang could have randomly been properly balanced with the mass & gravity of the universe, in order for stars and planets to form, so that life could exist here in our cosmos.
Design and Cosmology
In the following video, Dr. William Lane Craig discusses this current cosmological evidence:
The Evidence of Cosmology
Next --- Several of the following items deal with strengths of the four (known) basic forces of physics in the material universe, which hold everything together. Those four basic forces are: the force of gravity, the strong nuclear force, the weak nuclear force, and the electromagnetic force. The strengths of these four forces are extremely finely tuned and balanced with each other and with the amount of matter in the universe, which makes life possible in the present cosmos. ---What is the chance that such fine-tuning happened by chance? --- (Note: If a scientist can improve the accuracy in the numbers used for probabilities here, such information would be appreciated.)
2. The Force of Gravity
It is now known that if the force of gravity were any weaker, stars would not have compacted tight enough together so that nuclear fusion would occur. Fusion is necessary to produce the heavier elements upon which life depends (such as carbon, nitrogen and oxygen) ---and without fusion, there would only be hydrogen and helium in all the universe. On the other hand, if gravity were any stronger, stars would burn so hot that they would burn up in about one year or so (ref. G. Easterbrook, cited, p.26). As it is, the gravitational force is so finely tuned, that the average star is capable of burning in a stable fashion for about 80 billion years (ref. H. Ross, cited, p.60).
How finely tuned is gravity? -- Well, the strength of gravity could be at any one of 14 billion billion billion settings, but there is only one setting which is adequate (and optimal) for a universe with intelligent life to exist.
-- To illustrate: This is as if you had a measuring tape with one-inch sections stretched across the known universe, it would be 14 billion billion billion inches long, and only one or two of those inches in the middle is the optimal strength-setting for gravity. If you moved the strength-setting to the right or left just a couple of inches, then intelligent life could not exist (though bacterial life might survive with gravity stronger or weaker by one setting up or down).
THE PROBABILITY: Although the force of gravity could obviously have attained a large number of wrong magnitude-ranges, the chance of it being correct for intelligent life to exist, is one chance out of 14 billion billion billion. --Thus, we can conservatively say that it was about one chance out of 1,000,000,000,000,000,000,000 (or 1 out of 10^21, or 1 out of a billion trillions) that the force of gravity might have randomly attained such an advantageous strength for the making of life-necessary elements in the stars.
3. The Strong Nuclear Force
This is the force which binds the protons and neutrons together in atomic nuclei.
If the strong nuclear force were very slightly weaker by just one part in 10,000 billion billion billion billion, then protons and neutrons would not stick together, and the only element possible in the universe, would be hydrogen only. There would be no stars, and no planets or life in the universe. (Ref., Dr. Robin Collins of Messiah College).
However, if the strong nuclear force were slightly too strong by the same fraction amount, the protons and neutrons would tend to stick together so much that there would basically only be heavy elements, but no hydrogen at all --If this were the case, then life would also not be possible, because hydrogen is a key element in water and in all life-chemistry.
THE PROBABILITY: If the strong nuclear force were slightly weaker or stronger than it in fact is, then life would be impossible. Therefore, we can very conservatively say that it was about one chance out of 1,000,000,000,000 (1 out of a trillion) that the strong nuclear force might have randomly possessed the correct strength to make life possible in our cosmos.
What would happen if the strong nuclear force were a bit weaker?
Barrow, J D and Tipler, F J, ‘The Anthropic Cosmological Principle’ Oxford University Press 1986, p. 327
If the strong force were a bit weaker, it would not be able to hold atomic nuclei together against the repulsion of the electromagnetic force. According to Barrow and Tipler:
‘A 50% decrease in the strength of the nuclear force… would adversely affect the stability of all the elements essential to living organisms and biological systems.’2
A bit more of a decrease, and there wouldn’t be any stable elements except hydrogen.
4. The Weak Nuclear Force
The weak nuclear force is what controls the rates at which radioactive elements decay. If this force were slightly stronger, the matter would decay into the heavy elements in a relatively short time. However, if it were significantly weaker, all matter would almost totally exist in the form of the lightest elements, especially hydrogen and helium ---there would be (for example) virtually no oxygen, carbon or nitrogen, which are essential for life.
In addition, although heavier elements necessary for life are formed inside giant stars, those elements can only escape the cores of those stars when they explode in supernova explosions, however, such supernova explosions can only occur because the weak nuclear force is exactly the right value. As Professor of astronomy, Paul Davies, describes this situation: "If the weak interaction were slightly weaker, the neutrinos would not be able to exert enough pressure on the outer envelope of the star to cause the supernova explosion. On the other hand, if it were slightly stronger, the neutrinos would be trapped inside the core, and rendered impotent" (My emphasis.) (ref. P.C.W. Davies, The Accidental Universe, London, 1982, p.68.)
THE PROBABILITY: Considering the fine-tuning of the weak nuclear force for both the rate of radioactive decay as well as the precise value required to allow supernova explosions, it is probably conservative to say that it was one chance out of 1000 that the weak nuclear force was at the right strength to permit these processes so that life would be possible.
5. The Electromagnetic Force
If the electromagnetic force (exerted by electrons) were somewhat stronger, electrons would adhere to atoms so tightly that atoms would not share their electrons with each other ---and the sharing of electrons between atoms is what makes chemical bonding possible so that atoms can combine into molecules (e.g., water) so that life can exist. However, if the electromagnetic force were somewhat weaker, then atoms would not hang onto electrons enough to cause any bonding between atoms, and thus, compounds would never hold together. In addition, this fine-tuning of the electromagnetic force must be even more stringent if more and more elements are to be able to bond together into many different types of molecules.
THE PROBABILITY: Considering the range of electromagnetic force that might have occurred, it is reasonable to say that the probability of the electromagnetic force being balanced at the right level for many thousands of compounds to function for the making of chemical compounds necessary for life, is one chance out of 1000.