Exploding stars point to a young universe
Where are all the supernova remnants?1
Posted on homepage: 20 July 2011 (GMT+10)
A supernova,2 or violently exploding star, is one of the most brilliant and powerful objects in God’s vast cosmos. On average, a galaxy like our own, the Milky Way, should produce one supernova every 25 years.
When a star has exploded in this way, the huge expanding cloud of debris is called a SuperNova Remnant (SNR). A well-known example is the Crab Nebula in the constellation of Taurus, produced by a supernova so bright that it could be seen during daytime for a few weeks in 1054. By applying physical laws (and using powerful computers), astronomers can predict what should happen to this cloud.
According to their model, the SNR should reach a diameter of about 300 light years3 after 120,000 years. So if our galaxy was billions of years old, we should be able to observe many SNRs this size. But if our galaxy is 6,000–10,000 years old, no SNRs would have had time to reach this size. So the number of observed SNRs of a particular size is an excellent test of whether the galaxy is old or young. In fact, the results are consistent with a universe thousands of years old, but are a puzzle if the universe has existed for billions of years. The conclusions can be seen from the simple table shown below:
|Number of observable SNRs predicted if our galaxy were…||Number of SNRs actually observed|
|… billions of years old||… 7000 years old|
As can be readily seen above, a young universe model fits the data of the low number of observed SNRs. If the universe was really billions of years old, there are 7000 missing SNRs in our galaxy.
Not only that, but the predictions for the Milky Way’s satellite galaxy, the Large Magellanic Cloud are also consistent with a young universe. Theory predicts 340 observable SNRs if the LMC were billions of years old, and 24 if it were 7000 years old. The number of actually observed SNRs in the LMC is 29. [See Detailed discussion and calculations]
As the evolutionist astronomers Clark and Caswell say, ‘Why have the large number of expected remnants not been detected?’ and these authors refer to ‘The mystery of the missing remnants’.4
There should be no mystery—Psalm 19:1 says: ‘The heavens declare the glory of God; and the firmament sheweth his handiwork.’ Supernovas declare His mighty power, but are still only finite expressions. The low number of their remnants is a pointer to God’s recent creation of the heavens and earth.
How do supernovas happen?
An ordinary star is a gigantic ball of gas, about a million times more massive than the earth—our sun is a medium-sized star. It is potentially stable for a long time, because the energy produced by the core produces an enormous outward pressure, which balances the inward force of gravity on its huge mass.
However, when the nuclear fuel runs out, there is no longer any force to balance its gravity. If the star is very massive, most of it collapses very fast — in about two seconds. This releases a huge amount of energy—one supernova will out-shine all the billions of stars in its galaxy. The collapse is so violent that the electrons and nuclei are crushed together and produce a core of neutrons. This core is so dense that a teaspoonful would weigh 50 thousand million tons on earth. It cannot be compressed any further, so the incoming material from the rest of the star meets a solid wall. This material bounces off the core, rushes outward and shines very brightly. The remaining core, only about 20 km in diameter, is called a neutron star. Because it is spinning very fast, and has a strong magnetic field, we observe regular radio pulses, so the object is called a pulsar.
The energy produced by a supernova is mind-boggling: 1044 joules. It is the same as if each and every gram of the earth’s mass was converted to a nuclear bomb 200 times more powerful than the one dropped on Hiroshima. That amount of energy would fuel 80 million sun-like stars for 100 years!
Detailed discussion and calculations
A widely-accepted model of supernova expansion predicts three stages:
1) The first stage starts with debris hurtling outwards at 7000 kilometres per second. After the material has expanded for about 300 years, a blast wave forms, ending the first stage. By this time it reaches a diameter of about 7 light years.5 This is an immense object—about 25,000 times larger than our solar system, which is ‘only’ about eight light hours across (about 8600 million km or 5400 million miles).
Since the first stage should last about 300 years and one SNR should occur every 25 years, there should now be 300/25 first stage SNRs in our galaxy, or about 12. We should not expect to see them all—astronomers calculate that only about 19% of SNRs should be visible,6 that is about two of the 12. It makes no difference whether the universe is thousands of years old as the Bible indicates, or billions of years old as evolutionary theory asserts. Actually we see five first stage SNRs (this is within the uncertainty range of the calculation).
2) The second stage SNR, known as the adiabatic7 or Sedov stage, is a very powerful emitter of radio waves. This is predicted to expand for about 120,000 years and reach a diameter of about 350 light years. After this, it starts to lose thermal (heat) energy and begin the third stage. Now, if the universe was billions of years old, we would predict (remember, one supernova every 25 years, and taking into account SNRs in the 300-year first stage) that in our galaxy there would be about (120,000–300)/25 second stage SNRs, or about 4800. But if the universe has only existed for about 7000 years, then there would be only enough time for (7000–300)/25, or about 270. Astronomers calculate that 47% should be visible, so evolutionary/uniformitarian theory predicts about 2260 second stage SNRs, while the Biblical Creation theory predicts about 125. The actual observed number of second stage SNRs is a good test of which theory best fits the facts.
There are actually only 200 second stage SNRs observed in our galaxy! This is in the right ball park for Biblical creation, but is totally different from evolutionary predictions. Evolutionists at present have no answer to the problem of the missing supernova remnants.
3) The third, or isothermal,8 stage is theorised to emit mainly heat energy. This stage would theoretically only start after 120,000 years, and would last about one million to six million years. The SNR would end its career when it either collided with similar SNRs at a diameter of about 1400 light years, or became so dispersed that it would be indistinguishable from the ֹvacuum’ of space at a diameter of about 1800 light years.
One calculation makes the generous (to evolutionary theory) assumption that the third stage starts at about 120,000 years and a diameter of about 340 light years, and lasts to an age of one million years and 650 light years. Thus if the universe was billions of years old, there should be (1,000,000–120,000)/25 third stage SNRs in our galaxy, or about 35,000. Of these, about 14% should be observable, or about 5000. However, if the universe is only about 7000 years old, no SNR should be old enough to have reached the third stage, so there should be absolutely none, under currently accepted models. This is another test of the two theories, an old vs. a young universe.
There are actually no third stage SNRs observed in our galaxy!
References and notes
- This article is based on a paper by Keith Davies, Distribution of Supernova Remnants in the Galaxy, Proceedings of the Third International Conference on Creationism, Creation Science Fellowship, Pittsburgh, ed. E. Walsh, pp. 175–184, 1994. Return to text.
- See the article ‘supernova’, Encyclopædia Britannica, 15th Ed., 11:401, 1992. Return to text.
- A light year is a measure of distance, not time. It is the distance that light nowadays travels for one year in a vacuum—9.46 million million kilometres (5.87 million million miles). Return to text.
- Clark and Caswell, 1976. Monthly Notices of the Royal Astronomical Society, 174:267; cited in Ref. 1. Return to text.
- Mr Davies’ original draft of Ref. 1 had 1.28 parsecs, which is 7 light years. Somehow in the final version, a typo occurred and 7 ly became 7 pcs, which would be 23 ly. Return to text.
- Keith Davies, Distribution of Supernova Remnants in the Galaxy, Ref. 1, has detailed observational limitation formulæ. Return to text.
- Adiabatic means ‘not transferring heat to or from its surroundings’. During the second stage, the SNR loses very little thermal energy. Return to text.
- Isothermal means ‘staying at the same temperature’. During the third stage, the SNR should stay at about the same temperature and radiate excess thermal (heat) energy. Return to text.