The overwhelming majority of astronomers settle for the Huge Bang – the speculation that the universe started about 13.8 billion years in the past in a fiery cataclysm. Nonetheless, this concept is just not accepted by everybody. Some Huge Bang skeptics declare that the universe is about 6,000 years previous, whereas others declare that the universe is everlasting. Though they disagree with one another, each agree that the Huge Bang principle is improper, and one remark they level to is the existence of estimated stars whose age is older than the universe itself. If such a star existed, it might be the loss of life knell of the Huge Bang.
“star of methuselah”
Dubbed the “star of Methuselah,” HD 140283 is actually previous and is usually accepted as one of many oldest recognized stars. A paper revealed in 2013 estimated its age at 14.45 billion years, with an uncertainty of ±0.8 billion years. That is older than our most correct estimate of the age of the universe, 13.797 ± 0.023 billion years.
Whereas the Methuselah star is just not distinctive (within the sense that there are different stars which can be equally historic), it’s the oldest star for which the quoted uncertainty is comparatively low, and thus is regarded by these people who don’t consider the Huge Bang as offering the strongest argument towards the speculation.
A star is born
Astronomers consider that HD 140283 is previous as a result of the star has a really low “metallicity”. Metallicity, to astronomers, is a measure of the share of a star’s chemical composition that’s composed of parts aside from hydrogen and helium.
When the universe started, the universe consisted virtually completely of hydrogen (75%) and helium (25%), with a tiny hint of heavier parts (~0.01%). (These percentages mirror mass content material; when merely counting atoms, hydrogen was 92% and helium 8%.) This was additionally the preliminary formation of the primary stars, which shaped maybe as early as 100 million years after the Huge Bang. These stars, which astronomers name third stars, had been a lot heavier and brighter than the Solar, and of their cores, stellar fusion cooked up the primary sorts of heavy parts. Cluster III stars lived just a few million years earlier than exploding in supernovae, which blasted their heavier parts throughout the universe.
Heavy parts combined with hydrogen and helium gasoline, forming cluster II stars, and the method repeated once more, with these subsequent supernovae including heavier parts to the universe. The outcome was an I-number of stars with a comparatively excessive composition of heavy parts. Our solar is the inhabitant of I-star.
Nonetheless, the star of Methuselah is the star of Inhabitants II: a cosmic relic from the beginning of the universe. They comprise a lot much less oxygen and iron than, for instance, our solar. Astronomers use a mixture of measured star brightness, noticed percentages of non-hydrogen and non-helium parts, and complex fashions of stellar evolution to find out the star’s age. And as talked about earlier, in 2013, astronomers estimated an age larger than the age of the universe. So, is that this an actual downside? Is HD 140283 the loss of life knell for the Huge Bang?
No. For instance, different calculations of the star’s age point out that he’s a lot youthful. One estimate in 2015 places the age at 13.7 ± 0.7 billion years, whereas an estimate in 2021 places the age at an earlier age of 12 ± 0.5 billion years. The truth that completely different students estimate such a variety of ages signifies that the discrepancy is far ado about nothing.
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And even when the seemingly problematic 2013 estimates are 100% dependable, we must be cautious. Importantly, we should not solely examine the dot estimate for the star’s age with that of the Universe (that’s, 14.45 versus 13.797 billion years), however we should additionally account for uncertainties. The uncertainty in estimating the age of the Methuselah star is ±0.8 billion years, which signifies that the precise age of the star is between 13.65 and 15.25 billion years. (Technically talking, there’s a 70% probability that the precise age of the star is inside this vary, and a 30% probability that it’s outdoors the vary. This additionally means that there’s a 15% probability that the precise age of HD 140283 is lower than 13.65 billion years. )
Whereas the 2013 estimate for the age of the Methuselah star means that it could be older than the universe, the truth that this estimate is additionally According to the star being smaller than the universe, the scientific group does not see it as an issue. It is just a problem amongst those that wish to disprove the Huge Bang Principle.