Why the universe was created? Part 1
Stephen Hawking question
Stephen Hawking, one of the greatest scentists of this era, raised this issue years ago in his popular book “A Brief History of Time”.
He suggested that this “vast number of stars and galaxies seems a waste.”
Hypothesis of abiogenesis
In 1920s Russian biologist Alexander Oparin and British scientist J. B. S. Haldane presented the hypothesis of abiogenesis, the idea that life could have arisen from non-living matter.
They stated that the conditions on the primitive Earth favored chemical reactions that synthesized complex organic compounds from simpler inorganic precursors.
Miller Urey experiment
In 1952, Nobel laureate Harold Urey at the University of Chicago deputed his student Stanley Miller to test the hypothesis of abiogenesis.
They created conditions thought to be present in the atmosphere of the early, prebiotic Earth.
The experiment used methane (CH4), ammonia (NH3), hydrogen (H2), in ratio 2:1:2, and water (H2O) followed by passing of an electric arc.
Why these gases were chosen?
Hydrogen:
Hydrogen, the most abundant element in the universe, originated during the early moments of the Big Bang, within a few minutes of its inception.
Specifically, it formed during a period known as Big Bang nucleosynthesis, where protons and neutrons, produced in the initial hot, dense conditions, combined to create hydrogen nuclei. Later, these nuclei captured electrons as the universe cooled, forming neutral hydrogen atoms around 370,000 years after the Big Bang.
Hydrogen makes up the vast majority of the universe’s atoms, with an estimated 73% of the total mass. So it is believed to have played a role in the formation of organic molecules.
Methane:
Methane was chosen because it was hypothesized that early Earth had a reducing atmosphere, meaning it lacked free oxygen. Methane, being a simple carbon-containing molecule, was thought to be a significant component of such an atmosphere.
It was mainly released into the atmosphere through volcanic eruptions. Inorganic reactions involving rocks, water, and heat can also produce methane. It can also be formed through reactions driven by light and heat in aqueous environments, involving methylated sulfur and nitrogen compounds.
Methane was abundant in the early Earth’s atmosphere, with estimates of 1,000 times the current levels. This likely contributed to the planet’s early warmth, potentially facilitating the emergence of life.
Ammonia:
Similar to methane, ammonia was considered a component of the early Earth’s atmosphere, providing a source of nitrogen, which is essential for biological molecules like amino acids. Ammonia is thought to have formed in the early universe, likely within the dense gas and dust clouds that eventually formed stars and planets.
The most widely accepted theory suggests that ammonia was brought to Earth via asteroids and meteorites. These objects are rich in organic molecules, including ammonia. Ammonia is a precursor to various complex biological molecules like amino acids and DNA.
Why electric arc was used?
Electric arc was used to simulate lightening. It was hypothesized that energy and heat provided by lightening was crucial for blendng of these gases and production of organic molecules.
Result:
Applying an electric arc (simulating lightning) resulted in the production of amino acids, the basic building blocks of proteins.
This experiment provided early evidence for the idea that life could have originated from simple inorganic molecules through chemical reactions in a reducing atmosphere.
Origin of genetic molecules
Proteins are coded from genetic molecules. So the question is how they originated?
The origin of both DNA and RNA is linked to the RNA world hypothesis, suggesting RNA may have preceded DNA in early life. It’s believed that the building blocks of RNA (nucleotides) may have formed spontaneously in the early Earth’s “primordial soup”.
RNA’s ability to store genetic information and catalyze chemical reactions made it a prime candidate for the first replicator, while DNA later evolved for more stable genetic storage.
So it is now known that inorganic substances such as hydrogen, ammonia and methane which were formed early after the big bang were essential for the creation of life.
Importance of heavy metals for the creation of life
But what about the heavy metals? Why they were created?
It is hypothesized that the hydrogen gas clouds formed after Big Bang, collapsed under gravity, forming stars and the first generation of heavy elements through nuclear fusion within their cores.
It took three generations of stars to have enough heavy elements to allow life. That’s not even mentioning supernovae that take time and yet provide the heaviest elements like Uranium and Thorium.
These very heavy elements are needed for the Earth’s tectonic plate action and hot rotating core which gives us our magnetic field. That field is totally necessary to protect us from radiation from the sun and universe (stellar wind). Otherwise, there cannot be life.
We are all stardust
There are some facts which make a person wonder it’s very existence.
In fact, we are all stardust.
Every atom in our body came from a star that exploded billions of years ago, and the atoms in your left hand probably came from a different star than your right hand.
We couldn’t be here if stars hadn’t exploded, because the elements – the carbon, nitrogen, oxygen, iron, all the things that matter for evolution and for life – weren’t created at the beginning of time. They were created in the nuclear furnaces of stars, and the only way for them to get into your body is if those stars exploded. The stars died so that we could be here today.
(to be continued)
References:
- Stephen Hawking. A Brief History of Time: From the Big Bang to Black Holes. 1988. Bantam Dell Publishing Group, UK. ISBN 978-0-553-10953-5.
- Witzany, Guenther (2016). “Crucial steps to life: From chemical reactions to code using agents” (PDF). BioSystems. 140: 49–57. Bibcode:2016BiSys.140…49W. doi:10.1016/j.biosystems.2015.12.007. PMID 26723230. S2CID 30962295.
- Howell, Elizabeth (2014). “How Did Life Become Complex, And Could It Happen Beyond Earth?”. Astrobiology Magazine. Archived from the original on 15 February 2018. Retrieved 14 April 2022.
- Oparin, Aleksandr Ivanovich (2003) [1938]. The Origin of Life. Translated by Morgulis, Sergius (2 ed.). Mineola, New York: Courier. ISBN 978-0-486-49522-4. Archived from the original on 2 April 2023. Retrieved 16 June 2018.
- Life on early Earth could have been seeded by comets …Astronomy Magazine. https://www.astronomy.com › science › comets-and-me. 23-Apr-2024