A faint young sun would have kept the Earth in a deep freeze
A star like our Sun has about ten billion years worth of nuclear fuel. Billions of years of nuclear fusion would change the Sun's characteristics. Leading secular astronomers and astrophysicists have accepted for decades basic physics calculations which show that the sun would have been nearly a third cooler a few billion years ago and that the Earth's oceans then would have frozen over. However, ice-age knowledge notwithstanding, no mainstream scientific camp claims that the earth was covered in ice for any period of time, let alone for billions of years. Based on the timeline of the claimed evolution of both the solar system and its life, a temperate Earth is required for those early billions of years, first, for life to originate in some warm pond, then for liquid seas to fill with living creatures and for some of those creatures to begin dwelling on land. Further, if the Earth had been frozen over, it would not absorb the Sun's life-giving rays but reflect them back out into space.
The illustration above presents NASA's conception of the faint young sun being orbited by the matter that was to coalesce, allegedly, to form the planets (a possibility that Isaac Newton specifically rejected). Without reservation, evolutionists call upon the most strained rescue devices rather than to ackowledge that their theory may be in error. They make extreme secondary assumptions about how to warm up such an early Earth by trapping extra solar energy during the alleged billions of years while the Sun was cooler, and then they gradually tweak those claimed conditions as the eons pass to adjust simultaneously for the changing Sun and the changing Earth, all to prevent what was a too-cold Earth now from overheating. Such time-sensitive fine-tuning of complex eco-system factors was completely unpredicted by the big bang model and instead results from story-telling techniques designed to accommodate contrary evidence.
Here's the Point: The faint young sun problem is one of many examples of major observations which conflict with the secular world's primary axiom that nothing created everything. There is so much overt evidence that does not fit with the big bang model, that the Real Science Radio hosts of YoungEarth.com were able to interview one of the world's leading atheistic physicists, Lawrence Krauss, and memorialize the URL for that show page as: rsr.org/evidence-against-the-big-bang! On this particular matter, if the solar system really was billions of years old, the Earth would still be frozen. Because it's not, we can know that it's not.