The science writer Denis Overbye has a piece at the New York Times (gift link) in which he notes his dissatisfaction (or depression) at the thought that in billions of years time, there will be a last sentient thought in the universe, as it dissolves into a sort of heat death.
I think it is unwise to base too much thought on current theories. As he notes himself:
You may point out that it is way too soon to be prescribing a future for the universe. New discoveries in physics could provide an escape hatch. Maybe dark energy will not be constant; maybe it will turn around and recompress the universe. In an email, Michael Turner, the cosmologist emeritus formerly at the University of Chicago who coined the term dark energy, referring to the Greek letter symbolizing Einstein’s cosmological constant said, “Lambda would be the most uninteresting answer to the dark energy puzzle!”
Update: a recent paper on the topic is relevant here:
After nearly 13.8 billion years of nonstop expansion, the Universe could soon grind to a standstill, then slowly start to contract, new research published in the journal Proceedings of the National Academy of Sciences suggests.
In the new paper, three scientists attempt to model the nature of dark energy – a mysterious force that seems to be causing the Universe to expand ever faster – based on past observations of cosmic expansion.
In the team's model, dark energy is not a constant force of nature, but an entity called quintessence, which can decay over time.
The researchers found that, even though the expansion of the Universe has been accelerating for billions of years, the repellent force of dark energy may be weakening.
According to their model, the acceleration of the Universe could rapidly end within the next 65 million years – then, within 100 million years, the Universe could stop expanding altogether, and instead it could enter an era of slow contraction that ends billions of years from now with the death – or perhaps the rebirth – of time and space.
No comments:
Post a Comment