With Thales and other philosophers of his time, thinkers began postulating a universe that was in tune with nature, based on physical and natural properties. Thus, early astronomers set forth to observe and mathematically analyze the universe empirically. So, unless you want to imagine a bunch of unobservable universes that allow you to pretend you can do statistics on them, you are stuck with the one we live in that includes all space, time, matter, and energy. The “all” in that last sentence is what really makes the consequences of having to reboot a cosmological model so consequential. As Marcelo explored in his book The Dancing Universe, there are only a limited set of logical options for dealing with the origin and evolution of everything.

The real problem is that, at the “event horizon” — the outer boundary of a black hole — both general relativity and quantum mechanics come into play. In this artist’s rendering, the black hole known as Cygnus X-1 sucks in matter from a companion star. Although we understand how black holes form, scientists can’t say what happens inside one. Are we any nearer to answering the “what came before” question that we were a generation ago?

How to become a cosmologist

Some exoplanets may have life—they may even harbor aliens who know all the answers already. Since then, the pace of advancement has crescendoed rather than slackened. By this point scientists understood where almost all the elements that form planets, stars and galaxies originated.

Astronomers call for renaming the Magellanic Clouds

Read more about Cosmology here.

The Almagest was Ptolemy’s most famous work, the word literally meaning “The Greatest.” In it, he offered a comprehensive treatise on astronomy that synthesized and expanded upon the known astronomical knowledge of his time. It consisted of 13 books and covered various topics specific to theories and models of the cosmos. These included observations, mathematical models, and tables of planetary positions. The Almagest became the authoritative astronomical text in the Western world for centuries.

What Do Astronomers Do? (Plus Salary Info and Necessary Skills)

An Earth-like planet passing a sunlike star can cause a dimming of about one part in 10,000 once per orbit. The Kepler spacecraft launched in 2009 found more than 2,000 planets this way, many no bigger than Earth. The new discrepancy—called the sigma-eight tension—involves measuring the density of matter in the universe and the degree to which it is clumped up, as opposed to being uniformly distributed. The universe cooled rapidly as it blew outward, however, and by 10–35 second after the Big Bang, the epoch of inflation occurred, enlarging the universe by a factor of 1050 in only 10–34 second. During this wild period, cosmic strings, monopoles, and other exotic species likely came to be. As sensational as inflation sounds, it explains several observations that would otherwise be difficult to reconcile.

The strength of cosmological arguments from contingency is their seeking an ultimate explanation rather than only a first cause. Beings have causal relations, but also an ontological status, i.e., contingency or necessity. Contingent beings & series must have an external explanation since it is their nature to depend on something else for their existence. Leibniz bases his argument on the principle of sufficient reason, which does both the job of the causal principle and arguments against the infinite regress. It shows that there must be not just any causal explanation, but a causal explanation which provides an ultimately sufficient reason for everything that exists. This strengthens the argument by making it dependent on only one claim. Cosmological arguments are typically a posteriori arguments, which means they are based on experience.

Leibniz’ a priori version of the cosmological argument attempts to show that an infinite regress is impossible because it violates the principle of sufficient reason. An infinite series of contingent beings would be without reason for existing. We cannot say the ‘whole universe/series’ is even a valid concept, let alone that it is contingent.