2025.12.06 – Where Did the Universe Begin, and Was There a “Before”?

Key Takeaways

Simple ideas up front

• The Big Bang is the name for a very hot, very dense early phase of the universe when space started to expand.
• The beginning did not happen in one single spot inside space; it is the early state of all space.
• If “universe” means “everything that exists”, there is no outside place where it could start.
• Science today can describe the universe back to a very early moment, but not what, if anything, came before that moment.
• Possible futures such as a “Big Rip”, where the universe tears itself apart, are ideas under study, not firm predictions.

Story & Details

A hot start, not a simple explosion

In December 2025, the basic picture of the early universe is well tested. When astronomers measure light from distant galaxies, they see that almost all of them are moving away. The farther a galaxy is, the faster it seems to move. This fits with a simple idea: space itself is stretching.

If space is stretching now, then in the past everything was closer together. The universe was smaller, much hotter, and much denser than it is today. NASA describes the Big Bang as this very hot, dense beginning and the slow cooling and expansion that follow, not as a firework exploding into empty space [1][2].

Light from the young universe is still around. It has cooled and now arrives as a soft microwave “glow” that fills the sky in every direction. The European Space Agency calls this glow the cosmic microwave background and treats it as a fossil picture of the universe when it was only a few hundred thousand years old [3]. This light is strong evidence that the universe really did pass through a hot, dense phase.

The problem with “where”

Daily life trains the mind to think that everything happens somewhere. A child is born in a city. A storm forms in a region of sky. A star forms in a cloud of gas. In every case, the event takes place inside a bigger setting.

It is natural to try the same idea on the universe itself and ask: “Where did the universe begin?” This sounds simple but hides a trick. The word “where” already assumes a space that exists first, so that things can sit inside it.

Now take the word “universe” in a strict way: all of space, all of time, and everything in them. If this is the meaning, then any real place is already part of the universe. There is no larger room around it. In that strict sense, the universe does not begin inside a place. The “place” is part of what begins.

Cosmology talks instead about an early state of the whole of space. At that time, space everywhere is extremely hot and dense. As time goes on, distances between galaxies grow. No centre point is picked out. Every region can trace its story back to the same kind of early state.

A tiny language detour makes this a bit concrete: in Dutch, the word “heelal” is a common word for “universe”. The question “Where did the heelal begin?” runs into the same problem. If the heelal is “everything”, there is no bigger container to point to.

The puzzle of “before”

The word “before” also comes from daily life. It assumes that time is already running. One thing happens, then another thing happens later.

Modern physics treats time as part of the universe, not as a stage outside it. Using current theories, scientists can follow the history of the universe back to a very early moment when it is extremely hot and dense. NASA’s cosmic history pages describe a brief phase of extremely fast expansion near this start, known as inflation, that helps explain why the universe looks so smooth on large scales [4].

Close to that first moment, however, the usual laws become unclear. Values such as density and temperature reach extremes. Researchers expect that a more complete theory, one that joins gravity and quantum physics, is needed there. For now, no such full theory is confirmed.

Because of this, there is no agreed scientific answer to questions like “What was there before the universe?” or “What was time doing before it began?” Some ideas say there might have been an earlier state, or even many cycles of universes. Others say that asking for a “before” the start of time is like asking for a point north of the North Pole. These ideas are discussed, but none has strong evidence yet.

Can something come from “nothing”?

Behind the questions about “where” and “before” stands a sharp intuition: it feels possible that something might somehow come from nothing, but not that it could be born in nothing. The word “in” points to a container. If there really were “nothing at all”, then there would be no container.

This small shift in words shows why the topic is so hard. On one side is logic: if the universe is all that exists, an outside place for its birth cannot exist as well. On the other side is feeling: the mind is used to boxes inside bigger boxes and finds it hard to stop. Much of the tension in the public debate comes from this clash between strict meanings and deep habits of thought.

How the story might end

Thinking about the beginning of the universe almost always leads to questions about its end. One dramatic idea is the “Big Rip”. In this scenario, the mysterious dark energy that speeds up the expansion of the universe becomes stronger over time. If that happens, expansion could grow so fast that, in the far future, galaxy clusters, galaxies, stars, planets, and even atoms are pulled apart. Space.com describes this as a possible fate of the universe, driven by a special kind of dark energy sometimes called phantom energy [5][7].

Other possible endings are less violent. The universe might keep expanding forever, getting colder and more empty in a “Big Freeze”. Or expansion might slow and reverse, ending in a “Big Crunch” where everything falls back together [6][7].

As of late 2025, observations tell scientists that the expansion of the universe is speeding up, and that dark energy is real in some sense. They do not yet show which, if any, of these endings will actually happen.

Conclusions

The Big Bang describes a universe that begins in a very hot, very dense state and then expands. In this picture, the beginning is not a blast at one spot inside space. It is the early state of all space at once.

When “universe” means “everything that exists”, the usual question “Where did it begin?” does not quite fit. Any real place is already part of that “everything”, so it cannot stand outside it as a cradle. In the same way, “What was before the universe?” reaches beyond what present-day science can test, because time itself belongs to the universe’s story.

Research on dark energy, on the first tiny fraction of a second, and on the possible futures of the cosmos continues. New telescopes, such as missions designed to map the sky in detail, keep adding data. For now, the firm ground is the path from the hot, dense early universe to the rich, expanding cosmos seen today. Around that path remain questions that are simple to ask, difficult to answer, and powerful enough to stretch both language and imagination.

Selected References

[1] NASA – “The Big Bang”
https://science.nasa.gov/universe/the-big-bang/

[2] NASA Space Place – “What Is the Big Bang?”
https://spaceplace.nasa.gov/big-bang/

[3] European Space Agency – “Cosmic Microwave Background (CMB) radiation”
https://www.esa.int/Science_Exploration/Space_Science/Cosmic_Microwave_Background_CMB_radiation

[4] NASA – “Cosmic History”
https://science.nasa.gov/universe/overview/

[5] Space.com – “What is the big rip, and can we stop it?”
https://www.space.com/universe-the-big-rip-can-we-stop-it

[6] Space.com – “Endless Void or Big Crunch: How Will the Universe End?”
https://www.space.com/13393-universe-endless-void-big-crunch.html

[7] Wikipedia – “Big Rip” (background summary, cross-checked with institutional sources)
https://en.wikipedia.org/wiki/Big_Rip

[8] NASA Science – “What is the big bang? Astro-Investigates Ep. 4” (YouTube)
https://www.youtube.com/watch?v=qsoLni0I5_U

Appendix

Big Bang
The Big Bang is the name for the very hot, very dense early phase of the universe and the expansion that followed, not a simple explosion inside empty space.

Big Rip
The Big Rip is a possible future of the universe in which expansion speeds up so strongly that, in the far future, even galaxies, stars, planets, and atoms are pulled apart.

Cosmic microwave background
The cosmic microwave background is faint microwave light that fills all of space and comes from the young universe, acting like a fossil picture of conditions long ago.

Dark energy
Dark energy is the unknown cause of the observed speeding up of the universe’s expansion, seen through its effects on galaxies and space but not yet directly detected.

Inflation
Inflation is a very short period of extremely fast expansion near the start of the universe’s history that helps explain why space looks smooth and similar in all directions on large scales.

Multiverse
The multiverse is a group of ideas that suggest there may be many different universes, where the visible universe is just one region in a larger reality.

Phantom energy
Phantom energy is a suggested type of dark energy that becomes stronger as the universe expands and could, if it exists, lead to a Big Rip.

Universe
The universe is all physical reality: every region of space, every moment of time, and everything that exists within them, from tiny particles to vast clusters of galaxies.