Updated date:

Why the Universe Is Mostly Empty Space


Glenn Stok has a Master of Science degree. He studies cosmology to understand the Universe and shares his ideas and research in his essays.

The Universe is mostly empty space

The Universe is mostly empty space

There is a vast amount of space between planets, solar systems, and galaxies. But if we look inward, deep within atoms and molecules, we find an enormous empty space there too.

I'll take you on an illustrative tour both outward and inward. Let's start with a quick review of where we are in the Universe.

Where Are We?

Our planet Earth is the third from the Sun in our solar system, and our solar system is off to one side of our Milky Way Galaxy. When we look up at the sky on a clear night, we can see a band of stars. That milky white band of stars is the other end of our galaxy. That's why we call it the Milky Way.

It wasn't long ago when people believed the Earth was flat and that it was the center of the Universe. We have come a long way in a few hundred years, and we know a lot more now.

What We Already Know

  • We know that the gravitational pull of our Moon affects our tides.
  • We know that Solar Flares can affect our radio communications and electronics.1
  • We know that the Earth does not take exactly 365 1/4 days to go around the Sun. Besides adding a day every four years with a leap year, we have to skip a leap year every hundred years. We also need to adjust the calendar with leap seconds added every so often.2
  • We know that the Universe is expanding. We have the technology to record distances and movements of other bodies in space. Based on these measurements, we can tell that everything is moving apart, moving away from one central point that could indicate the origin of The Big Bang.3

Why Is Space so Empty?

If the Universe is indeed expanding from a single point, which cosmologists believe in having begun with the Big Bang, then one can understand why there is so much emptiness between everything.

The Universe may have no end in sight. That is hard for the human mind to conceive. We tend to want to place end-points on anything physical since the notion of infinity is somewhat incomprehensible.

If we travel to the end of the Universe, we may discover an endless journey.

The journey inward might be limitless, too, as we look deep within the subatomic particles of an atom.

Subatomic particles include the neutrons and protons that make up the nucleus of the atom and the electrons that spiral around the nucleus in an orbital cloud.

The nucleus of an atom is virtually 100% of the entire atom’s mass. If you were to enlarge a single atom to 500 square feet, the size of the nucleus would still be like a speck of dust. The space between it and the outer band of electrons is merely empty space.

Scientists have already found previously undiscovered subatomic particles in an entire physical world of their own deeper within the nucleus, known as Quarks and Leptons.4

The Emptiness of Matter

There might be no end to the limits of our Universe. It can merely keep expanding, creating more emptiness within.

No matter what technology we develop to reach out into space, we are limited to the problems of distance and the speed of light.

We can send out to space robotic missions that send back information about their discoveries. However, the farther we reach out, the longer it takes for the signals to return to Earth. Eventually, it becomes impossible to receive returned data in a reasonable period, limiting our ability to gain further knowledge of outer space.

We do know that there is some form of energy field that spreads throughout the entire Universe. Dr. Peter Higgs proposed this idea in 1964. A discovery by atom-smashing physicists on July 4th, 2012, is named after him.

The frontier of space might lead us to the ends of the Universe. However, we can discover an entire unexplored world if we travel inward, within inner-space.

Outer Space Vs. Inner Space

Ever since the Big Bang, we imagine the Universe as a bubble with a radius of 13.6 billion light-years. However, we don't know if there are any limits at all. The Universe might be infinite, both outward and inward.

If we can go endlessly outward, there might also be no limit to how far we can go inward. That inner world might affect our outer world just as much as all the known objects in outer space.

Inner space is just as massive and limitless, and it has yet to be fully discovered and understood.

Today we have the ability to go deeper and deeper into inner space with new technology already in existence. We have instruments that can visualize individual atoms, but we can go even deeper than that!

With a breakthrough discovery on July 4th, 2012, at the European Organization for Nuclear Research (CERN) in Switzerland, scientists believe they have discovered a subatomic particle, known as Higgs Boson (named after Dr. Peter Higgs who I mentioned earlier).

The Higgs Boson particles might explain why objects have mass. The more mass objects have, the more gravitational pull they have on one another.

Higgs Boson subatomic particle discovered on July 4th, 2012

The Physical Effects of an Empty Universe

Despite the emptiness, all mass in our Universe has a powerful force on one another.

The Sun's gravity holds the Earth and all the other planets in their orbits. In addition, all planets in our solar system pull on one another, causing minor fluctuations of their orbits. Even our Moon causes the Earth to wiggle. Did you feel that?

We might say that to some infinitesimal degree, every object in all the other galaxies has some form of effect on objects close to home.

As enormous as outer space is, inner space is just as limitless. There is mostly nothing in it, and therefore there’s a lot of room.

The point I'm making is that there is mostly empty space deep within—so much empty space that you might be able to take the entire Universe and squeeze it into a small ball. Then keep squeezing it until you get down to a point, a point so little that has no dimension—no width, length, or height.

That may be the point where our present Universe began with another Big Bang.

In Conclusion

There is so much more to discover. Going deeper into the empty space of atoms may eventually reveal the secrets of the Universe and provide a better understanding of the laws of physics.

Outer space is not the final frontier. We are only now discovering an endless world within the emptiness of everything in our Universe.


  1. John Papiewski. (April 24, 2017). How Solar Flares Affect Communication.” Sciencing
  2. Glenn Stok. (June 25, 2012). The Algorithmic-Rule for Leap Years and Leap Seconds.” Owlcation
  3. Avery Thompson. (April 26, 2017). How We Know the Universe Is Expanding, and Accelerating.” Popular Mechanics
  4. Erik Gregersen, Senior Editor. (Retrieved April 2021). “Fundamental Force.” Encyclopaedia Britannica

© 2012 Glenn Stok


Andrew Smith from Richmond, VA on August 11, 2016:

Great stuff. I really enjoy thinking about this type of stuff, and do so frequently (it's either history or physics, with precious little time for anything else, other than jiu jitsu). Keep it up, Glenn!

Nathan Bernardo from California, United States of America on July 18, 2012:

Absolutely fascinating article. It seems we have much potential for exploration much closer to home. I like this approach and also your evocative and articulate explanations.

Related Articles