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Why the Universe Is Mostly Empty Space


Glenn Stok has a Master of Science degree. He studies cosmology to understand the Universe and writes about it to share his research.

Outer space is not the final frontier. We have yet to discover an endless world within the emptiness of everything in our Universe.

Looking outward, there is a vast amount of space between planets, solar systems, and galaxies. But even when we look inward, deep within atoms and molecules, we find an enormous empty space between the electrons circling the nucleus of atoms.

I'll take you on an illustrative tour both outward and inward. There is an endless world within the emptiness of everything in our Universe. Let's start with a quick review of where we are in the Universe.

The Universe is mostly empty space

The Universe is mostly empty space

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, deep within our world, might have no limits either. Scientists are already finding previously undiscovered subatomic particles that have fundamental interactions in an entire physical world of its own within atoms.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.

To give you an idea of how far apart the parts of an atom are, if one were to enlarge a single atom to be the size of our solar system, the electrons going around the nucleus would be equivalent to the planets going around the Sun.

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. After all, if the Big Bang did occur, that may be the point where we all began.

We can go even deeper inward. Inside the nucleus of atoms, we already have discovered Quarks, which have more mass than the electrons around the nucleus, though a Quark is smaller in size.

There is so much more to learn about our Universe. 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.


  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. "Fundamental Interaction." Wikipedia

© 2012 Glenn Stok


Glenn Stok (author) from Long Island, NY on August 11, 2016:

goatfury - It's good to know there are others who think about these things. I appreciate your comment. Thanks.

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.

Angelo52 on July 05, 2012:

The final frontier, other than the two possibilities presented here - of an infinite universe and an infinite inner space - could also be of the mind and the soul. Could our minds (as a race and given enough time) continously expand in capabilities? Is death but a gateway to another existence? If so perhaps the mind coupled with our demise in this form is the beginning of a final frontier.

Glenn Stok (author) from Long Island, NY on July 05, 2012:

cclitgirl, Actually, Cyndi, I read about it early this morning. But I didn't think of writing a Hub about it until I read your Q&A question. We must be on the same wavelength (no pun intended). They call the Higgs Boson the God particle because it explains how the universe is tied together. Thanks for selecting this as best answer and for voting up.

Cynthia Calhoun from Western NC on July 05, 2012:

Way to go on this awesome hub!! That's EXACTLY why I asked the question. :D Did you hear on the news yesterday that these physicists think they found the "god" particle - essentially the potential to reason why we're here? That's what inspired the question. I love that you talked about atoms, too, because, yes, it's like there's infinite space in-between the quarks and waves and all that other stuff. Nice! Voted up and shared.

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