Will Our Universe End?

Will Our Universe End?

The short answer is, most likely, yes that our Universe will end. The latest research of the Cosmic Microwave Background (CMB) by ESA’s Planck Telescope indicates that our Universe may end in the future in a collapse. But don’t worry as this collapse won’t happen for many, many years. Read on to understand what will happen to humans, Earth, space, and our Universe if this fate is true.

Dr. MMM of AstroPicionary has taught astronomy to over 10,000 higher education students over 15 years at a Carnegie Level R1 type University in the USA. The author continues to teach more than 10 classes of astronomy and physics each year at different colleges and universities. Here, Dr. MMM discusses a topic that is interesting to learners.

Did Universe Expansion Climax?

If our Universe is has reached fullest expansion, then the end of the Universe has begun! The answer as to whether our Universe has reached fullest expansion depends upon analysis of Cosmic Microwave Background (CMB) data.

CMB is radiation in the microwave sub band of the radio band; the radio band is one of six bands in the Electromagnetic (EM) Spectrum. Simply put, these microwaves are everywhere in space today, in all directions you look in your clear night sky. This YouTube video below explains CMB radiation on the AstroPictionary channel:

AstroPictionary YouTube video on CMB using History of the Start/End of Universe

Analysis of CMB radiation data obtained using ESA’s Planck telescope indicates that our Observable Universe continues to expand outward today. Analysis of this same microwave radiation data using NASA’s previous generation telescope, WMAP, also indicated that the Observable Universe was expanding outward when the data was analyzed, which is about twenty years ago.

Our Universe has always seemed to expand outward since a time of the Big Bang. Notice the shape of the Universe drawn in the History of the Universe image shown in the YouTube video above. With time increasing to the right, the Universe is drawn to continuously expand outward to a time of today.

Keep in mind that Observable Universe is not the same as Universe. Universe includes everything in space whereas Observable Universe does not. The YouTube video below explains our Observable Universe on the AstroPictionary Channel:

Explanation of Observable Universe on AstroPictionary YouTube Channel

Although our Observable Universe continues to expand outward, does it still accelerate? Read on to see if our Observable Universe continues to accelerate outward, expand outward at constant speed, or decelerate outwards.

Has Universe Acceleration Ceased?

If Universe acceleration outward has ceased, then the Universe is either expanding outward at constant speed or has totally stopped. If so, a start of an end of the Observable Universe may have begun.

Let’s first look at analysis of twenty year old CMB data from WMAP, then look at a history of the Universe’s expansion rate before moving on to looking at predictions of the Universe’s future expansion rate based on this WMAP and other telescope data analyses. We also take a look at analysis of CMB data from today’s Planck telescope to see if Observable Universe expansion rate has changed over the last twenty years or so, potentially providing a clue as to whether our Universe’s end has begun.

History of Observable Universe Acceleration

Analysis of CMB data obtained from about twenty years ago using NASA’s WMAP space telescope found that the Observable Universe has been accelerating outward. Although the Observable Universe has been accelerating outward, not always has this been the case.

Let’s take a look at a sketch of the Universe’s acceleration over time: As shown below, the Universe expanded quickly after the Big Bang and then slowed. After the first stars and galaxies formed, the Universe returned to outward acceleration. Acceleration continues to the present day. As suggested in the sketch, a change from slowing expansion to accelerating expansion occurred around 7.5 billion years ago.

Sketch of Start/End of Universe courtesy of Ann Field, STSci under Public Domain

Based on WMAP and other telescope data analyses from about twenty years ago, our Observable Universe’s future expansion rate is outward acceleration.

As shown in the sketch above, as the Observable Universe accelerates outward beyond the Present Day, groups and clusters of galaxies continue to move further apart. The sketch shows three clusters of galaxies at a time labeled Present. These same three clusters are seen in the future area of the sketch (i.e., the black area at the top of the sketch). Analysis of data from telescopes such as WMAP suggests galaxies still cluster in the future; however, the blackness of space between the clusters will increase due to an outward accelerating Observable Universe. Notice that the blackness of space between the clusters has grown larger in the future area of the sketch. Is this sketch entirely correct? Let’s find out.

Acceleration of Observable Universe Today

Analyses of CMB radiation data obtained using ESA’s Planck telescope indicate that our Observable Universe acceleration has not ceased. Our Observable Universe is neither coasting at a constant speed outward nor has stopped accelerating outwards.

Although our Observable Universe continues to accelerate outward today, Planck data analyses suggest that this acceleration is not as fast. Read on to better understand effects due to a slowing of our Observable Universe’s acceleration.

What Slowing Acceleration Looks Like

Analysis of CMB radiation obtained using ESA’s Planck telescope indicates that our Observable Universe is still accelerating, just not as fast. Does this slowing acceleration indicate a start to the end of our Universe?

Let’s look at acceleration: Shown below are two cars accelerating to the right as measured from the same starting line on the left. Both cars accelerate to the right; however, the bottom car’s acceleration is slower than the top car’s.

Animation of car acceleration courtesy of El-macho under CC0 1.0

Let’s look at an analogy of acceleration: Let present day be the starting line of the cars. Let the top car represent acceleration of the Observable Universe using WMAP space telescope data from about twenty years ago. Let the bottom car represent acceleration of the Observable Universe using Planck space telescope data from today. Like the bottom car accelerating slower than the top car, today’s Observable Universe is accelerating slower than Observable Universe of about twenty years ago.

Although the Observable Universe continues to accelerate outward, today’s Observable Universe accelerates at a slower rate outward than that of about twenty years ago. Conclusions cannot yet be drawn as to whether our Observable Universe is decelerating and thus a beginning to an end.

More data is needed to determine whether Plank telescope data supports an anomaly or the start of our Observable Universe’s deceleration. If the former, then WMAP analyses of CMB data remains the standard and our Observable Universe continues to accelerate outward. If the latter, then Planck analyses of CMB data becomes a new data point, indicating that our Observable Universe is decelerating; more to the point, an end to our Observable Universe has begun.

Read on to better understand effects of a slowing Observable Universe.

Our Future Observable Universe

Our future Observable Universe involves cannibalism of nearby galaxies. Observations of large central dominant (cD) galaxies show one very large, very massive galaxy cannibalizing other galaxies. In the future, we should see more of these cD type galaxies.

Besides an increasing number of cD type galaxies, space should not grow dark over time. Instead, space should increase in a total number of light sources as our Observable Universe ages.

Let’s look at these two features of our future Observable Universe.

A Cannibalizing Future Observable Universe

Although our Observable Universe is slowing its acceleration, our Observable Universe still continues to expand and accelerate outward today. Our Observable Universe will continue to have galaxies within clusters move toward each other and eventually merge via cannibalism. The YouTube video below explains cannibalism in astronomy on the AstroPictionary Channel.

YouTube video on Cannibalism in astronomy on the AstroPictionary Channel

As galaxies within clusters move closer together, cannibalism should increase in number in the future.

A Brightening Future Observable Universe

In addition to increased cannibalism, our Observable Universe will continue to have clusters of galaxies move apart. However, the blackness of space between these known clusters of galaxies will not continue to grow as once was hypothesized (see Sketch of Start/End of Universe above)! Instead, in areas of space once considered to grow dark or black over time due to our Universe accelerating outwards, our telescopes will see more points of light from galaxies we never knew existed!

As our Observable Universe continues to accelerate outwards, light from galaxies that we could not see in the past will arrive to Earth. Over time, our telescopes will be able to see more galaxies. Even though some existing clusters of galaxies will increase in cannibalism and move further apart, our clear night skies won’t become increasing dark! Instead, future clear night skies will show an increase in the number of distant light sources.

The animation below shows bright celestial objects moving further away from each other over time in an expanding, accelerating Universe as viewed from a stationary point within the field. Choose any two bright celestial objects and watch as the darkness of space between the two sources increases; however, the blackness of space between the two bright sources does not remain black for long; not long, watch as distant light sources come into view. Over time, the number of light sources seems to increase in this animation.

Animation courtesy of Jahobr under CC0 1.0

In Conclusion, we need to collect more CMB data to determine whether our Observable Universe is continuing to accelerate at the same rate or starting a new era of slowing expansion. Time will tell.

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About the author

Michele M. Montgomery earned a B.S. Degree in Nuclear/Mechanical Engineering from the Pennsylvania State University, an M.S. Degree in Physics from The University of Alabama with a concentration in Solar Physics, and a Ph.D Degree in Physics from Florida Institute of Technology with a concentration in close binary star systems. She joined the faculty at The University of Central Florida Physics Department in 2004 where she regularly taught astronomy, astrophysics, and cosmology. In 2006, she noticed that a large, urban college nearby to UCF did not teach astronomy at one of their largest campuses. She began teaching astronomy at this East Campus of Valencia College, a college that has more than 60,000 students; she still teaches four courses of astronomy each fall, spring, and summer semesters. The astronomy program atValencia College East has grown significantly with several more faculty added who teach astronomy.

By 2019, Dr. Montgomery has taught astronomy to more than 10,000 college and university students, both online and face-to-face. Many of her students have gone on to take her astrobiology, astrophysics, and space physics courses. 

By 2016, Dr. Montgomery had co-authored several astronomy texts and quiz/exam banks. Her work appears in several domestic and international astronomy text books (e.g., Horizons by Cengage, Universe by Cengage, Foundations of Astronomy by Cengage) that are used both at the higher education as well as at the high school levels. Starting in Fall 2019, Dr. Montgomery switched gears to authoring digital textbooks and research full time, while still teaching 12 courses of astronomy and up to eight conceptual, algebra, and/or calculus-based physics courses each year. Her research interests are numerical simulations using Smoothed Particle Hydrodynamics of close binary star systems. She also regularly is granted telescope time on the NASA's Kepler space telescope for observing eclipsing binary star systems. She has also observed using Gemini South, Keck, and Kitt Peak ground-based telescopes. Her major teaching areas are Astronomy, Astrobiology, Astrophysics, Cosmology, Space Weather/Space Physics.