The Science of the Real End of The World

“I hope you feel things you never felt before. I hope you meet people who have a different point of view. I hope you live a life you’re proud of, and if you’re not, I hope you have the courage to start all over again.” -Eric Roth, screenwriter

Forget the prognosticators, the fortune-tellers and the mediums. Pay no mind to the soothsayers, the prophets, the augurs and diviners. The seers see no more than any other sighted person, the omen-interpreters have been superseded by the ornithologists, the psychics made obsolete by the scientists.

Because if doomsday ever does approach, we won’t be warned because of an ancient prediction, but rather because we listened to and made steps towards understanding the Universe around us.

Image credit: NASA / Paul Chodas, Jon Giorgini & Don Yeomans / JPL NEO Program Office.

So forget about whatever end-of-the-world conspiracy you’ve heard, whether it’s the current flavor or any other, and let’s get right down to the science of it.

The world — the beautiful, terrifying, and wonderful Earth that all humans and our distant cousins and ancestors have lived upon — will not last forever, and neither will we, nor will our descendants. At some point, this will all be gone.

Image credit: the MODIS instrument on NASA's Terra satellite.

Our living world, the Earth, will not live forever, and neither will anything on it. But that is a simple scientific truth, and it is a consequence of the way we came to exist. We continue to learn as much as we can about how everything in the Universe works — from the origin of spacetime and matter to the origin and evolution of life on Earth — and it is, without a doubt, the most remarkable story ever conceived of.

Image credit: The Flame Nebula in IR by ESO / J. Emerson / VISTA. Mods unknown.

This Universe was born without life, planets, or even the elements needed to piece them together. It was only through a series of the most violent processes known in nature — where the plasma of the hot, early Universe cooled to form nuclei and atoms, those atoms cooled and contracted under gravity to form stars, generations of stars burned through their nuclear fuel, enriching the Universe with heavy elements — that enabled the Universe to eventually form new generations of stars with planets, complex molecules, and eventually life.

But just as Carl Sagan did exactly 16 years ago today, no living organism lives forever, and we all succumb to the mercy of time.

Image credit: Johan Mathiesen of

The death of an individual life is not the end of the world, but for each of us, when it comes to our own lives, it may as well be; it is the end of our personal world.

Coming to terms with our own mortality is something that it would not only serve us all well to do, but to recognize that this is a journey and an existential struggle that all humans should have the intelligence and bravery to face. If you don’t come to terms with that, how else would you come to terms with this next fact?

Image credit: Tony Narcisse.

Human life on this world will very likely continue to exist after you have ceased to do so.

There are seven billion of us now, inhabiting all seven continents, including many regions that were once thought to be uninhabitable. The damage that we do to this world and to one another can be catastrophic, but life is resilient and there are a great many of us. Moreover, the Earth comes equipped with a number of defenses against the most common types of dangerous occurrences, such as our substantial, layered atmosphere and our self-sustaining magnetic field.

Image/illustration credit: NASA.

Most of the doomsday scenarios you hear of — earthquakes, volcanoes, solar flares, nearby supernovae, asteroid strikes, etc. — would be potentially destructive to humans, but wouldn’t wipe out all humans on Earth. Unless a real catastrophe happens, humans will continue to exist for many generations to come.

But that does not equate to forever.

Image credit: Nuclear test on the Mururoa atoll in French Polynesia; AP Photo.

At some point in time, either through catastrophe or evolution, human beings will cease to exist.

There are some real catastrophes that can cause the extinction of our species. These can be man-wrought, such as through catastrophic modification of the environment, global nuclear war, or collapse of the food chain, or it can be natural, such as an “Earth-killer” asteroid strike, a very nearby supernova, or — perhaps most prosaically — enough time, genetic mutation, and natural selection so that our surviving descendants, long-term, cease to possess the qualities that we have determined “make us human.”

Image credit: Patrick Bolvin. Yes, it's a joke; I know that's not how evolution works!

But even in these catastrophic cases, even after the last human has died off, life on Earth will continue to exist.

During the worst mass extinctions in Earth’s history, 30-to-50% of the species living on our planet at that time died off. Even 65 million years ago, with the asteroid that wiped out the dinosaurs, more than half of the species survived! And no matter what doomsday scenario we concoct, there is nothing we’ve yet conceived of that could halt the life cycle of every bacteria, virus, protist and fungus on Earth, including species so far removed from our experience that they don’t even require the Sun!

Image credit: NOAA PMEL Vents Program.

The day will come, however, where even the most elusive life in the deepest hydrothermal vent will cease to survive and reproduce. An estimated one-to-two billion years in the future, all life on Earth will cease to exist. And you can thank the Sun for that.

Image credit: Wikipedia user RJHall, based on Ribas, Ignasi (2010).

As the Sun continues to burn through its nuclear fuel, it burns faster and more luminous, and over time, that increased energy output will be sufficient to increase the surface temperature of the Earth above the boiling point of water. And when it does, the oceans will cease to exist, and so will the basic biological processes that drive all life on Earth as we understand it.

In one sense, one-to-two billion years from now, that will be the end of the world. But in another sense, the Earth will still be here, albeit devoid of life, just like all the other worlds (we think) in our Solar System. But even that will not last forever.

Image credit: Atacama Large Millimeter/submillimeter Array (ALMA).

Because in five-to-seven billion years, the Sun will run out of hydrogen in its core and become over a hundred times as large and luminous as it is today, entering its red giant phase. At this point, it will roast the Earth with wave after wave of ionized plasma, stripping off our entire atmosphere and possibly engulfing our entire world into the central star itself.

That, truly, will be the end of the world.

Image credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA).

And yet, the many atoms that made up the Earth, that made up past and (relative to us) future life on Earth, and that make us up right now, will be returned to the interstellar medium, where they will someday make future generations of stars, planets, and possibly living creatures once again.

The real end of the world is not yet upon us, but when it does come, it is far more wonderful and terrifying than any doomsdayer has ever prophesied. And I hope you never forget just how spectacular and precious your existence — in the midst of all of it — happens to be.


  1. #1 Theo Dzielak
    December 20, 2012

    So beautifully stated in its simplicity, directness, and with its knowledge.

  2. #2 Pattye
    December 21, 2012

    just beautiful Professor. thank you

  3. #3 Stackpole
    December 21, 2012

    Well, yeah, but…

    12/21/12 (in the Central Time Zone where the Mayans lived) ain’t over yet…

  4. #4 BenHead
    New York
    December 21, 2012

    @Stackpole Maybe, but the exact moment of the solstice was over four hours ago as I write this. I like to think if the world was going to end for a completely non-scientific yet also not completely random and unpredictable reason, it’d be at that moment. So I’m going to say that “logically” we’re fine.

    And/or the Earth was already destroyed:

  5. #5 Ken Puck
    Cornwall, UK
    December 21, 2012

    I’m not waiting around to get roasted alive. I’m getting outta here!

  6. #6 Dark Jaguar
    December 21, 2012

    I accept that I’ll die, but I don’t have to like it. Assuming some amazing technology someday exists to digitize everyone alive at that point (a big assumption, bigger than transhumanists realize), I’d love to have it. Some say “you’ll get bored”, but assuming that level of technology, modifying my state of mind to NEVER be bored of living would be trivial.

  7. #7 Russ in Texas
    December 21, 2012

    So clearly we need really AWESOME technology to divert all that extra energy into warp-drives and stuff, so Terra remains nice and comfy. :)

  8. #8 Gbenga
    December 21, 2012

    You are nuts!

  9. #9 Joel
    December 21, 2012

    The only issue I have to this article is the author’s inclusion of nuclear war as a cause. It would be almost impossible for even the worst scenario of the cold war time for a thermonuclear war to have wiped out all life on the planet – or even all human life. A “global” thermonuclear exchange between the USA and Soviet Union and their allies, even in a worst case scenario would have involved nuclear exchanges that would have been limited (by and large) to the Northern Hemisphere, and (longitudinally) to a narrow band on this hemisphere. There were simply not very many targets in the Southern Hemisphere, and most of those would have been in Australia and possibly South Africa.

    Even at that time, over a billion people lived in parts of the world that would not have been affected, even by radiation – or only minimally.

  10. #10 mullah jim
    rigel 4
    December 21, 2012

    we here on rigel 4 know the date of your planet’s demise, and the form of your destructor.

  11. #11 derek
    December 21, 2012

    That graph makes me sad. By adopting a linear and not a logarithmic scale, Ribas loses the opportunity to show the nice linear relationship between luminosity, radius, and temperature

    log(L/Lo) = 2 log (R/Ro) + 4 log(T/To)

    I tried tracking the data source down but got lost in a nightmare world of .tar balls and postscript files.

  12. #12 robb
    December 21, 2012

    i just tried to find Australia on Google Maps and got a message:

    “404-the requested continent was not found”

    what does that mean?

  13. #13 Raju
    December 21, 2012

    A simple, scientific and down to earth approach to the End of the Earth scenario in distant future. End is unavoidable and as this article and Prof Brian Cox also states, in his Wonders of the solar system and wonders of the universe series, everything including the time itself will cease to exist and all that will remain will be a vast empty space with no dimensions at all. So lets all stop worrying about the end and live our lives to the fullest.

  14. #14 Allen
    December 21, 2012

    There is no scientific explanation for the beginning of the universe, so why should there be one for the end? Ex nihilo is something only God can do, and he has left us the evidence that he did it: great natural laws, love, beauty, and a beginning that can’t be explained without him. So this article is as much speculation as any other, and is no more science than a belief in the Bible.

  15. #15 Name Withheld
    December 21, 2012

    If the cheesey attempts at being lyrical, mystical, and profound were removed, this article would be about 2 paragraphs long. And don’t get me started on those goofy, big pictures. The author should start a cult.

  16. #16 Samuel
    December 22, 2012

    @Allen: “There is no scientific explanation for the beginning of the universe, so why should there be one for the end?”
    Because we know very well what is going to invariably happen to our sun. We’ve observed the death of stars, and we know that our very own sun will unavoidably have the same eventual fate. Once our sun is gone, our entire solar system is done for. Although technically, Earth will no longer be able to sustain life for quite some time before our sun implodes on us. All of this is assuming, of course, some massive asteroid doesn’t smack right into us first. Although I suppose if you were discussing the specifics of how life on Earth will end, you have a point. We can’t presume to know *exactly* how we’ll all be doomed; we simply know that it is an inevitability.

  17. #17 Douglas Watts
    December 22, 2012

    Ethan, I understand the overall arch of this, but it veers uncomfortably with climate change denialists saying that because in the Miocene or Jurassic most of Wyoming was a shallow sea that it’s okay now to burn all the coal on Earth and melt the ice caps just because it something like that happened 60 million years ago.

  18. #18 Keith M Ellis
    Kansas City, MO
    December 22, 2012

    “But just as Carl Sagan did exactly 16 years ago today, no living organism lives forever, and we all succumb to the mercy of time.”

    It’s true that Carl Sagan did not live forever on that day 16 years ago; but that’s also true about every other day.

  19. #19 copernicus34
    December 22, 2012

    @Douglass you (ie we) are not entitled to the earth climate we have today, to be forever. climate forces will modify over time with or without human participation.

  20. #20 Keith M Ellis
    Kansas City, MO
    December 22, 2012

    @copernicus34, that we are not “entitled” to a static climate is neither here nor there. We are entitled to nothing; certainly nothing else in the natural world. If we are not entitled to a friendly climate, we are not entitled to friendly weather, and we are not entitled to irrigated agriculture or aqueducts sending water to cities in the desert, or heat against the cold of winter. We are not entitled to protection or treatment from disease. We are not entitled to dredging harbors against silt. We are not entitled to anything we do that is an exertion of our will against the natural world to our own interest. If your principle premise is this lack of entitlement, then it follows that we are also not entitled to be doing the very things we are doing to alter the climate. So your argument isn’t even wrong, to quote Pauli — it’s trivially true, with no relevance at all.

    Yours is stupid argument. But I feel certain you believe that it is profound.

  21. #21 jojo
    December 26, 2012

    what a prosaic pathetic life you must lead to author this dross. the universe is definitely worse off because this dreck was written.

  22. #22 Paul R Jefferson
    Wilmington NC, USA
    December 26, 2012

    Very cogent article, not alarmist, but only too real. It makes me wonder about the succeedding generations and millenia to come when the atmospheres really start to change. How will the then-“humans” react. Will politeness still exist…or will the law of nature long since overridden everything and everyone? Glad to be here now, but not then…

  23. #23 dave the rave
    bothell, washington
    December 27, 2012

    Allen from Indiana, are you a professional comedy writer? Your post is most excellent parody, I was laughing out loud. Great send up of the insane faithiests. keep up the good satire.

  24. #24 Birger Johansson
    December 28, 2012

    A supercivilisation can move the Earth outwards by having massive asteroids cycle between Earth and Jupiter millions of times, transferring momentum (I am not saying it would be easy).
    With that technology, terraforming other planets would be almost trivial. Of course, we have no idea wether “strong” AI would be interested in that.

  25. #25 Siener2
    Far South of the Equator
    January 6, 2013

    Ethan, this is one of your most beautiful posts ever. I am sending it on to friends and family.

  26. #26 joseph berk
    owings mills md
    January 31, 2013

    Won’t the moon cycle away from us in one hundred thousand years? Won’t the planet become horribly unstable then for human life?
    Isn’t that how long we really have? (I have to plan for my retirement)

  27. #27 Sean T
    February 1, 2013

    joseph berk,

    The moon will not recede from the earth forever. Once the earth and moon become tidally locked, the recession will stop. The recession of the moon arises from the slowing of the earth’s rotation as a result of tidal friction. The tidal bulge generates friction on the earth, leading to the slowdown of the earth’s rotation. Energy is conserved, so the loss of energy associated with this slowdown must be accompanied by a gain in energy somewhere else. That gain comes by the moon’s moving to a higher energy orbit, ie. an orbit farther from the earth.

    Once the tidal friction stops, the recession will as well. The friction arises because the earth’s rotation is much faster than the moon’s revolution around the earth. At some point, the earth’s rotation will slow down to the point where the rotational period of the earth matches the revolutionary period of the moon. At that point, the tidal friction goes away and the moon stops receding.

    However, even if the moon were to disappear tomorrow, how would that make the earth unsuitable for life? I realize that the tides would be seriously diminished (there would still be small tidal effects from the sun), but that would only pose a problem for the original evolution of life, not for life currently in existence. Certainly, some species would likely go extinct (those living in the intertidal zone would likely be doomed), but why would life on earth in general be in any trouble?

  28. #28 Kasey
    February 12, 2013

    Although a very moving piece, i am confused in the part the rest heavy on the sun. Is the sun our main concern for the death of Earth? and if so, will all of the other planets essentially “die” too do to the sun becoming so large. this websites seems to agree that the Earth has increasingly become brighter, but they talking about “ice ball planets” migrate towards the sun over the years? Is this a bad thing, and is there something we could do to stop it.
    Another question i have, there has been much talk about people are to blame for when the Earth goes extinct. The whole “go green” that has become very much popular, could other plants be doing this same self-harm to other planets if they have living things on it?
    Lastly, is their any evidence that there will be another man-wrought devastation, and will it be as bad as the last one this planet has seen.

  29. #29 JP
    February 12, 2013

    It’s weird to think about the catastrophic events that could happen and still not completely eliminate the 7 billion people that inhabit this planet. I’ll never understand why people think nuclear war would do it when there are plenty of countries who would not be involved and would remain unaffected. I even think that if a sizable asteroid was approaching the earth that we have the technology and fire power able to disintegrate it before it enters the atmosphere. It’s important for us to continue to study the effects that we as humans are having on the earth and develop new methods to solve things such as energy crises and greenhouse effects. Even if it takes so much time that we ourselves don’t get to see the benefits, we could leave this world knowing that we made it a better place for our future generations. As much as people think they know, the end will never be certain.

  30. #30 Wow
    February 12, 2013

    Mars will probably be “fine”, but die a heat death anyway since the white dwarf won’t be warm enough to heat Mars beyond the temperature of, say, Neptune.

    The earth is actually about 95% of the way through the “goldilocks zone” to being too close to the sun.

    And, yes, the clathrate bomb could see CO2 levels and ecology change more devastating than that of the PETM which killed off many more species than the famous extinction that killed of the dinos.

  31. #31 Sarah
    United States
    February 12, 2013

    This post was very well developed, and it can be inferred that the poster is very passionate about this topic. The end of the world is something that has been debated and debated through numerous religions, personal views, and science observations and will continue to be until the end. What I found refreshing is the context which the end of the world was discussed. The frame of reference of Armageddon (human life, all life forms, and the planet itself) is exactly the ideas we need to further explore and debate on. It is very narrow minded for us as a species to only consider our own fate and when that may be. There are many more species out there that if the conditions are right will fill the void our species will leave behind. According to scientists and many other blogging site discussions (such as believe that squids and other similarly intelligent animals will have the best bet for fill our niche. Animals like us have only been around for a few million years, and each has had a limited reign on the planet like the dinosaurs. Something will take our place once we are extinct, and the world will keep on turning. The second topic of the planet being lifeless, I believe, will happen much closer to the complete annihilation of Earth. Even then, the chances are that microscopic organisms such as extremophiles will still survive. It is clear that we won’t see the complete and utter end of our planet with your example of the sun, but the questions are out there and there is much postulating left to do.

  32. #32 Joel P
    February 12, 2013

    Even though this would be in billions of years to come this is the single most real sounding event that could occur to destroy all human life. If the sun ceased to exist or boiled us over not a single human would survive and the Earth would no longer exist.

  33. #33 Conner
    February 12, 2013

    If the Earth is going to be “cooked” in an estimated 1-2 billion years from now, our technology will be so advanced that we as humans will be far from Earth, mabye even having a new sun? I do think that it is cool that we can already calculate when this event is going to happen through physics but what about random events such as a gigantic asteroid? Do we know when these events will happen?

  34. #34 Taylor Brown
    February 12, 2013

    I strongly agree with #29. We as humans are the main cause to the deterioration of Earth with global warming and the greenhouse effect being the top priorities. Yes, there are other catastrophes that can cause the ‘end of the world’ but humans are just accelerating Earth to its death. I can agree with the blog about nuclear wars and other such wars taking out a majority of the population but it wont take the whole population out.

  35. #35 Douglas Rigg
    February 12, 2013

    I agree with what the author says about the world eventually ending because all stars and objects in a galaxy come to an end. I disagree however that it will be because of any type of “Earth Killing” comet strike similar to what wiped out the dinosaurs. The Earth has always been subject to impacts by comets and asteroids, although big hits are very rare. The last big impact was 65 million years ago, and that led to the extinction of the dinosaurs. Today NASA astronomers are carrying out a survey called the Spaceguard Survey to find any large near-Earth asteroids long before they hit. The have already determined that there are no threatening asteroids as large as the one that killed the dinosaurs. All this work is done openly with the discoveries posted every day on the NASA Near-Earth Object Program Office website to prove this will not be the fate of the earth.

  36. #36 Taylor
    February 12, 2013

    I wanted to comment on the part of the article about evolution and humans ceasing to exist as humans. It is not possible for humans to exist as anything but what they are. Although, it is true that mutation occurs and can altar characteristics, proteins, etc. Mutation cannot change enough of a human to become something else like a pig. Evolution can only change a character in a small way over a long period of time. The only possible way for humans to evolve into something else would be to isolate themselves from the entire human population and only than after an extensive period of time like millions of years can they evolve. That however, is not even possible because humans make up too much of the earth to be isolated.

  37. #37 Crystal Weaver
    Morgantown, WV
    February 12, 2013

    Personally I feel as if humans will become extinct way before anything will ruin the life on earth or even once all life on Earth has disappeared. I feel that humans now a days are advancing too quickly which is also leading humans to be more unhealthy and less active. I have a feeling that no catastrophic event will take the life of humans but humans will take the life of humans. I do wonder what the world will be like once I am gone from my personal world but I am also curious as to how many universes have gone through the same destruction that our universe will some day face.

  38. #38 Richard
    February 12, 2013

    I agree with #26. As the moon begins to move away, the forces that come with it begin to become weaker. For example, the moon is responsible for our tides. Without those forces, our land would be either engulfed by water, or we could experience extreme weather changes. However, if the moon were to stay then I definitely agree with the idea of the sun engulfing our planet.

  39. #39 Caleb
    February 12, 2013

    This blog was interesting; however, I do question some of the logic. To say that the world will end in 5-7 billion years is an astronomical number. With that said, why would humans be wiped out before then? I understand that we continue to ruin the atomsphere daily (global warming), but what are the chances of an actual all out nuclear war or a disaster that wipes out all humans? It seems very unlikely, and like Douglas pointed out, hasn’t happened in 65 million years. Also, by that time it is likely that we would have some sort of technology to evade certain disasters.

    With that being said, I would also like to comment on the discussion involving evolution. I do not believe that evolution will be a factor in the extinction of the human race. It seems that we continue to evolve into a bigger, faster, stronger, and smarter species. If humans do continue this trend, there are limitless possibilities to what could be prevented from happening. Look into the past, even in the last couple hundred years and look at the species evolving at an astronomical rate and so is technology. The possibilities truly do seem limitless.

    With all of that said, I do believe that the end of the world will be a result of the sun changing phases and I also agree with the blog when it discusses the realization of death and the end of the human race. Overall, this blog was actually very thought provoking and does remind the audience that death is inevitable; however, no one can truly know what will happen in the next couple billion years. I mean, do you think George Washington could have predicted the iPhone 5?

  40. #40 Kylie
    February 12, 2013

    I’m glad to have stumbled on this inspiring article and get some kind of scientific understanding on how our universe will supposedly be like in the far future. It’s important to know that in 5 to 7 billion years from now the sun will literally burn up the earth due to its massive increase in size and lack of hydrogen in its core. For years there has been constant talk about the world coming to an end and tons of people out there believing these ignorant tales. This article allows you to get a more sense of belief and understanding of how the “end of the world” will be and why.

  41. #41 Logan
    February 12, 2013

    No one knows for sure how the world was created so how can they say at the end of the blog that new life might once again be formed? I think that the human race will cease to exist way before the sun has a chance to wipe us all out. If the above graph is correct and the sun is constantly getting hotter all the time and heating the earth, than are humans really the cause of global warming or is it just happening naturally from the sun? If this is the case than is there really anything we can do to stop global warming either?

  42. #42 Casey
    February 12, 2013

    According to Newtons 3rd Law, for every action, there is an equal but opposite action. So when stating that the moon begins to move away and the forces become weaker, doesn’t that just mean that the forces are just as weak towards the Earth? What does that do to the Moon? If the moon is responsible for our tides, is there anything that we do to the Moon that will decline as we move away? In stating that, how does that relate to the Suns forces? When its growing in magnitude like it says above in the blog, are the forces of the sun greater on the Earth than the Earth’s are on the Sun? Because if so, then that would no longer fall under Newton’s 3rd Law. If this is true about the Sun engulfing the Earth, will it continue down our solar system and engulf them as well?

  43. #43 Wow
    February 13, 2013

    “No one knows for sure how the world was created so how can they say at the end of the blog that new life might once again be formed?”

    Because the creation of the world isn’t anything about the creation of life on it.

  44. #44 Wow
    February 13, 2013

    “Without those forces, our land would be either engulfed by water, or we could experience extreme weather ”

    The moon doesn’t keep land above the ocean. Indeed the moon is why some of the land becomes inundated (by high tide).

    And weather is driven by the temperature difference between the equator and the poles, not the presence of the moon.

  45. #45 Jess
    February 13, 2013

    For the most part, I can see the logic that has been established in order to come to such conclusions, however there are a few discrepancies within the reasoning that I do not agree with.
    First, by now I believe that everyone knows that all living things will eventually come to die. In saying so, I do not agree that human life will cease to exist before the Earth has been fully eradicated of life. I largely disagree with the possibilities of a global nuclear war, collapse in the food change, and a change in evolution that will cause the demise of the human race. As long as the leaders and their countries continue to understand that in order to thrive they must assist and relieve one another, as long as farmers continue to produce and management of products are kept in control, then these so called catastrophes should not happen. Also, in terms of the evolution scenario, people have been around for a couple thousands of years and within the past few centuries, human anatomy or evolution has no changed to immensely, just purely our lifestyles and continued outbreaks of new diseases.
    Second, as a follow up, I believe that the sun burning its nuclear fuel, and causing the surface temperature of earth to rise above the boiling point of water, will be “the catastrophe” that extinguishes all life concurrent with the destruction of Earth, humans included. I believe this because as I am living in the present, and will not be around for the next thousand years or so, I judge that no weird environmental disaster will breakout, nor will any man-wrought destruction occur, or outlandish genetic mutation. Thus, the sun will cause the loss of life on Earth as well as the complete obliteration of Earth.
    Nevertheless, I do agree that this catastrophe will not happen for some time, and when it does the Earth will indeed be obliterated into essentially nothingness. Only if what has been described as the most violent processes known to nature – ” where the plasma of the hot, early Universe cooled to form nuclei and atoms, those atoms cooled and contracted under gravity to form stars, generations of stars burned through their nuclear fuel, enriching the Universe with heavy elements” – occurs, will life once again flourish in the universe.

  46. #46 Allyson
    February 13, 2013

    responsing to: There is no scientific explanation for the beginning of the universe, so why should there be one for the end?
    We know very well what is going to invariably happen to our sun. We’ve observed the death of stars, and we know that our very own sun will unavoidably have the same eventual fate. Once our sun is gone, our entire solar system is done for. Although technically, Earth will no longer be able to sustain life for quite some time before our sun implodes on us. All of this is assuming, of course, some massive asteroid doesn’t smack right into us first. Although I suppose if you were discussing the specifics of how life on Earth will end, you have a point. We can’t presume to know *exactly* how we’ll all be doomed; we simply know that it is an inevitability.

  47. #47 Daisy K
    February 13, 2013

    This conclusion could make sense. I agree more with the fact that human evolution will cease to exist. The human to pig evolution cartoon was funny, but it is true. At least in the U.S people are turning into pigs. Not only by being the most overweight, but also by our consumption of natural resources. Our global footprint is much larger than any other nation on Earth and the burning off fossil fuels is definitely having an effect on the global climate.

  48. #48 Sean T
    February 13, 2013


    I can certainly understand how it could be argued that life as we know it could not have evolved in the first place without the moon. The intertidal zones were likely crucial in the transition from organisms that could only survive in water to those that could live on land.

    However, there’s no reason that life would go extinct were the moon to disappear tomorrow. As wow correctly pointed out above, the moon has no bearing on the distribution of land masses on the earth, nor does it have any impact on the weather. The only significant effect of the moon on the surface of the earth is the existence of tides. These are most noticeable and significant near coastlines. Certainly organisms that inhabit the intertidal zones would likely go extinct, but life as a whole would continue on.

    Further, there’s no reason to believe that the recession of the moon would continue to go on indefinetly. You must understand the reason that the moon is receding to understand this. The moon creates tidal bulges on the earth. These tidal bulges, because of the moon’s revolution around the earth, travel at a speed that is slightly different than the rotational speed of the earth. This creates friction which slows the rotational speed of the earth. Energy is conserved. Slowing of the earth’s rotation is a decrease in energy. This decrease in energy must be accompanied by an increase in energy somewhere else. That somewhere else is that the moon goes into an orbit of higher energy, that is an orbit slightly farther away from the earth.

    Now, this is caused by the fact that the tidal bulges travel at a different speed than the rotational speed of the earth. At some point, however, the earth’s rotation will slow to the point where the rotational speed of the earth will match the revolution of the moon, and the tidal friction will be eliminated. This is called tidal locking, and a similar phenomenon is the reason that the moon’s revolutionary and rotational periods are identical. The end result, though, will be that the recession of the moon will cease.

  49. #49 Wow
    February 13, 2013

    “The intertidal zones were likely crucial in the transition from organisms that could only survive in water to those that could live on land.”

    Actually, that’s probably the LEAST supported reason for the moon being useful to the creation of intelligent life (there is no need whatsoever for a moon to create life).

    What a moon the SIZE of ours (compared to the planet it orbits) does for us is keep our orbital inclination stable. Any great deviation from this way up is sucked up by our Moon.

  50. #50 Wow
    February 13, 2013

    “I do not agree that human life will cease to exist before the Earth has been fully eradicated of life”

    Most species only survive a couple of million years before they are no longer fit to survive.

    Evolution has not stopped for humans. And a different species of human is no different than the past: Homo Erectus et al were all humans in their time.

    So either you widen species so far that it’s no longer a useful word, or you admit that our species AS IT CURRENTLY IS will end. Our lineal descendents will no longer be the human species we ourselves are, but they will to themselves (if they exist) be humans and it will be US who have gone extinct.

  51. #51 Wow
    February 13, 2013

    “I judge that no weird environmental disaster will breakout, nor will any man-wrought destruction occur”

    A judgement based on parochial and unsupported conjecture alone.

  52. #52 Sean T
    February 13, 2013


    “Within the past couple centuries, human anatomy has not changed significantly”

    WIthin the past couple of centuries, the average elevation of the Rocky mountains has not changed too significantly. The average position of the continental plates has not changed too significantly. The location of Niagara Falls hasn’t changed too significantly.

    The point is, in case you are unaware of the science behind my examples, that these things would NOT be expected to change significantly over a period of a couple of centuries. However, all of these HAVE changed significantly over longer time frames.

    Similarly, one would not expect to see any significant changes to human anatomy over a period of a couple of centuries. There would be change over a longer time frame, however. Consider: what is it that controls our anatomy? Mainly, it’s the information contained in our DNA. All that information consists of is a string of chemical “letters” that code for protein synthesis. Essentially DNA information is a string of letters chosen from the set A,C,G and T.

    Now, changes to DNA cause changes to the organism in which that DNA resides. Simplifying, suppose that an organism is coded by a string of 10 DNA “letters” and that these are CGATCGTAAC. Now, a mutation occurs, and a new organism is formed with the sequence CGATCGTAAT. Perhaps there’s no significant difference in outward anatomy, but the DNA has changed. Now, continuing, suppose we get another organism with CTATCGTAAT, then CTTTCGTAAT, and so on. It’s apparent that we could arrive at an organism with a completely different sequence. Would you then argue that no significant changes to outward anatomy could have occurred?

    Real organisms have much larger genomes, obviously, and many mutations cause the organism to be unable to produce. Further, random events might eliminate many mutations before they become widespread in the population. (Think, for instance about a newly born organism that contains a beneficial mutation, but gets eaten by a predator long before sexual maturity. That mutation might have been beneficial, but it won’t be fixed in the population.) Therefore, the process takes significantly longer than a couple of centuries.

  53. #53 taylor Slivka
    February 13, 2013

    I understand how life will not last forever. But can the moon and the sun really have so much to do with it as we expect? I also do not understand how much could be predicted especially since it is over a billion years from now. The earths rotation slowing causing the moon to not keep the earth as sheltered from the sun is a good claim, but is the earth going to slow and the moon disappear in the near fututre. We dont know.

  54. #54 Sean T
    February 13, 2013


    Good point about orbital inclination. I was talking, though, about life as we know it, and not specifically intelligent life. Certainly the moon is not needed for intelligent life. However, are you really saying that the evolution of all organisms would have proceded in the same way on a hypothetical planet exactly like the earth, but without a moon? The existance of fairly large tidal zones, for one thing, seems to me to be a farily significant environmental condition that would be non-existent on the hypothetical moonless earth. Certainly the organisms that evolved on this hypothetical earth would be different, no?

    Anyway, that wasn’t really my main point. My main point, which I’m sure you’d agree with, is that life on earth would go on, and do so pretty much unchanged (except for the intertidal ecosystem) were there no moon.

  55. #55 Ariel C.
    February 13, 2013

    If anything is going to happen to this “world”, it will be the result of our actions. Human life has become so destructive and careless with their actions (i.e. carbon emissions, pollution, nuclear technology) that they don’t realize what the consequences might turn into. It seems to me that long before any asteroid striking the earth or the sun explodes on us, we will be the cause of our own extinction. Chaos and destruction has engulfed the world and I can only imagine what events will continue to rise as things get worse and worse. Being a believer in the Bible, I wasn’t a huge fanatic of this piece, but it was well written and a good informative piece.

  56. #56 Wow
    February 13, 2013

    “about life as we know it, and not specifically intelligent life. Certainly the moon is not needed for intelligent life”

    I wasn’t clear enough.

    The stability the huge moon gives earth allows a system that is stable enough to evolve for long enough to produce intelligent advanced life. Three billion years were needed before any very complex life occurred (e.g. beyond bacteria-like organisms).

    Without the moon, another earth-like planet may not be stable enough to leave evolution run long enough to get to anything we’d call “advanced life”, but the production of early organisms below modern bacteria apparently only took a few hundred thousand years.

    To achieve that level of life, a moon isn’t needed.

    To get that level of life to increase in complexity to, say, fish, you need a lot longer and a relatively large moon may be required.

    So my post was intending to mean the opposite: we don’t need a moon for bacteria-like life on a planet, but there’s good evidence that we need a moon like ours for complex life to evolve.

  57. #57 CB
    February 13, 2013

    Sean T:
    “However, are you really saying that the evolution of all organisms would have proceded in the same way on a hypothetical planet exactly like the earth, but without a moon?”

    When you said “life as we know it” I assumed you meant in the broader sense of complex organic life, not “the exact spectrum of species that exist today”. Obviously that wouldn’t be the case, but it’s unlikely to be even on a completely identical earth with the same moon and everything because there are chaotic systems in play. So what?

    The broader question of whether biological life, including complex life, even land-based life, could evolve without a moon like ours is trickier, but seems to be “yes”.

  58. #58 CB
    February 13, 2013

    “Chaos and destruction has engulfed the world”

    No it hasn’t. We’re in an unprecedented era of peace and stability. Yes, accounting for everywhere that isn’t peaceful. If you were saying this in, say, 1942 then at least you’d be connected to reality, though obviously the chaos and destruction engulfing the world didn’t continue indefinitely.

    This comment reminds me of the people who speak in dire tones of how crime is increasing all the time, when the actual statistics say the opposite.

    “and I can only imagine what events will continue to rise as things get worse and worse.”

    Well yes. When the trend is only in your imagination, the outcome of that trend would naturally be as well.

  59. #59 SP
    May 22, 2013

    It’s nice…

  60. #60 The Truth
    June 6, 2013

    Where scientists die with their science ,Religion gives us hope of the new Earth & new Universe.
    Yes this earth & universe will collapse. The position as before big Bang. ALMIGHTY GOD will be all alone.

    Then HE will recrete another Earth & another universe
    & call the the day of Judgment.The result for pass: Paradise. This is absolute truth. THE ALMIGHTY GOD is ever living &
    HE Is the Creator & renovator of the vast Universe.

  61. #61 RAM CHARAN PS
    July 26, 2013

    i thnk the world doesnt comes to an end dats surely:)-

  62. #62 Wow
    July 27, 2013

    “Religion gives us hope of the new Earth & new Universe.”

    This is the reason why kids believe in Santa Clause, too: the hope that they get the shiny new bike for Christmas.

    However, most grown-ups have realised that this is not a proof of Santa’s existence, especially when they realise that everything they thought Santa did was done by them.

  63. #63 JL
    July 27, 2013

    All I say, if the gods are listening to all this, lets hope for the second round of human kind, if god within its entity of wisdom may decide to allow the human to live now or later, on this planet or the next, lets all grow up and face facts and reality, and live in harmony, we live upon 1 planet, we breath the same air drink the same water. We are human not beasts, we are supposed to be the intelligent beings, mmmmm.

  64. #64 cat
    July 30, 2013

    I’m scared…I don’t want to die! If it’s the end of the world or not, I just find dying scary.

  65. #65 Wow
    July 31, 2013

    You had no problems with the 15 billion years of nonexistence before you were born, what makes you think it will matter when you die?

    All you have to be scared of, and that only in a “I’m disappointed” way, is if you didn’t live a good life. It’s the only bit you can affect.

  66. #66 Matt
    August 21, 2013

    Why in the hell would u think its possible to actually predict the end of the world? It wouldn’t be possible due to the facts that everything can speed up or slow down so noone would actually know until it is too late this being said we will all die and most likely will be a fast death for most people get what I’m saying shit people use your brains

  67. #67 Wow
    August 21, 2013

    Why the hell do you think it is impossible to predict that the world will eventually end?

    Why the hell do you think the earth will survive the sun turning into a red giant and expanding to swallow Venus?

    Shit, why bother using your brain when all it can manage is to fail to think?

  68. #68 km
    August 30, 2013

    Its already past though.

  69. […] This post originally appeared on my blog for Psychology Today. Image credit: The MODIS instrument on NASA’s Terra satellite. […]

  70. […] at some point everything will cease to exist.  Most scientists accept that all we build with our hands or minds will die in the heat death of […]

  71. #71 Mark red
    September 18, 2013

    For me.This explanation is valid.Because if we base in the book of Bible.////nobody knows when the time shall come except God in heaven.The most significant thing is to meditate day and night not the book in the world ,But the word of God.Joshua 1<8.

  72. #72 Wow
    September 18, 2013

    And they shall lose those little raffia things that they only put down a minute ago…

  73. #73 Martin
    September 20, 2013

    This is the reason you fill like you have lived before and it is also the reason you fill like your life will start over again. Your atoms are bond to meet up again in the future ..
    7 billion years is just a blink of an eye.

  74. #74 Jim Milstead
    Bellingham WA
    September 26, 2013

    I hope we get rid of the tbaggers looooooooong before that.

  75. #75 12345
    October 19, 2013

    Nothing lives forever.

  76. #76 #1471
    October 23, 2013

    There are lots of different theories for how planet Earth will end, but no one knows for sure, even if someone was 100% positive that Earth will end in this way, he or she may not be around to see if they were right or not, but if this theory become more and more likely to happen then more and more people will start to believe that this will happen, I don’t think ever professor Steven Hawkins knows for sure how the our lives will all end, but he has been right a count less number of times so what evidence is their to say that he may be wrong about this theory nothing this is why he is one of the smartest men on the planet.

  77. #77 Wow
    October 23, 2013

    Nobdy is sure what will happen tomorrow, never mind in 2 billion years time.

    However, there’s a huge difference in what we are sure about and what we can say we’re sure about in the colloquial sense.

  78. #78 Dean
    United States
    October 26, 2013

    I’m 14 years old, and interested in this stuff. Wow.

  79. #79 Sourav Banerjee
    October 30, 2013

    I dont think that the world(The Earth) will last for the next 500 years…

  80. #80 Bob
    November 12, 2013

    There is one way that the earth will never not exist…

  81. #81 Ben
    mcgregor school
    December 16, 2013

    im just a teen and i dont get the how wont all humans get wipe out

  82. #82 Mark
    January 15, 2014

    Thank-you Ethan. I’ve studied or worked in the Biological Sciences since the year Carl Sagan died, 1996. I’ve been feeling anxious/depressed going into my mid-40’s and dealing with end of life/world thoughts, we consume a lot, which creates a lot of waste, its just what we do, we have no choice in that matter, and there are billions & billions of us. This gives me perspective that I had forgotten, we all eventually will go back home. You made me feel better about the Human race in a time when I needed to feel better.

  83. #83 Tristan Ludlow
    Fort Saskatchewan
    February 12, 2014

    If the earth comes into colision with the sun, it will just be another “big bang” expanding the space of the universe once again. Just a theory here, Histroy always repetes its self right? So if the universe started with a bang wont it end with one? Or maybe when we all explode the bioligee of all the humans will act like a virus and find a new host plantet to settle on and as a virus taking over any primary life form on that planet evoluting over time with the planet…… crazy theory but you can’t tell me or yourself its wrong huh?

  84. #84 Michael Kelsey
    SLAC National Accelerator Laboratory
    February 12, 2014

    @Tristan Ludlow #83: I think the phrase you’re looking for is “not even wrong.”

  85. #85 Wow
    February 13, 2014

    ” but you can’t tell me or yourself its wrong huh?”

    Well, THAT’S a crazy theory! :-)

    Remember: it’s fine to be wrong, it’s only omnipotent beings that can’t afford to be wrong. We haven’t got one of those posting here.

  86. #86 Wow
    February 13, 2014

    “we consume a lot, which creates a lot of waste, its just what we do, we have no choice in that matter”

    We do.

    I’m dropping out of the rat race and trimming sails. I bought quality gear and it lasts DECADES, so I don’t consume much unless something different I want to do comes along.

    You can’t stop others from doing different.

    But then again, you can’t stop murderers killing people, can you. Doesn’t mean you join in.

  87. #87 Philip Maguire
    April 3, 2014

    The fact that the earth will at some point cease to exist does not necessarily mean that life which originated on earth will also cease to exist. Over time we may develop modes of space travel that will allow us to colonise other worlds and even adapt them to our needs.

    Of course, the universe itself may ultimately cease to exist and that could well be the end of us.

    On the other the Christian faith predicts the end of this world and this universe and promises a new Heaven and a new earth.

    So, there is more than one potential outcome for humanity.

    We can’t be sure that this universe will still be in existence in two billion years but if even if it isn’t can you prove that humanity will no longer be in existence?

  88. #88 Ronnie
    May 1, 2014

    The strange thing is if we could find a way to get off this planet and create spAce stations and ships with enough artif energy and water and food, I can see our species scouring the galaxy in search of a new planet to inhabit. I know that seems far fetched, but this planet will destruct. Our sum will become white dwarf. Everything will burn up and if we leave earth we might have tech to survive while we travel through space. It’s a scary thought ; the world ending , but it has to happen. And we have to find a way to exist after that takes place. #findanewplanet

  89. #89 Thanks government
    June 16, 2014

    Well it would be great if I could do something with my life in case something big happens and kills me early that would be great. But oh yeah I forgot that we need money to do anything in life.

  90. #90 le roy
    cape town
    July 20, 2014

    Great info not to be holly or anything mybe the sun is hell as in the end it devource life and burns everything eventualy I’m convinst if u a bad person ull join ur sun in the end lol great info

  91. #91 Junlow
    September 17, 2014

    What if time machine was built? :O

  92. #92 Donovan
    December 20, 2014

    I’m actually planning to make a potion that will make anybody live forever (as a scientist) when I grow up or either ask a scientist nicely if he/she can see if he/she can make one and see if he/she can get the recipe right.

  93. #93 Donovan
    December 20, 2014

    Turns out the end of the world didn’t happen 2012 and the Mayans set the time if I’m correct.

  94. #94 Wow
    December 20, 2014

    2012 is just when their calendar cycled round. It was no more “the end of the world” than December is the end of the world because we have run out of month names.

    Doesn’t make for good newspaper copy, however.

  95. #95 Michael Hammer
    United States
    December 21, 2014

    All life just happened by random chance. We are no different than a new strain of bacteria. We will leave the same way. Just fade away over time, as things continue to change. Bugs will be next, and the last creatures to rule the earth. It’s our turn now, but it will end. Nothing last forever. The earth will be gone, and some new ” bugs ” will be starting on some far away planet.

  96. #96 Wow
    December 22, 2014

    But that doesn’t mean that there’s no point or need to our lives. It just means it’s up to us to make a point (or not) of it.

  97. #97 raja
    January 8, 2015

    It is sure that earth will destroy this day is end life but again it develop i know how and I know about it very clear because of some things which i clear when some person need this story for world And i am sure it is possible to calculate with my idea but if we start search from today then we want to calculate some happens for some years then it is possible we declare end year for human or like in between 1 to 100 years time calculation is possible . But if any person give any date for end day then i am 100% sure this person is lie .

  98. #98 Samuel
    January 24, 2015

    Heaven is Real And so is hell. If not, the earth will never come to an end. Scientist always come out with evidence to prove their their points. this should tell you that everything on earth happens for a reason. Be Wise Lovely People

  99. #99 Dave Pearce
    Tweed Heads N.S.W Australia
    January 27, 2015

    I feel that mankind would have left this earth millions of years before the sun turned nova. Taking all earth life forms with us. Our I.Q. would be so advanced that we would interpret the suns actions and act accordingly. Resettling on other planets in other star systems. The technology to cope would have been learned over thousands of years giving us a very good chance at survival. However! with all the ecology problems we have caused the earth at the present time it is unlikely that the world would survive our ‘tampering with nature’ and will decline to a point where it will be unable to substain life and we will not be able to leave as we would not have obtained the technology to do so in time!

  100. #100 Ted Taylor
    Lake Balboa, CA
    March 6, 2015

    These comments make be wonder, like art and music, has basic physics just stopped being taught at schools altogether? Figures the first three to go would be the most important to a civilized society.

  101. #101 Amanda
    manitoba, Canada
    March 17, 2015

    Yea right! It is know 2015 and look I’m living. IDIOTS!

  102. #102 Jeff Howington
    March 23, 2015

    Does the food chain explain Eternal Life for all life ?