Ask Ethan: Will Future Civilizations Miss The Big Bang?
“If intelligent life re-emerges in our solar system in a few billion years, only a few points of light will still be visible in the sky. What kind of theory of the universe will those beings concoct? It is almost certain to be wrong. Why do we think that what we can view now can lead us to a “correct” theory when a few billion years before us, things might have looked completely different?”
Incredibly, the Universe we know and love today won’t be the way it is forever. If we were born in the far future, perhaps a hundred billion years from now, we wouldn’t have another galaxy to look at for a billion light years: hundreds of times more distant than the closest galaxies today. Our local group will merge into a single, giant elliptical galaxy, and there will be no sign at all of young stars, of star-forming regions, of other galaxies, or even of the Big Bang’s leftover glow. If we were born in the far future, we might miss the Big Bang as the correct origin of our Universe. It makes one wonder, when you think about it in those terms, if we’re missing something essential about our Universe today? In the 13.8 billion years that have passed, could we already have lost some essential information about the history of our Universe?
And in the far future, might we see something that, as of right now, hasn’t yet grown to prominence? Let’s explore this and see what you think!
Ask Ethan: What Does The Future Of Science Look Like?
“I would like to read or hear some on what scientists are planning to do next. What’s in the pipeline, on the drawing board or just an idea up for discussion?”
If it seems like there are deeper views, revolutionary finds, small advances, and better constraints coming out in science all the time, that’s because this is exactly what scientists are doing. While you may commonly hear about some of the greatest machines and observatories of all-time like the LHC and Hubble, the reality is that there are dozens of observatories and experiments all working together to unveil the secrets of the Universe. Want a taste of what’s coming in the future, and how it’s going to push forward and change what we know even more significantly? This past week, I had the pleasure to attend the latest American Astronomical Society meeting, and one of the things I was able to learn from this is the roadmap over the next few years and decades for NASA, the NSF, and other physics-and-astronomy based agencies. The future is bright, and that it’s being done on a stagnant budget is all the more impressive.
Come learn what we all have to look forward to, and imagine what we could do if we truly invested in science, all on this week’s Ask Ethan!
Even While The World Suffers, Investing In Science Is Non-Negotiable
“Although our space program seems to lead us away from our earth and out toward the moon, the sun, the planets, and the stars, I believe that none of these celestial objects will find as much attention and study by space scientists as our earth. It will become a better earth, not only because of all the new technological and scientific knowledge which we will apply to the betterment of life, but also because we are developing a far deeper appreciation of our earth, of life, and of man.”
Every so often, the argument comes up that science is expendable. That we’re simply investing too much of our resources — too much public money
— into an endeavor with no short-term benefits. Meanwhile, there’s suffering of all kinds, from poverty to disease to war to natural disasters, plaguing humanity all across the country and our world. Yet even while there is suffering in the world, investing in our long-term future is indispensable. This story is nothing new. Back in 1970, shortly after the first Moon landing, a nun working to alleviate poverty in Africa, Sister Mary Jucunda, wrote to NASA, and begged them to stop this frivolous waste of resources, and instead to use their funding for the benefit of humanity. The letter made it all the way to Ernst Stuhlinger, then the Associate Director of Science at NASA. Stuhlinger’s response was all at once compassionate and convincing, and helped convince Jucunda — as well as skeptics everywhere — of the value that science has to offer.
Come see the full story, and read Stuhlinger’s complete, original letter, on the non-negotiable value of science to our world!
The Four Ways The Earth Will Actually End
“3.) Reduction to a barren rock. You thought having our oceans boil was bad? How about the prospect of having every atom of atmosphere ejected from our world. Of everything that ever lived on the surface reduced to charred ash; of the record of everything that living creatures left behind turned into dust. With enough heat and energy, that’s exactly what would happen to any world, with Mercury, the closest planet to the Sun, being a prime example. In another five-to-seven billion years, this is exactly what will happen to Earth, as the Sun runs out of hydrogen fuel in its core. When that occurs, the core will contract, heat up, and begin fusing helium to release even more energy than before. In this state, the Sun turns into a helium-burning red giant, and nothing on Earth can withstand this.”
Here on Earth, we hear every so often about a conspiracy of how the world will come to an end. The end of the Mayan calendar; Y2K; an encounter with Nibiru; or a biblical prophesy come true are only a small selection of what people “predict” will bring a demise to our world, and soon. Yet even most of the egregious natural or human-caused disasters won’t bring an end to even our species, much less the entire world. Scientifically, the end of the world will happen in four stages. The first one is straightforward and inevitable: humanity will only continue to exist for so long. But the subsequent disasters that bring an end to our world are entirely predictable, and include the boiling of our oceans, the charring and evaporation of our atmosphere, and finally the loss of the remaining Earth-corpse to the vastness of the Universe in one of three possible ways. The world will indeed come to an end, but none of the conspiracy theories can stand up to the actual science.
Come get the full story on the four different ways, in order, that the Earth will someday come to an end!
Ask Ethan: Can Failed Stars Eventually Succeed?
“Will the orbit of these [brown dwarfs] over a long period of time, eventually become smaller and smaller from the loss of energy through gravitational waves? Will they then eventually end up merging? If so, what happens in a [brown dwarf] merger? Will they merge to become an actual star that goes through fusion? Or is it something else entirely?”
For every star that’s out there in the Universe, for every object that ignited hydrogen fusion in its core, there are many other objects out there that never got massive enough to do so. The largest failures, those that gathered between 13 and 80 Jupiter masses’ worth of material, are known as brown dwarfs. They achieve deuterium fusion in their core, but never cross that critical threshold to become true stars. Many brown dwarfs, just like many stars, though, come in binary systems. If you were to add up all the mass in some of these systems, it would, in fact, be enough to create a star out of. The closest brown dwarf binary to us, Luhman 16, has exactly the right conditions that it could create a star if a merger ever took place.
What are our prospects for this pair of failed stars, or any failed star, eventually succeeding after all? Find out on this week’s Ask Ethan!
LIGO’s Successor Approved; Will Discover Incredible New Sources Of Gravitational Waves
“The huge advance of LISA, though, will be the ability to detect objects spiraling into and merging with the supermassive black holes at the centers of galaxies. Stars and other forms of matter are constantly falling into black holes at the galactic center, both in our own galaxy and well beyond. These events often result in the ejection of matter, the acceleration of charged particles and the emission of radio and X-ray light. But they should also result in the emission of gravitational waves, and LISA will be sensitive to those. For the first time, we’ll be able to see supermassive black holes in gravitational waves.”
There’s no doubt that LIGO has given us one of the most incredible breakthroughs of the 21st century: the direct detection of gravitational waves. But as wonderful as LIGO is, so far it’s only been able to detect the very final stages of mergers of stellar mass-scale black holes, and only every few months at that. The technique of laser interferometry is sound and powerful, but properties inherent to Earth itself fundamentally limit how good LIGO can potentially be. But these restrictions go away if we go to space! Not only can we eliminate seismic noise, cease accounting for the curvature of the Earth, and get a better vacuum for free, but we can achieve much longer baselines. By sending a series of spacecraft up into orbit behind the Earth, we can detect more massive, more distant, and slower-period sources than LIGO could ever hope to see.
LISA is the gravitational wave observatory of the future, and the European Space Agency just greenlit it for 2034! Come get the exciting news and find out what science it will be able to do today!
What Will The Death Of The Milky Way Look Like?
“On Earth, we’ve got another billion years or two before the oceans boil and the planet becomes uninhabitable. The Sun will heat up, swell into a red giant, fuse helium in its core, then blow off its outer layers and contract into a white dwarf. But new stars will pop up, too, and shine, and keep the galaxy alive and rife with stars far into the future. But even our own Milky Way will cease to exist: first as we know it, and later on, entirely. When enough time passes, there will be no stars, stellar remnants, or even black holes left at all. This is the cosmic story of the ultimate end of our home in space.”
In the far future, all the galaxies within our Local Group will merge together, with enough gas and stellar material to form trillions upon trillions of new stars. But the amount of fuel is finite, and gravitational interactions are chaotic. At some point, the star forming material contained in our galaxy will come to an end, while more and more stars and stellar remnants are ejected from the galaxy. What will be left, at that point? Just a few stellar corpses orbiting in a halo of dark matter around a central, supermassive black hole. That mass will grow larger and larger, up until a certain point. Once it’s grown all it can, Hawking radiation will result in the decay of that central black hole, unbinding the last structures of normal matter. In the end, there will be nothing left but a large, massive clump of dark matter in the abyss of empty space.
Need something to look forward to? How about the death of the Milky Way, and the return of the Universe to a cold, empty, unstructured state!