The universe is about 14 billion years old. And it will be 10.000 times older when the last stars burn out. The universe may look static and dark to us. But it is still in a violent final phase of the big bang. Compared to what follows, the big bang is still going on.
Before stars even formed the universe went through multiple development stages on vastly different timescales. It all started at the earliest observable time, the Planck time, a ridiculously tiny 10 to the minus 43 seconds. At 10 to the minus 36 seconds a process called inflation began to grow the universe very quickly. When inflation ended, the universe had spent 99.9 % of its age inflating. From this point of view, everything before inflation appeared just as an initial flash.
Then for a long time many things happened while the fundamental forces of nature unfolded and the laws of physics as we know them came into being. If someone had observed inflation come and go, then this next phase would have been unimaginably long. A 1000 billion billion billion times longer than inflation had lasted. But finally, quarks condensed into hadrons. Protons and neutrons formed. When that happened, the universe was just a microsecond old.
The universe continued to expand and cool down until electrons and protons could combine to hydrogen atoms. Imagine, you just observed hadron condensation. Then you had to wait another 10 billion billion times longer until hydrogen atoms formed. That's 400.000 years after the birth of the universe. And it is still 3000 K hot.
Now things happen in quick succession. Only 1000 times longer than everything before hydrogen atoms and the first stars light up. Stars form galaxies, life appears and hairless apes gaze to the stars. From our point of view, the first stars appeared after only 1% of the age of the universe. 100 times later, now at 13,8 billion years, mighty galaxy clusters are in full swing. The dark matter halo of galaxies sucks in intergalactic hydrogen, galaxies merge, stars explode, supermassive black holes shoot gas and jets into the intergalactic medium. A wild time.
The universe started out at ridiculously high temperatures. It cooled down. But it is not yet cold. Stars are hot. They flood the universe with radiation and even where the stars never shine, the universe has a decent background temperature of several degrees. Cold for us, but a lot more than nothing.
Radiation is everywhere. We are living in the afterglow of the big bang. With an emphasis on "glow". The universe is still very bright in the microwave range of the electromagnetic spectrum. Our eyes cannot see microwaves. But they are there. The universe is still glowing bright from every direction and uncountable stars do their part to keep it up.
New stars will be born and will die for a long time to come. The smallest live 1000 times longer than our sun. But eventually, the last stars fade. The universe gets dark. That's when the radiation frenzy of the big bang finally ends. The universe will then be 10.000 times older than now. From that point of view, we had been living in the first percent of a percent of the universe. Quarks had condensed into nucleons. Nucleons combined to atoms. Atoms formed stars. Stars kept radiation going. The violent phase of forming and radiating is over when the last stars fade. This is the end of a universe flooded by radiation. A 100 trillion years from now. The end of the radiation epoch. The real end of the big bang.
Times are starting to drag. Nothing happens quickly anymore. No more stars popping in and out of existence. No more flashlights in the dark. No more radiation sources. Only cold planets orbiting black dwarf stars, iron balls, slowly tumbling neutron stars, and black holes in dark galaxies. It's the quiet grown-up phase of the universe. Except for the occasional collision, which sends a blindingly bright spark into the universe.
What does not collide finally spreads evenly. Planets wander off and dark solar systems dissolve. It took a long time until the last star burnt out. And over 100.000 times that duration, galaxies also dissolve thermodynamically. They lose their stars to the void. Iron balls and black holes are still there. But they are now evenly distributed and rarely meet each other. The radiation that was produced in earlier times is also still there. But it is spread out over a vastly larger universe. Photons are so red shifted to ultra-long wavelengths that they are barely noticeable. For all practical purposes, radiation is gone.
The universe is now so dark, that the faint glow of hawking radiation becomes the new standard. Black holes slowly start to evaporate. Hawking radiation of stellar black holes is so weak, that it is not measurable in our bright universe. On the contrary, our times are still so warm that black holes can inhale the cosmic microwave background and grow a little bit. But then, at the beginning of the end of times, hawking radiation is the only light source. It is weak. If there is any life, then it lives slowly. It will perceive the entire age of stars, a 100 trillion years, like the blink of an eye. On these timescales, a photon every billion years is considered a bright light source. Again, there are flashlights in the dark. But on a totally different scale than the long-forgotten stars.
Even though the universe is huge, black holes still find each other. But between each collision lies a timespan like an entire radiation epoch. Now that counts as the blink of an eye. A hypothetical life form might then be based on ultra-rare quantum tunneling events and it will be living by hawking radiation. It might see black holes as we now see stars and perceive the flashes of merging black holes like we see super novae in distant galaxies all the time. For this kind of life, the universe is filled by shining stellar black holes and glowing supermassive black holes. When black holes lose mass this way, they shine even brighter. Until they explode. Flashes of black hole explosions and collisions are everywhere.
Remember the long time until dark galaxies dissolved. That was long after all stars went the black hole or iron ball path. It takes a trillion trillion trillion trillion times that again until stellar sized black holes evaporate. That's not "just" a trillion trillion trillion trillion years. It's trillion trillion trillion trillion times all that was before, which already was a billion times longer than our current 13.8 billion years universe. It's a long time, even for ultra-slow quantum tunneling life that lives off a photon every billion years.
Then only real behemoths remain. Giant black holes that dwarf our current supermassive black holes. They have the mass of galaxy superclusters. And they also evaporate. But exponentially slower due to their size. It takes another trillion trillion trillion times more.
Eventually there are only ridiculously red-shifted photons left in a ridiculously large universe. The hypothetical quantum tunneling life will be long gone. Our biological way of life is 1 billion years old. It might last 10 billion, maybe even 1000 billion years. The quantum tunneling life may last trillion trillion trillion times longer. It will regard our phase as one of the early stages of the universe. As the last part of the big bang, when the universe was still hot. The black hole era is the real "life" of the universe. Everything before that is just the big bang. An unmeasurable short flash bevor black holes emerged and stayed. And went.
On a logarithmic timescale we live much closer to the begin of everything than to the end. We are now in the first third of the logarithmic timescale. We live off the stars. We think that our time is the real time of the universe and that the big bang was a flash 13.8 billion years ago where nucleon and atom synthesis happened.
The second third of the logarithmic timescale belongs to the hypothetical quantum tunneling life. They live off black holes. And they do this an unimaginable 10 to the 40 times longer than we did. They think that their time is the real time of the universe and the big bang was just a flash a trillion trillion years ago including a brief stellar phase that gave them their black holes.
We don’t know much about the third part of the timescale. Maybe it is just boring for another 10 to the 40 times longer. Maybe there is life so strange and slow, that it regards the earlier – already unimaginable slow – quantum tunneling life as just the blink of an eye. Just a flash before their own real time began.
Intro in DE as posted:
Intro in EN as posted:
Intro in DE as posted:
Ich habe da mal eine These:
Ich behaupte, dass der Urknall noch im Gange ist.
Der Urknall endet erst, wenn die letzten roten Zwerge verblassen. Dann endet die Epoche der Strahlung. Mit der Epoche der Schwarzen Löcher (BH-Epoche) beginnt die wahre und viel längere Geschichte des Universums. Alles was vor der BH-Epoche war, ist aus Sicht der BH-Epoche nur ein kurzer Blitz. Was wir als Urknall bezeichnen bis zur Nukleonensynthese, inklusive H-Rekombination, unser heutiges 14 Milliarden Jahre Zeitalter und die weiteren 100 Billionen Jahre der Sterne sind im Vergleich zur BH-Epoche eine wilde strahlenreiche explosive Anfangszeit. Die BH-Epoche erwarten wir zwischen 10^40 und 10^100 Jahre. Das ist noch weit weg und dann unvorstellbar lange.
Mir ist klar, dass man als Urknall im Sinne von Knall=kurz normalerweise nur die erste Sekunde, maximal Minuten bezeichnet. Schon H-Rekombination wird als "400.000 Jahre nach dem Urknall" bezeichnet wird. Oder zählt man H-Rekombination noch zum Urknall? Wenn 400.000 Jahre gehen, dann auch 13 Milliarden oder 100 Billionen. Die Abgrenzung auf Mikrosekunde (Hadronen), Minuten (Nukleonen) oder 400.000 Jahre (H-Rekombination) erscheint mir etwas willkürlich. Das ist nur eine Frage der Skalierung. Skalierung relativiert sich aber sehr, wenn zig-Zehnerpotenzen dazukommen.
Bei der H-Rekombination war das Universum ca. 3000 K warm. Jetzt noch 3 K. Mikrowellenhintergrund (CMB) ist überall. Wir sehen es nicht, aber im richtigen Mikrowellenspektrum ist der Himmel noch hell erleuchtet. So richtig "vorbei" ist der Urknall erst, wenn das nicht mehr so ist.
Ruhig wird das Universum erst, wenn Sterne keine Strahlung mehr beitragen und CMB so ausgedünnt und rotverschoben, dass er nicht mehr messbar ist. Dann sind die einzigen Ereignisse ein einziges Photon Hawking Strahlung pro Milliarde Jahre von einem stellaren Schwarzen Loch und alle Billion Billion Jahre im ganzen sichtbaren Universum eine BH-Kollision.
Würde man auf diesen Zeitskalen beobachten und entsprechend langsam leben, dann würde man stellare BH wie Sterne am Himmel strahlen sehen und zwischendurch glüht ab und zu schwach ein SMB. Für sehr lange Zeit. Es ist die ruhige, stabile Zeit des Universums. Und rückwirkend erscheint alles inklusive der Epoche der Sterne nur als ein kurzer Blitz. Denn der Unterschied zwischen Hadronensynthese bei einer Mikrosekunde und dem Ende der Sterne bei 100 Billionen Jahren ist aus Sicht der BH-Epoche bei 10^40 Jahren nicht groß.
Was haltet ihr davon?
Könnte man das so sehen?
Sind wir noch in der Endphase des Urknalls?
Aus der Sicht von BH-Epoche-Wesen vermutlich schon.
I have a theory and I would like your opinion.
I maintain that the Big Bang is still going on when we take time scales into account.
I maintain that the Big Bang ends when the last red stars fade away. Then the epoch of radiation ends. With the epoch of the black holes (BH-era) begins the true and much longer history of the universe. Everything that was before the BH-era is, from the point of view of the BH-era, only a short flash. What we call the Big Bang until nucleon synthesis, including H-recombination, our present 14-billion-years and 100 trillion more years of red stars is just, a wild, radiation-rich explosive beginning time, compared to the BH-era. We expect the BH-era to last between 10^40 and 10^100 years. That is still far away and then unimaginably long.
I am aware that the term Big Bang in the sense of bang=short might be limited to the first second, maximum minutes. H-recombination is often called "400.000 years after Big Bang". Or does H-recombination count as part of the Big Bang? If 400,000 years are part of the Big Bang, then 13 billion or 100 trillion could also work. A limitation to microseconds (hadrons), minutes (nucleons) or 400,000 years (H-recombination) seems somewhat arbitrary. It is only a question of scaling. But scaling is very much put into perspective when tens of powers of ten are added.
At H-recombination the universe was about 3000 K warm. Now it's still 3 K. Cold for us, but not compared to 10^-6 K in labs. Microwave background (CMB) is everywhere. We do not see it, but in the right microwave spectrum the sky is still brightly lit. One could argue that Big Bang is only really "over" when there is no (I mean "much much less") radiation all around.
The universe only becomes calm when stars no longer contribute radiation and the CMB is so thinned and redshifted that it can no longer be measured. Then the only events are a single photon of hawking radiation per billion years from a stellar black hole and every trillion trillion years in the whole visible universe a BH collision.
If someone were to observe on these time scales and live correspondingly slowly, they would see stellar BHs shining like stars in the sky. And SMBs would faintly glow from the distance. For a veeery long time.
This is the quiet, stable time of the universe. In retrospect, everything including the epoch of the stars only appears as a short flash. Because the difference between the synthesis of hadrons at one microsecond and the end of the stars at 100 trillion years is not big from the point of view of the BH-era at 10^40 years.
Admitted, this is only about terms and definitions. Not physically relevant.
What do you think about this?
Is this reasonable?
Are we still in the final (long) phase of the Big Bang?
From the point of view of BH-era beings we probably are.