The Journey
Entropy
One light left on.
01 · The gradient
92°C
Stay.
The other glass is on the table.
S = k log W
Ludwig Boltzmann
W is the number of microscopic arrangements that still appear, at our scale, as the same glass and the same room. A hot glass in a cooler room is a rare arrangement. A room at one temperature is common. There are more ways to be mixed.
Rudolf Clausius, 1865. The energy of the universe is constant. The entropy of the universe tends toward a maximum. The energy does not leave. The difference does. It can no longer scald a mouth or turn a wheel.
02 · The arrow
Elon Musk. He wrote the sentence on 9 May 2017, and again in 2019, 2020, 2022, and twice in 2023. The word he used for the ending changed. The journey did not.
2017
If heat death of the universe is the destination, it really is all about the journey
The post
9 May 2017 · 22:38:52 UTC
Both links were in the post.
2019
If heat death will be inevitable end of Universe, it actually *is* all about journey 🤔
Entropy is the source and the end of life in this instance of the Multiverse
The post
30 January 2019 · 20:07:22 UTC
The asterisks around is are his. They stay.
2020
If heat death is the end of the universe, it really is all about the journey
2022
If the Universe is headed for heat death, then it really *is* all about the journey
The post
29 May 2022 · 23:09:58 UTC
A reply, not a shout into the void. The asterisks stay.
2023
If heat death is the fate of the Universe, it really is all about the journey
The post
24 April 2023 · 21:08:04 UTC
Another reply. The hinge word is fate.
2023
If heat death is the end of the universe, it really is 💯 about the journey
The post
25 November 2023 · 22:05:08 UTC
The hundred stays. It is part of the sentence.
Nearby sentences, not the seven
Close to the sentence. Not the sentence.
Earlier the same day
Entropy is the ultimate boss battle.
Held aside. Not one of the seven.
The clause is gone
It really is all about the journey!
No heat-death clause.
Three words
Heat death of the universe.
A fragment.
03 · Inside the second law
Heat flows from warmer to cooler. It does not reverse on its own.
That is the second law. The energy remains. What is lost is the difference that could still do work. Entropy is the name of that loss.
What an organism feeds upon is negative entropy.1
A living body is not a closed jar. It takes in sunlight or food, energy still gathered into a usable difference, and it gives heat and spent matter back to the room. That is how a leaf, or a person, stays more ordered than the air. The order is local. The entropy of the body and its surroundings still rises. He chose the phrase so a reader would feel the contrast. Writing only for physicists, he said, he would have said free energy.
The law does not reverse on its own. In 1956 a story asks a machine whether it can be reversed anyway.
Note 1. Schrödinger, What Is Life?
1. Erwin Schrödinger, What Is Life? The Physical Aspect of the Living Cell (Cambridge: Cambridge University Press, 1944), chap. 6.
Schrödinger, Erwin. What Is Life? The Physical Aspect of the Living Cell. Cambridge: Cambridge University Press, 1944.
04 · Asimov
How can the net amount of entropy of the universe be massively decreased?
Insufficient data for a meaningful answer.
He asks it in 1956, and then he keeps the room while the people change. Two men at a machine. A family between stars. Minds that no longer need bodies. At last one intelligence, and the stars going out, and the question still unanswered. The recurrence is the story. He does not spend the question on a comfort before the last line.
The story, and where it was printed
November 1956. Science Fiction Quarterly. Isaac Asimov later called it his favorite of his own. Literary fiction. Not a prediction. The two lines above are the story’s recurring exchange, shortened only in the answer’s later wording.
05 · Adams
42
The answer arrived. The question did not.
Two decades after that refusal, a radio comedy asks a computer named Deep Thought for the Answer to Life, the Universe and Everything. It takes seven and a half million years. It is polite. It gives them 42, and then it explains that the number means nothing until someone knows what was actually asked.
What is the Answer to Life, the Universe and Everything?
That is what they asked. The question that would make 42 mean something is not in the episode.
Where the number first arrived
8 March 1978, 22:30 GMT. BBC Radio 4. The first episode of The Hitchhiker’s Guide to the Galaxy. Deep Thought. Literary fiction, two decades after Asimov. They share a refusal. They do not prove each other.
The Book of 42 begins after this absence.
06 · Cipher
42 arrived without the question that would explain it. The sums below are a different kind of number. They count letters. They do not recover the question Adams withheld, and they are not a reading of the posts.
English letters only. A is 1, B is 2, through I as 9, and then the count begins again. The number under each letter is that value. Add the numbers. The red figure is the sum.
Entropy and love
E5N5T2R9O6P7Y7A1N5D4L3O6V4E5
69
Love is the answer
L3O6V4E5I9S1T2H8E5A1N5S1W5E5R9
69
The Beginning
T2H8E5B2E5G7I9N5N5I9N5G7
69
Her word, counted the same way. Not a sentence he wrote.
Question
Q1U6E4S8T7I9O3N4
42
Humanity
H1U6M5A8N4I9T7Y2
42
How the letters were counted
English letters only. Spaces ignored. Full reduction counts A as 1 through I as 9, then begins again. Reverse reduction runs the other way.
Entropy, counted straight through and then reduced, meets the answer at 41. The same total. Not the same sentence.
The journey. 141, then 51, then 48.
Heat death. 72, then 36, then 45.
The Last Question. 205, then 61, then 83.
07 · A possible last sky
No difference left to spend.
The glass at the start was this law, in one room. Work needs a difference in temperature, or pressure, or light. Heat death is the name for a future in which those differences have been spent, if expansion continues under a steady dark energy and the second law still holds. It is not a date on a calendar. A rip, or a collapse, would be a different model. No one has observed the end.
Plates held aside
The Pillars of Creation. Stars forming. Not a death. NASA, ESA, CSA, STScI. J. DePasquale, A. Koekemoer, A. Pagan.
Good morning, Earth. Orbital sunrise, 26 June 2026. NASA / Chris Williams.
Three cosmic futures. Heat death, a Big Rip, a Big Crunch. Conditional. Not a photograph.
08 · With someone
The other glass is still on the table. Someone asks how the day went, and then has the patience to hear it.
09 · Nine years on
The posts stopped in 2023. In July 2026 he said the sentence aloud. In September he wrote it once more.
She asked whether he still put the chance of a catastrophe at 10 to 20 percent. He answered with the heat death of the universe, and the journey.
If heat death is how the Universe ends, it really is all about the journey …
Elon Musk