less than sixteen amino acids and other organic compounds were produced under the conditions that exist between the stars using nothing more than the ingredients of molecular clouds. The proteins of all living things on Earth are composed of combinations of twenty amino acids.”
Ethan grasped where Hassim was going just before Rachel did.
“All life might be very similar in a fundamental way,” he said.
“Yes,” Hassim agreed, and tapped his own chest. “The chemical reactions that support metabolism in all of our bodies involve just eleven small carbon molecules such as acetic and citric acids. These eleven molecules would have been sufficient to produce chemical reactions that led to the development of biomolecules such as amino acids, lipids, sugars, and eventually early genetic molecules like RNA on Earth. Metabolism came first, the fuel for life, before cells or replication or anything else. Life then followed as a natural result of chemical metabolism. If it happened here on Earth, then it could happen anywhere on suitable planets harboring liquid water, and life might follow a similar path of evolutionary development that leads eventually to intelligence.”
Rachel caught on quickly.
“And if an intelligent species evolved on a planet reasonably close by, and was only ten thousand years more advanced than us …”
“Even a thousand years more advanced might do it,” Hassim said. “In two hundred years mankind has gone from wooden sailing ships and witchcraft to landing on the moon and nuclear power. Think what we could be like in another thousand years.”
“It would look like magic,” Ethan said, remembering Arthur C. Clarke’s Third Law. “Or God. But could they be that much more advanced than us?”
“The universe has been producing stars for over thirteen billion years,” Hassim explained, “and the elements required for life have been in place within galaxies for at least eight billion years. By our planet’s timeline of evolution, it’s quite possible that advanced, intelligent life has existed in our universe for the past four billion years or so. The technology of such civilizations could be advanced on a scale completely unimaginable to us.”
“If so,” Ethan challenged, “then why would they bother with us at all?”
“We can only speculate,” Hassim admitted, “but such civilizations may well have been forced to travel through space as their parent stars aged and became unstable: the window in which our own Earth can support complex life is surprisingly short in cosmological terms, ending as the sun grows hotter and Earth is no longer able to harbor liquid water. However, although life may be common in the universe, intelligent life will be much rarer, and if you were an advanced race traveling the stars and found early humans struggling to survive after a climatic disaster, wouldn’t you be tempted to stop and help them or at least investigate?”
Rachel stood up, pacing again as she struggled with the consequences of her newfound knowledge.
“But if this actually happened, surely our ancestors with their newly acquired skills might have recorded it better, in more detail?”
“Perhaps they did,” Hassim said. “But we haven’t learned to recognize the signs for what they are yet.”
“How do you mean?” Ethan asked.
“Imagine,” Hassim suggested, “that you’re living in ancient Egypt, before the pyramids or technology, and down from the skies come beings that reveal great knowledge to you and then vanish again. As you struggle to capitalize upon this new knowledge, would you not be tempted to beg them for help, to make contact again?”
“I guess so,” Ethan agreed.
“And how would you do that?” Hassim asked.
“I’d make a sign,” Ethan said cautiously, “in the ground or something.” Then he got it. “A big sign, big enough to see from the air.”
“Exactly,” Hassimm nodded. “You’d create megastructures, hoping that your mysterious flying benefactors would see them and return.”
Rachel seemed bemused.
“You’re talking about the pyramids, aren’t you?”
“Not just the pyramids,” Hassim replied. “Almost every major ancient megastructure, and I can prove it too. Have either of you heard of something called a cargo cult?”
Rachel was about to answer, but Mahmoud got up from the crate upon which he had been sitting and looked at her.
“Whatever your daughter was dabbling in, it is better left alone. There are some things we weren’t meant to see,” he warned before looking at Yossaf. “Time to check the tunnels.”
Ethan watched as the two Palestinians went in opposite directions.
“Why would MACE abduct Lucy when they could just have taken the remains and left her there?” he asked Hassim.
“The reason for that, my friend,” Hassim said, “is almost too horrific to