Today is the International Day of Peace (“Peace Day”). Established in 1981 by a unanimous United Nations resolution, the General Assembly has declared this as a day devoted to “commemorating and strengthening the ideals of peace both within and among all nations and peoples.”
When Homer’s Iliad was first written down in the 8th century BCE, the story of the Trojan war was already an old one. From existing oral tradition, audiences knew the tales of the long siege, the epic duels outside the city walls, and the cunning trick that finally won the war.
In the end, the magnificent city was burned to the ground, never to rise again.
But had it ever existed? By the time the field of archaeology began to take shape in the 19th century, many were skeptical, considering the epic to be pure fiction, a founding myth imagining a bygone heroic era. But some scholars believed that behind the superhuman feats and divine miracles there must have been a grain of historical truth – a war that was really fought, and a place where it happened.
Frank Calvert was one such believer. He had spent his youth traveling and learning about ancient civilizations before accompanying his brother Frederick on a diplomatic mission to the northwest Anatolian region of Çanakkale. It was here that Homer described the Greek encampment at the mouth of the Scamander river. And it was here that fate brought Frank into contact with a journalist and geologist named Charles Maclaren. Locals and travelers had long speculated that Troy might’ve stood on one of the surrounding hilltops. But Maclaren had been one of the first to publish a detailed topographical study of the area. He believed he had found the site – a 32-meter mound known by the name Hisarlık, derived from the Turkish word for “fortress.” Frank Calvert began to survey the site, but lacked the funds for a full excavation. This was where the wealthy German businessman and amateur archaeologist Heinrich Schliemann came in. At Calvert’s invitation, Schliemann visited the grounds in 1868, and decided to excavate. Eager to find the ancient city, Schliemann tore massive trenches all the way to the base of the hill. There, he uncovered a hoard of precious artifacts, jewelry, and metalwork, including two diadems and a copper shield. Schliemann took full credit for the discovery, announcing that he had found Troy and the treasure of its king Priam. But the real treasure was elsewhere.
When later archaeologists studied the site, they realized that the mound consisted of no less than nine cities, each built atop the ruins of the last. The layer Schliemann had uncovered dated back to the Mycenaean Age, more than 1,000 years too early for Homer. But inside the mound was indeed evidence for a city that had thrived during the Bronze Age, with charred stone, broken arrowheads, and damaged human skeletons suggesting a violent end. It was Troy VII, contained in the middle layers and now ravaged for a second time by Schliemann’s careless excavation. The settlement, spanning some 200,000 square meters and home to as many as 10,000 people, thrived until around 1180 BCE. Its position at the southern entrance of the Dardanelles strait would’ve made a formidable strategic location for both defense and trade. Most importantly, there are the remains of a massive fortification wall – perhaps the very same one from which Priam and Hector once watched the Greeks approach.
Of course, it’s difficult to be certain that these ruins are the true remains of ancient Troy, and scholars still dispute whether the Trojan War as described by Homer ever happened. Yet the evidence is strong enough that UNESCO has labelled Hisarlık the archeological site of Troy. Regardless of its identity, thanks to persistence, a bit of faith, and a lot of research, archaeologists are bringing the long-buried secrets of an ancient, lost city to light.
“I was a conductor on the Underground Railroad, and I can say what many others cannot. I never ran my train off the track, and I never lost a passenger.”
Escaping slavery; risking everything to save her family; leading a military raid; championing the cause of women’s suffrage; these are just a handful of the accomplishments of Harriet Tubman, one of America’s most courageous heroes.
In fact, how do any toxic animals survive their own secretions? The answer is that they use one of two basic strategies: securely storing these compounds or evolving resistance to them. Snakes employ both strategies – they store their flesh-eating, blood-clotting compounds in specialized compartments that only have one exit: through the fangs and into their prey or predator and they have built-in biochemical resistance. Rattlesnakes and other types of vipers manufacture special proteins that bind and inactivate venom components in the blood.
Poisonous and venomous animals aren’t the only ones that can develop this resistance: their predators and prey can, too. The garter snake, which dines on neurotoxic salamanders, has evolved resistance to salamander toxins through some of the same genetic changes as the salamanders themselves.
That means that only the most toxic salamanders can avoid being eaten— and only the most resistant snakes will survive the meal. The result is that the genes providing the highest resistance and toxicity will be passed on in greatest quantities to the next generations.
As toxicity ramps up, resistance does too, in an evolutionary arms race that plays out over millions of years. This pattern appears over and over again. Grasshopper mice resist painful venom from scorpion prey through genetic changes in their nervous systems. Horned lizards readily consume harvester ants, resisting their envenomed sting with specialized blood plasma. And sea slugs eat jellyfish nematocysts, prevent their activation with compounds in their mucus, and repurpose them for their own defenses.
Hallucinatory experiences are much more closely tied to ordinary perception than we once thought.
We know from fMRI studies that hallucinations activate the same brain areas as sight, areas that are not activated by imagination. Many other hallucinations, including smells, sights, and sounds, also involve the same brain areas as real sensory experiences. Because of this, the cerebral cortex is thought to play a part in hallucinations. This thin layer of grey matter covers the entire cerebrum, with different areas processing information from each of our senses. But even in people with completely unimpaired senses, the brain constructs the world we perceive from incomplete information.
For example, our eyes have blind spots where the optic nerve blocks part of the retina. When the visual cortex processes light into coherent images, it fills in these blind spots with information from the surrounding area. Occasionally, we might notice a glitch, but most of the time we’re none the wiser. When the visual cortex is deprived of input from the eyes, even temporarily, the brain still tries to create a coherent picture, but the limits of its abilities become a lot more obvious.
By studying hallucinations, we stand to learn a great deal about how our brains construct the world we see, hear, smell, and touch. As we learn more, we’ll likely come to appreciate just how subjective and individual each person’s island universe of perception really is.
The biggest obstacles a human would encounter living on the moon is cosmic radiation. Unlike the Earth, the moon has no atmosphere and no magnetic field. A person on its surface could receive over 400 times the maximum safe dosage of heavy ion radiation, enough to be fatal within ten hours, even in a spacesuit.