Explorations of the Universe

Blues for the Red Planet

Visions of Mars

• Why Martians? Mars is the nearest planet with a visible surface, and superficially looks Earthlike.

• Mars became a mythic arena for us to play out our fantasies.

• The martial-sounding music used in the video is from a suite by Gustav Holst called The Planets

War of the Worlds

• Written by H.G. Wells in 1897, the first work of science fiction to depict aliens with nothing in common with humans.

• The video depiction of aliens focusing on Earth is unrealistic; telescopes simply cannot see details that small

• In 1938, a celebrated broadcast of War of the Worlds caused a nationwide scare.

The Canals of Mars• In 1877, the Italian astronomer Giovanni

Schiaparelli announced that he saw canali on Mars.

• Canali means "channels" in Italian, but was promptly mistranslated into English as "canals"

• The American astronomer Percival Lowell was the most famous champion of canals on Mars

Schiaparelli’s Mars

Lowell’s Mars

Lowell’s Venus

All astronomers agreed Lowell’s canals were the product of

intelligence.

The only question was which end of the telescope the intelligence was

on.

The “Threshold Effect

• Dubious Effects always on the threshold of detectability

• Resist all efforts to amplify or record• Almost always prove spurious• Examples– Canals on Mars– N-Rays– Cold Fusion

The fantasy was simply more exciting than the reality.

• Alfred Russell Wallace pointed out correctly that Mars was too cold and airless for canals to work.

• Long after most astronomers ceased to believe in canals, popular media continued to speculate about the canals.

• Similarly, long after astronomers knew that Venus was too hot for life, popular media speculated about life on Venus.

Viking missions to Mars, 1976

• Viking 1 and 2 carried several experiments to detect life

• The results were ambiguous. The soil reacted vigorously with the nutrients, then tapered off in activity.

• The conclusion of most scientists is that the reactions were due to inorganic chemical reactions.

Reasons to be a "Carbon chauvinist".

• Carbon can bond to four neighboring atoms• Carbon can bond to other carbon atoms,

sharing one, two, or three electrons• These properties make it possible to form a

vast array of organic molecules• No other element has these properties

Reasons to be a ”Water chauvinist".• Water stays liquid over a wide range of

temperatures. • Water is a polar or asymmetrical molecule. It

attracts ions easily, making it a good transporter of nutrients

• It does not dissolve organic molecules (so we do not dissolve in our own cell fluids)

You can buy the exact number and proportion of atoms to make a human for only a few dollars.

• You can buy the exact number and proportion of atoms to make a Lexus from a junkyard for only a few dollars, too

• If you want to talk about the exact arrangement of the atoms, the price goes up sharply.

• Buying the exact organic molecules that make up a human would cost millions of dollars, and many cannot yet be synthesized at all