The first of five clues. Each one below gives a little more away.
I am a time machine, and I only look backwards.
Galileo pointed one of me at Jupiter and got into a great deal of trouble.
The finest of me left the planet entirely, to escape the air.
I gather light, which is why bigger is always better.
Astronomers look through me at the stars.
Telescope
Every telescope is a time machine you cannot steer. The light you catch tonight left its star long before anyone thought to look.
The first patent application came from a Dutch spectacle-maker, Hans Lippershey, in 1608, and was refused on the grounds that the idea was too easy to copy. Galileo heard of it, built a better one within months, and within a year had found four moons around Jupiter — proof that not everything circled the Earth. Newton sidestepped the colour fringing of lenses by using a curved mirror instead, and every large telescope since has followed him. The largest of all now leave the planet: air blurs and glows, and above it even a modest mirror sees further.
Reading five clues at once is not the game. In the real thing they arrive one at a time and every wrong guess costs an hour. Play mystery #15 · today's mystery · the vault
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