Seeing Farther

A few months back,

Mike Sowden

wrote about this amazing portal connecting two cities in two different nations, in a manner of speaking.

Here’s Mike:

In 2021, Vilnius (Lithuania) and Lublin (Poland) built these livestreaming 'portals' - oh come on, let's not mess about, they're Stargates - allowing residents to wave to each other from 600km away but also be right there, face to face.

This eventually sent my brain down the following rabbit hole. I want to share some of this wonder I still feel with you today.

I want to set the stage way back. For nearly all of our existence, we humans have looked at things that are far away with only our eyes. Our ancient ancestors studied cloud formations to know whether it was likely to rain, intensely studied far-away animal herds to determine where they were going next, and distant fires that might be getting closer.

We also looked further out than our little terrestrial sphere.

This was useful! You could reliably meet someone somewhere when the moon was full again, and if you were trying to plant and grow seeds, you could work out the best time to plant and harvest. As farming took center stage, this tracking became ever more important.

After hundreds of generations of study and of tribal knowledge being passed down locally and orally, people started writing down the things they saw out there.

Ancient civilizations eventually developed complex star charts and astronomical knowledge, and where language wasn’t available to use, they built structures like Stonehenge to operate as observatories.

The Greeks even built a fully functioning analog computer more than 2000 years ago, just so that they could track the motions of the planets and stars. You can read about this stunning mechanism here:

Antikythera Mechanism

Unfortunately for humanity, there was only so far we could see with the naked eye. Fortunately for us, rudimentary lens-like things were creeping into existence during antiquity. The most famous example of this is the Nimrud Lens, which may have worked something like this:

This “lens” had a 3x magnifying effect, but the distortions would have been pretty bad. Exciting! But also: still pretty lousy.

The lenses made their way into a telescope by the turn of the 17th century, as Galileo leveraged his expertise as a lens maker who was curious about the cosmos, creating an effective refracting telescope. Galileo’s invention focused the light into a focal point, and then another lens magnified the (newly concentrated) image. In this way, you could see things you never could before.

Galileo saw moons orbiting Jupiter, and in an instant, he knew that was Copernicus had said in his On the Revolutions of the Heavenly Spheres was true: the earth was not the center of everything we could see in the cosmos. While Copernicus had only published his work the same year he died, Galileo was not so lucky.

Ultimately, in spite of having seen for his own eyes those moons going around another planet, he was forced to recant the heliocentric view in order to avoid a much harsher punishment than being found guilty of heresy and confined to house arrest for the rest of his life.

At the end of the same century (the 17th), Newton stood on Galileo’s shoulders and created a drastically improved telescope based on mirrors. Lenses bend light at weird angles, but mirrors don’t, so the image was much clearer before being magnified. Now, bigger and bigger telescopes could be created and used, since crafting a good lens was very, very expensive … and not nearly as effective.

This process of gradual improvements in design led to Edwin Hubble’s observation that the universe is expanding. We could now peer backwards in time by billions of years.

Edwin Hubble. NASA/ESA

Eventually, the same sort of concepts were used to measure different types of light that’s not even visible to the naked eye. Radio telescopes opened a new window into the universe, revealing new phenomena like pulsars and quasars. From infrared to X-rays, and beyond, we’re constantly figuring out new ways to “see” things that are far away.

Today, we have corrective help from AI and advanced computer systems that allow us to greatly refine images from afar, arrays of telescopes that work together to act as one mega-telescope, and a group of connected, dedicated astronomers who are instantly privy to the research their colleagues publish.

What could help us see further still? Gravitational waves, X-rays, or something we haven’t even thought about yet?