The Telescope: A Time Machine?

While telescopes might seem like glorified binoculars, there’s more to them than that.

Most objects in space are very far away, which means their light is fairly dim by the time it reaches us. Telescopes collect and magnify this light.

These instruments have allowed astronomers to discover much of the universe, measure the speed of light, and even confirm Copernicus’ model of heliocentrism (the sun being at the centre of our solar system). Modern telescopes provide evidence of billions of galaxies, and may soon answer the age long question: “Are we alone?”

But what does that have to do with time? Well, light takes time to travel; A light year is the distance light travels in a year. For example, the nearest galaxy to ours is the Andromeda galaxy; about 2.5 million light years away. We see Andromeda as it was 2.5 million years ago. Through telescopes, we see objects as they were when they released the light that travelled across the universe to get to us. So when we use telescopes to look at more distant objects, we are also looking farther back in time. In fact, many of the stars we see at night may already be long gone.

In 13.8 billion years, how much has already disappeared? We are all time travellers, now.

- Cheryl Moskowitz

The Hubble telescope may have taken pictures of some of the oldest galaxies, but the James Webb telescope can look back even further. This telescope will help astronomers look back in time to the Dark Ages of the universe. There may not have been much to see then, but the real interest is in looking for the first light. The strategy behind the James Webb telescope will allow us to answer when the Dark Ages ended, and even explain the nature of dark matter, which makes up about 80% of the universe.

At the end of the day, telescopes reveal to us the intricacies of the universe and allow us to look farther. Telescopes will answer our endless questions, but until then, we can only hope the years have been kind to the stars.