The largest telescope that will ever be built*

And the stars were beautiful. ■ AD: 👨‍💻 NordVPN's best deal is here: nordvpn.com/tomscott - with a 30-day money-back guarante

It was a pleasure hosting you, Tom! What a great video. We love your enthusiasm and the way you explain the technical challenges behind building such large optical telescopes.

Nice of Tom to put in a disclaimer that gifts from the Extremely Large Telescope will not influence his review of it. It makes me much more inclined to buying my ridiculously big telescopes from the Extremely Large Telescope people.

One interesting thing I noticed was that you had a lot of people from different countries all working together for the sake of astronomy. It’s kinda touching to see people from around the globe working towards a very human endeavor

As a physicist, this is perhaps one of the best science communicator videos out there. Tom's enthusiasm and emphasis on the technical challenges AND achievements is outstanding! Thank you

The fact that ESO had at one time proposed an even bigger telescope called the Overwhelmingly Large Telescope says it all when you gave scientist to naming things

Only Tom Scott can make a 5 minute video give 30 minutes worth of information. And only Tom Scott can make a 30 minute video feel like 5 minutes. Stunning work good sir. Stunning.

I had 8 minutes so I thought a Tom Scott video would be perfect. 15 minutes in I realized this wasn’t a standard Tom Scott video. 😅 What an incredible place, science, and engineering. And incredible work filming and presenting it. What an incredible vote of confidence in your team to invite you out to see the site!

I have been working for this Observatory for decades, I put my hands in so many things you showed here and so far it is the best video I have seen. Because of the quality of the explanations, because of the enthusiasm. In 30min you manage to cover a lot of things happening there (not all), that's remarquable. I am a bit disapointed to hear that you had to pay your fly ticket, but I guess ESO has not yet seen the importance of this kind of work for its communication. So a small message to those responsibles at ESO, please make it easier next time.

A 30-minute video with Tom?! A blessing!

Is this video a glimpse into Tom's future? Nearly 30 minutes long, a deeper and more complex treatment of the subject, so much production values that there are actual credits for the production team, something that definitely won't be coming out every Monday... and it's still Tom being Tom. I am here for this, even if I'm barely able to follow.

This video is at (or above) the level of quality I'd expect from a tv network documentary. Really amazing work, Tom and team. Fascinating stuff.

Man Tom, you really won the career lottery. Visiting the most interesting places on earth and sharing them with the world. We'll miss you on your hiatus, but you've earned it.

As a physicist watching this, please don't apologize for the analogy between radio waves and bass at 17:30. It's exactly accurate and a great example of science communication like so many other explainations in the video. Thank you for the great job on this one. Seems like it really paid off to redo the script as the final version is just amazing and worth every minute of watch time.

The idea that we are able to spray down 7g of aluminum, pretty much atom by atom, on such a large surface is insane

That's why I love the documentaries of Tom. Slow pace, explaining and showing everything as detailed as possible, admitting there could be errors on the information so we don't accept this as the ultimate library, everything set so great that a 30min video feels like a 10min one. Your videos are such a relaxing and learning experience.

I don't know what kind of production team you have to help with all this but it is easy to recognize a colossal and effective effort. This felt like a ready-made presentation from the BBC. Thank you for all the time you put into this!

9:37 Fun fact about the air conditioning in these big observatories: When doing optical observations, it's important for the air to be still and stable. Introducing a temperature gradient to the air can cause distortion in the image observed by the telescope. To avoid this, large observatories often keep the telescope chamber (the dome) chilled to the expected overnight temperature, so that when they open the telescope to the night air, there is as little gradient in air temperatures between the telescope and the night sky as possible.

Concerning your worry about the length of the video in the newsletter: don't worry Tom. We like your videos because they are always as long as they need to be to fit all the information you have for us. And having such a detailed video once in a while is phenomenal.

This video is paced to perfection, it felt like a 5-10 minute journey where every bit of information led to something new and built upon the rest, this is definitely one of your best!