The Einstein Telescope | Hacker News Reader

The Einstein Telescope

einsteintelescope.nl

73 pointsbelter19 comments

I was under the impression that the future of gravity wave observation was goong to be pulsars, telescopes measuring tiny changes in pulsar frequency to detect gravity waves. Doing so means baselines measured not in kilometers but lightyears.

Using pulsars to detect gravitational waves can only detect gravitational waves at certain wavelengths. (Kind of like a radio dish being able to pick up radio waves, but not the visible spectrum like a camera)

We will need gravitational detectors of different lengths to detect and observe the broad spectrum of gravitational waves.

> The Einstein Telescope can only take measurements in a tranquil environment, like that in the border region between the Netherlands, Belgium and Germany.

I love how this is both true, yet historically quite amusing, not even considering recent European events. Pretty sure that region has more unexploded bombs buried than it has cows. And that area has a lot of cows.

Unexploded bombs aren't what they're worried about. (That's just a minor safety concern common to innumerable construction projects in many places in Europe.) They are worried about continuous/repeated sources of vibration from either geology or human activities.

The region is relative far from larger cities, so I wouldn't expect many bombs to be there. While there are still plenty of bombs being found in Germany, most of them are in the city centers as bombing was concentrated there.

Well, sure. But the allies bombed just about anywhere for any reason. I'm sure there are many remote fields which could have been holding areas for things that would have made good targets. And if a bomb missed a convoy on either side of a road, it could sink waaaay into a mud bog, not go off and barely leave a trace behind. If that "road" was a temporary detour through farmland for a few months in 1941? Yikes!

I don't know anything about the chemistry of explosives but if those bombs didn't explode for 80 years are they going to explode now? Furthermore they are a problem if they build on them. If one explodes away from the telescope they lose minutes of data, probably not a big deal.

Yes, unfortunately, there is still a risk. Just a few months ago a bomb was set off in the center of Munich at the train station during construction work.

That seem to be a failure of a certain brand analogue computer used for precision bombing at that time. They have to switch to carpet bombing. Still would they just bomb a field I wonder even carpet bombing.

I guess the project would also help with clearing up old bombs. Do they state the budget anywhere? This looks like a BIG project.

I think it's around 10 billion euros IIRC? Definitely more than 1 billion and less than 50

Which one is the correct/legit website?

OP's or this one http://www.et-gw.eu/ ?

also: https://en.wikipedia.org/wiki/Einstein_Telescope

I think et-gw.eu is more like the home page of the scientific collaboration (which, at such an early stage, is often just a loose confederation of researchers without authoritative central leadership) while the OP link is a marketing effort by their Dutch contingent to raise support for a particular geographic location. From the "about" page:

> This website is an initiative by the project team investigating the possible candidacy for the Einstein Telescope on behalf of the Netherlands. It includes employees of the Dutch National Institute for Subatomic Physics (Nikhef), the Province of Limburg and the Netherlands Foundation of Scientific Research Institutes (NWO-I).

These sorts of collaborations often only solidify around a central leadership with actual authority when significant funds for the project are allocated.

Really and if not cost prohibited Noooo central leadership please.

I am a huge proponent of academic independence, but without central leadership a device like this simply will not get built. It's not about cost, it's about coordination. For more detailed arguments on the type of research that requires centralization, see here: https://www.dayoneproject.org/post/focused-research-organiza...

If anyone's curious about the improvement this detector can make compared to previous gravitational wave detectors; this is what they report on their website:

> The European Einstein Telescope will be able to detect up to a thousand times more sources of gravitational waves than any of its predecessors.

And this can be found on their wikipedia page:

> The arms will be 10 km long (compared to 4 km for LIGO, and 3 km for Virgo and KAGRA), and like LISA, there will be three arms in an equilateral triangle, with two detectors in each corner.

How does this help humanity?

1. Everything that humanity discovers helps humanity, because knowledge is something we value.

2. Things it helps us discover about the universe may lead to new discoveries in physics (consider how astronomical observations helped in discovering and confirming relativity), which ...

2a. ... are in themselves a gain for humanity (see #1), and ...

2b. ... may lead to technological advances (e.g., relativity led to nuclear power and nuclear weapons, which may or may not have been a win for humanity overall but are certainly major advances in what humankind is capable of doing; also, e.g., GPS accurate enough to be useful).

3. Any discovery may end up being valuable in ways no one ever suspected ahead of time.

4. The project will provide employment for many scientists, and thereby contribute to whatever further work they and their institutions do later, which will be valuable in the same sorts of ways as the Einstein Telescope itself.

5. The project will provide a precedent for government spending on science, which there should be more of for the reasons given above.

(Does it help humanity enough that if we had to choose between this and feeding starving people in the world's poorest places we should choose this? Probably not. Does it help humanity enough that if we had to choose between this and buying a few more fighter jets we should choose this? Probably. In practice, neither of those is likely to be a decision anyone's making.)

How does it not?

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