James Webb Infrared telescope

Sure, but that doesn’t mean that the infrared pictures cannot be recalculated into pretty visible colors. Some of the most famous Hubble pictures were made in IR as well (near IR, but just as invisible to our eyes)


Close now to L2 - and minus 209C on the telescope side, which is quite chilly, given that absolute zero is −273.15 degrees C.

avec space-y music:

Yep, the final correction burn apparently going well, and the individual mirror segments have been raised from their launch positions. All going well!

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Aaaand we are in orbit! Massive congrats!


Cool. Really cool.


Now “engineers will begin the sophisticated three-month process of aligning the telescope’s optics to nearly nanometer precision.”

And if those all line up to form a single, more than 6M diameter golden lens - let the photons roll in from the vastness of spacetime…


I can’t imagine how it is for some people who have worked on this for 25 years. Or in the case of Kip Thorne and LIGO, to have started working on something that nobody thought possible as a post-graduate student in 1970, and then making it actually work 45 years later. Amazing achievements.


They are probably delighted that nothing has yet failed - and in a horrible state of suspense in case a mirror gets stuck, or a rogue bollide rams into the scope before it collects any data.


As regards LIGO, I have still not understood what the discovery of waves in the gravitational field tells us about how that field operates (or exists) in relation to the fields in the standard model - if anything?

Arguably, the gulf between QFT and GR is the biggest hole in our current understanding of the observable universe, which is why I ask that Q.

Does the LIGO finding give us any clues as to why gravity is not observed in quantum fields?

Or what type of field gravity is in relation to the known quantum fields?

I think the mirrors are safely in place after the lift from their launch restraints, but now it’s about the minuscule corrections of their shape, I guess plenty to still be concerned about. But yeah, the collision angst must be the worst. All going well, you look at the data coming in, and then from one moment to the next there’s simply nothing.

I believe there is some hope that data about the gravitational wave background will help string theory along, and string theory of course would be a candidate for finally adding gravity to the standard model, or rather going beyond it. Or it might exclude string theory and people can focus on something else - which of course would be a bummer for those who invested their whole career into something that would suddenly just be an odd 10-dimensional maths model :confused:
But I think it’s early times for this, and at the moment the more tangible thing is having the first cosmological observation tool that is not based on photons.

(The waves in space time as such were predicted by GR anyway and nobody doubted their existence, just the possibility to measure them)

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The gulf is certainly the case. It’s mind blowing that the two best theories in existence, both being backed by huge amounts of evidence and making perfect predictions every single time, have nothing to do with each other :joy:

But as per my previous post, I don’t think that LIGO data is telling us anything about this, yet. I think the status is that it needs several steps, the data being used to try and refine the beyond-the-standard-model theories, strengthening some and weakening others, and so on, and then in turn using improved theories to tackle this pesky problem.

As far as I can tell, the state of things are papers like these, i.e., groundwork (and gibberish to me :slight_smile: )

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Yes, thanks for that.

Those 3 are all string theory papers, which, as you say, is one school of thought that the answer may come from.

When you think about how Einstein made his great leaps forward on relativity, it was more through his qualitative imagination of how radiation, matter and gravity were related that allowed him to advance our understanding.

The maths came almost as an afterthought or a formality.

Perhaps that is to some extent the case with particular variants of String Theory too, although an infinite number of models seems to be possible within the maths of string theory, each of which would have different qualitative implications.

(I do love the fact the arxiv.org is out there as an accumulation of non-peer reviewed ideas that would otherwise be killed by the weight of the peer review process.)

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I’m sure the other quantum gravity theories are producing similar papers, trying to dig something out of the LIGO data.
Agree on Einstein’s imagination, though I think that, understandably, the math gets short change in its popular renditions and it was more a part of his thinking than we commonly think (even though he didn’t invent it and had to learn it). Not sure if string theory is really similar, it sometimes seems to me more like the other way around, math that’s looking for an application. In any case, most of it has played exclusively in the realm of math for decades. It’s understandable of course, given its problems with making provable predictions, and admittedly the math made a lot of progress. But I think that’s a large part of why they are so excited by LIGO, in particular as the LHC didn’t find evidence for supersymmetry (which wasn’t an expectation, but there was some hope).

Speaking of the LHC, it has exciting times ahead as well.

Yes, there’s a field of QG theories too.

What news is there from the LHC?

Run 3 is around the corner I think, followed then by another shutdown and further upgrades. Wiki:

Long Shutdown 2 (LS2) started 10 December 2018. The LHC and the whole CERN accelerator complex is being maintained and upgraded. The goal of the upgrades is to implement the High Luminosity Large Hadron Collider (HL-LHC) project that will increase the luminosity by a factor of 10. LS2 is projected to end in 2021, followed by Run 3. The HL-LHC should be operational by 2026. The Long Shutdown (LS3) in 2020s will take place before HL-LHC project is done.

Update - LS2 seems behind schedule (covid) and run 3 will be in 2022/23. Nice overview:

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My gut says that this will (if anything) lead to an increase in the number and type of (exotic) fields in the standard model.

But hopefully something more interesting than that.

Considering that I will probably not get to see the LHC successor, it’s all I have :slight_smile: Let’s hope

Who knows?

I hope to keep going until 2050, when I’ll be 86.

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I will be 81 in 2050, the problem will be digging a 100 km tunnel and filling it with “stuff” until then :slight_smile:

Probably they’ll bung it up into ‘space’ - or fire at the Moon?