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Hopefully NATO and Russia avoid a nuclear war. It would be nice to see this before we vanish... — Manuel

I was just talking about this with my wife! She's really scared. Let's hope the best and keep looking out for supernovae to find out about dark energy, instead of thermonuclear annihilation we never asked for.

It is very worrisome. I know these topics can be very tiring - the boy who cried wolf type of thing - but, there's only so many risky situations that need arise before an accident happens.

And right now, NATO especially, but also Russia, are seeing who can take a bigger piss.

It would be better to see these images by far. But we have to get there. It would be a shame to miss out.

Hopefully NATO and Russia avoid a nuclear war. It would be nice to see this before we vanish... — Manuel

At least we die happily then...

Spacecraft controllers have begun powering up the four cutting-edge instruments on NASA's James Webb Space Telescope as they prepare for the observatory's first glimpses of a target star.

https://www.space.com/james-webb-space-telescope-turns-on-cameras

Also contains a good explanation of why the instrument has to operate at near-absolute zero degrees (which Is actually very simple when you read it. If it were generating any infrared - heat energy - then it would drown out the extremely faint infra-red radiation that it’s designed to capture.)

What if light waves get stretched further? Don't they become radio waves? What's an infrared telescope like JWST doing at L₂? Isn't it tuned to the wrong fequency? A Doppler effect query.

Second question: If we travel at very high speeds, do light waves become gamma rays (wave compression, Doppler effect) and won't that kill us, almost instantaneously as it were?

A selfie from L2 :grin: :up:

https://www.space.com/webb-telescope-space-selfie-nircam

Through the lenses of my very basic telescope, the Orion nebula looks like this — Olivier5

You have a cool telescope, even if you say it's basic.

"That star, called HD 84406, is located 241 light-years from Earth and part of the constellation Ursa Major, the Great Bear. The images will not be used for science, but will help the ground teams align the 18 golden segments of Webb's 21-foot-wide (6.5 meters) main mirror.

The images will be taken by Webb's Near Infrared Camera (NIRCam), which first has to cool down to its operational temperature of minus 244 degrees Fahrenheit (minus 153 degrees Celsius).

At the beginning, we will have 18 individual blurry images," Mark McCaughrean, a scientist at the JWST Science Working Group and senior advisor at the European Space Agency (ESA), who is familiar with the process, told Space.com . "At the end, we will have one nice sharp image."

Or then we have blurry image and a huge collective D'OH!

The redshift of the distant universe (most of the other galaxies) is due to the expansion of space over time. The more distant the source, the older the light, and the more stretched it has become as space expands. Radiation that has stretched so far as to become radio frequency, dates back to the early universe, before the formation of stars and galaxies, I think.

https://www.space.com/25732-redshift-blueshift.html

In relation to redshift due to expansion of space, the shifts observed due to actual relative motion are rather small.

https://www.forbes.com/sites/startswithabang/2019/11/07/this-is-how-distant-galaxies-recede-away-from-us-at-faster-than-light-speeds/?sh=6f8ba9ed72a2

Oh, ok! We've already surveyed the radio part of the spectrum OR it's not not that long/too far yet for the first starlight to become radio.

Theoretically, as more time passes and more distance is interposed the frequency of light should drop to zero. In other words, darkness is light waves stretched into a straight line (zero frequency). Amazing! Darkness, no such thing!

You have a cool telescope, even if you say it's basic. — ssu

Ok, I was lying. Through the lenses of my very basic telescope, the Orion Nebula looks like this:



To my defense, it's not easy to find such a low quality pic of it on the Internet, precisely because everyone posting pics of it nowadays have better equipment than I do...

This one above was taken by Henry Draper, an American amateur astronomer, on September 30, 1880 with his Clark telescope of 11 inches aperture and an exposure of 51 minutes. It was the first photograph ever taken of any nebula.

https://articles.adsabs.harvard.edu/cgi-bin/t2png?bg=%23FFFFFF&/seri/MNRAS/0042/600/0000367.000&db_key=AST&bits=4&res=100&filetype=.gif

Update from James Webb

On March 11, Webb completed "fine phasing," a critical stage that ensures Webb's optical capabilities are working how they should. During the tests, the team didn't encounter any issues and determined that Webb can observe light from distant objects and feed that light into the science instruments aboard the observatory.

More at

https://edition.cnn.com/2022/03/16/world/james-webb-space-telescope-mirror-alignment-scn/index.html

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What's the latest on the JWST? Will it radically transform our understanding of the universe, ourselves?

There haven't been many updates of late. I daresay much of what is discovered will only really be comprehensible to specialists. They're going to have trouble out-doing Hubble in terms of popular spectacle.

What's the latest on the JWST? Will it radically transform our understanding of the universe, ourselves — Agent Smith

It will, Agent, my dear. The true nature of dark energy will be revealed. Probably it is finally shown by observation, that the present big bang episode is just one in an infinite row! Imagine you and me philosophizing in every new universe, after each new big bang. That would be heaven on Earth. We could feel how the gods once felt!

I daresay much of what is discovered will only really be comprehensible to specialists. — Wayfarer

That takes me out of the running, I'm a generalist, a little bit of this, a little bit of that, you know, jack of all trades, master of none!

Better than our most optimistic prediction” – first images from James Webb exceed all expectations

In case anyone's interested,

Lagrange points (aspects of the so-called three-body problem) are points in space at which the gravity of two masses cancel each other out OR where the centrifugal force is equal to the gravitational force acting in the opposite direction.

The JWST was placed at Lagrange points to minimize the need for orbital corrections and/or to make them easier; plus, the sun and the earth are close enough to each other in the sky at Lagrange points which means sun-shielding is a much simpler task (less variation in sunshine).

Fun fact: Lagrange points are part of the famous three-body problem, the precursor to chaos theory (kind courtesy of Henri Poincaré). Will things go awfully wrong for the JWST or will it go as planned?

Agent Smith! What great contribution my dear! Don't worry love. Webb will oscillate happily along during her looking at the baby universe, in the safe shadow Earth offers her. What will she show us? The observations can reveal the expansion speed of the universe shortly after the bang. Shall we come to understand the nature of dark energy. Or even dark matter?

Will things go awfully wrong for the JWST or will it go as planned? — Agent Smith

JWST got through all 344 single-point failures - things that, if they had gone wrong, would have doomed the mission. So - so far it is going exactly as planned, astonishingly well, in fact.

Did they expect it to go wrong?

Just before it launched, I think I posted a link to a story about one of the design engineers who was throwing up with stress in the lead-up to the launch, because of the number of things that could go wrong, and the intricacy of the deployment operation. Early on in the thread, there's a link to a video 'Building JWST' which is what got me interested - the engineering and testing involved was mind-boggling. And the stakes were very high, had it failed there was very little chance of having another go, as the amounts of $ involved are also mind-boggling.

But so far, so good!

Are you more interested in the technology than the cosmology?

I feel that the underlying urge of getting to the bottom or the end or the beginning of it all - whether by cosmology on one end or particle physics on the other - might turn out to be a bit of a wild goose chase. But the technological and engineering skills, and the science, is fascinating in its own right.

JWST got through all 344 single-point failures - things that, if they had gone wrong, would have doomed the mission. So - so far it is going exactly as planned, astonishingly well, in fact. — Wayfarer

Devil's luck or good planning! Can't tell which! :smile:

Definitely planning. Minute, precise, meticulous, checked and double-checked.

Definitely planning. Minute, precise, meticulous, checked and double-checked. — Wayfarer

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one of the design engineers who was throwing up with stress — Wayfarer

How I'd love to be him/her! That's called commitment! :cry: = :vomit: :point: :heart:

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