Jump to content

The James Webb Space Telescope and stuff


Streetwind
 Share

Recommended Posts

Good news on the political front: looks like Webb will enjoy continued funding!

James Webb Space Telescope's early science thrills Congress | Space

Quote

 ...we quite often hear in government how things don't work," Rep. Donald Norcross, D-N.J., said during the hearing. "I just want to say thank you for exceeding our expectations."

Quote

The successful launch of NASA's first step back to the moon, Artemis 1, which happened in the middle of the night preceding this hearing, added to the air of celebration and confidence in NASA's abilities. And despite the numerous setbacks the $10 billion observatory faced prior to launch, the hearing solidified JWST's status as a worthy investment.

 

Link to comment
Share on other sites

Web is mooning the MAZ:

"After several months of discussions, NASA optics and micrometeoroid experts working on the James Webb Space Telescope have figured out how to reduce micrometeor damage to the $10 billion machine: turn it around."

https://www.theregister.com/2022/11/21/nasas_jwst_meteor_avoidance_plan/

 

Link to comment
Share on other sites

  • 2 weeks later...
1 hour ago, JoeSchmuckatelli said:

Typically reserved reporting from the popular media 

https://www.foxnews.com/science/oldest-known-galaxies-spotted-james-webb-space-telescope

Question - how much longer until they decide the universe is older than the current expectation? 

It's a bit more complicated than that.  The size and age of the visible universe (ie. the part that from the expansion of the universe isn't effectively receding from us at greatest that the vacuum speed of light and thus permanently detached from us) are roughly known, but in the details, there's a mismatch between methods to determine the rate of universe expansion.  This is an current and active area of research.

 

 

Link to comment
Share on other sites

4 hours ago, Jacke said:

This is an current and active area of research.

Nice video - thanks.  Oddly enough, I started the 'Science Articles' thread because all the 'Crisis in Cosmology' articles I was linking in 'Questions That Don't' faded uppage quite rapidly. 

I've been following Freedman's work for some time.  I knew we were waiting for JWST info and missed the article she links to (the one where some researchers looked at a different team's view of the one galaxy, compared it to Hubble data and showed that Freedman's team might not find what they're looking for).

It's one of those 'fun to be on the sidelines' controversies - where people who've made their entire career pursuing proof of LCDM and expansion actively resent people suggesting their presumption might be incorrect.  Even when housed in language where 'your ladder measurements may be off' (not directly saying expansion is incorrect), some of the LCDM proponents have been intense in their reactions.  (In the late 90s it was actually almost career-ending to question its presumptions.)

Frankly - I like the idea that LCDM is 'wrong' simply because I don't like the idea that we know everything already.  Yes it has been a fantastic tool - but if it becomes non-career-ending to nibble at the edges of the theory, we are likely to get researchers who make new discoveries that give us an even better refined view of the cosmos than we currently enjoy.

Link to comment
Share on other sites

3 hours ago, JoeSchmuckatelli said:

Nice video - thanks.  Oddly enough, I started the 'Science Articles' thread because all the 'Crisis in Cosmology' articles I was linking in 'Questions That Don't' faded uppage quite rapidly. 

I've been following Freedman's work for some time.  I knew we were waiting for JWST info and missed the article she links to (the one where some researchers looked at a different team's view of the one galaxy, compared it to Hubble data and showed that Freedman's team might not find what they're looking for).

It's one of those 'fun to be on the sidelines' controversies - where people who've made their entire career pursuing proof of LCDM and expansion actively resent people suggesting their presumption might be incorrect.  Even when housed in language where 'your ladder measurements may be off' (not directly saying expansion is incorrect), some of the LCDM proponents have been intense in their reactions.  (In the late 90s it was actually almost career-ending to question its presumptions.)

Frankly - I like the idea that LCDM is 'wrong' simply because I don't like the idea that we know everything already.  Yes it has been a fantastic tool - but if it becomes non-career-ending to nibble at the edges of the theory, we are likely to get researchers who make new discoveries that give us an even better refined view of the cosmos than we currently enjoy.

I don't necessarily think Lambda-CDM is wrong so much as incomplete.  There are gross observational features that compose it, like Dark Matter being observed as separable from Baryonic Matter, so no requirement to fiddle with Gravity.  Low variation at great separations almost requires something like Cosmic Inflation.

But I wonder if there's some cockups like I read from Lee Smolin's books on the mess that is String Theory.  Like thinking some stuff has been proved when it actually hasn't.

Speaking of Smolin, I still have to read his book Time Reborn.  Along with Gödel, Escher, Bach (got halfway on that book so many times...) and The Feynman Lectures on Physics.

https://en.wikipedia.org/wiki/Time_Reborn

Edited by Jacke
Link to comment
Share on other sites

1 hour ago, Jacke said:

Like thinking some stuff has been proved when it actually hasn't.

I found Sabine Hossenfelder's videos on Subir Sarkar's work quite interesting.  

The first video (7 mins) during which she talks about his paper.  


The second video is a 45 min interview which I found also worth watching.   


Now I don't have the background to assess his conclusions, but if he is right then the expansion of the universe might not be accelerating after all.

His paper is at https://arxiv.org/abs/1808.04597 .
 

Edited by AVaughan
Link to comment
Share on other sites

7 hours ago, Jacke said:

Gödel, Escher, Bach

One of my favorite books to never quite read.  I get a section done here read something new there and years later find myself rereading something as if for the first time! 

6 hours ago, AVaughan said:

Sarkar's work

His paper caused a bit of consternation when it came out. 

From what I understand he's (and team) actually respected enough that he could not be written off as a quack.  

Link to comment
Share on other sites

Webb takes a peek at the Hubble Ultra Deep Field.

This area is in and around the Hubble Space Telescope’s Ultra Deep Field. Scientists used Webb’s NIRCam instrument to observe the field in nine different infrared wavelength ranges. From these images, the team searched for faint galaxies that are visible in the infrared but whose spectra abruptly cut off at a critical wavelength. They conducted additional observations (not shown here) with Webb’s NIRSpec instrument to measure each galaxy’s redshift and reveal the properties of the gas and stars in these galaxies.

STScI-01GKT0TT83R41FVZ9JGNWGB2AH.png

I can't count that high, but if you multiply 100 Billion by all the little dots (except for the star)... that's a lot of stars, given that pretty much everything you see in the image is a galaxy.

 

JWST Advanced Deep Extragalactic Survey (JADES) (webbtelescope.org)

Edited by JoeSchmuckatelli
Link to comment
Share on other sites

On 12/10/2022 at 6:55 PM, Jacke said:

This is an current and active area of research.

Here's one of the newer 'crisis in Cosmology' articles - it came out after Webb data started flowing.  I've cited this before - but its a pretty good read (in case you missed it)

JWST's First Glimpses of Early Galaxies Could Break Cosmology - Scientific American

Link to comment
Share on other sites

  • 2 weeks later...

The last futile attempt to prevent the inevitable.
JWST has seen too much. Many best people got worried. 

A year ago they were believing, it will help in scientific life. And what they got, is that it's hammering the comfy known world.

JWST, the Mirror of Doom.

Edited by kerbiloid
Link to comment
Share on other sites

8 hours ago, kerbiloid said:

The last futile attempt to prevent the inevitable.
JWST has seen too much. Many best people got worried. 

A year ago they were believing, it will help in scientific life. And what they got, is that it's hammering the comfy known world.

JWST, the Mirror of Doom.

Yeah - some old guy probably flicked the switch because he just could not take it anymore. 

Link to comment
Share on other sites

Popper defined scientific cycles that are reflected in history fairly well.  The degree to which technology expands the data we get to see the world seems to be at the very foundation of this cycle with a phase-lagging social smugness-humility cycle

Edited by darthgently
Link to comment
Share on other sites

Pretty amazing picture - but I can't figure out how to imbed it. 

 

content://media/external/downloads/6990

 

"In clusters of galaxies, there is a fraction of stars that wander off into intergalactic space because they are pulled out by huge tidal forces generated between the galaxies in the cluster. The light emitted by these stars is called the intracluster light (ICL) and is extremely faint. Its brightness is less than 1% of the brightness of the darkest sky we can observe from Earth. This is one reason why images taken from space are very valuable for analyzing it."

https://www.google.com/amp/s/scitechdaily.com/james-webb-telescopes-unparalleled-view-of-the-ghostly-light-in-galaxy-clusters/amp/

 

Link to comment
Share on other sites

20 minutes ago, HebaruSan said:

Do you mean this one?

ngcb2

(I used the "Insert image from URL" button in the lower right.)

No - although it's cool - the black on white (which has design elements of an actual astronomy still... But apparently some colorization elements from NASA (at least according to the complaints comments.))

When I click on it I get a pdf

Edited by JoeSchmuckatelli
Link to comment
Share on other sites

6 hours ago, HebaruSan said:

the one

Yeah - that is a cool image - and evocative of the light between galaxies. 

Thanks! 

Interestingly - I'm pretty sure it's the same image - but with a different artistic impression. 

 

Old astronomy stills used to look like that.  Pretty sure Webb is only sending data and the team can create an image from the data, but the whole thing is a lot more complex than just capturing an image on a CCD or CMOS

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...