<p>The James Webb Space Telescope is very specifically built to look at infrared light, not microwaves, so it hasn't collected information about the Cosmic Microwave Background directly. However, you might have recently heard about JWST and CMB in the same discussion because JWST has been observing Cepheid variable stars, which are related to CMB in an indirect sort of way.</p>
<p>The ongoing so-called &quot;crisis in cosmology&quot; is that there are two ways to measure the expansion of the universe: one by examining the CMB, and the other by observation of supernovas, using Cepheid variables to determine distance calibrations. The &quot;crisis&quot; is that the two measurements' error bars have shrunk to the point that they no longer overlap: there is no value that could fit both measurements. We have two ways to measure expansion, and they fundamentally disagree on the answer.</p>
<p>JWST recently did some work to see if the Cepheid distance values were being biased by other nearby stars interfering with our brightness measurements (which was one theory of why we might be seeing this divergence), but the result was that no, we actually had done a good job of adjusting for that and our distance measurements seem to be working correctly -- so the &quot;crisis&quot; continues.</p>
<p>Footnote: I dislike the term &quot;crisis&quot; because it implies that there's an emergency, that our whole understanding of the universe and physics itself is in danger of collapse -- which is of course absurd. As it's said, scientific progress very rarely sounds like &quot;Eureka! I have found it!&quot;; instead it usually sounds like &quot;Huh. That's weird...&quot;  The fact that we have two measurements that disagree is not a terrible thing (however frustrating it might be for the theorists), because it's a signpost that shows us that there's something we should study right over there.</p>

CC BY-SA 4.0
2023-09-25T13:36:13.817Z
2023-09-26T14:59:53.410Z
2023-09-26T14:59:53.410Z
Darth Pseudonym
<p>I need to know about the data, which scientist have already received from JWST about the CMB.</p>

CC BY-SA 4.0
2023-09-25T06:39:07.467Z
JWST doesn't observe in the microwave range...
Sten
CC BY-SA 4.0
2023-09-25T07:01:40.360Z
@Sten But couldn’t this information be obtained indirectly using his measuring instruments?
ayr
CC BY-SA 4.0
2023-09-25T07:32:30.167Z
@dtn something like measuring heating of gas by the CMB?
Sten
CC BY-SA 4.0
2023-09-25T08:10:14.720Z
@Sten or something like a microwave radiometer with Horn antennas, like [here](https://122.physics.ucdavis.edu/course/cosmology/sites/default/files/files/CMB/cmb_guide.pdf). True, I don’t know if there is similar equipment at JWST. Or calculating microwave background parameters from other measured data using mathematical models.
ayr
CC BY-SA 4.0
2023-09-25T08:58:36.250Z
Here you have all the data: https://archive.stsci.edu/missions-and-data/jwst
planetmaker
CC BY-SA 4.0
2023-09-25T09:07:33.733Z
@planetmaker and all these cameras, instruments, spectrographs, are they some kind of unique instruments that were developed specifically for this telescope or are they some kind of “mass” instruments, from which we can simply choose the ones we like?
ayr
CC BY-SA 4.0
2023-09-25T10:33:06.660Z
@dtn I don't understand your question or how it is related to the topic of this question. You can use all the data however you like, and the instrument design and calibration is also available so everyone can derive meaningful conclusions from them. How does the *process* of instrument design matter here? (hint: of course it has unique instruments - but not that unique that their principles are unique).
planetmaker
CC BY-SA 4.0
2023-09-25T10:40:50.490Z
Can you be clearer about what effects the JWST might be sensitive to, or change your question so it is clearly asking IF (and how) there is anything that JWST can learn about the CMB?
ProfRob
CC BY-SA 4.0
2023-09-25T11:08:26.473Z
@planetmaker My question is not directly related to the topicstarter question.  He can help make clarification.  My question was about: how the set of instruments of the telescope being created is determined.  If, for example, a camera is needed, is it also created from scratch for a specific telescope or is it selected from existing models?  Does the mission include the ability to measure previously unforeseen parameters (as in the case of the CMB)?
ayr
CC BY-SA 4.0
2023-09-25T13:03:16.257Z
@dtn That's not really a discussion to have in the comments of somebody else's question, but if you want to post your own question, feel free.
Darth Pseudonym
CC BY-SA 4.0
2023-09-25T14:40:00.190Z
@DarthPseudonym and where is it better to ask this question: Astronomy, Physics or Space Exploration Stack Exchange?
ayr
CC BY-SA 4.0
2023-09-25T15:05:30.593Z
@dtn whatever fits - depends on your exact question; astronomy might be suitable. But as you might know, SE works strictly on a basis of one question, only answer way - and comments are only for clarifications regarding the question and not extended off-topic discussions.
planetmaker
CC BY-SA 4.0
2023-09-26T09:23:55.707Z
@planetmaker https://astronomy.stackexchange.com/questions/54845/formation-of-spacecraft-instrumentation
ayr
CC BY-SA 4.0
2023-09-26T09:24:17.350Z
@DarthPseudonym https://astronomy.stackexchange.com/questions/54845/formation-of-spacecraft-instrumentation
ayr
<cosmic-microwave-background>
How much data are with cosmologist from JWST about CMB?
Jahid Hossain
# How much data are with cosmologist from JWST about CMB?

(Asked by: username_0 on 2023-09-25)

I need to know about the data, which scientist have already received from JWST about the CMB.

**Tags:** cosmic-microwave-background

> **Comments:**
> **username_1**: JWST doesn't observe in the microwave range...  
> **username_2**: @username_1 But couldn’t this information be obtained indirectly using his measuring instruments?  
> **username_1**: @dtn something like measuring heating of gas by the CMB?  
> **username_2**: @username_1 or something like a microwave radiometer with Horn antennas, like [here](https://122.physics.ucdavis.edu/course/cosmology/sites/default/files/files/CMB/cmb_guide.pdf). True, I don’t know if there is similar equipment at JWST. Or calculating microwave background parameters from other measured data using mathematical models.  
> **username_3**: Here you have all the data: https://archive.stsci.edu/missions-and-data/jwst  
> **username_2**: @username_3 and all these cameras, instruments, spectrographs, are they some kind of unique instruments that were developed specifically for this telescope or are they some kind of “mass” instruments, from which we can simply choose the ones we like?  
> **username_3**: @dtn I don't understand your question or how it is related to the topic of this question. You can use all the data however you like, and the instrument design and calibration is also available so everyone can derive meaningful conclusions from them. How does the *process* of instrument design matter here? (hint: of course it has unique instruments - but not that unique that their principles are unique).  
> **username_4**: Can you be clearer about what effects the JWST might be sensitive to, or change your question so it is clearly asking IF (and how) there is anything that JWST can learn about the CMB?  
> **username_2**: @username_3 My question is not directly related to the topicstarter question.  He can help make clarification.  My question was about: how the set of instruments of the telescope being created is determined.  If, for example, a camera is needed, is it also created from scratch for a specific telescope or is it selected from existing models?  Does the mission include the ability to measure previously unforeseen parameters (as in the case of the CMB)?  
> **username_5**: @dtn That's not really a discussion to have in the comments of somebody else's question, but if you want to post your own question, feel free.  
> **username_2**: @username_5 and where is it better to ask this question: Astronomy, Physics or Space Exploration Stack Exchange?  
> **username_3**: @dtn whatever fits - depends on your exact question; astronomy might be suitable. But as you might know, SE works strictly on a basis of one question, only answer way - and comments are only for clarifications regarding the question and not extended off-topic discussions.  
> **username_2**: @username_3 https://astronomy.stackexchange.com/questions/54845/formation-of-spacecraft-instrumentation  
> **username_2**: @username_5 https://astronomy.stackexchange.com/questions/54845/formation-of-spacecraft-instrumentation  

---

## 1 answers

### Answer by username_5 on 2023-09-25. Score: 4

The James Webb Space Telescope is very specifically built to look at infrared light, not microwaves, so it hasn't collected information about the Cosmic Microwave Background directly. However, you might have recently heard about JWST and CMB in the same discussion because JWST has been observing Cepheid variable stars, which are related to CMB in an indirect sort of way.

The ongoing so-called "crisis in cosmology" is that there are two ways to measure the expansion of the universe: one by examining the CMB, and the other by observation of supernovas, using Cepheid variables to determine distance calibrations. The "crisis" is that the two measurements' error bars have shrunk to the point that they no longer overlap: there is no value that could fit both measurements. We have two ways to measure expansion, and they fundamentally disagree on the answer.

JWST recently did some work to see if the Cepheid distance values were being biased by other nearby stars interfering with our brightness measurements (which was one theory of why we might be seeing this divergence), but the result was that no, we actually had done a good job of adjusting for that and our distance measurements seem to be working correctly -- so the "crisis" continues.

Footnote: I dislike the term "crisis" because it implies that there's an emergency, that our whole understanding of the universe and physics itself is in danger of collapse -- which is of course absurd. As it's said, scientific progress very rarely sounds like "Eureka! I have found it!"; instead it usually sounds like "Huh. That's weird..." The fact that we have two measurements that disagree is not a terrible thing (however frustrating it might be for the theorists), because it's a signpost that shows us that there's something we should study right over there.


---

