JWST - 100 Times more powerful than Hubble?

[Bannerdog]

Numerous publications have stated that JWST is "100 times more powerful than Hubble".

What does that mean?  JWST has a surface area about 6.5 times that of Hubble.

Is there any objective basis to the "100 times", or is that just a quasi-meaningless phrase, intended to convey JWST's capabilities?

And,  why is the JWST so frequently compared to Hubble, rather than to the Herschel Space Observatory?

JWST and Herschel are/were both infrared telescopes, operating at Sun-Earth L2, while Hubble is mainly a visible light telescope, in LEO.

Thanks

[michael8554]

The media need a "wow" figure to impress the masses.

It images much further into the IR, maybe that's the comparison.

Michael

[vlaiv]

I think we can easily come up with x100 figure.

You say that light gathering surface is ~x6.5, although Wiki gives ~ x5.61 (25.4m2 vs 4.525m2). Then there is part of spectrum that it covers - HST covers something like 1.5µm range (UV/Vis/NIR) while JWST covers about 28µm range (0.6µm-28.3µm to be precise).

There ya go - 5.61 * 28 / 1.5 = 104.72

104.72 - more "photon gathering capability"

[Stu]

18 minutes ago, vlaiv said:

I think we can easily come up with x100 figure.

You say that light gathering surface is ~x6.5, although Wiki gives ~ x5.61 (25.4m2 vs 4.525m2). Then there is part of spectrum that it covers - HST covers something like 1.5µm range (UV/Vis/NIR) while JWST covers about 28µm range (0.6µm-28.3µm to be precise).

There ya go - 5.61 * 28 / 1.5 = 104.72

104.72 - more "photon gathering capability"

Bingo! Simples when you have Vlaiv on the team 👍

[Solar B]

It may only (if that’s appropriate) have 💯 

more times of resolution capability ,

However the sensitivity of the equipment it possesses is on an altogether another level.

Brian 

 

[Lee_P]

9 hours ago, Bannerdog said:

And,  why is the JWST so frequently compared to Hubble, rather than to the Herschel Space Observatory?

JWST and Herschel are/were both infrared telescopes, operating at Sun-Earth L2, while Hubble is mainly a visible light telescope, in LEO.

Thanks

The general public have heard about Hubble, and know it's good. Herschel hasn't entered the public consciousness in the same way. 

I wrote this article (aimed at children) and flagged the fact that Webb will be much further away than Hubble 😛

 

Edited October 4, 2021 by Lee_P

[oscar_camilleri]

Its for the same reason you see statements saying " the universe is at your grasp" or " marvel at the countless galaxies, nebulae ,etc"" on boxes of cheap £25 rubbish toy telescopes which are barely good enough to show the moon. 

Because statements like these make the product , or news or whatever sell more.

[Lee_P]

1 hour ago, oscar_camilleri said:

Its for the same reason you see statements saying " the universe is at your grasp" or " marvel at the countless galaxies, nebulae ,etc"" on boxes of cheap £25 rubbish toy telescopes which are barely good enough to show the moon. 

Because statements like these make the product , or news or whatever sell more.

I think this is quite a cynical comparison, and I’d like to explain why.

Any reputable journalists writing about JWST will be getting information from fact sheets produced by the JWST’s press department. Members of this department are professional communicators, not tabloid hacks, and it’s their job to raise public awareness of JWST. The statement given by the OP, “JWST is 100 times more powerful than Hubble”, will have gone through a lot of approval stages, including being checked by scientists working on JWST, before being given to journalists to re-use. And, as vlaiv aptly demonstrated, the maths behind the statement is sound. Sure, it’s a simplification, but that’s the nature of science communication – you’re often talking to a lay audience after all. And you need good sound-bites to get any coverage in the mass media.

This is very different to the dubious statements printed on the side of cheap telescope boxes, where the motive is all about shifting units and making money, and the truth is bent to breaking point.

[oscar_camilleri]

45 minutes ago, Lee_P said:

I think this is quite a cynical comparison, and I’d like to explain why.

Any reputable journalists writing about JWST will be getting information from fact sheets produced by the JWST’s press department. Members of this department are professional communicators, not tabloid hacks, and it’s their job to raise public awareness of JWST. The statement given by the OP, “JWST is 100 times more powerful than Hubble”, will have gone through a lot of approval stages, including being checked by scientists working on JWST, before being given to journalists to re-use. And, as vlaiv aptly demonstrated, the maths behind the statement is sound. Sure, it’s a simplification, but that’s the nature of science communication – you’re often talking to a lay audience after all. And you need good sound-bites to get any coverage in the mass media.

This is very different to the dubious statements printed on the side of cheap telescope boxes, where the motive is all about shifting units and making money, and the truth is bent to breaking point.

Hi Lee 

I can appreciate that a reputable journalist would ensure that his facts are straight, however please be aware that its the editor who finally has the privilege of deciding the headline on an article , and whilst press articles about the JWST would have been fact checked by countless scientists, it will be the editors intention to big it up as much as they can to make sure they get more hits on the article or sell more copies of the relevant publication. 

lets just say that a particular person is running for presidency and he lets out that when he was a kid he nicked a chocolate bar from his local shop once.  To an editor the headline " Shoplifter has a chance to run for president"" will attract more views than " John Smith is a candidate for the next presidential election". Technically the shoplifter part is true, but then again it is taking liberties with the available information to make it sound more interesting to the casual viewer than it might actually be.

So in simple terms its just clickbait , yes the maths behind the JWST will most probably mean that it is indeed 100x more powerful than the Hubble, however the statement is subject to interpretation ( how is it 100x more powerful ? is it visually more powerful ? etc? ) and was purely selected to get more people interested or curious enough to read the article 

[Lee_P]

56 minutes ago, oscar_camilleri said:

Hi Lee 

I can appreciate that a reputable journalist would ensure that his facts are straight, however please be aware that its the editor who finally has the privilege of deciding the headline on an article , and whilst press articles about the JWST would have been fact checked by countless scientists, it will be the editors intention to big it up as much as they can to make sure they get more hits on the article or sell more copies of the relevant publication. 

lets just say that a particular person is running for presidency and he lets out that when he was a kid he nicked a chocolate bar from his local shop once.  To an editor the headline " Shoplifter has a chance to run for president"" will attract more views than " John Smith is a candidate for the next presidential election". Technically the shoplifter part is true, but then again it is taking liberties with the available information to make it sound more interesting to the casual viewer than it might actually be.

So in simple terms its just clickbait , yes the maths behind the JWST will most probably mean that it is indeed 100x more powerful than the Hubble, however the statement is subject to interpretation ( how is it 100x more powerful ? is it visually more powerful ? etc? ) and was purely selected to get more people interested or curious enough to read the article 

For context about my viewpoints, I should flag that science journalism is my profession. (This is me). I’ve worked in the press teams for Hubble, ESA, ESO, and the IAU – and have covered a lot of astronomy stories as a journalist too. Also, I recently organised a meeting between scientists working on JWST and science communication / public engagement professionals, to help both groups with conveying to the public just exactly what JSWT is and does. So, this is kinda my thing.

You seem to have taken objection with the fact that a headline was selected to get people interested enough to read the article. That’s exactly what a headline should do! I’d agree that it was clickbait if it was completely outlandish – “new space telescope used to communicate with aliens!” But the fact flagged isn’t that. Again, vlaiv showed with simple maths that it’s accurate. I grant you that the fact on its own certainly benefits from clarification, and ideally that would be supplied too. But it wouldn’t fit into a headline. (Also, we’re assuming that the “100 times” was actually a headline).

I also do training for science communicators, and teach the difference between accuracy and precision. If something is accurate, it’s true. If something is precise, it’s very specific. “Pi is three and a bit” is accurate but not precise. “Pi is 4.648265” is precise but not accurate. If you have experience in an area, such as we all have in astronomy, we tend to want our information to be accurate and precise. But when communicating to a lay audience, accuracy is important; precision less so. This can be a tough concept to get your head around, but it’s useful to know. The “100 times” fact is accurate but not precise, which may be why you don’t like it, but a lay audience would likely be fine with it.

In short, I have no objections with the two points the OP raised; specifically, comparing the JWST to Hubble, or the “100 times” fact. The wording may not appeal to you, but I doubt you’re the target audience.

Interesting discussion by the way

 

[oscar_camilleri]

21 minutes ago, Lee_P said:

For context about my viewpoints, I should flag that science journalism is my profession. (This is me). I’ve worked in the press teams for Hubble, ESA, ESO, and the IAU – and have covered a lot of astronomy stories as a journalist too. Also, I recently organised a meeting between scientists working on JWST and science communication / public engagement professionals, to help both groups with conveying to the public just exactly what JSWT is and does. So, this is kinda my thing.

You seem to have taken objection with the fact that a headline was selected to get people interested enough to read the article. That’s exactly what a headline should do! I’d agree that it was clickbait if it was completely outlandish – “new space telescope used to communicate with aliens!” But the fact flagged isn’t that. Again, vlaiv showed with simple maths that it’s accurate. I grant you that the fact on its own certainly benefits from clarification, and ideally that would be supplied too. But it wouldn’t fit into a headline. (Also, we’re assuming that the “100 times” was actually a headline).

I also do training for science communicators, and teach the difference between accuracy and precision. If something is accurate, it’s true. If something is precise, it’s very specific. “Pi is three and a bit” is accurate but not precise. “Pi is 4.648265” is precise but not accurate. If you have experience in an area, such as we all have in astronomy, we tend to want our information to be accurate and precise. But when communicating to a lay audience, accuracy is important; precision less so. This can be a tough concept to get your head around, but it’s useful to know. The “100 times” fact is accurate but not precise, which may be why you don’t like it, but a lay audience would likely be fine with it.

In short, I have no objections with the two points the OP raised; specifically, comparing the JWST to Hubble, or the “100 times” fact. The wording may not appeal to you, but I doubt you’re the target audience.

Interesting discussion by the way

 

Hi Lee, please note that I haven't taken offence with headline or insinuate that you trying to mislead anyone. I think we did get a bit lost in translation here. 

My point was that like any other headline its there to catch your attention or pique your interest.