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What is Webb observing now?

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Re: What is Webb observing now?

#61

Post by jajko »

bobbob1921 wrote: post #55
RajT88 wrote: post #36

Earlier quoted context omitted.

“Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space.” Per wikipedia: The observable universe contains as many as an estimated 2 trillion galaxies and, overall, as many as an estimated 10^24 stars – more stars (and earth-like planets) than all the grains of beach sand on planet Earth.…

I have always found the analogy all the grains of sand on the beaches of earth to be something that helps accurately convey large numbers to myself and others. Somethings I’ve always wondered about this analogy: 1 – at what depth are they referring to, i.e. if you’re at a beach and dig down two feet you’re still Coming in contact with sand (and grains of sand). Do these count also? 2 – if you wade out into the ocean…

As per parents numbers, its way way more than all the grains of sand anywhere on Earth.

Re: What is Webb observing now?

#62

Post by tayo42 »

basil-rash wrote: post #46
ianburrell wrote: post #45

Earlier quoted context omitted.

Webb won't ever provide a recent view since the images belong to the research group and are only made public when the results are released. Also, Webb can't provide a video feed since it is taking long exposures, and probably only sends results back to Earth when image is finished. The images are in the infrared and only look good when processed.

> only look good when processed Ehh. I personally can’t stand all the post processing folks love to make their results look “magazine ready”. I think the most minimal transformation possible to map the data into 0xRRGGBB would look the best, ideally with a simple standardized algorithm that doesn’t allow for any “artistic license”.

That's what they do already. Each wavelength that comes from different atoms gets a different color.

Re: What is Webb observing now?

#63

Post by basil-rash »

BurningFrog wrote: post #52
basil-rash wrote: post #46

Earlier quoted context omitted.

> only look good when processed Ehh. I personally can’t stand all the post processing folks love to make their results look “magazine ready”. I think the most minimal transformation possible to map the data into 0xRRGGBB would look the best, ideally with a simple standardized algorithm that doesn’t allow for any “artistic license”.

Everything Webb sees is infrared light, which is invisible to humans, so you have to do some processing to make them look good.

Yes, that is what the map does. Convert values from one domain to another. That is the purpose of mapping. The point is to make it as simple and consistent as possible.

Re: What is Webb observing now?

#64

Post by basil-rash »

sneak wrote: post #50
basil-rash wrote: post #46

Earlier quoted context omitted.

> only look good when processed Ehh. I personally can’t stand all the post processing folks love to make their results look “magazine ready”. I think the most minimal transformation possible to map the data into 0xRRGGBB would look the best, ideally with a simple standardized algorithm that doesn’t allow for any “artistic license”.

I encourage you to try some raw file photography and processing. A bitstream from a sensor is not an image and there is no “correct” or “accurate” image from a captured signal. Think of it like using a linear or log scale for a chart axis: neither is “more correct”, neither is taking “artistic license”.

Poor example, given many photographs shoot raw precisely because it gives them more room for artistic decisions in post. Obviously the standardized algorithm should have basic factors like gamma and general phase shifting incorporated, but the idea of being able to adjust the maps delta between arbitrary adjacent inputs is of questionable benefit to the community. It’s akin to adjusting levels via curves with many points, and it’d be incorrect to say folks are taking artistic liberties when they do that.

Re: What is Webb observing now?

#65

Post by devwastaken »

__egb__ wrote: post #59
ianburrell wrote: post #45

Earlier quoted context omitted.

Webb won't ever provide a recent view since the images belong to the research group and are only made public when the results are released. Also, Webb can't provide a video feed since it is taking long exposures, and probably only sends results back to Earth when image is finished. The images are in the infrared and only look good when processed.

To expand on this, Webb uses the Deep Space Network (DSN) to communicate with us. It can’t stream data back 24/7. There are generally three contacts per day each lasting a few hours, but I believe this is dependent on the scheduling of contacts with other missions that also use the DSN. Also, the science data that is sent back is a stream of packets from all the data that was taken since the last contact. The packets…

Is it possible to put an antenna on a roof and capture this data?

Re: What is Webb observing now?

#66

Post by Retric »

devwastaken wrote: post #65
__egb__ wrote: post #59

Earlier quoted context omitted.

To expand on this, Webb uses the Deep Space Network (DSN) to communicate with us. It can’t stream data back 24/7. There are generally three contacts per day each lasting a few hours, but I believe this is dependent on the scheduling of contacts with other missions that also use the DSN. Also, the science data that is sent back is a stream of packets from all the data that was taken since the last contact. The packets…

Is it possible to put an antenna on a roof and capture this data?

Some of it, though no single location is always able to point in the right direction.

The signal is also really weak coming from 30x the distance to geostationary orbit and setup for the DSN, so you need a large parabolic antenna.

https://www.nasa.gov/directorates/somd/space-communications-...

Re: What is Webb observing now?

#67

Post by Tagbert »

wang_li wrote: post #56
_trampeltier wrote: post #49

Earlier quoted context omitted.

IR pictures would be not RGB, just black/white (or whatever palette you like). But yes, it would be possible. For ex. from Flir Thermal cameras, you also can output the image just as spreadsheet. You can even choose the values as temperature (which is calculated) or just as energy (what the sensor gets).

Light isn’t RGB. We just receptors that react to certain wavelengths. I suspect the sensors on the telescope have a range of wavelengths they are sensitive to. It would be a straightforward translation to shift it to map it to the visible spectrum without varying the relative intensities to accentuate certain aspects of the image.

The IR may be in a very narrow band. The visible wavelengths have different colors because there are a range of wavelengths that correspond to different cones in our eyes that roughly match red:green:blue sensors. If you shift the IR frequency up into the visible range, you would just get a luminance image (like grayscale) centered on one visible wavelength like red.

False color imaging sometimes applies colors to different luminance levels or sometimes it takes multiple images at different wavelengths and assigns RGB values to each of those wavelengths. The results are informative but require some editorial / aesthetic decisions to produce the best results.

Re: What is Webb observing now?

#68

Post by Tagbert »

asdff wrote: post #51
basil-rash wrote: post #46

Earlier quoted context omitted.

> only look good when processed Ehh. I personally can’t stand all the post processing folks love to make their results look “magazine ready”. I think the most minimal transformation possible to map the data into 0xRRGGBB would look the best, ideally with a simple standardized algorithm that doesn’t allow for any “artistic license”.

It would be nice if they stopped with the false color, and just scaled it to whatever color an astrounaut might see from that point of view.

just bring it up in an editor and drop the saturation to zero. That will take it back to a luminance map image.

Re: What is Webb observing now?

#69

Post by RajT88 »

jajko wrote: post #61
bobbob1921 wrote: post #55

Earlier quoted context omitted.

I have always found the analogy all the grains of sand on the beaches of earth to be something that helps accurately convey large numbers to myself and others. Somethings I’ve always wondered about this analogy: 1 – at what depth are they referring to, i.e. if you’re at a beach and dig down two feet you’re still Coming in contact with sand (and grains of sand). Do these count also? 2 – if you wade out into the ocean…

As per parents numbers, its way way more than all the grains of sand anywhere on Earth.

I started doing the math based on some assumptions, but this guy came up with 500 quadrillion grains:

https://science-atlas.com/faq/how-many-grains-of-sand-are-th...

Which is 5x10^17 versus 10^24.

Way more stars!

Re: What is Webb observing now?

#70

Post by iraqmtpizza »

shigawire wrote: post #28
iraqmtpizza wrote: post #26

Earlier quoted context omitted.

science is just a spinoff of philosophy which was religiously motivated. what kind of drug-induced state do you have to be in to think that the Romans would have been flying around the Earth if only everyone thousands of years prior was magically a self-absorbed nihilist

Rude phrasing, you shouldn't do that.

I thought that atheists believed that politics and religion have caused most if not all wars in history?

Guess what was the impetus for developing technology? War. i.e. politics by other means. Guess that Stalin developed technology for the love of the game, though. Not for war or politics or anything.

Or are we saying that religion and politics have moderated the impulse to war? i.e. in an ancient atheist world, war would have been much more furious and necessary for survival, so the pressure to develop technology would have been much greater than it was with all those pacifist monks running around spoiling everyone's armed conflict fun with their woo-woo? -- Maybe ICBMs should have been invented around the time that Byzantium was founded

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