James Webb Telescope

[Trebuchet]

There was a great example of a design allowing a single failure to cause the failure of redundant systems in United Flight 232 that crashed in Sioux City Iowa in 1989. This was a Lockheed L1101, a Tri jet (two engines under the wings, one engine in the tail). .

[pedant mode] DC-10 [/pedant mode]
McDonnell Douglas afterward did considerable research into controlling airplanes with engines alone. But it died after the Boeing merger.

 

[smartcooky]

[pedant mode] DC-10 [/pedant mode]
McDonnell Douglas afterward did considerable research into controlling airplanes with engines alone. But it died after the Boeing merger.

Oh yeah... I often get those two mixed up

L1011 "in the tail"
DC-10 "on the tail"

 

[smartcooky]

I'm glad I got caught up here after the fact. I think waiting through each tensioning would have been stressful. I can only imagine what it must be like for the engineers!

I will try to check in on main mirror deployment, though. (Friday?)

Mirror deployment is in three steps

1. Secondary mirror
Coverage begins Wednesday, Jan 5, 9:45 am EST on https://www.nasa.gov/nasalive

2. Primary mirror port section
No overage announcement yet

3. Primary mirror starboard section
TBD Friday, Jan 7 on https://www.nasa.gov/nasalive

 

[smartcooky]

Latest cold side temperatures

Primary Mirror: -147°C (down from -132°C yesterday)
Instrument Radiator: -197°C (down from -194°C yesterday)

 

[Puppycow]

While we are waiting for the secondary mirror to deploy, here's a little 10-minute video that discusses the possibility of Webb discovering life on exoplanets:


https://www.youtube.com/watch?v=06jlaYGBh08

It has instruments that could potentially analyze the chemical components in the atmosphere of a transiting exoplanet using transmission spectroscopy. If we happen to find any planets with atmospheres similar to our own, that would be strong evidence that something biological is happening on that planet. Photosynthesis, for example.

 

[smartcooky]

Secondary mirror is successfully deployed

 

[Samson]

While we are waiting for the secondary mirror to deploy, here's a little 10-minute video that discusses the possibility of Webb discovering life on exoplanets:


https://www.youtube.com/watch?v=06jlaYGBh08

It has instruments that could potentially analyze the chemical components in the atmosphere of a transiting exoplanet using transmission spectroscopy. If we happen to find any planets with atmospheres similar to our own, that would be strong evidence that something biological is happening on that planet. Photosynthesis, for example.

Failure to find such evidence will be a significant setback to the argument from incredulity about all those trillions of prospects.

 

[Samson]

Secondary mirror is successfully deployed

Thanks for commentary smartcooky.
Are we in the home stretch?

 

[Steve]

Failure to find such evidence will be a significant setback to the argument from incredulity about all those trillions of prospects.

I disagree.

 

[shemp]

While we are waiting for the secondary mirror to deploy, here's a little 10-minute video that discusses the possibility of Webb discovering life on exoplanets:


https://www.youtube.com/watch?v=06jlaYGBh08

It has instruments that could potentially analyze the chemical components in the atmosphere of a transiting exoplanet using transmission spectroscopy. If we happen to find any planets with atmospheres similar to our own, that would be strong evidence that something biological is happening on that planet. Photosynthesis, for example.

I strongly suspect that, as an "intelligent" civilization, there's a strong likelihood that we are presently alone in our galaxy. I'm pretty convinced that most "intelligent" civilizations quickly become victims of their own success, and that those that survive this probably turn inwards and never leave their planet or solar system; the difficulty of interstellar travel for flesh-and-blood beings is too great. If we do encounter anything "intelligent" it will probably be robots or nanoprobes. But I'm betting we don't. However, finding solid evidence of single-cell or "non-intelligent" multi-cell life would still be an astonishing achievement. I hope I live long enough to see it.

 

[slyjoe]

Thanks for commentary smartcooky.
Are we in the home stretch?

Sort of. The deployment steps remaining are:
1. Aft Radiator deployment
2. Port Primary Mirror wing deployed
3. Starboard Primary Mirror wing deployed

Webb would then be considered "fully deployed", but each of 18 primary mirror segments has to be moved out of its launch configuration. Then comes the L2 insertion burn.

Then I would consider it done.

 

[Puppycow]

Failure to find such evidence will be a significant setback to the argument from incredulity about all those trillions of prospects.

I'm not sure I quite understand what you mean by that. The argument from incredulity about what exactly? The so-called "Fermi Paradox"?

I strongly suspect that, as an "intelligent" civilization, there's a strong likelihood that we are presently alone in our galaxy. I'm pretty convinced that most "intelligent" civilizations quickly become victims of their own success, and that those that survive this probably turn inwards and never leave their planet or solar system; the difficulty of interstellar travel for flesh-and-blood beings is too great. If we do encounter anything "intelligent" it will probably be robots or nanoprobes. But I'm betting we don't. However, finding solid evidence of single-cell or "non-intelligent" multi-cell life would still be an astonishing achievement. I hope I live long enough to see it.

I'm pretty much in agreement with you about that. I don't expect Webb to find signs of intelligent technological extraterrestrials, but would be pleasantly surprised if it did. I do hold out a slim hope that it might find signs of extraterrestrial life of some sort. Just not other people like us. Maybe there's a planet of dinosaurs or who knows what within our galactic neighborhood. Not that we would know what form that life would take. But an oxygen-rich atmosphere would point to the presence of photosynthesizing plants. That would be amazing if we found that.

 

[Samson]

I'm not sure I quite understand what you mean by that. The argument from incredulity about what exactly? The so-called "Fermi Paradox"?



I'm pretty much in agreement with you about that. I don't expect Webb to find signs of intelligent technological extraterrestrials, but would be pleasantly surprised if it did. I do hold out a slim hope that it might find signs of extraterrestrial life of some sort. Just not other people like us. Maybe there's a planet of dinosaurs or who knows what within our galactic neighborhood. Not that we would know what form that life would take. But an oxygen-rich atmosphere would point to the presence of photosynthesizing plants. That would be amazing if we found that.

Incredulity that we could be alone. But look at one common ancestor on a perfect planet for life.
Trillions of places yet it occurred exactly once with 4 amino acids.

 

[smartcooky]

Incredulity that we could be alone. But look at one common ancestor on a perfect planet for life.
Trillions of places yet it occurred exactly once (that we have found so far) with 4 amino acids.

FTFY

 

[Samson]

FTFY

Trillions of spots on THIS planet

 

[smartcooky]

Trillions of spots on THIS planet

 

[Puppycow]

For all we know it may have happened many times, but only one line survived the early days. The one that evolved into the fittest forms in the beginning. The others were outcompeted and went extinct. Evolution is an arms races.

 

[Samson]

Yep
Trilions of primordial ponds or whatever but just one "pond" that combiñed into that universal ancestor.
Trillions on planet Earth is simple math.

 

[Ziggurat]

For all we know it may have happened many times, but only one line survived the early days. The one that evolved into the fittest forms in the beginning. The others were outcompeted and went extinct. Evolution is an arms races.

If a new line of life started on earth again today, would we even know? I suspect not. I suspect it would quickly get snuffed out by existing life which is already much more optimized. So it’s even possible that the process continues to this day, but without effect anymore.

 

[RecoveringYuppy]

For all we know it may have happened many times, but only one line survived the early days. The one that evolved into the fittest forms in the beginning. The others were outcompeted and went extinct. Evolution is an arms races.

And for all we know it wasn't one line all the way back. We are pretty certain that Eukarya (that's basically all life large enough to see and even some you can't see) was the product of a merger of lines. Bacteria have lateral gene transfer which doesn't make for well defined lines. Whatever came before might be the same. I certainly don't expect that all the chemicals of the simplest life form we know of now could have been produced simultaneously in one decisive reaction.