No solar visor on helmet ON THE MOON

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No solar visor on helmet ON THE MOON
« on: April 17, 2014, 03:15:09 PM »
How is this possible without burning his eyes out? Forward to 7:20
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Helmet
Besides covering a spacewalker's head, the helmet has a Vent Pad. This pad directs oxygen from the Primary Life Support Subsystem and Hard Upper Torso to the front of the helmet. The helmet keeps the oxygen at the right pressure around the head. The main part of the helmet is the clear plastic bubble.

The bubble is covered by the Extravehicular Visor Assembly. The visor is coated with a thin layer of gold that filters out the sun's harmful rays. The visor also protects the spacewalker from extreme temperatures and small objects that may hit the spacewalker.
http://www.nasa.gov/audience/foreducators/spacesuits/home/clickable_suit_nf.html
« Last Edit: April 17, 2014, 03:37:44 PM by EarthIsASpaceship »

Re: No solar visor on helmet ON THE MOON
« Reply #1 on: April 17, 2014, 04:03:54 PM »
How is this possible without burning his eyes out? Forward to 7:20
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Helmet
Besides covering a spacewalker's head, the helmet has a Vent Pad. This pad directs oxygen from the Primary Life Support Subsystem and Hard Upper Torso to the front of the helmet. The helmet keeps the oxygen at the right pressure around the head. The main part of the helmet is the clear plastic bubble.

The bubble is covered by the Extravehicular Visor Assembly. The visor is coated with a thin layer of gold that filters out the sun's harmful rays. The visor also protects the spacewalker from extreme temperatures and small objects that may hit the spacewalker.
http://www.nasa.gov/audience/foreducators/spacesuits/home/clickable_suit_nf.html

Good question, and I think I might have a satisfactory answer for you: the intensity of sunlight in space at 1 AU from the sun is a lot lower than you might expect. At 1 AU from the sun, the amount of energy transmitted by sunlight to a surface that is perpendicular to the incoming rays is about 1.4 kW per square meter. To put this in perspective, Class 3 welding shields can protect a welder's eyes from most of the light given off by a welding arc flash (highly dangerous to your eyes), and these shields are rated for blocking up to 1,000 kW per square meter. That means that at the typical distance a welder would be viewing an arc flash, if he wasn't wearing his shield, his eyes would be absorbing more than 700 times more energy than an astronaut on the ISS or on the moon looking at the sun WITHOUT their visor. And since we know that observing arc flashes without eye protection will not instantly lead to blindness (though repeated exposure over time will cause damage), the astronauts don't seem to be at risk for going blind, even if they forget to put their visor down.
Those who have an excessive faith in their theories or in their ideas are not only poorly disposed to make discoveries, but they also make very poor observations.
Claude Bernard, 1865

Re: No solar visor on helmet ON THE MOON
« Reply #2 on: April 18, 2014, 01:59:59 AM »
Who the hell told you that the sun's radiation can "burn out your eyes" in no atmosphere? Seriously, I wanna know!

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Son of Orospu

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Re: No solar visor on helmet ON THE MOON
« Reply #3 on: April 18, 2014, 04:21:31 AM »
Are you serious? 

Quote
The outer sun visor is made from a polycarbonate plastic and coated with a thin layer of gold. This combination gives complete protection to the astronaut. Why? Your eyes can focus both visible and near IR light onto your retina equally well. Your eye has visible receptors but not IR ones. When intense visible light hits these receptors, the receptors transmit information letting you know that this is painful and will cause damage if you don’t either close them or look away. On the other hand, without IR receptors, you wouldn’t realize that your eye was being “burned” with an intense IR source. Therefore, astronauts need IR protection from intense sunlight above the earth atmosphere.
« Last Edit: April 18, 2014, 04:56:07 AM by jroa »

Re: No solar visor on helmet ON THE MOON
« Reply #4 on: April 18, 2014, 05:11:24 AM »
Who the hell told you that the sun's radiation can "burn out your eyes" in no atmosphere? Seriously, I wanna know!

Are you serious? 

Quote
The outer sun visor is made from a polycarbonate plastic and coated with a thin layer of gold. This combination gives complete protection to the astronaut. Why? Your eyes can focus both visible and near IR light onto your retina equally well. Your eye has visible receptors but not IR ones. When intense visible light hits these receptors, the receptors transmit information letting you know that this is painful and will cause damage if you don’t either close them or look away. On the other hand, without IR receptors, you wouldn’t realize that your eye was being “burned” with an intense IR source. Therefore, astronauts need IR protection from intense sunlight above the earth atmosphere.

Jroa: Your last post was in response to Donk3y's question about who said that an astronaut's eyes would be burned out by the sun, right?

If so, I think you have drastically misunderstood the line you quoted where it is said that their eyes would be "“burned” with an intense IR source." This line doesn't follow the spirit of the question being asked in the OP - EarthIsASapceship was describing an intense and acuity destructive effect of the sun's light on the eyes of an astronaut , while the line you quoted was not making such a dramatic statement. Your quote was referring to the effect of infrared radiation on the retina and how the damage to the eyes can go unnoticed by the observer since our photoreceptors are not sensitive to this spectrum. IR actually caries less energy per photon than other higher frequency photons, with photons in the UV range having the most energy and thus being the most dangerous (see my welding arc flash statement above). Also, the sun emits most of its light outside of the IR spectrum, so only minimal protection (e.g. gold tinted visors) are needed to protect from IR alone.
Those who have an excessive faith in their theories or in their ideas are not only poorly disposed to make discoveries, but they also make very poor observations.
Claude Bernard, 1865

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Re: No solar visor on helmet ON THE MOON
« Reply #5 on: April 18, 2014, 05:17:54 AM »
Yes, but you are forgetting about the UV light that the light emits. 

Re: No solar visor on helmet ON THE MOON
« Reply #6 on: April 18, 2014, 05:24:59 AM »
Yes, but you are forgetting about the UV light that the light emits.

How long do you think you have to wait until your eyes actually start burning? I think you're having the same misconception the OP is having, that your eyes would instantly burn in flames... *facepalm*

And no, they don't burn... They get damaged over long periods of time, but they don't burn, as in, they don't go up in flames...
« Last Edit: April 18, 2014, 05:36:15 AM by Donk3y »

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sceptimatic

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Re: No solar visor on helmet ON THE MOON
« Reply #7 on: April 18, 2014, 05:30:34 AM »
Yes, but you are forgetting about the UV light that the light emits.

How long do you think you have to wait until your eyes actually start burning[/n]? I think you're having the same misconception the OP is having, that your eyes would instantly burn in flames... *facepalm*

And no, they don't burn... They get damaged over long periods of time, but they don't burn, as in, they don't go up in flames...
Earthisaspaceship isn't saying his eyes would set on fire. She's saying the radiation would burn out his eyes, meaning he would be rendered blind. You know what she meant.

Re: No solar visor on helmet ON THE MOON
« Reply #8 on: April 18, 2014, 05:39:40 AM »
Yes, but you are forgetting about the UV light that the light emits.

How long do you think you have to wait until your eyes actually start burning[/n]? I think you're having the same misconception the OP is having, that your eyes would instantly burn in flames... *facepalm*

And no, they don't burn... They get damaged over long periods of time, but they don't burn, as in, they don't go up in flames...
Earthisaspaceship isn't saying his eyes would set on fire. She's saying the radiation would burn out his eyes, meaning he would be rendered blind. You know what she meant.

There are the words "burning your eyes out" and "damaging your eyes" for a reason, don't you think?
And yes, he does damage his eyes, but not to the extent the OP is assuming. I'll just quote theodorus here:

Quote from: TheodorusOfSamos
...To put this in perspective, Class 3 welding shields can protect a welder's eyes from most of the light given off by a welding arc flash (highly dangerous to your eyes), and these shields are rated for blocking up to 1,000 kW per square meter. That means that at the typical distance a welder would be viewing an arc flash, if he wasn't wearing his shield, his eyes would be absorbing more than 700 times more energy than an astronaut on the ISS or on the moon looking at the sun WITHOUT their visor. And since we know that observing arc flashes without eye protection will not instantly lead to blindness (though repeated exposure over time will cause damage), the astronauts don't seem to be at risk for going blind, even if they forget to put their visor down.

Re: No solar visor on helmet ON THE MOON
« Reply #9 on: April 18, 2014, 05:53:27 AM »
Yes, but you are forgetting about the UV light that the light emits.

No, I didn't forget about UV light from the sun, I was just addressing your last post which only concerned the hazards of IR light. For UV light and the visual spectrum of light (and IR for that matter), see my comment above about the average energy transmitted by sunlight to an object in space near earth, the energy imparted on an UNPROTECTED astronaut's eyes would be 1.4 kW per square meter. This is at least 700 time LESS energy transmitted than that from a welding arc flash, which is at least 1,000 kW per square meter. And because short term exposure to the light from a welding arc is not immediately destructive to the UNPROTECTED eye, we can infer that the light from the sun will be safe for at least short term exposure. Obviously, eye protection in  space would be advisable, but not absolutely necessary.
Those who have an excessive faith in their theories or in their ideas are not only poorly disposed to make discoveries, but they also make very poor observations.
Claude Bernard, 1865

Re: No solar visor on helmet ON THE MOON
« Reply #10 on: April 18, 2014, 06:06:28 AM »
In addition to that, the transparent part of the helmet also absorbs and reflects some of the IR, VIZ and UV light...

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Re: No solar visor on helmet ON THE MOON
« Reply #11 on: April 18, 2014, 06:08:14 AM »
I have had both welding arc skin burns and welding arc blindness.  I can assure you, you never want to go through the blindness part.  I got these in short amounts of time while not using the proper PPE (Personal Protective Equipment). 

How much UV is coming out of an arc welding stick compared to the UV hitting your eyes while you are in your yard? 

Re: No solar visor on helmet ON THE MOON
« Reply #12 on: April 18, 2014, 06:20:19 AM »
I have had both welding arc skin burns and welding arc blindness.  I can assure you, you never want to go through the blindness part.  I got these in short amounts of time while not using the proper PPE (Personal Protective Equipment). 

How much UV is coming out of an arc welding stick compared to the UV hitting your eyes while you are in your yard?

I too have suffered temporary blindness from welding arc flash, my father is a welder by trade and he used to do a lot of work on cars and such at home and on at least two occasions I didn't listen to him and forgot to but on eye protection when he was welding. I agree, it is not fun, but it is also temporary, my eyes weren't burned out like the OP described, and they weren't permanently damaged from what I and my optometrist can tell. AND because the light from the sun is at least 700 time WEAKER in earth orbit than that of a welding arc, an astronaut's eyes wouldn't even come close to being "burned out".

To answer your second question about how much UV light from the sun reaches your eyes here on earth, see the chart listed below  the yellow area indicates the radiation that reaches you WITHOUT an atmosphere, and the red indicates what you actually get at sea level here on earth.
Those who have an excessive faith in their theories or in their ideas are not only poorly disposed to make discoveries, but they also make very poor observations.
Claude Bernard, 1865

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Starman

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Re: No solar visor on helmet ON THE MOON
« Reply #13 on: April 18, 2014, 06:26:02 AM »
Nice chart and I understand it completely . They will not have a clue what it means.

Re: No solar visor on helmet ON THE MOON
« Reply #14 on: April 18, 2014, 06:36:10 AM »
Jroa: sorry, I forgot to make the direct comparison between the irradiance from UV light given off by a welding arc flash vs the sun at sea level. As I referenced in the first response to the OP, most of the energy emitted by a welding arc in the form of light is carried by UV radiation, so UV would be responsible for a large fraction of the 1,000+ kW per square meter transmitted to the human eye. From the chart I posted, we can see that UV light transmits of energy from the sun to your eye at sea level in earth's atmosphere is at most about 0.4 kW per square meter at sea level within earths atmosphere.

Notes: the Y axis of the graph I posted is normalized to the wavelength of the emitted light, so to get a value for kW per square meter for UV light, you need to multiply the value of the y axis by the wavelength you are interested in and divide that by 1000 to convert W to kW. To be as generous to you as possible, I took that wavelength of low UV to give you the upper limit to the amount of UV that reaches your eye on earth - if we took higher UV wavelengths, we'll see that even less of that energy gets to you.
Those who have an excessive faith in their theories or in their ideas are not only poorly disposed to make discoveries, but they also make very poor observations.
Claude Bernard, 1865

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Re: No solar visor on helmet ON THE MOON
« Reply #15 on: April 18, 2014, 04:38:09 PM »
The whole point is that your eyes can not withstand direct sun light.  Not even after been filtered through the Earth's atmosphere, let alone getting it directly from the sun in outer space.  Think about it. 

Re: No solar visor on helmet ON THE MOON
« Reply #16 on: April 18, 2014, 04:51:02 PM »
The whole point is that your eyes can not withstand direct sun light.  Not even after been filtered through the Earth's atmosphere, let alone getting it directly from the sun in outer space.  Think about it.

is it bad in the short term? yea, of course, is it REALLY bad for an extended period of time? yea. Are you going to cause permanent, irreparable harm after a short amount of time? not likely, whether on earth, or in space.

Re: No solar visor on helmet ON THE MOON
« Reply #17 on: April 18, 2014, 05:28:11 PM »
How long do you think you have to wait until your eyes actually start burning? I think you're having the same misconception the OP is having, that your eyes would instantly burn in flames... *facepalm*

And no, they don't burn... They get damaged over long periods of time, but they don't burn, as in, they don't go up in flames...
No Donkey ass, it was a figure of speech.  I meant from radiation, not flames.

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Re: No solar visor on helmet ON THE MOON
« Reply #18 on: April 18, 2014, 05:30:14 PM »
How long do you think you have to wait until your eyes actually start burning? I think you're having the same misconception the OP is having, that your eyes would instantly burn in flames... *facepalm*

And no, they don't burn... They get damaged over long periods of time, but they don't burn, as in, they don't go up in flames...
No Donkey ass, it was a figure of speech.  I meant from radiation, not flames.
Radiation is a general term. Could you break it down for us?

Re: No solar visor on helmet ON THE MOON
« Reply #19 on: April 18, 2014, 05:36:00 PM »
Nice chart and I understand it completely . They will not have a clue what it means.
Can you be any more arrogant?   ::)

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Re: No solar visor on helmet ON THE MOON
« Reply #20 on: April 18, 2014, 05:37:13 PM »
Nice chart and I understand it completely . They will not have a clue what it means.
Can you be any more arrogant?   ::)
Explain me the radiation you are talking about.

Re: No solar visor on helmet ON THE MOON
« Reply #21 on: April 18, 2014, 05:39:05 PM »
Why should I?  You seem to know everything already. 

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Re: No solar visor on helmet ON THE MOON
« Reply #22 on: April 18, 2014, 05:47:06 PM »
Why should I?  You seem to know everything already.
You are like a typical conspiracy theorist. You take something like radiation and think it is deadly rays from space because you saw a few movies. You did not specify if it was IR, visible light, UV, x-ray or gamma rays. It makes a big difference. What you are really trying to say that the whole moon program was a fake because you were TOLD and BELIEVE that radiation from space will harm your eyes.

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Son of Orospu

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Re: No solar visor on helmet ON THE MOON
« Reply #23 on: April 18, 2014, 08:04:27 PM »
You seem like a typical denier.  No amount of evidence will ever convince you that your beliefs are wrong. 

Re: No solar visor on helmet ON THE MOON
« Reply #24 on: April 18, 2014, 08:08:12 PM »
You seem like a typical denier.  No amount of evidence will ever convince you that your beliefs are wrong.

Evidence isn't "we say it's so, so it's so"

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Son of Orospu

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Re: No solar visor on helmet ON THE MOON
« Reply #25 on: April 18, 2014, 08:10:23 PM »
But, that is what you seem to be saying. 

Re: No solar visor on helmet ON THE MOON
« Reply #26 on: April 18, 2014, 08:14:26 PM »
But, that is what you seem to be saying.

no, we're saying
1) people did experiments
2) peers of those people did experiments
3)????

46565445) We accept those answers

you say:
1) Someone 150 years ago, who claims to be a Dr, but was really just a snake oil salesman claims to have done some experiments
2) I'm short sighted and narrow minded and can only look past my eyeballs so I believe him
3) done!

Re: No solar visor on helmet ON THE MOON
« Reply #27 on: April 18, 2014, 11:04:59 PM »
How long do you think you have to wait until your eyes actually start burning? I think you're having the same misconception the OP is having, that your eyes would instantly burn in flames... *facepalm*

And no, they don't burn... They get damaged over long periods of time, but they don't burn, as in, they don't go up in flames...
No Donkey ass, it was a figure of speech.  I meant from radiation, not flames.

lol... It's not enough to damage their eyes on the long term... Not even enough to damage them short term. They removed their shield for less than 10 minutes and they didn't look directly at the sun.
But photon radiation is the least of their worries.
Here, watch these, maybe you might actually learn something...  ::)

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th3rm0m3t3r0

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Re: No solar visor on helmet ON THE MOON
« Reply #28 on: April 18, 2014, 11:17:19 PM »
Nice chart and I understand it completely . They will not have a clue what it means.
Why'd you have to tell us you understand it, and then instead of saying something relevant and pertinent to the graph, insult every FE enthusiasts' intelligence level?


I don't profess to be correct.
Quote from: sceptimatic
I am correct.

Re: No solar visor on helmet ON THE MOON
« Reply #29 on: April 28, 2014, 08:17:21 AM »
There is more than one visor, the protective visor and the sun visor.

"The protective visor is an ultraviolet-stabilized polycarbonate
shield which affords impact, micrometeoroid, and ultraviolet
ray protection.
It can be positioned anywhere between
the full-UP and full-DOWN positions and requires a force of
2 to 4 pounds for movement. A coating is added to the inner
surface of this assembly. The elastomer seal on the upper
surface of the stiffener prevents light passage between the
two visors. The protective visor can be lowered independently
of the sun visor,
but cannot be raised independently with the
sun visor in the DOWN position.

The inner surface of the polysulfone sun visor has a gold
coating which provides protection against light and reduces
heat gain within the helmet.
The visor can be positioned
anywhere between the full-UP and full-DOWN positions by exerting
a force of 2 to 4 pounds on the pull tabs. The sun
visor cannot be independently lowered unless the protective
visor is in the DOWN position, but it can be raised or lowered
independently when the center eyeshade is in the full-UP
position and the protective visor is in the DOWN position."

http://www.hq.nasa.gov/alsj/alsj-EMU1.pdf#page=92