The Sun is Invisible in space!!

originally posted by: GallopingFish
Ouch,

Im not pushing it or anything, I'm interested in other points of view. The dudes in the video are pretty serious..

Infact is anyone out there considering that maybe inside a star something is happening that we don't know about??

I sure as hell don't because I didn't go to middle school.

a reply to: Nyiah

Well they say a star is sustained nuclear fusion, the fact that we can't replicate this (though much time and effort has been spent trying to create a nuclear fusion reactor) means that indeed there is a lot happening that we don't know about. We have an idea of what's going on but we are far from mastery of the concept it appears. It's possible we've even made inaccurate presumptions about fusion that are limiting our understanding of it as well! Modern science does have its' flaws.

a reply to: darkbake

Yes in theory it seems 100% accurate that you wouldn't be able to identify the approximate location of the sun in a clean vacuum if you were faced in its' general direction but in space there is dust so the suns light will reflect off of the dust and color it. That means that the suns' apparent color will depend on what dust is in between you and the sun. Also space suits have a rounded glass visor with a tint so that could reflect enough rays to make its' approximate location visible as well.

originally posted by: youdidntseeme

But light is made up both of waves and particles (matter). This matter is known as photons...has mass too...
So when we are looking at light, we are looking at matter. So if there was no matter, there is no light either.

Unless there has been some big news since I was at school, aren't photons massless?

But anyway, yes, you can argue that without matter you wouldn't be able to see light. But that is only because you cannot detect light without some kind of interaction, and that interaction requires matter.

The point, in relation to the mindboggingly stupid video in the OP, is that it doesn't matter whether the light travels straight to you through a vacuum or bounces through an entire fairground Hall of Mirrors, if it strikes the receptors in your eye then you can see it, and if it doesn't then you can't.

originally posted by: On7a7higher7plane
a reply to: darkbake

Yes in theory it seems 100% accurate that you wouldn't be able to identify the approximate location of the sun in a clean vacuum if you were faced in its' general direction but in space there is dust so the suns light will reflect off of the dust and color it. That means that the suns' apparent color will depend on what dust is in between you and the sun. Also space suits have a rounded glass visor with a tint so that could reflect enough rays to make its' approximate location visible as well.

I think you misspelled "100% inaccurate".

In a clean vacuum, you would observe a perfect delineation between the surface of the sun, from which all the light is emanating, and total inky blackness from which not a single photon was emanating. (Ignoring messy realities like solar flares etc, which would affect the definition of where the sun stopped and the vacuum began! Let's just assume that the Sun is a big, perfect, glowing sphere for the purposes of this argument.)

Where do you get this crazy idea that light needs to "reflect off dust" in order to make it visible?

Light travels in straight lines. If there is a straight line from your eye to the sun's surface then you will see it, if there isn't then you won't. Capisce?

Is the public understanding of basic, primary-school science REALLY this poor?

a reply to: On7a7higher7plane

Vacuum

A vacuum is defined as "space that is devoid of matter." Since light contains matter in the form of protons, once the light enters said vacuum, it is no longer a vacuum. The article also describes space as an 'imperfect vacuum.'

Outer space has very low density and pressure, and is the closest physical approximation of a perfect vacuum. But no vacuum is truly perfect, not even in interstellar space, where there are still a few hydrogen atoms per cubic meter.

Since space is not a perfect vacuum, albiet the closest approximation we can see, those few hydrogen atoms per cubic meter are enough to make the suns light visible as well.

originally posted by: youdidntseeme
a reply to: On7a7higher7plane

Vacuum

A vacuum is defined as "space that is devoid of matter." Since light contains matter in the form of protons, once the light enters said vacuum, it is no longer a vacuum. The article also describes space as an 'imperfect vacuum.'

Light doesn't consist of protons. Were you thinking of photons perhaps?

Since space is not a perfect vacuum, albiet the closest approximation we can see, those few hydrogen atoms per cubic meter are enough to make the suns light visible as well.

Hydrogen atoms (which do consist of protons, and electrons too!) have absolutely nothing to do with whether you can see visible light. Do you really think a few hydrogen atoms per cubic metre is enough to magically affect visible light? If I gave you a glass jar completely full of hydrogen gas then would it look any different from a totally empty glass jar?


I thought I'd seen some nonsense on the internet, but this thread is astonishing! Light does not require a medium through which to travel. Have I gone back in time to the 19th century and the "luminiferous aether"? I thought Michelson and Morley had done away with that idea in the 1880s!

a reply to: OpenEars123

How do you explain the Bat signal then?

What more needs to be explained?



You see it don't you?

Also if you remember they usually shine it off the clouds, but please remember it was a cartoon then a movie so it doesn't really need to be explained.

a reply to: Rob48

Yes Photons, my mistake, and I agree with you, no matter is required for light to travel, the thread is pretty bogus.

a reply to: youdidntseeme
No worries - not aimed at you, just that I'm astounded (and depressed|) by the general level of ignorance on display in the video and the thread!

But you do understand that the few atoms floating around in interstellar space have absolutely no bearing on whether or not the sun is visible, right?

By the way, if you can't see the sun in space then how come you can take a photograph of it?

Here's one, from about 4 billion miles away, taken by the Voyager 1 probe:



Normally spacecraft avoid pointing visible-light cameras at the sun, for obvious reasons - it's so bright, and the cameras are typically designed to view very faint stars etc, so it would overwhelm the optics and possibly burn it out. (Al Bean discovered something similar, to his cost, on Apollo 12, when he accidentally pointed the TV camera at the sun within moments of unpacking it, and fried the circuitry!)

You can see in the above image that even from beyond the orbit of Pluto, the sun is still bright enough to overload the optics and cause serious lens flare.

If you are looking into a flashlight, or the sun you don't actually see the sun or flashlight, just the light from those objects reflecting on your eye lens, so you don't see light sources in realtime... I guess that's what the youtuber meant.

originally posted by: drneville
If you are looking into a flashlight, or the sun you don't actually see the sun or flashlight, just the light from those objects reflecting on your eye lens, so you don't see light sources in realtime... I guess that's what the youtuber meant.

So if you had no eyes, you wouldn't be able to see? OK, that's one of the few things on this thread that makes sense

originally posted by: Rob48


So if you had no eyes, you wouldn't be able to see? OK, that's one of the few things on this thread that makes sense

Finally making sense of all of this now!

I'm a little surprised the so called experts would jump on and be so condescending. I'm no expert but I understood what you were attempting to explain without watching the video. Although I can't say I subscribe to what is being sold here, if I understand the concept it means you are referring to outer space as a vacuum and as such has no matter, therefore lightwaves have nothing to travel off of, therefore the lightwave has nothing to travel on to reach your eye.

In my layman mind I would see it like this. Suppose outer space was a true vacuum (to which I don't believe and no phage I don't want to hear about it) and there were no particles at all in outer space. IMO if you looked at the sun you wouldn't see it. Assume we use simple logic and say that it is self-evident that the sun is combustable energy. Lets also PRETEND that there is 0 particles in space between you and the Sun. We would than have to assume whatever matter is combusting on the Sun can't escape its "atmosphere". If all this was true than I would assume you couldn't see the sun because the light must travel off of particles to reach your eye.

However, I don't believe there are no particles in space not to mention we have yet to truly identify what dark matter is. So even if it has unusual properties it is still matter also.....Although I get the argument, I can't pick up what the old man is putting down.

Thanks for sharing though. Can't help but think of this quote for this conversation:

All truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident.

a reply to: Rosinitiate

if I understand the concept it means you are referring to outer space as a vacuum and as such has no matter, therefore lightwaves have nothing to travel off of, therefore the lightwave has nothing to travel on to reach your eye.

As I said, is this the 19th century? The theory that light requires a medium in which to travel was disproven back in Victorian times! Light waves do not need "something to travel off of"

Suppose outer space was a true vacuum (to which I don't believe and no phage I don't want to hear about it) and there were no particles at all in outer space. IMO if you looked at the sun you wouldn't see it.

Light travels in straight lines. If there is no matter between you and the sun then what is blocking the light from reaching your eye? Answer: NOTHING.

What on Earth were people doing at school?

If this is the standard of science knowledge of people who have (presumably) completed their education, I am seriously worried. In another 100 years we'll be back to living in caves, at this rate...

So many ATS members seem to have an interest in "unexplained phenomena", and yet don't have even the most elementary grasp of everyday phenomena such as light! If you don't even know how light behaves then how do you expect to be able to know what you are looking at?

originally posted by: wildespace
This is gonna be GaryN's favourite thread.

You're right, where is he?

He seems to be confusing seeing a sideways light beam with seeing light shining directly into your eye or camera. When you look at the Sun or any other source of light (in space or otherwise), photons enter your eye directly and you see light. It doesn't have to bounce off anything first. Apollo astronauts used stars for navigation on their way to the Moon.

Yes the first video started out making sense, when he inferred that light rays aren't seen as they pass through a vacuum or air, unless there's dust in the air, which is for the most part true. But then he went off the deep end when he said you can't see the sun from space, which I'm surprised nobody posted a picture contradicting that claim yet, but this disproves his claim:

blogs.discovermagazine.com...

Sunrise from the International Space Station. (Image: Karen Nyberg, NASA)

Anyone who hasn't seen this related video on this topic should watch it. It's less than 1 minute long, and funny:

Richard Feynman on hungry philosophers (or do we see objects or only their light)

originally posted by: dragonridr

Its times like these i have concerns for Humanity.

Now your should be able to have a good understand of the MH370 thread.

a reply to: Rob48

For starters....get a grip. Most of what was taught in science to many has become old hat and most people don't bother to study up on space science thereafter and certainly nothing around them encourages them do so anyway. If you re-read my post I stated repeatedly I don't prescribe to that theory just that I understood the argument, nor do I accept any current "theory" as self-true either.

If this is the standard of science knowledge of people who have (presumably) completed their education, I am seriously worried. In another 100 years we'll be back to living in caves!

If this is the type of behavior and attitude we can accept from "evolved" and "educated" humans, I am seriously worried. In another 100 years we will have assimilated ourselves from war and ignorance.

originally posted by: Rosinitiate
a reply to: Rob48

For starters....get a grip. Most of what was taught in science to many has become old hat and most people don't bother to study up on space science thereafter and certainly nothing around them encourages them do so anyway.

And yet people seem to waste hours watching ignorant rubbish on YouTube? What is encouraging them to do that? Maybe they could use the time to crack open a textbook or read a serious website instead. You know - learn something real?

If this is the type of behavior and attitude we can accept from "evolved" and "educated" humans, I am seriously worried. In another 100 years we will have assimilated ourselves from war and ignorance.

I do not think that word means what you think it means. And besides, if people were more focused on facts and less focused on stupid baseless beliefs (eg religion), there would be a LOT fewer wars on this earth.