Shenzhou 7?

[SolusLupus]

Okay, outside of the unnecessary snarkiness not doing anything for you, Vincent, do keep in mind that the flag is attached to something that's moving.  For instance, if I hold a string in zero gravity and move, the string will move differently than I will; it won't retain its shape and just move, but will hover a bit for a moment, while it still has flexibility.

If I'm explaining this poorly, someone please tell me.

[VincentMcConnell]

Here is a video of Ed White's Gemini 4 spacewalk.

Notice how at 0.47 there is a strap and a loop visible, both of which are 'floating' upwards of their own volition. Notice how as he sets up the camera at about 1.16 the coiled tether is floating upwards rather than sitting against the spacecraft.
Violating the laws of physics? Filmed underwater? Or just the natural tendency of the things in question?

How many times do I have to clear this up??
Ed White used a NITROGEN GUN to maneuver. That causes him to develop relative velocity and motion to the tether and strap... Inertia dictates they must move. On the Chinese video, however, it's clear that they float up without any kind of force throughout the video.

[VincentMcConnell]

...do keep in mind that the flag is attached to something that's moving.  For instance, if I hold a string in zero gravity and move, the string will move differently than I will; it won't retain its shape and just move, but will hover a bit for a moment, while it still has flexibility.
If I'm explaining this poorly, someone please tell me.

No, I understand what you're talking about. Watch the flag though. At moments when the Taikonaut's hand is still and the flag is limp for a second, it will strangely start to float up for no reason...

[SolusLupus]

I honestly don't see anything unusual.  Even the most subtle of hand movement can change the way an object moves; I should know, it's an easy way to slip a blow past defenses as a fencer.

[Tanalia]

Also, there is a natural tendency for flexible objects to straighten -- to relieve compression and tension.  On Earth, a rope will usually just lie there, the friction with the ground overwhelming the straightening forces.  In space, the tethers are only restricted by the by the end attachments, so they will tend to equalize the strain along the length, forming arcs.

The same thing happens with the flag.  When not being whipped about, it tends to straighten directly out from the rod.  The way it was gripped, this direction was "up" a lot of the time, but not always.  In particular, just before it was stowed, it was aimed almost directly at the camera.

As for the color of the Earth, it's simply slightly over-exposed.

[gillianren]

According to Mary Roach in Packing For Mars, there are always fans running in the ISS to prevent bubbles of CO2 from forming around astronauts.  Is this true?  Could this be an issue?

[cjameshuff]

According to Mary Roach in Packing For Mars, there are always fans running in the ISS to prevent bubbles of CO2 from forming around astronauts.  Is this true?  Could this be an issue?

For the flag? Not during the spacewalk, for obvious reasons.
As an unrelated question, "bubble" is probably a misleading word, but the lack of natural convection could indeed lead to a still astronaut developing a region of high CO2 around them. It could also lead to  uncomfortable increases in temperature around the astronaut, or incidents like a piece of overheating electronics going unnoticed until it starts a fire, rather than being discovered by its odor. Establishing an overall circulation pattern also tends to collect small items in predictable locations.

Anyway, going back and watching the video...the tether's obviously stiff and springy, the clasps at the ends jiggle and slide around without any evidence of damping by water drag, various small straps tend to project out at the same direction from the astronaut independent of their orientation, the flag flops around, sometimes flying ahead of the stick it's attached to and clearly not being dragged through water, the person doing the EVA several times ends up drifting around a pivot, clearly not settling to an equilibrium position due to imperfect neutral buoyancy or being slowed by water drag...

It also looks largely lit by indirect light from the Earth. You can see parts of the suit go into direct sunlight a few times later on, and it saturates the camera. Indirect light from Earth, the big blue object in the background, will be tinted blue. Color balancing the video to make the white suit and spacecraft look white will make the Earth look faded. Readjusting the balance to make Earth blue will make white things lit by that blue light also appear blue. It looks exactly as it should under those lighting conditions, and certainly isn't evidence of a hoax.

It doesn't look one bit like it's under water. It doesn't make sense for them to fake it. There is no reason to think they couldn't have the capabilities they claim, they are in fact in a better position to achieve those capabilities than we were when we did our first spacewalks. There is just no reason whatsoever to think this was faked.

[SolusLupus]

See, this is the problem:

Generally, when you see something that does not behave or look just what you might expect, that could simply be because you're not used enough to what's being handled to be able to tell.

While asking questions about it is fine for learning, or even if you have doubts, once you start using it as evidence of a large conspiracy is where it falls into woo-woo territory.

Vincent, you could easily have learned more about the subject, instead of going on about how we're only believing China was in space purely because they told us so.  But when you do the latter, you look foolish; there's a lot more involved than just our eyes and ears.  There's radio, there's satellites, there's a lot of people involved on the project that live in an extremely globalized world, even in China (the Great Firewall of China is practically a non-issue at this point), and there are expert engineers in other countries that would pounce on the idea that China was faking things.

It's much better to treat these things with humility and give yourself a chance to learn, than to go about and act as if you're superior to the world.

[Jason Thompson]

Here is a video of Ed White's Gemini 4 spacewalk.

Notice how at 0.47 there is a strap and a loop visible, both of which are 'floating' upwards of their own volition. Notice how as he sets up the camera at about 1.16 the coiled tether is floating upwards rather than sitting against the spacecraft.
Violating the laws of physics? Filmed underwater? Or just the natural tendency of the things in question?

How many times do I have to clear this up??
Ed White used a NITROGEN GUN to maneuver. That causes him to develop relative velocity and motion to the tether and strap... Inertia dictates they must move.

How many times do i have to spoon feed you? The two sections I pointed you to specifically in that video occur before he does any kind of manoeuvring. The strap is floating upwards from his body, and the tether is floating upwards from the attachment point, while he is still seated in the capsule, BEFORE he does any kind og manoeuvring with that gun at all.

[ka9q]

According to Mary Roach in Packing For Mars, there are always fans running in the ISS to prevent bubbles of CO2 from forming around astronauts.  Is this true?  Could this be an issue?

Not outside, of course, but ventilation definitely moves things around inside. Astronauts report often finding lost objects (as well as lots of debris) stuck to the filters of air return vents.

A few years ago I had what I thought was a brilliant idea for an educational physics video made in space. I wanted to show the effect of the earth's gravity gradient. Objects floating freely inside a spacecraft are essentially in their own independent orbits. In theory, an object freely floating near the floor of the ISS, i.e., closer to the earth than the ISS's center of mass, would be in a slightly shorter period orbit than the ISS itself, so it would tend to move forward along the velocity vector. An object near the "ceiling" would tend to move against the velocity vector.

Similarly, a floating object left or right of the station center of mass would be in a slightly different orbital plane than the station itself. It would oscillate on its own around the center line, completing one full cycle per orbit.

I had the opportunity to ask two experienced astronauts if this would work: Dr. Owen Garriott and his son Richard. Both immediately shot down my idea, explaining that the ventilation currents are so strong that they would easily overwhelm the effect I was trying to demonstrate. I think Owen did say that he tried to create the effect himself inside a storage locker on Skylab, out of reach of the ventilation ducts, but I don't remember if he succeeded.

This effect would be present during an EVA, and it might be worth looking for. It will be rather subtle, and it does seem more likely that any free-floating and untethered object would have enough residual velocity to fly away from the spacecraft and out of camera view.

[ka9q]

How many times do I have to clear this up??
Ed White used a NITROGEN GUN to maneuver.

Actually, his maneuvering gun used oxygen, not nitrogen, and White depleted it fairly rapidly.

[gillianren]

Thanks, everyone--I forgot we were talking about a spacewalk.  I feel well and truly dumb now!

[Jason Thompson]

Hm. So you're now saying that flags like to float up in free -fall? hahahahaaha. That's a good one.

That is not what I said. Lose the attitude, re-read what I said, and consider the fact that I am more familiar with the visual record of space flight history and the laws of physics as they pertain to it than you are.

Flexible objects in free-fall and vacuum will adopt their lowest energy configuration. The concept of 'up' is irrelevant, since in this case it is only relative to the orientation of the camera. If the flagpole is oriented with the flag atached on the 'upward' side of it, then the flag will naturally tend to straighten out and point 'upwards', because being flat is a lot more energetically favourable for that sheet of what appears to be paper or somesuch material than being curled up. Similarly the tether on the taikonaut is attached to his body at a point 'lower' than the rails he clips the other end onto. They will therefore naturally tend to try and straighten out, but since they are restrained at both ends they will instead adopt their lowest energy configuration, which is a long, smooth curve. The location of the attachment points and the length of the tether dictate this curve places the middle of the tether 'higher' than either end, and so yes, it will appear to float 'upwards', because it adopts the shape with the least stored elastic energy in it. That is the important law of physics here, which you are missing.

[ka9q]

You can learn a lot of physics from space flight; that's one of the neatest things about studying it.

Lots and lots of systems seek their lowest energy states because they're following one of the most important laws in all of physics: the second law of thermodynamics. It states that any form of energy can be turned into heat, but heat energy cannot be turned back into another form of energy with 100% efficiency. It also says heat spontaneously flows from a hot object to a cold one, but never from cold to hot. In the far distant future all the mass and energy in the universe will become heat at a constant temperature, and nothing interesting will ever happen again. This will be the "heat death" of the universe.

When something as simple as a tether assumes its lowest energy state, that excess energy doesn't just disappear. It has to go somewhere because the first law of thermodynamics says that energy is conserved. As the "springiness" in the tether flexes it, that excess energy becomes heat. It warms up. Even in space, warm objects tend to radiate their heat away toward objects at lower temperatures. That energy won't come back, and even if it did it wouldn't spontaneously turn back into mechanical energy. So the tether seeks its lowest energy state and stays there until some external force intervenes.

[Andromeda]

Excellent posts, Jason and ka9q.