http://en.wikipedia.org/wiki/File:Guisard_-_Milky_Way.jpg

Post a reply to this message

Invisible wrote:
> I can only presume this must be due to light pollution.

You need to go out someplace like 50 miles from the nearest street light. 
It's really rather overwhelming.

> Well, photons are quantum, right?

I'm not sure you'd see a point source. You need enough surface that the 
likelihood of multiple photons reaching your eye in a short interval is 
positive.

> (Interestingly, I'm told it *is* possible to make a light source that 
> emits individual photons, one at a time, on que. And that when you do 
> this, things like the double-slit experiment still show multiple waves 
> interferring and reinforcing - despite this being obviously 
> impossible... Wave-particle duality is weird!)

It's only impossible if you think the interference is caused by waves, which 
it isn't.

-- 
Darren New, San Diego CA, USA (PST)
   Human nature dictates that toothpaste tubes spend
   much longer being almost empty than almost full.

Post a reply to this message

Invisible wrote:
> But where do you have to go? Outer Mongolia?

Most national parks in the USA are big enough.

> (Also... where the hell *is* that anyway?!)

Know how China has a concave top? In there.

-- 
Darren New, San Diego CA, USA (PST)
   Human nature dictates that toothpaste tubes spend
   much longer being almost empty than almost full.

Post a reply to this message

Bill Pragnell wrote:
> I'd think it was a single shot. I bet you could get away with up to a minute of
> exposure, and it's very wide angle so any movement would be less noticeable.

You can also buy telescope tripods that will use a small motor to turn the 
telescope in counterpoint so the stars appear stationary. I imagine the same 
would work for a camera, and then it would be the ground that's blury.

-- 
Darren New, San Diego CA, USA (PST)
   Human nature dictates that toothpaste tubes spend
   much longer being almost empty than almost full.

Post a reply to this message

Bill Pragnell wrote:
> I'm not sure. The fact that it's a nearly-complete panorama makes it even more
> complicated - I guess it must have been unwrapped from a fisheye.
> 
> I'd think it was a single shot. I bet you could get away with up to a minute of
> exposure, and it's very wide angle so any movement would be less noticeable.
> 
> Any expert photographers here want to comment?

Servo motors work wonders, when you can gear them correctly.

There are several tripod heads designed to track correctly against the
spin of the earth, allowing for long exposures. Anything that works for
for automatic telescopes can do the same work for a camera.

Or for cheap, a really long bolt, two pieces of wood, and a hinge. They
are called equatorial mounts or, for the cheapest ones, barn door trackers.

Post a reply to this message

>> I can only presume this must be due to light pollution.
> 
> You need to go out someplace like 50 miles from the nearest street 
> light. It's really rather overwhelming.

I don't know if any such place exists in the UK. Unless maybe you sail 
50 miles out to sea...

>> Well, photons are quantum, right?
> 
> I'm not sure you'd see a point source. You need enough surface that the 
> likelihood of multiple photons reaching your eye in a short interval is 
> positive.

I doubt your eyes can see single photons anyway...

>> (Interestingly, I'm told it *is* possible to make a light source that 
>> emits individual photons, one at a time, on que. And that when you do 
>> this, things like the double-slit experiment still show multiple waves 
>> interferring and reinforcing - despite this being obviously 
>> impossible... Wave-particle duality is weird!)
> 
> It's only impossible if you think the interference is caused by waves, 
> which it isn't.

Well, the books seem to claim that it *is* caused by waves, but they 
babble some nonesense about a "quantum superposition of states" to make 
up for the fact that this explanation makes no sense at all.

Post a reply to this message

Invisible wrote:
> This is awesomer:
> 
> http://en.wikipedia.org/wiki/File:Perseid_Meteor.jpg
> 
> Here in the name of God does the night sky actually look like this?!

Dunno, but now that it is cold I may have to find a map and make a
scouting expedition to find a place. City lights are annoying here, but
that picture looks like what I grew up seeing. Even there, the lights
are brighter at night, they finally put up street lamps, and the
neighbors leave their post lamps on, now.

But here, a half hour on the road will get me clear of the city and put
me in farm land. That's always a good start, with the side of a mountain
as a back up plan.

Post a reply to this message

> You can also buy telescope tripods that will use a small motor to turn the 
> telescope in counterpoint so the stars appear stationary. I imagine the 
> same would work for a camera, and then it would be the ground that's 
> blury.

That was my point, I know how to keep the stars sharp or to keep the ground 
sharp, but how to get both in the same photo?

Post a reply to this message

> City lights are annoying here, but
> that picture looks like what I grew up seeing.

I have never, ever, in my entire life, seen anything that remotely 
approximates this, except on TV and in posters. Every time I see 
something like this in films it looks like over the top CG, because real 
skies never, ever look like this.

It's quite impressive driving home, actually. By the time you reach 
Weedon, you can already tell where MK is because one entire side of the 
sky is bright orange. (I have no idea how far it is from Weedon to MK, 
but it's surely more than 10 miles.)

If you approach from the south, there's high ground that way. As you 
come down the hill, you can see the entire city laid out before you. It 
looks utterly huge. It seems to extend from one horizon to the other. 
(Obviously an effect of the terrain and it's slope.) And the entire 
thing is glowing.

I don't know about you, but when I look up at the orange horizon when 
I'm more than 10 miles away, I wonder what the HELL the council's 
electricity bill must be, and how much of the light we're paying for is 
leaking uselessly into the sky rather than illuminating the streets... 
Surely there's some more-efficient way to do this?

Post a reply to this message

scott wrote:
>> You can also buy telescope tripods that will use a small motor to turn 
>> the telescope in counterpoint so the stars appear stationary. I 
>> imagine the same would work for a camera, and then it would be the 
>> ground that's blury.
> 
> That was my point, I know how to keep the stars sharp or to keep the 
> ground sharp, but how to get both in the same photo?

Really, really friggin' BIG lenses, as a guess...

Apparently bigger lenses capture more light and generate better images. 
Seen any telescopes recently? Big, aren't they? ;-)

Post a reply to this message