Ask a physicist anything. (2)

[Chesterton]

No if the earth was flat you would be able to see all the way to the edge. With a round earth the higher you are the further around the curvature you see.

I see what you're saying, but I was thinking of actual distance, not just what can be seen.

 

[canehdianhotstuff]

The straight line of sight distance d in kilometers to the true horizon on earth is approximately

d = sqrt{13h}

where h is the height above ground or sea level (in meters) of the eye of the observer.

 

[Wiccan_Child]

Wouldn't the distance to the horizon be different on a hillside than it would be on a flat plain?

No.

Actually, it would. Imagine you're on a perfectly flat sphere (in a vacuum, of course). You can see out to a certain distance (it would circumscribe a line of latitude, assuming you're sitting at a pole). As your elevation increases (for no clear reason, a thin mountain is forming beneath you), you can see further and further out. As you head for infinity, you will eventually see the equator.

The straight line of sight distance d in kilometers to the true horizon on earth is approximately

d = sqrt{13h}

where h is the height above ground or sea level (in meters) of the eye of the observer.

13? Kilometres? That's oddly specific... I smell an atheist conspiracy!

 

[canehdianhotstuff]

Yes, 13km...approximately anyways. There are more complex ways of doing it, that is just one of the easier formula's.

 

[Chesterton]

I just found something which struck me as funny. If you Google "iss v", it will suggest a menu of choices including things like "iss viewing" and "iss viewing from earth". :o Wow, Google is more popular than we thought.

 

[catzrfluffy]

But since you have to walk down the hill, doesn't that add extra distance?

 

[Wiccan_Child]

But since you have to walk down the hill, doesn't that add extra distance?

It would, but it's generally not taken to be walking distance, but rather the degree of latitude you can see down to (assuming a perfect sphere). Plus, even if you did do walking distance, a small increase in elevation corresponds to a massive increase in the distance-to-the-horizon: being flat on the ground, the distance is zero, while being 6' up, the distance is measured in miles.

 

[Merlin]

Aliens. Or magic. Or magic aliens.
.

good physicist answer

 

[Wiccan_Child]

good physicist answer

Do you have a better one?

 

[Chesterton]

Aliens. Or magic. Or magic aliens.

I smell a successful new off-shoot religion: Physitology[sub]TM[/sub]

 

[Merlin]

Do you have a better one?

i guess there's not much point to this thread

 

[Wiccan_Child]

i guess there's not much point to this thread

The 1500+ posts beg to differ. You ask a question, and I attempt to answer it. The premise is one of physics ("Why does ice float?"), but any questions are welcome, as are anyone's attempts at an answer.

Of course, occasionally, my omniscience fails me, and I can't answer a question. There's no need to get in a huff about it, m'dear.

 

[Wiccan_Child]

My first, tho’ water, cures no thirst,My next alone has soul,And when he lives upon my first,He then is called my whole.

A pat on the back for anyone who can solve this riddle.
Here's a clue (highlight the text to read it):

Spoiler

it's a single word, two syllables, and the riddle is referring to said syllables

 

[SithDoughnut]

A pat on the back for anyone who can solve this riddle.
Here's a clue (highlight the text to read it):

Spoiler

it's a single word, two syllables, and the riddle is referring to said syllables

Ooh ooh ooh I know this one!

Is it

Spoiler: My Answer

seaman

?

 

[Cabal]

A pat on the back for anyone who can solve this riddle.
Here's a clue (highlight the text to read it):

Spoiler

it's a single word, two syllables, and the riddle is referring to said syllables

I didn't get the second part of it - my solutions were

Spoiler

seafood and seatrain

.

 

[Wiccan_Child]

Ooh ooh ooh I know this one!

Is it

Spoiler

seaman

?

That's it . *pats back*

I didn't get the second part of it - my solutions were

Spoiler

seafood and seatrain

.

You got the first bit right.

Spoiler

For the second bit, think more... theologically.

 

[pgp_protector]

Actually you can use [spoiler=My Title]This is Hidden[/spoiler]
To create this

Spoiler: My Title

This is Hidden

As White Text shows up quite nicely on some of Themes

 

[Wiccan_Child]

Actually you can use [spoiler=My Title]This is Hidden[/spoiler]
To create this

Spoiler: My Title

This is Hidden

As White Text shows up quite nicely on some of Themes

All the more reason to get a proper theme, none of these poncy neon jobs.

Also, I'm liking those 'noparse' tags, that'll make it handy when I'm educating ze children.

I take it you can't use the 'spoiler' tags on their lonesome, then? You need a

Spoiler: sdf

?

 

[pgp_protector]

All the more reason to get a proper theme, none of these poncy neon jobs.

Also, I'm liking those 'noparse' tags, that'll make it handy when I'm educating ze children.

I take it you can't use the 'spoiler' tags on their lonesome, then? You need a

Spoiler: sdf

?

Spoiler: sdf

I you can use something like a space

Spoiler:

Trying Blank Spoiler

 

[SithDoughnut]

All the more reason to get a proper theme, none of these poncy neon jobs.

Also, I'm liking those 'noparse' tags, that'll make it handy when I'm educating ze children.

I take it you can't use the 'spoiler' tags on their lonesome, then? You need a

Spoiler: sdf

?

Spoiler: sdf

After testing it out, you don't have to type anything after the =, although it comes out like this

Spoiler

It just says 'Spoiler for'

So it works but the spoiler title makes no sense.