July 2025 Photo Theme - Stone
- Alchemist - Jul 2, 2025 - 10:18pm
Annoying stuff. not things that piss you off, just annoyi...
- islander - Jul 2, 2025 - 9:23pm
Wordle - daily game
- geoff_morphini - Jul 2, 2025 - 8:48pm
Israel
- R_P - Jul 2, 2025 - 8:22pm
Trump
- Red_Dragon - Jul 2, 2025 - 5:35pm
Trump Lies™
- R_P - Jul 2, 2025 - 5:01pm
Country Up The Bumpkin
- buddy - Jul 2, 2025 - 4:06pm
Best Song Comments.
- ScottFromWyoming - Jul 2, 2025 - 3:41pm
NY Times Strands
- maryte - Jul 2, 2025 - 3:37pm
NYTimes Connections
- maryte - Jul 2, 2025 - 3:28pm
Outstanding Covers
- NoEnzLefttoSplit - Jul 2, 2025 - 2:38pm
Protest Songs
- R_P - Jul 2, 2025 - 2:20pm
Name My Band
- oldviolin - Jul 2, 2025 - 2:11pm
Bug Reports & Feature Requests
- bobrk - Jul 2, 2025 - 1:16pm
Democratic Party
- NoEnzLefttoSplit - Jul 2, 2025 - 1:04pm
Fox Spews
- islander - Jul 2, 2025 - 10:39am
Immigration
- R_P - Jul 2, 2025 - 10:29am
Republican Party
- ColdMiser - Jul 2, 2025 - 8:14am
Music Videos
- black321 - Jul 2, 2025 - 8:02am
Today in History
- Red_Dragon - Jul 2, 2025 - 7:59am
Economix
- rgio - Jul 2, 2025 - 7:37am
New Music
- ScottFromWyoming - Jul 2, 2025 - 7:30am
Radio Paradise Comments
- GeneP59 - Jul 2, 2025 - 6:59am
Mixtape Culture Club
- KurtfromLaQuinta - Jul 1, 2025 - 8:34pm
Carmen to Stones
- KurtfromLaQuinta - Jul 1, 2025 - 7:44pm
The Obituary Page
- sunybuny - Jul 1, 2025 - 7:03pm
Climate Change
- R_P - Jul 1, 2025 - 5:27pm
Baseball, anyone?
- rgio - Jul 1, 2025 - 11:06am
Artificial Intelligence
- drucev - Jul 1, 2025 - 8:58am
President(s) Musk/Trump
- VV - Jul 1, 2025 - 8:10am
June 2025 Photo Theme - Arches
- Alchemist - Jun 30, 2025 - 9:10pm
Please help me find this song
- LazyEmergency - Jun 30, 2025 - 8:42pm
Forum Posting Guidelines
- rickylee123 - Jun 30, 2025 - 6:17pm
Thanks William!
- buddy - Jun 30, 2025 - 5:49pm
USA! USA! USA!
- buddy - Jun 30, 2025 - 4:50pm
Living in America
- R_P - Jun 30, 2025 - 3:15pm
M.A.G.A.
- R_P - Jun 30, 2025 - 12:50pm
Gardeners Corner
- marko86 - Jun 30, 2025 - 10:39am
Comics!
- Red_Dragon - Jun 30, 2025 - 7:59am
Birthday wishes
- Coaxial - Jun 30, 2025 - 6:36am
Talk Behind Their Backs Forum
- VV - Jun 30, 2025 - 5:39am
Global Mix renaming
- frazettaart - Jun 29, 2025 - 9:23am
Iran
- R_P - Jun 28, 2025 - 8:56pm
Live Music
- Steely_D - Jun 28, 2025 - 6:53pm
What Are You Going To Do Today?
- ScottFromWyoming - Jun 28, 2025 - 10:17am
• • • The Once-a-Day • • •
- oldviolin - Jun 28, 2025 - 9:52am
Musky Mythology
- R_P - Jun 27, 2025 - 3:00pm
Know your memes
- oldviolin - Jun 27, 2025 - 11:41am
What Makes You Sad?
- oldviolin - Jun 27, 2025 - 10:41am
Calling all Monty Python fans!
- FeydBaron - Jun 27, 2025 - 10:30am
Strips, cartoons, illustrations
- R_P - Jun 27, 2025 - 10:23am
SCOTUS
- Red_Dragon - Jun 27, 2025 - 8:30am
Framed - movie guessing game
- Proclivities - Jun 27, 2025 - 6:25am
Yummy Snack
- Proclivities - Jun 26, 2025 - 1:17pm
Parents and Children
- kurtster - Jun 26, 2025 - 11:32am
What Makes You Laugh?
- NoEnzLefttoSplit - Jun 25, 2025 - 9:36pm
PUNS- Political Punditry and so-called journalism
- oldviolin - Jun 25, 2025 - 12:06pm
Lyrics that strike a chord today...
- black321 - Jun 25, 2025 - 11:30am
What The Hell Buddy?
- oldviolin - Jun 25, 2025 - 10:32am
Astronomy!
- black321 - Jun 25, 2025 - 8:58am
The Grateful Dead
- black321 - Jun 25, 2025 - 7:13am
Billionaires
- R_P - Jun 24, 2025 - 4:57pm
Great guitar faces
- Steely_D - Jun 24, 2025 - 4:15pm
Buying a Cell Phone
- Steely_D - Jun 24, 2025 - 3:05pm
Anti-War
- R_P - Jun 24, 2025 - 12:57pm
Photography Forum - Your Own Photos
- Alchemist - Jun 24, 2025 - 10:40am
RIP Mick Ralphs
- geoff_morphini - Jun 23, 2025 - 10:40pm
Congress
- maryte - Jun 23, 2025 - 1:39pm
Europe
- R_P - Jun 23, 2025 - 11:30am
the Todd Rundgren topic
- ColdMiser - Jun 23, 2025 - 7:58am
What are you doing RIGHT NOW?
- GeneP59 - Jun 21, 2025 - 6:14pm
Rock & Roll Facts
- Coaxial - Jun 21, 2025 - 6:10pm
Poetry Forum
- SeriousLee - Jun 21, 2025 - 5:20pm
And the good news is....
- Red_Dragon - Jun 21, 2025 - 3:39pm
Gaje Gipsy Swing
- bartanandor - Jun 21, 2025 - 10:53am
|
Index »
Regional/Local »
Elsewhere »
Science in the News
|
Page: Previous 1, 2, 3, 4, 5 ... 9, 10, 11 Next |
Red_Dragon

Location: Gilead 
|
Posted:
May 30, 2011 - 7:42pm |
|
helenofjoy wrote:This made my face hurt.
yes.
|
|
jadewahoo

Location: Puerto Viejo, Costa Rica Gender:  
|
Posted:
May 30, 2011 - 6:55pm |
|
beamends wrote: Or coffee.
|
|
beamends


|
Posted:
May 30, 2011 - 3:26pm |
|
oldslabsides wrote:I bet this makes a wave, too Or coffee.
|
|
Lazy8

Location: The Gallatin Valley of Montana Gender:  
|
Posted:
May 30, 2011 - 3:23pm |
|
helenofjoy wrote:This made my face hurt.
I forgot to mention: point the knife away from your face!
|
|
helenofjoy

Location: Lincoln, Nebraska Gender:  
|
Posted:
May 30, 2011 - 3:22pm |
|
Lazy8 wrote: oldslabsides wrote:now wait a minute...What if this were filmed from above the trombone? Or from beneath; would the "shockwave" still be in the shape of an arc? Something about the perspective here just doesn't seem real to me. Yes. Shockwaves are a finite thickness, and what you see is the light bending as it passes thru the shockwave. From the side the light passes thru more of the shockwave along the leading surface of the shock than is does behind the leading surface on its way to you, so you see it in profile. Here's a way to think about it that might help: hold an imaginary half of a pumpkin in your hand with the guts all scooped out. It's a pretty much a uniform thickness. Now imagine you have a long pumpkin-carving knife you can poke thru the pumpkin, and poke it thru near the open end of the pumpkin, all the way across. It goes thru nearly perpendicular to the outer surface, which penetrates nearly the minimum amount of pumpkin possible while still getting thru both sides. Now poke it thru sideways across the bottom of the pumpkin. Since it goes thru the wall at a shallower angle it goes thru more pumpkin on its way out the other side. Poke it thru low enough and its whole trip thru will be inside the wall of the pumpkin. A ray of light taking that path will see the maximum amount of distortion from the differential index of refraction of the shock wave—not because it spent more time in the different index, but because it had farther to go before its path straightened out again when it reached undisturbed air on the other side. So rays of light along the leading surface of the shock will appear to show it in cross-section. This made my face hurt.
|
|
Lazy8

Location: The Gallatin Valley of Montana Gender:  
|
Posted:
May 30, 2011 - 3:16pm |
|
oldslabsides wrote:now wait a minute...What if this were filmed from above the trombone? Or from beneath; would the "shockwave" still be in the shape of an arc? Something about the perspective here just doesn't seem real to me. Yes. Shockwaves are a finite thickness, and what you see is the light bending as it passes thru the shockwave. From the side the light passes thru more of the shockwave along the leading surface of the shock than is does behind the leading surface on its way to you, so you see it in profile. Here's a way to think about it that might help: hold an imaginary half of a pumpkin in your hand with the guts all scooped out. It's a pretty much a uniform thickness. Now imagine you have a long pumpkin-carving knife you can poke thru the pumpkin, and poke it thru near the open end of the pumpkin, all the way across. It goes thru nearly perpendicular to the outer surface, which penetrates nearly the minimum amount of pumpkin possible while still getting thru both sides. Now poke it thru sideways across the bottom of the pumpkin. Since it goes thru the wall at a shallower angle it goes thru more pumpkin on its way out the other side. Poke it thru low enough and its whole trip thru will be inside the wall of the pumpkin. A ray of light taking that path will see the maximum amount of distortion from the differential index of refraction of the shock wave—not because it spent more time in the different index, but because it had farther to go before its path straightened out again when it reached undisturbed air on the other side. So rays of light along the leading surface of the shock will appear to show it in cross-section.
|
|
Red_Dragon

Location: Gilead 
|
Posted:
May 30, 2011 - 8:13am |
|
ptooey wrote:We're a little short on brass instruments, actually. I've got 2 guitars, a drum set, a piano, and a harmonica (oh, and I'm expecting a ukulele on Thursday  .) The kids have an accordion and a cello.  I bet this makes a wave, too
|
|
ptooey

Location: right behind you. no, over there. Gender:  
|
Posted:
May 30, 2011 - 8:05am |
|
NoEnzLefttoSplit wrote:
Yeah, but what about the trombone?
We're a little short on brass instruments, actually. I've got 2 guitars, a drum set, a piano, and a harmonica (oh, and I'm expecting a ukulele on Thursday  .) The kids have an accordion and a cello.
|
|
NoEnzLefttoSplit

Gender:  
|
Posted:
May 30, 2011 - 8:02am |
|
ptooey wrote: Yeah, I've got a couple of old scientific surplus catalogs sitting at the house. I'll check into what they've got. It really doesn't look all that tough.
Yeah, but what about the trombone?
|
|
ptooey

Location: right behind you. no, over there. Gender:  
|
Posted:
May 30, 2011 - 7:58am |
|
ScottFromWyoming wrote: I thought that might be trouble $250 is the price for new. Talk to someone there about what you need: a mirror out of a trashed telescope, it can have some scratches, I doubt that will matter much. Yeah, I've got a couple of old scientific surplus catalogs sitting at the house. I'll check into what they've got. It really doesn't look all that tough.
|
|
ScottFromWyoming

Location: Powell Gender:  
|
Posted:
May 30, 2011 - 7:56am |
|
ptooey wrote: Dammit. Dammit, dammit, dammit.
*heads off to e-bay*
Edit: $250 for an 8" mirror. Ahh. Nope.
 I thought that might be trouble $250 is the price for new. Talk to someone there about what you need: a mirror out of a trashed telescope, it can have some scratches, I doubt that will matter much.
|
|
Red_Dragon

Location: Gilead 
|
Posted:
May 30, 2011 - 7:47am |
|
ptooey wrote: Dammit. Dammit, dammit, dammit.
*heads off to e-bay*
|
|
ptooey

Location: right behind you. no, over there. Gender:  
|
Posted:
May 30, 2011 - 7:44am |
|
ScottFromWyoming wrote: Dammit. Dammit, dammit, dammit. *heads off to e-bay* Edit: $250 for an 8" mirror. Ahh. Nope.
|
|
ScottFromWyoming

Location: Powell Gender:  
|
Posted:
May 30, 2011 - 7:27am |
|
oldslabsides wrote:now wait a minute...What if this were filmed from above the trombone? Or from beneath; would the "shockwave" still be in the shape of an arc? Something about the perspective here just doesn't seem real to me. The depth of field is so shallow that it essentially is showing you just a cross-section of the half-a-bubble wave. Nearer to or further from the lens is out of focus so it doesn't show up.
Edit: well I was on the right track crack. Schleiren photography note the link from there to Collimated light
A do-it-yourself guide to Schlieren photography
|
|
NoEnzLefttoSplit

Gender:  
|
Posted:
May 30, 2011 - 6:47am |
|
oldslabsides wrote:now wait a minute...What if this were filmed from above the trombone? Or from beneath; would the "shockwave" still be in the shape of an arc? Something about the perspective here just doesn't seem real to me. i think its because the wave will travel slower as it propagates out to the sides, kind of like waves turning the corner at the beach, presuming you have a beach with corners, that is..
|
|
oldviolin

Location: esse quam videri Gender:  
|
Posted:
May 30, 2011 - 6:41am |
|
oldslabsides wrote: yes, but the contact lens has an edge in addition to its convex side...
who said anythin' about hatin'?
But I see the edge. Don't you? just rattling your cage...
|
|
Red_Dragon

Location: Gilead 
|
Posted:
May 30, 2011 - 6:36am |
|
oldviolin wrote:
look at a contact lens from the side...any side, and it's the same. The shock wave is basicallythe same convex shape. maybe... stop hatin' on peoples horn bones will ya? yes, but the contact lens has an edge in addition to its convex side... who said anythin' about hatin'?
|
|
beamends


|
Posted:
May 30, 2011 - 6:35am |
|
oldviolin wrote:
look at a contact lens from the side...any side, and it's the same. The shock wave is basicallythe same convex shape. maybe... stop hatin' on peoples horn bones will ya?
or the shock wave from an explosion, wherever you view from it's still dome shaped (in ideal conditions).
|
|
oldviolin

Location: esse quam videri Gender:  
|
Posted:
May 30, 2011 - 6:32am |
|
oldslabsides wrote:now wait a minute...What if this were filmed from above the trombone? Or from beneath; would the "shockwave" still be in the shape of an arc? Something about the perspective here just doesn't seem real to me. look at a contact lens from the side...any side, and it's the same. The shock wave is basicallythe same convex shape. maybe... stop hatin' on peoples horn bones will ya?
|
|
Red_Dragon

Location: Gilead 
|
Posted:
May 30, 2011 - 6:19am |
|
now wait a minute...What if this were filmed from above the trombone? Or from beneath; would the "shockwave" still be in the shape of an arc? Something about the perspective here just doesn't seem real to me.
|
|
|