[ ]   [ ]   [ ]                        [ ]      [ ]   [ ]

MQA Stream Coming to BLUOS - nickt1 - May 21, 2022 - 1:09am
 
Wordle - daily game - NoEnzLefttoSplit - May 20, 2022 - 10:15pm
 
Live Music - oldviolin - May 20, 2022 - 7:06pm
 
Favorite Quotes - Bill_J - May 20, 2022 - 7:05pm
 
What is the meaning of this? - oldviolin - May 20, 2022 - 7:04pm
 
Neil Young - oldviolin - May 20, 2022 - 6:50pm
 
Today, I learned... - haresfur - May 20, 2022 - 5:51pm
 
songs for drella - haresfur - May 20, 2022 - 5:47pm
 
Chicago 25 Or 6 To 4 - Steely_D - May 20, 2022 - 2:42pm
 
Trump - Red_Dragon - May 20, 2022 - 2:36pm
 
Things You Thought Today - Red_Dragon - May 20, 2022 - 10:51am
 
Reccomended System or Powered Speakers - KurtfromLaQuinta - May 20, 2022 - 7:04am
 
Dialing 1-800-Manbird - miamizsun - May 20, 2022 - 6:50am
 
Radio Paradise Comments - miamizsun - May 20, 2022 - 6:48am
 
Counting with Pictures - darkblue - May 20, 2022 - 6:21am
 
Today in History - Red_Dragon - May 20, 2022 - 6:05am
 
Derplahoma! - sunybuny - May 20, 2022 - 5:41am
 
Unquiet Minds - Mental Health Forum - miamizsun - May 20, 2022 - 5:16am
 
The Obituary Page - thisbody - May 19, 2022 - 10:01pm
 
Name My Band - haresfur - May 19, 2022 - 8:10pm
 
songs that ROCK! - Red_Dragon - May 19, 2022 - 5:10pm
 
Online Radio Platforms - Steely_D - May 19, 2022 - 4:03pm
 
Brag about your stereo - miamizsun - May 19, 2022 - 3:16pm
 
All Dogs Go To Heaven - Dog Pix - islander - May 19, 2022 - 3:00pm
 
COVID-19 - Red_Dragon - May 19, 2022 - 1:50pm
 
Testing your Metal? - oldviolin - May 19, 2022 - 12:11pm
 
Ukraine - NoEnzLefttoSplit - May 19, 2022 - 10:37am
 
Help Finding A Song - nightdrive - May 19, 2022 - 10:19am
 
Lyrics - oldviolin - May 19, 2022 - 8:17am
 
What Did You Do Today? - miamizsun - May 19, 2022 - 4:08am
 
New Song Submissions system - danielh - May 19, 2022 - 2:09am
 
What Makes You Sad? - Coaxial - May 18, 2022 - 6:42pm
 
NASA & other news from space - GeneP59 - May 18, 2022 - 4:37pm
 
Talk Behind Their Backs Forum - GeneP59 - May 18, 2022 - 4:12pm
 
Guided Meditation by Bill - thisbody - May 18, 2022 - 2:45pm
 
January 20th, 2005 ~ Boycott And Meditation Day - thisbody - May 18, 2022 - 2:34pm
 
Mixtape Culture Club - miamizsun - May 18, 2022 - 1:55pm
 
Economix - thisbody - May 18, 2022 - 1:48pm
 
Japan - Red_Dragon - May 18, 2022 - 10:58am
 
Race in America - Red_Dragon - May 18, 2022 - 7:36am
 
North Korea - Red_Dragon - May 17, 2022 - 9:07pm
 
Photography Forum - Your Own Photos - KurtfromLaQuinta - May 17, 2022 - 11:24am
 
"2000 Mules" movie purports to prove 2020 election was st... - rgio - May 17, 2022 - 7:02am
 
Vinyl Only Spin List - kurtster - May 16, 2022 - 8:44pm
 
Buddy's Haven - oldviolin - May 16, 2022 - 6:31pm
 
• • • The Once-a-Day • • •  - oldviolin - May 16, 2022 - 6:18pm
 
Environment - Red_Dragon - May 16, 2022 - 4:42pm
 
RightWingNutZ - Red_Dragon - May 16, 2022 - 4:24pm
 
260,000 Posts in one thread? - oldviolin - May 16, 2022 - 3:24pm
 
New Music - miamizsun - May 16, 2022 - 12:37pm
 
• • • Clownstock • • •  - oldviolin - May 16, 2022 - 10:17am
 
What the hell OV? - miamizsun - May 16, 2022 - 9:40am
 
Supreme Court Rulings - Red_Dragon - May 16, 2022 - 9:33am
 
Outstanding Covers - oldviolin - May 16, 2022 - 8:35am
 
Watching My Mind Slip Away... - oldviolin - May 16, 2022 - 6:05am
 
Great Old Songs You Rarely Hear Anymore - Alchemist - May 15, 2022 - 10:12pm
 
TuneIn difficulties - KurtfromLaQuinta - May 15, 2022 - 7:02pm
 
Terrorist Watch! - Steely_D - May 15, 2022 - 5:17pm
 
Climate Change - Red_Dragon - May 15, 2022 - 1:31pm
 
Spain - Red_Dragon - May 15, 2022 - 11:04am
 
Get Your Godcast! - Red_Dragon - May 14, 2022 - 4:52pm
 
TV shows you watch - Red_Dragon - May 14, 2022 - 4:03pm
 
Republican Party - rgio - May 14, 2022 - 3:15pm
 
The Abortion Wars - Red_Dragon - May 14, 2022 - 2:20pm
 
Guns - Red_Dragon - May 14, 2022 - 2:08pm
 
Finland - Red_Dragon - May 14, 2022 - 11:28am
 
CRAZY Flooding Video! - Red_Dragon - May 14, 2022 - 7:35am
 
Bluesound MQA stream not working for me - Juancastilo - May 14, 2022 - 6:48am
 
Australia has Disappeared - Red_Dragon - May 14, 2022 - 6:07am
 
Gotta Get Your Drink On - Antigone - May 13, 2022 - 5:25pm
 
The Dragons' Roost - GeneP59 - May 13, 2022 - 7:15am
 
Women in the World - miamizsun - May 13, 2022 - 6:21am
 
2020 Elections - Red_Dragon - May 12, 2022 - 12:34pm
 
George Carlin - GeneP59 - May 12, 2022 - 7:35am
 
Stuff I've Said Out Loud - GeneP59 - May 12, 2022 - 7:25am
 
Index » Regional/Local » Elsewhere » Science in the News Page: Previous  1, 2, 3, 4, 5, 6, 7, 8, 9, 10  Next
Post to this Topic
Red_Dragon

Red_Dragon Avatar



Posted: Aug 18, 2011 - 10:39am

one step closer to SKYNET...
aflanigan

aflanigan Avatar

Location: At Sea
Gender: Male


Posted: Aug 11, 2011 - 9:09am

"HUGE" RESULTS RAISE HOPE FOR CANCER BREAKTHROUGH
justlistening

justlistening Avatar

Location: So. California
Gender: Male


Posted: May 31, 2011 - 3:45pm

THEN:

Robot to explore mysterious tunnels in Great Pyramid

For 4,500 years, no one has known what lies beyond two stone doors deep inside the monument
By Andrew Johnson


NOW:
Hidden no more: Pyramid findings rock the Web


Red_Dragon

Red_Dragon Avatar



Posted: May 30, 2011 - 7:43pm

 beamends wrote:

Or coffee.
 

Red_Dragon

Red_Dragon Avatar



Posted: May 30, 2011 - 7:42pm

 helenofjoy wrote:
This made my face hurt.

 
yes.
jadewahoo

jadewahoo Avatar

Location: Puerto Viejo, Costa Rica
Gender: Male


Posted: May 30, 2011 - 6:55pm

 beamends wrote:

Or coffee.
 
{#Roflol}

beamends

beamends Avatar



Posted: May 30, 2011 - 3:26pm

 oldslabsides wrote:

I bet this makes a wave, too

 

 
Or coffee.

Lazy8

Lazy8 Avatar

Location: The Gallatin Valley of Montana
Gender: Male


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

helenofjoy Avatar

Location: Lincoln, Nebraska
Gender: Female


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

Lazy8 Avatar

Location: The Gallatin Valley of Montana
Gender: Male


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

Red_Dragon Avatar



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

ptooey Avatar

Location: right behind you. no, over there.
Gender: Male


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

NoEnzLefttoSplit Avatar

Gender: Male


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

ptooey Avatar

Location: right behind you. no, over there.
Gender: Male


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

ScottFromWyoming Avatar

Location: Powell
Gender: Male


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

Red_Dragon Avatar



Posted: May 30, 2011 - 7:47am

 ptooey wrote:

Dammit.  Dammit, dammit, dammit. 

*heads off to e-bay*
 

ptooey

ptooey Avatar

Location: right behind you. no, over there.
Gender: Male


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

ScottFromWyoming Avatar

Location: Powell
Gender: Male


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

NoEnzLefttoSplit Avatar

Gender: Male


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

oldviolin Avatar

Location: esse quam videri
Gender: Male


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...
Page: Previous  1, 2, 3, 4, 5, 6, 7, 8, 9, 10  Next