Go Back   Two Wheel Fix > General > Off Topic

Reply
 
Thread Tools Display Modes
Old 10-17-2012, 10:05 AM   #101
anthonyk
WERA White Plate
 
anthonyk's Avatar
 
Join Date: Nov 2008
Location: Austin, TX
Moto: '01 Aprilia Falco
Posts: 1,041
Default

Quote:
Originally Posted by Homeslice View Post
I just want to make sure what it is we're disagreeing about. Are you saying that if you took 2 guys, both of them jumping from the same altitude, but one is doing it within the normal atmosphere while the other is doing it inside some kind of vacuum tube, that the first guy would feel the jump while the other wouldn't?
They would both feel the same initial sensation of falling or weightlessness. For the guy in the vacuum, that would persist. For the one in the atmosphere, he'd slowly transition back to "weighted" as air resistance started slowing his acceleration.
anthonyk is offline   Reply With Quote
Old 10-17-2012, 10:33 PM   #102
Homeslice
Elitist
 
Homeslice's Avatar
 
Join Date: Nov 2008
Location: SF Bay Area
Moto: Gix 750
Posts: 11,351
Default

Quote:
Originally Posted by Smittie61984 View Post
You're right except that in free fall in a vacuum where you have absolutely no forces acting on your at all the molecules in your body are going to fall at the same rate as yoru space suit or as if you were made out of solid steel. Everything falls at the same rate in a vacuum. If for some magical reason your stomach fell at say 9.80 meters per second per second and the rest of your body fell at 9.81 meters per second per second then you'd feel your stomach because your stomach would exert a force against your nerves which are trying to travel at a different velocity.

When you jump out of an airplane you are immediately subject to the affects of air resistance and pressure, like it or not. So in a sense, inside your body your guts want to fall at 9.81m/ss but due to air resistance you are actually falling at 9.70m/ss. Because of that you have a net Force and no matter how small a force, something with mass will experience acceleration.
This right here makes sense.
As for your vector post with arrows & shit, I only comprehended the first two-thirds of it. Sorry.
But this post right here makes sense.
So, I can see how air resistance would cause a difference in acceleration between your body and your guts, until terminal velocity is reached.
I would still argue that the initial shift from weighted to weightlessness is something anyone could feel, because as soon as you step off that platform, suddenly there is no force being exerted on your feet, knees, hips, back, neck, etc. Of course, that feeling would probably cease after a split second, so maybe Felix chose not to bother mentioning it, because it was so trivial when compared to the lack of freefalling sensation caused by the lack of air pressure.

Last edited by Homeslice; 10-18-2012 at 12:44 PM..
Homeslice is offline   Reply With Quote
Old 10-17-2012, 10:42 PM   #103
Homeslice
Elitist
 
Homeslice's Avatar
 
Join Date: Nov 2008
Location: SF Bay Area
Moto: Gix 750
Posts: 11,351
Default

Quote:
Originally Posted by Trip View Post

In space, if you jet yourself one way for just a moment, you will just keep accelerating with nothing to cause friction to slow you down, but you don't feel it at all.
Correction, you would keep accelerating only while the engine was on. When you shut it off, you would remain at the same velocity forever, unless disturbed.

Also, when you say "you don't feel it", I disagree, because your back would be pressed into the seat when you hit go. In fact that's the biggest BS about sci-fi movies, next to the noise in space issue.

Last edited by Homeslice; 10-18-2012 at 12:43 PM..
Homeslice is offline   Reply With Quote
Old 10-18-2012, 04:30 PM   #104
Smittie61984
I give Squids a bad name
 
Smittie61984's Avatar
 
Join Date: Mar 2008
Location: Fly Over State
Moto: 1996 CBR600 F3 (AKA the Flying Turd)
Posts: 4,742
Default

Quote:
Originally Posted by Homeslice View Post
I would still argue that the initial shift from weighted to weightlessness is something anyone could feel, because as soon as you step off that platform, suddenly there is no force being exerted on your feet, knees, hips, back, neck, etc. Of course, that feeling would probably cease after a split second, so maybe Felix chose not to bother mentioning it, because it was so trivial when compared to the lack of freefalling sensation caused by the lack of air pressure.
I don't know the actual feeling he would get. If there is one I doubt it's detectable by him. Mathematically, the moment his feet left the platform he wouldn't feel anything. Even his guts if they were amplified.

As you stated, correctly, about how once hte rocket turns off you are at a constant velocity with no acceleration (though technically I think you could say you are accelerating at 0 meters per second for every second), it's the same for your feet. If Felix jumped straight up, the absolute time, 1/(infinity) of a second, instantly in the true sense of instant, he is subject to the acceleration of gravity due to earth. It's illogical to think about but that is how it must work. Except at the quantam level.

Or say he shot himself straight up out of a cannon. Assume once he leaves the barrel, there isn't anymore force on him. If he was shot out with a velocity of 1million mph, he would feel he stopped right outside the barrell and wouldn't know when his velocity went to 0 or when he started coming back to earth (providing he has no reference points).

As for the scifi stuff. I don't watch too much science fiction stuff, but I think they've adopted now the warping of space*time where that stuff isn't a concern.
__________________
lifts - R.I.P.
Smittie61984 is offline   Reply With Quote
Old 10-18-2012, 04:46 PM   #105
fasternyou929
SFL Expatriate #2
 
fasternyou929's Avatar
 
Join Date: Nov 2008
Location: Raleigh, NC
Moto: CBR1000
Posts: 2,043
Default

Quote:
Originally Posted by Smittie61984 View Post
I don't know the actual feeling he would get.
Sure was a long journey to reach that conclusion.

Quote:
Originally Posted by Smittie61984 View Post
...you are at a constant velocity with no acceleration (though technically I think you could say you are accelerating at 0 meters per second for every second)
Have you ever heard someone try SO hard to speak authoratively and/or make things more complicated than they really are, only to lose credibility?
fasternyou929 is offline   Reply With Quote
Old 10-18-2012, 07:31 PM   #106
Smittie61984
I give Squids a bad name
 
Smittie61984's Avatar
 
Join Date: Mar 2008
Location: Fly Over State
Moto: 1996 CBR600 F3 (AKA the Flying Turd)
Posts: 4,742
Default

Quote:
Originally Posted by fasternyou929 View Post
Have you ever heard someone try SO hard to speak authoratively and/or make things more complicated than they really are, only to lose credibility?
Except when it comes to math and science I am very smart. Plus, I enjoy teaching people this stuff because it helps me. I give skype lesson's to my friend's daughters for their school work. Well, schoolwork that involves math or science. They're screwed if they have grammer or spelling questions.

I'm also very passionate about space travel. Anytime someone has interest in math, physics, chemistry, etc. I really jump on it. It's just on TWFix I try and do it in a more douchebag uppity fashion. People don't respond well to politeness on here.
__________________
lifts - R.I.P.
Smittie61984 is offline   Reply With Quote
Old 10-18-2012, 11:11 PM   #107
Sixxxxer
Like Gixxxxer But Not
 
Sixxxxer's Avatar
 
Join Date: Jul 2008
Location: Dirty Jersey
Moto: 2008 ZX6R
Posts: 4,891
Default

This went from a cool thread to the most boring thread in the world.
__________________
[FRSH]
Candy Plasma Blue
Sixxxxer is offline   Reply With Quote
Old 10-19-2012, 02:07 AM   #108
Homeslice
Elitist
 
Homeslice's Avatar
 
Join Date: Nov 2008
Location: SF Bay Area
Moto: Gix 750
Posts: 11,351
Default

Quote:
Originally Posted by Smittie61984 View Post
(though technically I think you could say you are accelerating at 0 meters per second for every second
Finally I understand why the seconds are squared. Been so many years since school that I forgot that shit. Its talking about a velocity increase of X mps every second. So, if the acceleration was 5 mpss, then the velocity would be 5 mps after the first second, 10 after the second, and so on.

But what if the rate of accel is increasing, how would you express that in one number?
Homeslice is offline   Reply With Quote
Old 10-19-2012, 10:52 AM   #109
OneSickPsycho
Ride Like an Asshole
 
OneSickPsycho's Avatar
 
Join Date: Feb 2008
Moto: nothing...
Posts: 11,254
Default

Quote:
Originally Posted by Smittie61984 View Post
Except when it comes to math and science I am very smart. Plus, I enjoy teaching people this stuff because it helps me. I give skype lesson's to my friend's daughters for their school work. Well, schoolwork that involves math or science. They're screwed if they have grammer or spelling questions.

I'm also very passionate about space travel. Anytime someone has interest in math, physics, chemistry, etc. I really jump on it. It's just on TWFix I try and do it in a more douchebag uppity fashion. People don't respond well to politeness on here.
Skype lessons, huh?

OneSickPsycho is offline   Reply With Quote
Old 10-19-2012, 12:20 PM   #110
azoomm
moderator chick

 
azoomm's Avatar
 
Join Date: Feb 2008
Location: Hill Country TX
Moto: Pasta Rockets
Posts: 8,917
Default

Quote:
Originally Posted by OneSickPsycho View Post
Skype lessons, huh?

Funny, that's what I read too
__________________
We have enough youth. How about a fountain of "smart"?

Come Play at the Track!!

http://www.elitetrackdays.com
azoomm is offline   Reply With Quote
Reply

Bookmarks

Tags
vacuum between the ears


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 10:22 AM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.