episodes 1215 'The Donation Oscillation' (February 7)

[Stephen Hawking]

That Vomit Comet experience looks really cool.

I'd love to do it.

[MsGreentea]

4 hours ago, Chrismo said:

It also had the most viewers of the season which is not an opinion. As to how boring it was I wonder what thread that was or maybe you could  tell me where you read how boring it was.

It had the most viewers and the weather was pretty good so it was certainly a success in that viewers weren’t snowed or frozen in at home.  I like the episode, it certainly was not amazingly fabulous or anything.  I had high hopes for the Wolowitzes and Raj plot, but the only really funny stuff was the preplanning scenes in the cafeteria and Wolowitz’s house.  I liked the Lenny plot well enough.  I just hope the finale brings a sweeter ending for Leonard and Penny.  

[djsurrey]

43 minutes ago, SRAM said:

1 hour ago, vonmar said:

The experience offered by ZERO-G is the only commercial opportunity on Earth for individuals to experience true weightlessness without going to space.

Zero G

It is the illusion of zero gravity, but actually it is nothing more than what a skydiver feels in free fall.  When space you actually feel zero gravity and it has effects  on your body and sense of balance, in free fall gravity is still in control in what your body feels, so again this is only an illusion.  What gets people sick on the vomit comet is the exaggerated sense of vertigo, the same sense they get on a roller coaster, or bumpy aircraft ride, not the feeling people get when their body loses its sense of gravity.  So saying that riding the vomit comet gives you the experience of weightlessness is actually wrong, it gives you the illusion of weightlessness.

That discussion gets dicey unless one defines gravity, weightlessness and illusion. I'd say one is weightless but it is not actually zero gravity.

The gravity is not zero because the law of universal gravitation.

The force is not felt because both the person and the aircraft are essentially in free fall. This is not an illusion. The same situation exists on the international space station. The difference is that it is in orbit. It is still in free fall but moving fast enough that the distance between it and the center of the earth is essentially constant. In either case if the frame of reference is the inside space one can not distinguish between zero gravity and free fall.

Edited February 9, 2019 by djsurrey

[SRAM]

12 minutes ago, djsurrey said:

That discussion gets dicey unless one defines gravity, weightlessness and illusion. I'd say one is weightless but it is not actually zero gravity.

The gravity is not zero because the law of universal gravitation.

The force is not felt because both the person and the aircraft are essentially in free fall. This is not an illusion. The same situation exists on the international space station. The difference is that it is in orbit. It is still in free fall but moving fast enough that the distance between it and the center of the earth is essentially constant. In either case if the frame of reference is the inside space one can not distinguish between zero gravity and free fall.

I’m sorry I can’t let this go, the force of gravity is felt on the vomit comet, the plane is put into a dive to match the fall velocity of its occupants to give the illusion that they are weightless, however the whole reason the plane and its occupants are diving towards earth is that they are not weightless and gravity is acting on them.  So the human body still feels the same gravitational force, there is still an up and down to the human body, and again what the occupants of the aircraft feel is a form of vertigo.

 In orbit, the spacecraft is so far away from the gravitational source that to the body it feels like gravity lost completely which has a huge impact on our balance system and how our body is actually is aligned, that is why astronauts have so much trouble when they return.  In space a body is not in free fall but is being taken along in a craft going at great speeds, in the tens of thousands of miles per hour, in a way like flying on an airliner,  whichresults in enough inertia to overcome gravity, drag of the thin remaining atmosphere, etc. without escaping the earths gravitational pull, it is a balancing act.  The weightless is actually achieved because the inertia of the body is enough to counter the remaining weak gravity force on the craft, you have a balance of forces.  This is not what is happening when you are plummeting back to earth, due to gravity, on the vomit comet.

 Actually I would feel much safer skydiving to get the same effect because if the vomit comet experiences structural failure during this high “G” maneuver, everyone dies because this is one of those unrecoverable situations,  at least with skydiving I would have a reserve chute in case of problems.  There is one difference though between the vomit comment and skydiving though that I must admit, you don’t get that wind in the face adrenaline rush in the vomit comet that you get in skydiving.

[djsurrey]

1 hour ago, SRAM said:

I’m sorry I can’t let this go, the force of gravity is felt on the vomit comet, the plane is put into a dive to match the fall velocity of its occupants to give the illusion that they are weightless, however the whole reason the plane and its occupants are diving towards earth is that they are not weightless and gravity is acting on them.  So the human body still feels the same gravitational force, there is still an up and down to the human body, and again what the occupants of the aircraft feel is a form of vertigo.

I have no connection with these aircraft but your description sounds wrong to me. For example if one were to put a three axis accelerometer in free fall it would register zero g. Vertigo has nothing to do with that.

1 hour ago, SRAM said:

In orbit, the spacecraft is so far away from the gravitational source that to the body it feels like gravity lost completely which has a huge impact on our balance system and how our body is actually is aligned, that is why astronauts have so much trouble when they return.  In space a body is not in free fall but is being taken along in a craft going at great speeds, in the tens of thousands of miles per hour, in a way like flying on an airliner,  whichresults in enough inertia to overcome gravity, drag of the thin remaining atmosphere, etc. without escaping the earths gravitational pull, it is a balancing act.  The weightless is actually achieved because the inertia of the body is enough to counter the remaining weak gravity force on the craft, you have a balance of forces.  This is not what is happening when you are plummeting back to earth, due to gravity, on the vomit comet.

Sorry. You are wrong. An object in orbit is in free fall. It is accelerating towards the center of the earth but the direction of travel and acceleration is constantly changing so the radius from the centre of the earth is constant.

Quote

Free fall[edit]

Gravity at the altitude of the ISS is approximately 90% as strong as at Earth's surface, but objects in orbit are in a continuous state of freefall, resulting in an apparent state of weightlessness.^[50] 
from https://en.wikipedia.org/wiki/International_Space_Station#Purpose 

1 hour ago, SRAM said:

 Actually I would feel much safer skydiving

Actually skydiving is somewhat different because the person quickly reaches terminal velocity. That means they do not remain in free fall because of air resistance which stops the acceleration.

Edited February 9, 2019 by djsurrey
correction to last point!

[Capt. Hilts]

22 hours ago, Tensor said:

I got some good laughs out of this episode.   Much better than the totally bullshit super asymmetry plot lines.   For a show that has prided itself on it's science for 12 years, the completely fake asymmetry idea has been a stain on the final season.  

And I think the 'will she want to have a baby, or won't she' thread is a stain on the final season.

I would prefer to see them doing something that makes them happy rather than arguing and manipulating each other about this topic.  

[Tensor]

 

27 minutes ago, Capt. Hilts said:

And I think the 'will she want to have a baby, or won't she' thread is a stain on the final season.

Who?  Not Penny, she’s made it clear she won’t.  Not sure where there was a she will this season, can you point it out?

27 minutes ago, Capt. Hilts said:

I would prefer to see them doing something that makes them happy rather than arguing and manipulating each other about this topic.  

I’ve been making that point for several years, about any topic. But now, we have Amy starting to manipulate Sheldon about kids. 

You don’t think it’s hypocritical for them to be proud of trying to keep things as scientific as possible, yet hold up a totally fake idea about symmetry as some sort of panacea, with a possibility of a noble prize?

[SRAM]

4 hours ago, djsurrey said:

I have no connection with these aircraft but your description sounds wrong to me. For example if one were to put a three axis accelerometer in free fall it would register zero g. Vertigo has nothing to do with that.

Sorry. You are wrong. An object in orbit is in free fall. It is accelerating towards the center of the earth but the direction of travel and acceleration is constantly changing so the radius from the centre of the earth is constant.

Actually skydiving is somewhat different because the person quickly reaches terminal velocity. That means they do not remain in free fall because of air resistance which stops the acceleration.

What you are talking about with a three axis accelerometer is based on a situation where the object has the accelerometer attached to it and based on its relative motion it appears that acceleration is zero, but that has nothing to do with the object when you look at the big picture.  The object still has gravity acting on it which is causing the object to fall to earth, when you put together your equation for terminal velocity of an object you set your object acceleration to zero, but you still need to use the acceleration of gravity in the equation to solve for terminal velocity, because gravity still is a constant force on the object.

Free-fall is the movement of an object solely by the force of gravity, the statement that the ISSS is in free-fall is bullshit, at the speed the ISSS is traveling it would immediately fly off into space if it didn’t have gravity to hold it in orbit, but because it has other forces acting on it, it is not in free-fall.  An object in orbit is like a tethered ball being rotated around a fixed point, gravity applying the force to hold the ball from flying off, that is nothing like freefall because there are multiple forces and they control the movement of the ball, not just the string acting like gravity.  Wikipedia has so much bullshit written by people that are not experts, engineers or scientists but think they know everything, it is ridiculous.

Sorry but skydivers are in free-fall because gravity is the only force responsible for their motion, that is the definition of free-fall.  

[Tensor]

 

50 minutes ago, SRAM said:

 

Free-fall is the movement of an object solely by the force of gravity, the statement that the ISSS is in free-fall is bullshit, at the speed the ISSS is traveling it would immediately fly off into space if it didn’t have gravity to hold it in orbit, but because it has other forces acting on it, it is not in free-fall.

Ignoring minor actions on the ISS (I'll put them back later, I promise), what other forces, besides gravity, are acting on the ISS?   The velocity of the ISS is irrelevant at this point.  Only when they do a burn to increase the height of it's orbit, is it under a force other than gravity.    How about the moon, what other forces are acting on the moon?

 

50 minutes ago, SRAM said:

 

 An object in orbit is like a tethered ball being rotated around a fixed point, gravity applying the force to hold the ball from flying off, that is nothing like freefall because there are multiple forces and they control the movement of the ball, not just the string acting like gravity.  

Bad analogy.  Anything in orbit is in free fall as gravity is the only force acting on it.  In the analogy, you have gravity (the string) and what else?   Atmospheric drag?  We're ignoring that remember.  Gravity itself?  You have to ignore that, the string is gravity.  Anything else?

 

50 minutes ago, SRAM said:

Wikipedia has so much bullshit written by people that are not experts, engineers or scientists but think they know everything, it is ridiculous.

I would have you check out any college physics text book.  Or possibly Feymann's Lectures or a first college class on general relativity, so you can compare the definitions.  Objects in orbit are, by definition, in free fall.  Now, getting to orbit, or dropping out of orbit there are other forces, but not simply being in orbit.  

50 minutes ago, SRAM said:

Sorry but skydivers are in free-fall because gravity is the only force responsible for their motion, that is the definition of free-fall.  

Actually, bringing back atmospheric pressure (I told you I would), a skydiver is less in free fall than any object in orbit.  Skydiver's have all sorts of atmospheric drag, that increases the lower they get.  Compared to that, the atmospheric drag on the ISS is negligible, and much closer to free fall than a sky diver.  

As for dj's explanation for an orbit, it's pretty much correct:  

Quote

It is accelerating towards the center of the earth but the direction of travel and acceleration is constantly changing so the radius from the centre of the earth is constant.

I would probably have used the word velocity, instead of acceleration (acceleration is a force).  But, yes, the acceleration toward the center of the Earth is the only force acting on the ISS.   The ISS falls toward the center of the Earth, but it's velocity moves it enough, that the Earth's surface has curved away from it, keeping it in a constant state of falling.    In a constant height orbit, the ISS is at the same height everywhere in it's orbit.   That doesn't happen as there are masscons on and under the earth that cause minor accelerations and of course there is atmospheric drag.  But, using simplifying assumptions (such as spherical cows or chickens), an object in orbit is in free fall.   

 

 

[veejay]

8 hours ago, Chrismo said:

Are they really going to move out of the building? Don’t think so

Why not? It's the final season. They can open a kindergarten or hold a coffee klatsch every day. I don't care. 😉

[son-goku5]

Interesting that the comment thread on an episode breaks down into a discussion about gravity 😄

Science bitch! 😄 😄 😄

My take on the episode. I thought it was funnier than some before, but I think that's mostly due to Zack's appearance. The guy can always make someone laugh, if only in exasperation about how one like him can even function.

I read that some people didn't understand how Sheldon could even consider offering his services for other people's offspring but I think it's quite congruent with Sheldon's behavior:

The reason may simply be jealousy.

Sheldon learned that someone wanted Leonard for something because of his smarts. Sheldon, who sees himself as superior to Leonard in every way, can't stand that and so, wants his genetic material to be chosen.

[Stephen Hawking]

11 hours ago, djsurrey said:

The gravity is not zero because the law of universal gravitation.

Hence why astronauts refer to microgravity, rather than weightlessness.

ETA: Interesting fact - The Vomit Comet was actually used to film many of the earth orbit scenes, in the movie Apollo 13.

Edited February 9, 2019 by Stephen Hawking

[Die Zimtzicke]

19 hours ago, Tensor said:

I’ve been making that point for several years, about any topic. But now, we have Amy starting to manipulate Sheldon about kids. 

You don’t think it’s hypocritical for them to be proud of trying to keep things as scientific as possible, yet hold up a totally fake idea about symmetry as some sort of panacea, with a possibility of a noble prize?

I want to actually see the ep before I decide how much manipulation is going on. As for the Nobel I really hope that doesn't pan out. They literally gave them an out when they set it up so that there are two conflicting papers.

Edited February 9, 2019 by Die Zimtzicke

[djsurrey]

2 hours ago, Die Zimtzicke said:

I want to actually see the ep before I decide how much manipulation is going on. As for the Nobel I really hope that doesn't pan out. TYhey literally gave them an out when they set it up so that there are two conflicting papers.

If the Nobel is announced in October it will be past the end date of the series. I'm thinking that unless there is a time jump that story line won't be finished.

[Capt. Hilts]

11 hours ago, Tensor said:

 

Who?  Not Penny, she’s made it clear she won’t.  Not sure where there was a she will this season, can you point it out?

I’ve been making that point for several years, about any topic. But now, we have Amy starting to manipulate Sheldon about kids. 

You don’t think it’s hypocritical for them to be proud of trying to keep things as scientific as possible, yet hold up a totally fake idea about symmetry as some sort of panacea, with a possibility of a noble prize?

"Will she" - the future indefinite.  The writers keep dancing around this topic to taunt fans.

Amy and Sheldon talked about kids before their first date, about having them on Mars, etc.  Nothing new there.  

As I don't write fan fiction, or read it, I don't bring the same intensity, or personal stake in these characters you bring to these discussions. 

I think the writers have come close to ruining the character 'Penny'.  Sad!

[djsurrey]

4 hours ago, Stephen Hawking said:

15 hours ago, djsurrey said:

The gravity is not zero because the law of universal gravitation.

Hence why astronauts refer to microgravity, rather than weightlessness.

Just to be clear when they or NASA say microgravity the frame of reference is the space station itself. 

When the frame of reference is the earth the acceleration due to gravity at the height of the space station is still 8.6 m/s2 which is much closer to what it is at the earths surface than to zero. (refs https://www.nasa.gov/centers/glenn/shuttlestation/station/microgex.html and https://www.loretobalbriggan.ie/physics/Sample problems and solutions/2008 q6 mech.pdf )

Quote

If you drop an apple on Earth, it falls at 1g. If an astronaut on the space station drops an apple, it falls too. It just doesn't look like it's falling. That's because they're all falling together: the apple, the astronaut and the station. But they're not falling towards Earth, they're falling around it. Because they're all falling at the same rate, objects inside of the station appear to float in a state we call "zero gravity" (0g), or more accurately microgravity (1x10^-6 g.)

Yet...

Quote

Many people mistakenly think that gravity does not exist in space. However, typical orbital altitudes for human spaceflight vary between 120 - 360 miles above Earth's surface. The gravitational field is still quite strong in these regions, since this is only about 1.8 percent the distance to the moon. Earth's gravitational field at about 250 miles above the surface is 88.8 percent of its strength at the surface. Therefore, orbiting spacecraft, like the space shuttle or space station, are kept in orbit around Earth by gravity.

 

[Kev0821]

bts_cali

Look at all of those wonderful people.

 

kunalkarmanayyar

That harness was all up in my business

 

missmayim

So envious you all got to do this!!!!

[Stephen Hawking]

I almost didn't recognise Jim Parsons there.  

[MsGreentea]

2 hours ago, Stephen Hawking said:

I almost didn't recognise Jim Parsons there.  

Do you mean Steve Holland.  I thought it might be Jim at first.

[Sah]

3 hours ago, Capt. Hilts said:

"Will she" - the future indefinite.  The writers keep dancing around this topic to taunt fans.

Amy and Sheldon talked about kids before their first date, about having them on Mars, etc.  Nothing new there.  

As I don't write fan fiction, or read it, I don't bring the same intensity, or personal stake in these characters you bring to these discussions. 

I think the writers have come close to ruining the character 'Penny'.  Sad!

How is the Penny character ruined by deciding to not have kids? She will still have a wonderful life with Leonard. Just because they may not have kids does not mean her or Leonard's life is over. There really is life to be lived without kids...Penny has matured and grown into her own person since we first met her. I don't see her as ruined. 

[legacy99]

How is the Penny character ruined by deciding to not have kids? She will still have a wonderful life with Leonard. Just because they may not have kids does not mean her or Leonard's life is over. There really is life to be lived without kids...Penny has matured and grown into her own person since we first met her. I don't see her as ruined. 

My opinion is that Leonard may except the no kids now but down the road a few years he may see families around him and start to realize what missing in his life and rethink his decision to stay with Penny

Sent from my SM-G930P using Tapatalk

[MsGreentea]

23 minutes ago, legacy99 said:

My opinion is that Leonard may except the no kids now but down the road a few years he may see families around him and start to realize what missing in his life and rethink his decision to stay with Penny

Sent from my SM-G930P using Tapatalk
 

If Leonard didn’t want children or was ambivalent about having children it would be fine, but he is neither.  I can not see Leonard leaving Penny ever, I also can’t see Leonard ever being really okay with not having kids (unless they couldn’t).  So he is kind of stuck.  Poor Leonard.  

[Stephen Hawking]

1 hour ago, MsGreentea said:

Do you mean Steve Holland.  I thought it might be Jim at first.

The guy on the extreme left, with his arm around Keith Carradine, isn't Jim Parsons?

[MsGreentea]

5 minutes ago, Stephen Hawking said:

The guy on the extreme left, with his arm around Keith Carradine, isn't Jim Parsons?

Sorry I thought you meant the flying photo 

[SRAM]

14 hours ago, Tensor said:

 

Ignoring minor actions on the ISS (I'll put them back later, I promise), what other forces, besides gravity, are acting on the ISS?   The velocity of the ISS is irrelevant at this point.  Only when they do a burn to increase the height of it's orbit, is it under a force other than gravity.    How about the moon, what other forces are acting on the moon?

 

Bad analogy.  Anything in orbit is in free fall as gravity is the only force acting on it.  In the analogy, you have gravity (the string) and what else?   Atmospheric drag?  We're ignoring that remember.  Gravity itself?  You have to ignore that, the string is gravity.  Anything else?

 

I would have you check out any college physics text book.  Or possibly Feymann's Lectures or a first college class on general relativity, so you can compare the definitions.  Objects in orbit are, by definition, in free fall.  Now, getting to orbit, or dropping out of orbit there are other forces, but not simply being in orbit.  

Actually, bringing back atmospheric pressure (I told you I would), a skydiver is less in free fall than any object in orbit.  Skydiver's have all sorts of atmospheric drag, that increases the lower they get.  Compared to that, the atmospheric drag on the ISS is negligible, and much closer to free fall than a sky diver.  

As for dj's explanation for an orbit, it's pretty much correct:  

I would probably have used the word velocity, instead of acceleration (acceleration is a force).  But, yes, the acceleration toward the center of the Earth is the only force acting on the ISS.   The ISS falls toward the center of the Earth, but it's velocity moves it enough, that the Earth's surface has curved away from it, keeping it in a constant state of falling.    In a constant height orbit, the ISS is at the same height everywhere in it's orbit.   That doesn't happen as there are masscons on and under the earth that cause minor accelerations and of course there is atmospheric drag.  But, using simplifying assumptions (such as spherical cows or chickens), an object in orbit is in free fall.   

 

 

I’m not going to get into a long discussion on your response because you are already commenting on things I never said.  This discussion blew up with the subject of Free-Fall so I’ll only reply to that, Free-Fall is simply defined as the movement of an object being SOLELY caused by gravity.  If you look at the velocity vectors of objects in space and the direction of the gravitational force you will quickly realize that they don’t meet the definition of Free-Fall.  You can quote all the bad analogies you want from the internet but that does not make it correct.