General Discussion

wercal

(1,370 posts)

72. To answer your moon question

Tue Feb 18, 2014, 08:23 PM

Feb 2014

"Are you also going to tell me that your "weight" is the same on, say, the moon?"

No, I'm not. That's why I've tried to qualify my statements as being on earth...and you got all bent out of shape about it and posted a photo of a spacewalk.

But w=mg works quite well for the model flying at 33k feet, in our atmosphere (to repeat the term that was so upsetting before).

"Free Fall" IS NOT weightlessness.

Once again, the example of weighing the fish in the elevator, in my Physics book, Serway, 2nd Edition, yada yada is specifically, quite targeted, deliberately, tailored towards explaining to a first year physics student that your weight is constant, no matter what the scale says.

"Free Fall" gives a sensation of weightlessness, because there is no upwards force on your body. But your weight is quite simply defined. Once again, it is the product of your mass and a constant force in nature (on earth, I will qualify)...and that constant force is gravity...'g'...a 'constant' used in thousands of physics equations. So, unless your mass changes, your weight stays the same.

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A short rant about the Kate Upton "vomit comet" photo shoot... [View all] rrneck Feb 2014 OP

thank you. I was just thinking we need at least a dozen threads on the topic Pretzel_Warrior Feb 2014 #1

... rrneck Feb 2014 #2

You sound like an asshole.... Captain Stern Feb 2014 #84

lol. hey, I'll take your backhanded compliment Pretzel_Warrior Feb 2014 #86

You probably still will. morningfog Feb 2014 #98

I was feeling lonely Pretzel_Warrior Feb 2014 #99

I guess I missed it. nt rrneck Feb 2014 #90

Yeah, I thought there was a rule against that sort of thing. JVS Feb 2014 #106

Good for you CFLDem Feb 2014 #3

No! Jet planes are for bombing foreigners and ferrying families with kids to Orlando! JVS Feb 2014 #4

I agree it's amazing. rrneck Feb 2014 #6

That's rather subjective Boom Sound 416 Feb 2014 #54

Of course it's subjective. rrneck Feb 2014 #121

I don't know Boom Sound 416 Feb 2014 #124

Yep. There are no absolutes. rrneck Feb 2014 #126

You know what Boom Sound 416 Feb 2014 #127

Thanks! nt rrneck Feb 2014 #130

The method was used much, much better for filming "Apollo 13" if you ask me. arcane1 Feb 2014 #59

It got attention because of boobies, rrneck Feb 2014 #122

You do know it is a commercial service jberryhill Feb 2014 #152

Sure. That doesn't make it any less wasteful. nt rrneck Feb 2014 #154

But if you had a 727... jberryhill Feb 2014 #158

If I had a 727 rrneck Feb 2014 #160

Take a look around the zero g website jberryhill Feb 2014 #163

Yep. You're right. They do some good work. rrneck Feb 2014 #165

i figure if boobs in space is the new thing, then we will be on alpha centauri within five years loli phabay Feb 2014 #5

You could get the same effect from a trampoline and photoshop. nt rrneck Feb 2014 #7

probably already been done, loli phabay Feb 2014 #8

True that. nt rrneck Feb 2014 #10

cant wait until its kates boobs on Mars, would speed up the space race loli phabay Feb 2014 #12

Probably the oldest incentive known to man. nt rrneck Feb 2014 #21

as it works and has been proven to again and again. loli phabay Feb 2014 #22

Just wait until they start moving at speed approaching the speed of light. JVS Feb 2014 #9

She was not weightless wercal Feb 2014 #11

Hence the use of the word "concept". nt rrneck Feb 2014 #13

Might want to edit out the part about zero gravity then. wercal Feb 2014 #19

Nah, I claim the Bluto exception. rrneck Feb 2014 #23

You'd better tell NASA they don't understand the concept.... jberryhill Feb 2014 #31

You are confused wercal Feb 2014 #38

No, see my #47. What we think of as microgravity is experienced in a falling elevator. nt stevenleser Feb 2014 #48

Better yet, see my Post #49 wercal Feb 2014 #52

You don't address microgravity. That's what we think of when we discuss "weightlessness" or stevenleser Feb 2014 #53

He's dug in jberryhill Feb 2014 #58

Why would I wercal Feb 2014 #63

Because that is what is at issue. nt stevenleser Feb 2014 #65

Lol jberryhill Feb 2014 #68

You seem to think it is wercal Feb 2014 #69

Okay, will you answer a direct question? jberryhill Feb 2014 #75

No they are not weightless wercal Feb 2014 #79

Gravity is still constant at the international space station. Travis_0004 Feb 2014 #94

Then weightlessness in popular vernacular is a misnomer. Gravitycollapse Feb 2014 #95

I believe you are conflating weight and mass pokerfan Feb 2014 #104

"You are confusing the force that you exert on the scale with weight" jberryhill Feb 2014 #51

You are wrong wercal Feb 2014 #56

"mg" is the force exerted on you at rest on the ground by the earth jberryhill Feb 2014 #57

That is a very false statement wercal Feb 2014 #64

I believe that once you stop accelerating, you could measure your weight in the elevator. Gravitycollapse Feb 2014 #77

The force of gravity is constant at a given distance, regardless of your movement. Gravitycollapse Feb 2014 #73

Orbiting height is not a different story jberryhill Feb 2014 #76

You know what I mean. The inverse square rule becomes more significant at greater distance. Gravitycollapse Feb 2014 #80

Elliptical, not parabolic muriel_volestrangler Feb 2014 #87

That's actually not pedantic at all. And it is totally a big error on my part. Gravitycollapse Feb 2014 #91

The point being.... jberryhill Feb 2014 #93

Weightlessness is thus a misnomer. The international measure of weight is the Newton. Gravitycollapse Feb 2014 #96

"Weightlessness is thus a misnomer" jberryhill Feb 2014 #97

It's a word that NASA uses all the time, as it does 'zero g' muriel_volestrangler Feb 2014 #105

It is still a misnomer. Gravitycollapse Feb 2014 #107

What difference would you expect in the weight of an object at the equator and ... muriel_volestrangler Feb 2014 #111

Gravity is subject to an inverse square law. Gravitycollapse Feb 2014 #117

"The difference amounts to approximately a half of one percent" muriel_volestrangler Feb 2014 #119

I just told you that. Gravitycollapse Feb 2014 #120

No, you didn't say anything like that muriel_volestrangler Feb 2014 #136

You don't even understand the words you are using here. Gravitycollapse Feb 2014 #138

You say it's 'negligible'; I, and the scientists, say it's clearly measurable muriel_volestrangler Feb 2014 #139

Go buy a dictionary and look up the definition of negligible. Gravitycollapse Feb 2014 #142

A half percent is not 'negligible' muriel_volestrangler Feb 2014 #144

Jesus Christ, are you unable to even look up the definition of negligible? Gravitycollapse Feb 2014 #145

I am a native speaker of English muriel_volestrangler Feb 2014 #146

As we are talking about perception of weight, a difference of half a percent is negligible. Gravitycollapse Feb 2014 #153

You do know why labs use balances, and not spring scales, eh? jberryhill Feb 2014 #148

"When an object is in free-fall, it does not make sense to talk about its "weight"." Gravitycollapse Feb 2014 #156

Because it is offensive to talk about weight jberryhill Feb 2014 #166

Try this.... jberryhill Feb 2014 #115

I know all of that. Gravitycollapse Feb 2014 #118

The international definition of temperature in deg C doesn't make you hot jberryhill Feb 2014 #141

What you just typed is completely nonsensical. Gravitycollapse Feb 2014 #143

The point is jberryhill Feb 2014 #147

The inability to measure weight does not mean a body is weightless. Gravitycollapse Feb 2014 #155

Weight is the FORCE exerted on the body jberryhill Feb 2014 #159

Umm.... jberryhill Feb 2014 #17

Would that condition be described by the special theory of relativity? rrneck Feb 2014 #20

It has nothing to do with relatively jberryhill Feb 2014 #26

I'm too tired. I'll take your word for it. nt rrneck Feb 2014 #28

Unless, that is, we get into Einstein's ideas about the equivalance of a gravitational field muriel_volestrangler Feb 2014 #83

Methinks I know quite a bit about Weightlessness wercal Feb 2014 #24

I see, and what does the atmosphere have to do with it? jberryhill Feb 2014 #30

You should check the stuff you scab from wikipedia before you post it wercal Feb 2014 #33

And you should take a physics course jberryhill Feb 2014 #37

You are right but I don't think many people understand this at all. There is no zero gravity. stevenleser Feb 2014 #43

W=mg wercal Feb 2014 #49

Look at the definition in the book jberryhill Feb 2014 #55

Using that logic, all objects would become weightless when not on the ground wercal Feb 2014 #61

No, not "on earth". Every object in the universe is being tugged on by the earth toward its center. stevenleser Feb 2014 #62

In my example wercal Feb 2014 #66

No.... jberryhill Feb 2014 #67

To answer your moon question wercal Feb 2014 #72

You are always 100% of the time subject to gravity. Even if you were outside the solar system. stevenleser Feb 2014 #47

"gravity up in orbit is around 10% of what we experience here on terra firma" - a number you pulled muriel_volestrangler Feb 2014 #70

I don't think he thinks the astronauts in the ISS are "weightless" jberryhill Feb 2014 #71

My fault - I meant to say 10% less than. wercal Feb 2014 #74

Okay, so why do the astronauts float around in the ISS? jberryhill Feb 2014 #78

NO!!!!!! wercal Feb 2014 #82

What difference does the atmosphere make? jberryhill Feb 2014 #92

You're not 'schooling' anyone muriel_volestrangler Feb 2014 #81

We spent more than that to look at a flag on the moon jberryhill Feb 2014 #14

We didn't go up there just to look at a flag. nt rrneck Feb 2014 #15

why do you hate science? Botany Feb 2014 #16

LOL! rrneck Feb 2014 #18

Barbarella made real Blue_Adept Feb 2014 #45

They did the same thing for Stephen Hawking. Warren DeMontague Feb 2014 #25

Hawking has a bit more gravitas. rrneck Feb 2014 #27

Being anti-decadence is overrated, in my experience. Warren DeMontague Feb 2014 #29

We all need to indulge in a bit of decadence now and then. rrneck Feb 2014 #32

I think our culture will survive the Zero-G bikini shoot. Warren DeMontague Feb 2014 #34

Of course it would. rrneck Feb 2014 #36

And again, there is a lot of carbon activity that you or i might consider "frivolous" Warren DeMontague Feb 2014 #39

You just insist in being reasonable rrneck Feb 2014 #41

I admit, sometimes I do it just to piss people off Warren DeMontague Feb 2014 #42

This message was self-deleted by its author rrneck Feb 2014 #50

The force of gravitas is constant at a given distance, regardless of your movement. Orrex Feb 2014 #161

Okay, I'm calling thread win right there. nt rrneck Feb 2014 #162

Not true. Warren DeMontague Feb 2014 #167

Maybe this is the break women are looking for... boston bean Feb 2014 #35

In space, no one can hear you Warren DeMontague Feb 2014 #40

Why do you care what AnalystInParadise Feb 2014 #44

It's a culture thing. rrneck Feb 2014 #46

The Taliban called, they want their talking point back... n/t bobclark86 Feb 2014 #60

They called the wrong number. rrneck Feb 2014 #88

One mans bullshit... Blue_Adept Feb 2014 #108

For the Love of God... rrneck Feb 2014 #113

Why do you care? AnalystInParadise Feb 2014 #125

It's a perfectly appropriate question. rrneck Feb 2014 #129

So shaming of women AnalystInParadise Feb 2014 #132

I don't think shaming the groups you mentioned is "cool" rrneck Feb 2014 #133

So AnalystInParadise Feb 2014 #137

So rrneck Feb 2014 #140

You are judging someone doing something you don't like AnalystInParadise Feb 2014 #149

A fine libertarian position you got there. rrneck Feb 2014 #150

Then you better not watch Barbarella.......... thelordofhell Feb 2014 #85

I've seen it. It had more redeeming value. Not a lot, but some. rrneck Feb 2014 #89

No different than spending 150 million on a movie. Correct? nt Logical Feb 2014 #100

Exactly the same rrneck Feb 2014 #102

Seems you give at least one counted fuck... Lost_Count Feb 2014 #101

Not about ogling naked women... rrneck Feb 2014 #103

Look. Sheldon Cooper Feb 2014 #109

I'm not sure how deep boobies actually dive snooper2 Feb 2014 #114

None of that was a waste....because here you are talking and ranting about it in a public forum. cbdo2007 Feb 2014 #110

That sort of thinking is a two way street and both directions lead to a dead end. rrneck Feb 2014 #116

I knew nothing about this, but will research it ......happily :) NM_Birder Feb 2014 #112

To tell the truth, I'm more offended by pictures of women with mops, Cleita Feb 2014 #123

All the effort making the video and all the controversy surrounding it made me seek it out. Bok_Tukalo Feb 2014 #128

Good. nt rrneck Feb 2014 #131

I'd like to see ole "Barbie", I mean "Kate" in about 10 years ... Peregrine Took Feb 2014 #134

Hey I'd do it if I got paid what she did. Cleita Feb 2014 #135

Huuuuhhhhh,huhhhh,huhhhh,hhhuuuuhhhhh......... Cofitachequi Feb 2014 #151

Any political squabbling aside, I can certainly agree that the "zero-G boobs" thing is inane and nomorenomore08 Feb 2014 #157

BOOBIES!!! PowerToThePeople Feb 2014 #164