(How much) does it matter when you weigh something?

[Raymond Lin]

(How much) does it matter when you weigh something?

And

Assuming the entire mass of the Milky Way acting as a single point it would take 12 years for mavity to pull you 1 metre closer. 1 metre out of 26500 light years.

The amount of time it takes for these tiny forces to compound into large effects is so far beyond the human lifespan I just cannot consider them as relevant.

So in short, to answer OP's question.

How much it matters? Tiny tiny tiny.

Does it matter? Not unless you are an immortal.



P.s. side note, Shayper is more than just a party animal shocker!

 

[EGuitarStar]

Read the religious books people that is where the answer is, not man made science.

/stupidity
/trolling
/religion

Nice thread this one.

 

[Shayper]

And



So in short, to answer OP's question.

How much it matters? Tiny tiny tiny.

Does it matter? Not unless you are an immortal.



P.s. side note, Shayper is more than just a party animal shocker!

Oi you! I'm not just a drunk face! I can do physics and maths too and chemistry

I do enjoy talking about these sort of subjects as well, shame there are no physicists that I know at uni. I just keep having conversations with philosophers

 

[Shayper]

Read the religious books people that is where the answer is, not man made science.

/stupidity
/trolling
/religion

Nice thread this one.

GD must have warped my tiny little mind. I can't tell if you are being serious

 

[Castiel]

I can sort of see what you're saying, but I still disagree. The problem for me is a matter of scale, both in space and time. The forces are so small that the amount of time they need to have any effect is overwhelmingly swamped by local effects.
You mention this Galaxy so I looked at some numbers (strictly Newtonian for time and simplicities sake). We're somewhere between 25-28 thousand light years away from the centre of our galaxy so I'll take the average of those two.
The total mass of the Milky Way is estimated at 2-3E42 kg, so lets call it 2.5 for now.
Assuming the entire mass of the Milky Way acting as a single point it would take 12 years for mavity to pull you 1 metre closer. 1 metre out of 26500 light years.

The amount of time it takes for these tiny forces to compound into large effects is so far beyond the human lifespan I just cannot consider them as relevant.

You are kind of missing the point, probably my fault to not explaining myself clearly.

I am not referring to it having a direct effect on an individual in a particular point of reference.

for example......(ignore the unlikely scenario, it is only illustrative of the concept)

A supernova the other side of the Galaxy shifts the orbit of a nearby Star, which in turn pushes the orbit of a planetoid thus turning it into a rogue planet which in turn enters into a neighboring Solar System and pushes the orbit of that Solar system out of sync which in turn shifts the orbits of its neighbouring systems and so on..........until the effect reaches our Solar system in the form of an Asteroid which through the string of connected events was pushed out from its orbit and slams into the newly formed Earth, thus creating a Satellite a third of the size of it's Parent which eventually leads to tidal forces that contribute to the birth of life in the Universe..... so while the Supernova had no direct effect on the Earth, it was too far away and the subjective time-frame too great....however through a string of related events it played an indirect part in the creation of life and thus indirectly it has effected my life.......

I am not talking about the scenario in the OP, but as a general point of the concept of an interconnected Universe where even the smallest change effects the whole, no matter how small or insignificant that effect may be. It is a philosophical question rather than a Scientific one.

 

[[FnG]magnolia]

As an aside, I do believe that there are a number of physics PhD's, professors, or general scientists here.

This is what my mantoddler tirade was about - I don't think there are, certainly not professors. I would be delighted to be proved wrong on this. I know we have at least two mathematics Profs and they've been very useful in the past in providing more 'solid' answers to maths questions.

I just find the whole guesswork and wiki-quoting that generally comes from these questions to be frustrating. It'd be nice to get an answer from someone who actually really knew their stuff. On the other hand, this is a discussion forum so it's probably just me getting uptight about things that don't really matter. Anyway, I meant no offence to anyone who had posted, I was getting wound up by the situation more than the replies.

 

[Shayper]

Well I for one wasn't wiki-quoting. A lot of what I've said I also said in a debate for an interview for a physics course for Southampton Uni.

Shame I didn't get the grades overall, the professor was brilliant to talk to!

 

[EGuitarStar]

GD must have warped my tiny little mind. I can't tell if you are being serious

I know GD does have its strangers and weirdos but hell no.

Religion exists to keep us all dumb and blind!

 

[Duff-Man]

This is what my mantoddler tirade was about - I don't think there are, certainly not professors. I would be delighted to be proved wrong on this. I know we have at least two mathematics Profs and they've been very useful in the past in providing more 'solid' answers to maths questions.

I just find the whole guesswork and wiki-quoting that generally comes from these questions to be frustrating. It'd be nice to get an answer from someone who actually really knew their stuff. On the other hand, this is a discussion forum so it's probably just me getting uptight about things that don't really matter. Anyway, I meant no offence to anyone who had posted, I was getting wound up by the situation more than the replies.

Did you read my post? Or did you simply dismiss it because I referenced wikipedia as the source for magnitude of the physical parameters? There should be plenty enough there that you can verify any of the variables with a couple of minutes on google if you like... The fact is, wikipedia often provides a useful summary of a topic, and is usually written in "layman-friendly" language, which is handy for anyone who is interested in the subject. What are you expecting? Peer-review sourced material on an internet forum?


It seems that you're interested in finding someone who is "qualified" to answer the question? I don't normally like to wave this stuff around online, but I have a PhD in mechanical engineering, and did a my undergraduate degree in maths at Cambridge. Right now I'm a post-doctoral researcher at a University. I've answered dozens of science and tech-related questions here over the years (... for example). I don't know if that changes anything - it certainly shouldn't. It doesn't change what I posted, how it answers the original question, or its validity. The great thing about forums is that we are all just words on a screen.

But hey - whatever. Dismiss everyone's answers as useless "wiki-quoting". I'm not sure what you were expecting? I could go into detail about how you could estimate the various quantities, but why bother when others have already made precise measurements - mapping the gravitational variation over the earth's surface via satellite? Research usually isn't about starting from scratch you know...

 

[David91]

I remember seeing a TV show a while back where they interviewed the developers of a mavity measuring device in a college in the US.

It had such an accurate measurement it could measure the change in mavity globally as the colleges football team played, and people moved to the stadium and back.

Unfortunately i can no longer remember where i saw it. Nice tidbit though!

 

[Duff-Man]

I remember seeing a TV show a while back where they interviewed the developers of a mavity measuring device in a college in the US.

It had such an accurate measurement it could measure the change in mavity globally as the colleges football team played, and people moved to the stadium and back.

It's amazing the sensitivity to which you can measure certain things.

The most comprehensive mapping of the Earth's gravitational variation was made recently, by the Goce satellite (link - to the guardian this time, to please the wiki-haters ). The satellite can detect variations in gravitation strength of one part in 10^13, which is a huge number! I heard a nice analogy for this level of sensitivity: It's equivalent that of detecting the disturbance of a feather falling on a supertanker

 

[[FnG]magnolia]

Did you read my post? Or did you simply dismiss it because I referenced wikipedia as the source for magnitude of the physical parameters? There should be plenty enough there that you can verify any of the variables with a couple of minutes on google if you like... The fact is, wikipedia often provides a useful summary of a topic, and is usually written in "layman-friendly" language, which is handy for anyone who is interested in the subject. What are you expecting? Peer-review sourced material on an internet forum?

Yes, I read your post.

It seems that you're interested in finding someone who is "qualified" to answer the question?

I thought I was being particularly clear on this point.

I don't normally like to wave this stuff around online, but I have a PhD in mechanical engineering, and did a my undergraduate degree in maths at Cambridge. Right now I'm a post-doctoral researcher at a University. I've answered dozens of science and tech-related questions here over the years (... for example). I don't know if that changes anything - it certainly shouldn't. It doesn't change what I posted, how it answers the original question, or its validity. The great thing about forums is that we are all just words on a screen.

The only thing it changes is how much faith I put behind the answer given.

But hey - whatever. Dismiss everyone's answers as useless "wiki-quoting". I'm not sure what you were expecting? I could go into detail about how you could estimate the various quantities, but why bother when others have already made precise measurements - mapping the gravitational variation over the earth's surface via satellite? Research usually isn't about starting from scratch you know...

I think you've completely missed the point of what I was trying to say.

 

[Tekgun]

I'm no physicist but wouldn't the weight stay the same?
mavity does not change the weight of something, astronauts visiting the moon are not lighter they just have less mavity force affecting them hence can jump about easier etc, but they still have the same weight.

 

[Duff-Man]

I'm no physicist but wouldn't the weight stay the same?
mavity does not change the weight of something, astronauts visiting the moon are not lighter they just have less mavity force affecting them hence can jump about easier etc, but they still have the same weight.

Their mass stays the same, but their weight will vary. The weight of an object is the force generated by mavity acting upon its mass.

The common misnomer comes from referring to our "weight" in kilograms. What we are really measuring is our mass, which we are inferring from the (relatively) constant gravitational field on our planet. Technically, our weight would be measured in Newtons rather than kilograms.

If you went to the moon, your weight would reduce, and so would the force required to move your body, but your mass would stay the same. If your mass is 80Kg, then you're 80Kg everywhere (even though you may be able to jump really high on the moon!).

I think you've completely missed the point of what I was trying to say.

Well the point I'm making is that it's impractical to expect people to provide a summary of their qualifications, in order to justify things posted on an internet forum.

Posts (and posters) should be judged only on their content. The skill, as always, is with the reader - to asses the quality of the information they are digesting, and take it accordingly. Facts can be easily checked, sources verified, and a quick search of past posting will show whether the poster knows what they're talking about, if it seems doubtful.

On the internet people are whatever they choose to be, to a certain extent, so listening only to people who claim to have certain qualifications is pointless.

 

[bJN]

I know GD does have its strangers and weirdos but hell no.

Religion exists to keep us all dumb and blind!

No, that's the media, bet let's not open that can of worms!

Shayper does know his stuff when it comes to Physics. He isn't as good at Chemistry though

And @OP: It will have an effect, however it won't affect it with much effect.

I love wordplay

 

[[FnG]magnolia]

snip ... really good stuff ... snip

Well the point I'm making is that it's impractical to expect people to provide a summary of their qualifications, in order to justify things posted on an internet forum.

Posts (and posters) should be judged only on their content. The skill, as always, is with the reader - to asses the quality of the information they are digesting, and take it accordingly. Facts can be easily checked, sources verified, and a quick search of past posting will show whether the poster knows what they're talking about, if it seems doubtful.

On the internet people are whatever they choose to be, to a certain extent, so listening only to people who claim to have certain qualifications is pointless.

I disagree, particularly where it concerns things I know little or, more often, nothing about the subject in hand. This is a relatively small forum and I will place more faith in an answer posted by someone I recognise as having a strong background in the 'thing' that is being discussed.

 

[bam0]

You are kind of missing the point, probably my fault to not explaining myself clearly.

I am not referring to it having a direct effect on an individual in a particular point of reference.

for example......(ignore the unlikely scenario, it is only illustrative of the concept)

A supernova the other side of the Galaxy shifts the orbit of a nearby Star, which in turn pushes the orbit of a planetoid thus turning it into a rogue planet which in turn enters into a neighboring Solar System and pushes the orbit of that Solar system out of sync which in turn shifts the orbits of its neighbouring systems and so on..........until the effect reaches our Solar system in the form of an Asteroid which through the string of connected events was pushed out from its orbit and slams into the newly formed Earth, thus creating a Satellite a third of the size of it's Parent which eventually leads to tidal forces that contribute to the birth of life in the Universe..... so while the Supernova had no direct effect on the Earth, it was too far away and the subjective time-frame too great....however through a string of related events it played an indirect part in the creation of life and thus indirectly it has effected my life.......

I am not talking about the scenario in the OP, but as a general point of the concept of an interconnected Universe where even the smallest change effects the whole, no matter how small or insignificant that effect may be. It is a philosophical question rather than a Scientific one.

Tbh I did wonder if that is what you were meaning, in a Rube Goldberg machine kind of way.

Like you say it's more of a philosophical position, but then I have to ask, what is a change? What is an event? Can two events cancel each other out completely, or their effect become so diluted that it in fact changes nothing? Throw a stone in a still pond and you'll see ripples for a long time, throw it in the sea and you'll be lucky to get any. Does the result from that stone being thrown in the sea really have any effect on the other side of the world?
Although to be honest philosophy isn't really a subject I've spent much time on so there's not much I can bring to this topic

 

[Pate]

 

[Threepwood]

Stars are made of us......in fact we are all made of the same stuff, we are connected to everything and everyone in the entire Universe, including the Universe itself by simply existing.

We are immortal....we just don't know it.

The all in all in all.

 

[Vonhelmet]

Magnolia, I don't get why you're being such an arse about this. The physics involved is well understood and, to be honest, fairly trivial. To work it out in detail would be laborious to the point of absurdity, but with some reasonable assumptions (point mass moon, natch) it's pretty simple stuff.

The answer is that the position of the moon would affect how much something weighs on earth. Moreover, as Castiel has intimated, the position or everything in the universe would affect how much something weighs on earth. The effect, however, would be vanishingly small.