It's not rocket science

[[XAP]Bob]

FWIW, I think he's confusing buoyancy with drag or at least combining them. What drag has to do with an objects density I've no idea...

Are you being serious?

If an object is denser, it falls faster, which creates more drag.
If an object is less dense, it falls slower, which creates less drag.

So drag must have something to do with density if it changes when density changes (assuming the same size object and they are spheres).

No - the drag changes with speed, not density.

Read your own explanation


Specifically drag changes with Frontal area, Coefficient of drag (which is itself a complex function of fluid viscosity, surface texture and geometry - and frequently changes with velocity) velocity, and rotational motion.

[kwackers]

In your example of course you can look 'up' or 'down' and see the same stars each time - You get pretty much 180 degree visibility across 180 degrees of rotation through the night.
there is a thin slice of sky near the sun you can't see each night, and that slice rotates throughout the year. As you'd know if you ever studied the skies...

That's a good point, rather stupidly I too fell into the trap of mentally seeing myself peering out away from the sun and then six months later staring in the opposite direction without considering that I can rotate the best part of 180 degrees during each evening and thus see nearly 360.

[Postboxer]

I agree with Bob.

The earth rotates, so it depends what time you are talking about 6 months from the same point. You'd have to be at the equator, at about the 21st March and 21st September looking straight up, even then, sweeping around the sky, or waiting through the night, you'd be able to see lots of the same stars.

You could then map all the stars in the sky, move to another part of the earth, map the next lot, until you have a whole map, which would kind of look like the inside of a globe, with us therefore stood on a globe that is spinning, looking out at them.

Drag is a variable, as for the same body, it isn't a constant, as it varies with speed. It is a force. It's what makes a bike slow down when you stop pedalling. Note how you wouldn't slow down at a constant rate, as the drag would reduce as your speed reduced.

So, how is density making something feel heavy, where is the force coming from? Is it some kind of invisible force I can't see, a bit like gravity? Or is it coming from a fluid pushing on a denser object or fluid?

[Manc33]

The earth rotates, so it depends what time you are talking about 6 months from the same point. You'd have to be at the equator, at about the 21st March and 21st September looking straight up, even then, sweeping around the sky, or waiting through the night, you'd be able to see lots of the same stars.

But what you're claiming then is that we can see around bends, or light can bend 180 degrees, or we can see through the Earth (without looking back). I am not sure whats the worst being able to see something in front of you thats behind you or seeing through the Earth while doing that.

You could then map all the stars in the sky, move to another part of the earth, map the next lot, until you have a whole map, which would kind of look like the inside of a globe, with us therefore stood on a globe that is spinning, looking out at them.

Yes I can imagine it like a massive planetarium but space isn't curved around us like that so you can't look back and see stars light curving around making that same star appear in your field of view, from 180 degrees away 6 months back. You could never see one single star (or constellation, or the Milky Way) like that, there in the sky after 6 months.

Drag is a variable

Drag is the result of one density sinking into another. It is particles against particles. It cannot vary if it exists at all. Its very existence is incorporated into the density of the objects, so how can drag be a variable? It actually isn't "there" unless an object moves, then it isn't a "force" because it is just the resistance of two objects colliding, all of that resistance (and drag) is down to the density levels of the objects. It isn't some separated off force. You can't bottle and store it.

...as for the same body, it isn't a constant, as it varies with speed. It is a force. It's what makes a bike slow down when you stop pedalling. Note how you wouldn't slow down at a constant rate, as the drag would reduce as your speed reduced.

Yes but this is the density of the air clashing with the density of my body and bike. I agree there's drag there, but it isn't a force in and of itself, how can it be?

This is almost as bad as gravity.

Drag is definitely there though I will say that, although not defining it the same way you are.

So, how is density making something feel heavy, where is the force coming from?

There doesn't need to be any force, just more particles in the same (or less) volume.

Is it some kind of invisible force I can't see, a bit like gravity? Or is it coming from a fluid pushing on a denser object or fluid?

I don't know why things "line up that way" or why up and down is up and down but that alone, the fact that things also rise up (and for the same reason things fall down) shows that nothing is necessarily even "being pulled towards Earth". Things rising up throws a huge spanner in the works and gives us concrete evidence of the environment being a scale of density.

Gravity seems to be wishful thinking or, having to include it because we already think we are on a spinning ball... that alone seals it for people, they don't even need to know about any proof or care because in that case (and I agree with this) you need a force.

Here's a question, can you name one single scientific equation that, if the gravitational formulae were removed, the equation wouldn't and couldn't work?

If so, what about if you replaced that gravitational 9.81m/s/s with just a rate of acceleration and did not tie any "pulling" with it, its the same right? You can just call it a D constant (although it is a variable but let's skip that for now) can't you? The rate of acceleration absolutely matters and is absolutely real... but that's it, that's where it ends. It is 9.81m/s/s but there's doesn't have to be "gravity" added to it.

If you removed the G constant from an equation and it breaks the equation... you're removing the rate of acceleration which is stupid. How can you remove "G" without removing 9.81m/s/s? One exists and one doesn't. All the calculations using gravity are using something like "6.67" or something... the actual figure Cavendish came up with so folks, its getting silly again, what is 6.67? If we have the figure of 9.81m/s/s already, where does this other Cavendish figure come in?

EDIT: Sorry its "6.67 x 10^-11 Nm²/Kg²"

So 9.81m/s/s has nothing to do with this?

So they are not tied together?

That is at least something because it means "6.67 x 10^-11 Nm²/Kg²" can be scrapped.

[[XAP]Bob]

The earth rotates, so it depends what time you are talking about 6 months from the same point. You'd have to be at the equator, at about the 21st March and 21st September looking straight up, even then, sweeping around the sky, or waiting through the night, you'd be able to see lots of the same stars.

But what you're claiming then is that we can see around bends, or light can bend 180 degrees, or we can see through the Earth (without looking back). I am not sure whats the worst being able to see something in front of you thats behind you or seeing through the Earth while doing that.

Err, did you read anything that was said above. You don't get one single point of night sky to look at, you get to see 180 degrees of sky from about 180 degrees of the earth's rotation - that's nearly the whole sky - wherever you are...
There is a small piece directly behind the sun that you can't see each night.

Note also that the milky way is something we are *in*. It doesn't matter which way you look - the milky way is in that direction...

MWMWMW SummerEartch Sun WinterEarth MWMWMWMW Of course you see it all year round.

You could then map all the stars in the sky, move to another part of the earth, map the next lot, until you have a whole map, which would kind of look like the inside of a globe, with us therefore stood on a globe that is spinning, looking out at them.

Yes I can imagine it like a massive planetarium but space isn't curved around us like that so you can't look back and see stars light curving around making that same star appear in your field of view, from 180 degrees away 6 months back. You could never see one single star (or constellation, or the Milky Way) like that, there in the sky after 6 months.

Er - yes you could - if only you understood enough (any) geometry.

Drag is a variable

Drag is the result of one density sinking into another. It is particles against particles. It cannot vary if it exists at all. Its very existence is incorporated into the density of the objects, so how can drag be a variable? It actually isn't "there" unless an object moves, then it isn't a "force" because it is just the resistance of two objects colliding, all of that resistance (and drag) is down to the density levels of the objects. It isn't some separated off force. You can't bottle and store it.

Drag is to do with things colliding (ish)
But it's entirely a surface phenomenon, and has no interest in the density of anything.
A plastic ball will have the same drag as a steel ball - assuming both are being pulled through the water at the same speed.
Drag creates variable acceleration (because it acts on different masses) and therefore needs eliminating from the experiment, or accounting for in the maths. You can't just leave it in there, and then take the numbers ignoring the change that is there because of drag.

Yes but this is the density of the air clashing with the density of my body and bike. I agree there's drag there, but it isn't a force in and of itself, how can it be?

What is it - it causes an acceleration, it's a force.

This is almost as bad as gravity.
Drag is definitely there though I will say that, although not defining it the same way you are.

No you're deliberately not defining it - seems to be a common tactic.

I'll help - the definition YOU decided to quote called it a force. It is a force.

Is it some kind of invisible force I can't see, a bit like gravity? Or is it coming from a fluid pushing on a denser object or fluid?

I don't know why things "line up that way" or why up and down is up and down but that alone, the fact that things also rise up (and for the same reason things fall down) shows that nothing is necessarily even "being pulled towards Earth". Things rising up throws a huge spanner in the works and gives us concrete evidence of the environment being a scale of density.

Buoyancy is a logical result of gravity.
Things rising does not put a spanner in the works of anyone except people who can't approach the issue with a clear logical thought process.

Gravity seems to be wishful thinking or, having to include it because we already think we are on a spinning ball... that alone seals it for people, they don't even need to know about any proof or care because in that case (and I agree with this) you need a force.

Here's a question, can you name one single scientific equation that, if the gravitational formulae were removed, the equation wouldn't and couldn't work?

Kellers laws (which, it should be noted) were derived from direct observation decades before Newton's work on gravitation. The gravitational equations complete and explain Kepler's laws - GR does so perfectly.

[/quote]If so, what about if you replaced that gravitational 9.81m/s/s with just a rate of acceleration and did not tie any "pulling" with it, its the same right? You can just call it a D constant (although it is a variable but let's skip that for now) can't you? The rate of acceleration absolutely matters and is absolutely real... but that's it, that's where it ends. It is 9.81m/s/s but there's doesn't have to be "gravity" added to it.[/quote]
Huh - can you translate this to english please. It might help you to use a dictionary to look up the meaning of some words...

If you removed the G constant from an equation and it breaks the equation... you're removing the rate of acceleration which is stupid. How can you remove "G" without removing 9.81m/s/s? One exists and one doesn't. All the calculations using gravity are using something like "6.67" or something... the actual figure Cavendish came up with so folks, its getting silly again, what is 6.67? If we have the figure of 9.81m/s/s already, where does this other Cavendish figure come in?

G and 9.81 (little g) are related only by the mass and radius of the earth.

G 6.67408 × 10-11 m^3/kg/s^2
g 9.81 m/s

Note that the units are different - they are different things...

EDIT: Sorry its "6.67 x 10^-11 Nm²/Kg²"

So 9.81m/s/s has nothing to do with this?

So they are not tied together?

That is at least something because it means "6.67 x 10^-11 Nm²/Kg²" can be scrapped.

No - 9.81 m/s is what you get when you plug the mass and radius of the earth into the gravitational equation with G - and then apply that to Newton's second law of motion.

g is a locally measured convenient figure - not a fundamental constant.
G is a fundamental constant.


If you are going to try to talk about this stuff you need to go and learn a little bit of physics.

It's like me trying to say that musical keys make not difference to anything - just because I don't understand how they work...

[Manc33]

I can't take seriously that any scientist would claim to be able to weigh the Earth. Not when the deepest anyone has ever drilled is 8 miles (Russians, taking 30 years then giving up because no material could take the heat).

[kwackers]

I can't take seriously that any scientist would claim to be able to weigh the Earth. Not when the deepest anyone has ever drilled is 8 miles (Russians, taking 30 years then giving up because no material could take the heat).

There are several easy ways to calculate the weight of the earth.

Drilling a hole to the centre is easily the most inaccurate and fortunately scientists know this and so have never tried.

[[XAP]Bob]

I can't take seriously that any scientist would claim to be able to weigh the Earth. Not when the deepest anyone has ever drilled is 8 miles (Russians, taking 30 years then giving up because no material could take the heat).

Why would you want drill anywhere to weigh the earth.

There are plenty of ways to measure things without taking them apart.

[53x13]

The drilling only stopped because the heat from the magma below was liquefying the granite as the drill head cut through it.

That would be super hot magma rotating around the earth's solid iron core, in a spherical earth model, but you maybe hadn't thought of that, before you said it...

[kwackers]

The drilling only stopped because the heat from the magma below was liquefying the granite as the drill head cut through it.

I reckon they stopped the drilling because they realised they were about to break through the flat earth. Imagine the mayhem! With no density to stop it everything would flow down that tiny hole until the world had disappeared like old bath water.

[reohn2]

Dear,oh dear!
This just gets worse or better depending on yer POV,I'm eagerly waiting for the alien abduction stories,Elvis is still alive,and perpetual motion vehicles.....

I'm waiting.........

[Mick F]

........ Elvis is still alive ...........

Gawd, I hope not.
In his heyday in the 50's and early 60's he was ok. Too yucky American for me, but ok I suppose.
Later, he was absolutely terrible, so goodness knows what he'd be like now!

[Manc33]

You think the Earth flies through space and we never feel it?
Next you'll be telling me Hillary Clinton is Mother Teresa!

You think the Earth flies through space at 1,300,000 MPH, but Polaris remains fixed in place for centuries?
Next you'll be telling me aliens run the White House.

You think water curves over great distances?
Next you'll be telling me... [insert random strawman].

You think Hawaii can see the Milky Way all year round on an Earth that faces the other way every 6 months?
Next you'll be telling me... [insert random strawman].

See anyone can do that, I can do it, but what does it solve?
Nothing at all which is why I never usually do it (creating strawman points).

It tends to be the only course of action left for people without any answers to anything. Its quite a giveaway.

That last one is absurd because to believe the official story we are supposed to believe what... the galaxy orbits Earth once a year?

That one wasn't a strawman by the way. That is the official claim if the galaxy passes us by in the sky, judging from the fact that Hawaii can observe this in real life. Not in the over elaborating minds of mathematicians... in real life.

[kwackers]

That last one is absurd because to believe the official story we are supposed to believe what... the galaxy orbits Earth once a year?

Where does anyone claim that?

The galaxy exists all around us, we're sat in the middle of it, you wouldn't claim there was something odd about sitting in a boat and seeing the ocean all around so what's your problem?

As for seeing it from Hawaii for all of the year, well if it's all around why wouldn't you.

Also you're completely ignoring a very simple fact.
Stood on the floor you can see 180 degrees from horizon to horizon.
Between sunset and sunrise the earth has spun through 180 degrees and during any point of the night you can look 180 degrees, which means from any point you can see a fairly large chunk of the sky over the course of the night.
(And that's before we concern ourselves with just how big the milky way is).

[[XAP]Bob]

You think the Earth flies through space and we never feel it.[\quote]
Yes, what would you expect to 'feel' - we can measure it though

You think the Earth flies through space at 1,300,000 MPH, but Polaris remains fixed in place for centuries?
[\quote]
No, but it is close enough to stationary for modern navigation. The geographical pole scribes a circle every 26,000 years - it's currently within a fraction of pointing straight at Polaris.

You think water curves over great distances?
[\quote]
Yes. And observation confirms it.

No, we are part of the Galaxy, it surrounds us completely, hence it is always visible - given sensibly dark skies.

You seem to be the one celebrating your own lack of answers, everyone else is providing sound and consistent answers...