Can this be right?

Hi,

It seems like the folks here are used to butting heads with "real" scientists and being censored and called names for that.

So I'm not sure if this is the right place to ask this but I was looking at this blog http://putnamca.wordpress.com and when I actually gave it some thought I thought it could be valid.

I know enough about science to maybe think that but I can't really explain it well - I think they are basically saying that the universal constant of G can be just the constant of the speed of light if looked at right.

I guess I was banned from the Physics Forum for asking the same question so I hope you guys aren't as close minded!

Thanks!!!

Holly

Hi

basically that guy found out that c = 1.005568553[insert fitting units] * 1/(16 * pi * G). so it's just constant = 2nd constant * 3rd constant (you could do the same with any other pair of physical contants). just take the classical formulas, put in the relation between c and G and fiddle around with mass, volume and density. all numbers that are left after that go into the "corrected" density and you'll arrive at the formulas he gave. they are not wrong but contain no revolutionary physics and won't help you in any way.

Hi

basically that guy found out that c = 1.005568553[insert fitting units] * 1/(16 * pi * G). so it's just constant = 2nd constant * 3rd constant (you could do the same with any other pair of physical contants). just take the classical formulas, put in the relation between c and G and fiddle around with mass, volume and density. all numbers that are left after that go into the "corrected" density and you'll arrive at the formulas he gave. they are not wrong but contain no revolutionary physics and won't help you in any way.

Yeah, I guess I sort of get that..but, basically when you say "[insert fitting units]" - can you help me understand how Newton didn't just "insert fitting units" to the constant of G when he came up with his original equation? What I did last night was look at Wikipedia for some clarification and it just got me more confused. Because it says that "The dimensions assigned to the gravitational constant in the equation above — length cubed, divided by mass and by time squared (in SI units, metres cubed per kilogram per second squared) — are those needed to balance the units of measurements in gravitational equations."

Which is basically all that this guy is doing, balancing his equation. (I didn't want to assume it was a "guy" but then I read his "About" page - thanks!)

Holly

Also you say they are not wrong but why is G still taught to us - I'm taking a physics class now, and the gravity equation doesn't ever relate to c? Isn't that a new way to look at it?

I will ask my instructor at my next class about his, but thank you, anyway.

Does anyone else have any idea?

Holly

Hi, iznih...I really sound like a pain in the butt, I know. but I'm reading your reply over and over and I keep thinking about this. Sorry, I'm just trying to understand -

I wanted to ask when you said "fiddle around with mass, volume and density" - wouldn't just fiddling around with one of those affect the other ones? Just because they are all "dependant" on the other ones? Does tha make any sense?

I really appreciate you helping me understand this stuff. It's all really cool stuff!

-H

Also you say they are not wrong but why is G still taught to us - I'm taking a physics class now, and the gravity equation doesn't ever relate to c? Isn't that a new way to look at it?

I will ask my instructor at my next class about his, but thank you, anyway.

Does anyone else have any idea?

Holly

In the time of Newton, the speed of light in a vacuum, the constant c, was unknown.  We can do it retroactively, of course, because we have all the necessary information.

Quote from: holly85 on October 05, 2010, 04:07:09 PM

Also you say they are not wrong but why is G still taught to us - I'm taking a physics class now, and the gravity equation doesn't ever relate to c? Isn't that a new way to look at it?

I will ask my instructor at my next class about his, but thank you, anyway.

Does anyone else have any idea?

Holly

In the time of Newton, the speed of light in a vacuum, the constant c, was unknown.  We can do it retroactively, of course, because we have all the necessary information.

Hi, Traxus!

Thank you for also trying to help me understand! I think I still have questions? If we can do it retroactivly, than why don't we? Like that blog says we can, we should get rid of G, right?

I think it would help me understand some of my physics homework better, at least!

-H

Yeah, I guess I sort of get that..but, basically when you say "[insert fitting units]" - can you help me understand how Newton didn't just "insert fitting units" to the constant of G when he came up with his original equation? What I did last night was look at Wikipedia for some clarification and it just got me more confused. Because it says that "The dimensions assigned to the gravitational constant in the equation above — length cubed, divided by mass and by time squared (in SI units, metres cubed per kilogram per second squared) — are those needed to balance the units of measurements in gravitational equations."

the purpose of constants is pretty much balancing equations. c is not that different, if you measure frequency and wavelenght of a lightwave you'll see that you need c with it's well known value to get it working. the only difference is that at some point in history we dedided to make c an exact value and derive e.g. the metre from it.

I really sound like a pain in the butt, I know.

No worries 

I wanted to ask when you said "fiddle around with mass, volume and density" - wouldn't just fiddling around with one of those affect the other ones? Just because they are all "dependant" on the other ones? Does tha make any sense?

i'll show you what i meant by fiddle around: take for example the classical expression for the gravitational accelaration g:
g=Gm/r^2
from c = 1.005568553[insert fitting units] * 1/(16 * pi * G) we get G=1.005568553 *1/(16 * pi * c)
=> g=1.005568553 *1/(16 * pi * c)*m/r^2
with m=d*V (d=density, V=volume) and V=4/3*pi*r^3 we get
g=1.005568553 *1/(12*c)*r*d
now we define 1.005568553 *1/12*d as a corrected density D and we arrive at the formula given in the blog:
g=D*r/c
please note: that's pure mathematics. the formula suggests a physical relation between gravity and c that does not necessarily exist. it might be there but to my knowledge we don't know (i'd love to see the derivation of his formulas).
btw: i saw that he completely omitted the 1.005568553 in his equations, i guess that why he arrived at slightly different values in his examples.

If we can do it retroactivly, than why don't we? Like that blog says we can, we should get rid of G, right?

what would be the benefit of getting rid of G? imo that blogger dislikes the fact that we don't know the exact value of G as it is just measured. he replaces G by c as it has a well defined value. instead of doing this he could also propose to give G an exact value. just cut off the last 2 or 3 digits and derive all other things (e.g. the density). no difference at all...
so why is this a bad idea? i guess there would be inconsistencies, e.g. two different approaches to calculate g could yield different results despite both equations being correct per definition.
 

Hi, again!

I just wanted to ask you a couple more questions.

Are you still around?

What do you think he means when he says that the speed of light is a constant of proportionalty? Is that what you meant when you said theres no physical relation between gravity and c? IS that right? Also he says that the Schwarzchild radius already does that. I looked up Schwarzchild radius at Wikipedia and got more confused.

At least you seem to be trying to help me understand! lol!

-H

yup, still around

constant of proportionality just describes the mathematical functioning of a constant. two pysical quantities a & b are proportional if there's a "constant of proportionality" x so that: a=x*b. whether there is a physical relation is another story.
tbh you should not bother about the stuff he wrote about the schwarzschild radius. i didn't look into it, but you won't need it to understand what he is doing in general.

Hi,

It seems like the folks here are used to butting heads with "real" scientists and being censored and called names for that.

So I'm not sure if this is the right place to ask this but I was looking at this blog http://putnamca.wordpress.com and when I actually gave it some thought I thought it could be valid.

I know enough about science to maybe think that but I can't really explain it well - I think they are basically saying that the universal constant of G can be just the constant of the speed of light if looked at right.

I guess I was banned from the Physics Forum for asking the same question so I hope you guys aren't as close minded!

Thanks!!!

Holly

Holly,
I looked over a couple of entries and found the site not worthy of consideration. The author does not understand how to handle significant digits or units of measure. He or she incorrectly applies formulas. Please don't waste your time.

If you'd like, as an exercise, to find where he's pulling the wool over your eyes, I would be willing to help. Otherwise, let's agree that he's a wacko.

Not that I would ever be seen dead teaming up with Clocktower in the upper fora, but this is not the upper fora.  

The man makes his first b*ll*cks by suggesting you can weight the earth. The earth has a mass. Weight is the effect of mass x gravity of earth. Earth would only weigh as he suggests, by sticking it on another earth of equal mass.

Ignoring that though, I am having trouble following the exact point of the article. So I'm going to skip to a bit that is just rubbish.

Additionally, if I had ever been taught, in any of my science classes from high school on, that I could just simply multiply the radius of a planet (or of the Sun, or of the Moon) by the density of the same, then divide by 12 times the speed of light, in order to find the surface gravity of said body, I think that would have, at the very least, helped prepare my brain for the mental onslaught that is GR. Perhaps the poster doesn’t yet see why that perspective on those relationships is new and exciting, but I do, and I am merely trying to help others see it, as well.

Ok, lets put that to the test.
Density of earth is 5454.5 kg/m^3
Radius of earth is 6378136 m
Speed of light is 300,000,000 m/s

He wants (density * radius)/ 12 * c = gravity which is m/s^2
Ignoring the numbers for a second ...

That is (Kg/m^3 * m) /  m/s
= kg/m^2 / m/s
= kg/m/s

What is a kg per m per second? A newton is a kgm/s^2 but its not that either. This is not an acceleration.
I want m/s^2 as my gravity and he has produced kg/m/s.

Its a dimensional nonsense. The key to finding his error will be in his posting dissecting the units as I have done. Dimensional analysis.

I know enough about science to maybe think that but I can't really explain it well - I think they are basically saying that the universal constant of G can be just the constant of the speed of light if looked at right.

Well yes it could because they are both constants. So saying c ~ G as a function of density and radius are true. However one is a velocity, the other is an acceleration. He has equated the ratio of density * size of a sphere to is gravity as a constant which happens to be roughly 3,600,000,000 which is also 12 times the speed of light. However when using one to find another, the dimensional nonsense arises.

The numbers come out right, but for the wrong reasons.

Well that's my reasoning anyway.  
Maybe ClockTower has more to add, or would rather spend his time picking fault with my suggestion?  

Not that I would ever be seen dead teaming up with Clocktower in the upper fora, but this is not the upper fora. 

The man makes his first b*ll*cks by suggesting you can weight the earth. The earth has a mass. Weight is the effect of mass x gravity of earth. Earth would only weigh as he suggests, by sticking it on another earth of equal mass.

Ignoring that though, I am having trouble following the exact point of the article. So I'm going to skip to a bit that is just rubbish.

Quote

Additionally, if I had ever been taught, in any of my science classes from high school on, that I could just simply multiply the radius of a planet (or of the Sun, or of the Moon) by the density of the same, then divide by 12 times the speed of light, in order to find the surface gravity of said body, I think that would have, at the very least, helped prepare my brain for the mental onslaught that is GR. Perhaps the poster doesn’t yet see why that perspective on those relationships is new and exciting, but I do, and I am merely trying to help others see it, as well.

Ok, lets put that to the test.
Density of earth is 5454.5 kg/m^3
Radius of earth is 6378136 m
Speed of light is 300,000,000 m/s

He wants (density * radius)/ 12 * c = gravity which is m/s^2
Ignoring the numbers for a second ...

That is (Kg/m^3 * m) /  m/s
= kg/m^2 / m/s
= kg/m/s

What is a kg per m per second? A newton is a kgm/s^2 but its not that either. This is not an acceleration.
I want m/s^2 as my gravity and he has produced kg*m*s or kgms.

Its a dimensional nonsense. The key to finding his error will be in his posting dissecting the units as I have done. Dimensional analysis.

Quote

I know enough about science to maybe think that but I can't really explain it well - I think they are basically saying that the universal constant of G can be just the constant of the speed of light if looked at right.

Well yes it could because they are both constants. So saying c ~ G as a function of density and radius are true. However one is a velocity, the other is an acceleration. He has equated the ratio of density * size of a sphere to is gravity as a constant which happens to be roughly 3,600,000,000 which is also 12 times the speed of light. However when using one to find another, the dimensional nonsense arises.

The numbers come out right, but for the wrong reasons.

Well that's my reasoning anyway. 
Maybe ClockTower has more to add, or would rather spend his time picking fault with my suggestion? 

Actually, I commend you for taking the time. I'm too lazy to do so, unless the OP requests. Overall, I concur with your analysis, but didn't look at every detail.

Actually, I commend you for taking the time. I'm too lazy to do so, unless the OP requests. Overall, I concur with your analysis, but didn't look at every detail.

OMG! We agree on two things in the same thread. 

You guys seem really knowledgable, and far more helpful then my teacher at school.

So I guess I'm probably pissing you off by being so stupid, but if the numbers work out like you say and the dimesions of G are already so weird (like Newton made then up to just match his numbers) I'm still not getting why it's not a good thing to use a constant that really is constant, like c?

I feel sooo bad for not getting it,and I'll shut up if your frustrated with me.

Thank u!!

H-

You guys seem really knowledgable, and far more helpful then my teacher at school.

So I guess I'm probably pissing you off by being so stupid, but if the numbers work out like you say and the dimesions of G are already so weird (like Newton made then up to just match his numbers) I'm still not getting why it's not a good thing to use a constant that really is constant, like c?

I feel sooo bad for not getting it,and I'll shut up if your frustrated with me.

Thank u!!

H-

Because as I stated above, the units are all wrong. Example.
Suppose you weight 55kg.
Now I could calculate your weight as mass x gravity. Now if I then told you that you weigh 55 seconds, or 55 metres, would either of those answers be correct? Yep, the number is good, but its total nonsense.
That is the problem with this guys assumption, as I demonstrated a few posts ago.
His acceleration is which should be in m/s^2 is actually in kg/m/s.
A kilogram per meter per second? That's not an acceleration, so its as useful as me telling you, that you weigh 55 degrees Fahrenheit.

Put it this way. If the author had unified gravity and the speed of light, he wouldn't have written it all down in a blog. He'd have kept it very secret, submitted if for peer review, and would now be sat at home waiting for his Nobel prize.

And yes, we are all super knowledgeable. That's how we know earth is flat.
(don't be putting that on your homework though).

Hey!

So I've been doing alot of homework for school which is alot of gravity equations and I;m trying to keep using the equations from the blog, and they work out pretty good, except for the units, like you said.

But then I was tring to do some unit stuff, and I had this question? The blogger doesn't do this, but could you just put the units from G down on the bottom with the 12 from his equation? You'd have to flip them so they work, of course!

so, like this - 12 kg*s^3/m^4? I think I have that right.

To me, that makes as much sense as Newton's picking his units, in the first place, since you said he did it just to make the units work out? And you could still use c in Newtons equation.

Anyway, I thought I would ask...

H-

Mmmmm. I'm not sure you are getting this. He has made a constant out of part of the gravity equation. It happens to be 12 times the speed of light. That is all. Why not forget his silly abuse of science and just learn the constant if you are that keen on taking a short cut? But this is ultimately homework. Its for learning, so why not do it the right way? You will become a fairly horrible scientist if all your equations have stupid units after them.

"So Holly85, do you know how much fuel we need for the first stage booster?"
"Oh yes, I have calculated it to exactly 180,007 lumens."
"I'm sorry?"
"Well I swapped gravity for light and ..."
"Thank you. Can someone get me an employment agency"

I see you graded you last post H-
That will become a horrific reality if you keep holding onto this silly blog. Forget it, it was mildly interesting,  and if nothing else, you learnt how important dimensional analysis is for scientists and engineers. That is far more fascinating than that man's blog and much more useful.
http://en.wikipedia.org/wiki/Dimensional_analysis
Once you understand how that works, you really will have an advantage over your classmates. Once you finish a calculation, do this for a quick check instead of banging the numbers in again. You might make the same mistake again with the numbers, especially if you rearranged a formula incorrectly. Checking it dimensionally balances will let you know you didn't mess the process up.