Rudolfhendriques's thread.

The non amateur stuff. Hawking, black holes, that sort of thing

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joe
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Post by joe »

I'd like to think that this is a serious scientific forum but also a forum that encourages those who are not serious scientists (the vast majority of users) to get involved too. This part of the forum is here for those who want to talk about and learn about the science of astronomy. It would be a quiet place indeed if only those with scientific backgrounds contributed. There are countless physics forums elsewhere ont'internet that are better suited to serious discussion, in my opinion. It's clear, however, that no one wants a forum full of pseudo-science and mysticism.

Here, there are several regular contributors who are familiar with contemporary physics/astrophysics and often take the time to provide valuable information and explain where our errors lie. That is a better way to end a thread than locking it.
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Post by Quasar »

joe wrote:I'd like to think that this is a serious scientific forum but also a forum that encourages those who are not serious scientists (the vast majority of users) to get involved too. This part of the forum is here for those who want to talk about and learn about the science of astronomy. It would be a quiet place indeed if only those with scientific backgrounds contributed. There are countless physics forums elsewhere ont'internet that are better suited to serious discussion, in my opinion. It's clear, however, that no one wants a forum full of pseudo-science and mysticism.

Here, there are several regular contributors who are familiar with contemporary physics/astrophysics and often take the time to provide valuable information and explain where our errors lie. That is a better way to end a thread than locking it.
Thankyou joe for allowing the thread to continue. Lets put this puppy to bed once and for all.
Ruud is suggesting that modern thinking is wrong in the fact that photons do not leave their source at C. He argues that as matter travels through time, photons are left in our past at C and that time is the constant in this argument. The basis for the argument is that photons have no mass and are unable to travel into the future (or spacetime) with matter.

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Post by RL Astro »

I will admit to being more open to Ruuds idea than I was at first now that it has been properly explained in the other (locked) topic (not meaning to insult your English there Ruud - it's far far better than my Dutch :wink: ). I can accept he may well have something here but until there's mathematical evidence I can't accept the theory. Until then it remains just a neat idea :)

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Post by Quasar »

RL Astro wrote:I will admit to being more open to Ruuds idea than I was at first now that it has been properly explained in the other (locked) topic (not meaning to insult your English there Ruud - it's far far better than my Dutch :wink: ). I can accept he may well have something here but until there's mathematical evidence I can't accept the theory. Until then it remains just a neat idea :)
Hi RL Astro,
There are several threads I believe on the forum at the moment where Ruud's principle comes into play. One is where GeorgeC suggests that the land of the very small can be applied the the land of the very big and also the question of time travel and the its possible applications.
Einstein suggests that all matter moves forward through spacetime. This statement I believe is fundamentally one of the most important statements he made.
Ruud's principle is built largely upon this statement. So lets examine what we would construde has being 'matter'. Obviously the atoms which make up all visible matter are included, this would be the whole of the atom including the orbitting Electron and the other elimentary particles. We know that all constituant parts of the atom make up its mass and each respective part has it's own mass.
Do we include Photons as part of the atom? By and large I believe that most people do not and they also believe that the photon has zero rest mass. If we were to say that Photons' because they have zero rest mass do not travel forward through spacetime with all the other mass - I don't think that Einsteins' statement is under threat.
Einstein also commented that 'time stands still' at C. If we attemped to approach light speed. As we get nearer to C the more massive we become because we know that speed increases mass. If we reach light speed then we would become infinately massive and time would stand still. Not disimilar to the singularity in a black hole.
If Einstein is telling us this then he is clearly stating that a Photon cannot move forward in spacetime, but is frozen at zero, having zero rest mass.
When matter moves forward through spacetime it does so as a constant, this constant has no name or mathematical symbol. We cannot call it C because that would be incorrect. The only mathematical principle I can apply at this stage would be :- The constant of matter moving forward in spacetime has a habit of leaving Photons behind in three dimensional space at a velocity of 300,000KM\s. This however is not the velocity of matter moving through 3 dimensional space.

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Post by joe »

Quasar wrote: If we reach light speed then we would become infinately massive and time would stand still. Not disimilar to the singularity in a black hole.
It is dissimilar. Black holes have measurable masses. I don't know of any that have infinite mass.
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Post by Quasar »

joe wrote:
Quasar wrote: If we reach light speed then we would become infinately massive and time would stand still. Not disimilar to the singularity in a black hole.
It is dissimilar. Black holes have measurable masses. I don't know of any that have infinite mass.
HI Joe,
lets say you have a Massive object in space, a massive star for example that is 100 Solar masses. We look at it through our telescope and discover than it creates a huge gravitational field which can bend spacetime and the trajectory of light. It does not have a event horizon.
Then we look in a different part of the cosmos and discover a black hole of 90 solar masses, an intermediate as I believe they are known. This blackhole does have a event horizon and we cannot see into the middle of it. Can you explain Joe why gravitational objects like this differ from one another?
Last edited by Quasar on Wed Jun 25, 2008 2:08 pm, edited 1 time in total.

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Post by joe »

Only after you acknowledge that black holes do not have infinite mass. :wink:
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Post by Quasar »

joe wrote:Only after you acknowledge that black holes do not have infinite mass. :wink:
OK I will rephrase it, the matter has zero volume but the gravitation pull and density are infinate. :wink:

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Post by RL Astro »

Quasar wrote:Can you explain Joe why gravitational objects like this differ from one another?
My understanding, limited as it may be, is that the black hole distorts spacetime more because its mass is more localised, so to speak. The star's mass is spread over a distance of several hundred thousand miles (the star's size). The black holes mass is spread over a singularity the size of a pin head.

Something like that anyway :)

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Post by joe »

RL explains it plainly enough. You might as well ask why a 900 solar mass star and a 900 solar mass black hole appear differently since they both contain the same amount of mass. They exert the same gravitational attraction after all. The difference is that the black hole mass has collapsed to a tiny volume.
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Post by Earthshine »

RL Astro wrote:
Quasar wrote:Can you explain Joe why gravitational objects like this differ from one another?
My understanding, limited as it may be, is that the black hole distorts spacetime more because its mass is more localised, so to speak. The star's mass is spread over a distance of several hundred thousand miles (the star's size). The black holes mass is spread over a singularity the size of a pin head.

Something like that anyway :)
I stand corrected but, as I believe it, a black hole does not have mass, as in essence, it is not a physical object as such, but a region of space with a singularity at its centre. The collapsing star causes a black hole to form, the black hole being the point beyond which light cannot escape from the gravity of the collapsing star, i.e. the point at which the escape velocity of the star is equal to, or greater than the speed of light.

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Post by GeorgeC »

A black hole does have mass. There is one at the centre of our own galaxy, and its mass is exerting a force on all the objects orbiting the galaxy centre. Because the hole can never be seen directly, its presence is inferred from the rate of rotation of the stars around it. They are moving so fast that there must be something very massive at the centre.
Black hole density is something else - I have no idea if density makes sense because the volume occupied by the black hole cannot be measured. If it is a true singularity then I suppose the density is infinite.

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Post by Earthshine »

GeorgeC wrote:A black hole does have mass. There is one at the centre of our own galaxy, and its mass is exerting a force on all the objects orbiting the galaxy centre. Because the hole can never be seen directly, its presence is inferred from the rate of rotation of the stars around it. They are moving so fast that there must be something very massive at the centre.
Black hole density is something else - I have no idea if density makes sense because the volume occupied by the black hole cannot be measured. If it is a true singularity then I suppose the density is infinite.
Then Wikipedia must be wrong, and all I have perceived from the books I have read, must also be wrong.

From Wikipedia http://en.wikipedia.org/wiki/Black_hole:
..general relativity describes a black hole as a region of empty space with a pointlike singularity at the center and an event horizon at the outer edge..
I'm not saying it isn't due to mass, I'm just saying the black hole itself doesn't have the mass, the star causing it does.

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Post by joe »

Earthshine wrote:I'm not saying it isn't due to mass, I'm just saying the black hole itself doesn't have the mass, the star causing it does.
Oh, that's splitting hairs, surely? Don't we all take for granted, at least at this level, that a black hole refers to the singularity, the space surrounding it, the event horizon and all the other stuff? I can only remember reading books that say black holes have mass. Yes, they go on to say where the mass resides but only when relevant do they differentiate between black hole and singularity.
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Post by Cliff »

Dear Quasar
I accept the principle that anyone can post their astronomical \ cosmological thoughts\ideas on this forum.
However, having said that I also think it is acceptable for someone to suggest that one or other posted pet theory is rubbish.
I also do not think it is necessary that someone who disagrees with one or other pet theory should be expected to prove that someones pet theory is rubbish. In my opinion it should be up to anyone producing a pet theory to demonstrate the theory has real merit. To my mind there is also no merit in a pet theory supporter jumping in and saying that he agrees with whatever pet theory without substantiating the theory in some plausible way. I can make some allowance for anyone not speaking English too well. I can even make some allowance for an amateur scientist not being able to thoroughly describe their pet theory. I personally also like the idea of amateur scientists having their own pet theories. However, they must not go round saying that their pet theories are necessarily good unless they are solidly proven to be wrong.
I think Quasar and Ruud have suggested that Quantum theory and Einstein are a bit up the creek. I personally cannot prove or disprove quantum and or Einstein's theories, but my limited understanding of them suggests they have great merit.
I am afraid I cannot say the same for Ruud's ideas (although I have not followed them through in great detail, because quite frankly from the bits I have read, I think they are either wrubbish or just plain rong.
Best of luck from Cliff

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