A few questions about astronomy/astrophysics.

Sort:
Akiko_Ito
mxdplay4 wrote: Kazue_Fukiishi wrote:

"inherent mass" is not a term used by any scientist.


You can use the term 'invariant mass' then.  To be correct for the people who already understand it.


 Neither term is relevant to light.


Akiko_Ito
Yourself wrote: Kazue_Fukiishi wrote: mxdplay4 wrote: Loomis wrote:

mxdplay4: "Stuff like sunlight exerting pressure because it has mass is actually pretty standard easy physics."

 Even massless particles like photons can carry momentum.


Photons have relativistic mass due to their velocity, but no inherent mass like we are used to in everyday situations (resting mass).  I'm not disagreeing with Loomis since his statement is correct in the major sense.  But it just shows that this is a very difficult area to get your head around. 


 Photons do not have relativistic mass. They have zero mass period. They exert momentum effects because of their velocity. They ACT like they have mass, but do not have mass. "inherent mass" is not a term used by any scientist.


 

 The key term here is relativistic mass.  Photons have no rest mass (invariant mass, intrinsic mass, and proper mass are all terms for this), but they do have mass because they carry energy.  By mass-energy equivalence they also have mass. 

 

Relativistic mass (or apparent mass) is the sum of a particle's rest mass and the mass from kinetic energy.  An observer who sees an object moving near the speed of light would measure the mass of that object to be larger than its rest mass (which is the mass measured when the object is stationary w.r.t. the measuring reference frame).  This "extra" mass is actually the kinetic energy that the object possesses due to its motion.


 Don't dig any deeper. You won't get out. The "extra" mass for real particles only, comes from the relavistic 4-vector expression for the total eneergy of a particle.


Loomis
billwall wrote: I think the entire Penrose family (father, 3 sons and daughter - all famous mathematicians and scientists) is perhaps the smartest group of people as a family that has ever lived.  And they all play chess.

 Check out the Bernoulli family.

http://en.wikipedia.org/wiki/Bernoulli 


Yourself
Daemon_Panda wrote:

AHA!!!

I got it!!!

...I think...

 Tell me if I am wrong

 

Light is pure energy

Since nothing can have more energy than pure energy, it is therefore impossible for any object to exceed the speed of pure energy, hence, no object can exceed the speed of light. 


 That doesn't make sense.  Individual photons carry relatively little energy, which depends on their frequency (e.g. a red photon of wavelength 700 nm carries an energy of 2.84*10^-19 Joules.  The amount of chemical potential energy stored in the food I eat contains far more energy than that.

 

If you want to know why objects with a non-zero rest mass can't reach the speed of light, simply study relativity instead of trying to make up your own pseudo-scientific reasons (I'm not trying to be mean here, please don't take it that way).

 

 "This is wrong. A "noise" or sound is a sinusoidal longitudinal vibration in a medium"

 

Sound is very rarely sinusoidal.

 

" Don't dig any deeper. You won't get out. The "extra" mass for real particles only, comes from the relavistic 4-vector expression for the total eneergy of a particle."

 

The extra mass comes about because it makes the equation for momentum more convenient.  In classical mechanics momentum is given by p = m*v where m is the mass and v is the velocity of a particle.  In relativity, a particle's momentum goes to infinity as it approaches the speed of light.  The momentum equation is modified to replace m (which is the rest mass of the particle) with M (the relativistic mass of the particle).

 

The total energy of a particle isn't a vector quantity, either.  The energy appears in the momentum 4-vector. 


Sharukin
Loomis wrote: I actually replaced my random number generator with a string theorist. Whenever I need a random number, I just ask him how many dimensions there are in the universe.

 5 is sufficient.


Akiko_Ito
Sharukin wrote: Loomis wrote: I actually replaced my random number generator with a string theorist. Whenever I need a random number, I just ask him how many dimensions there are in the universe.

 5 is sufficient.


 Prove it.


Sharukin
Kazue_Fukiishi wrote: Sharukin wrote: Loomis wrote: I actually replaced my random number generator with a string theorist. Whenever I need a random number, I just ask him how many dimensions there are in the universe.

 5 is sufficient.


 Prove it.


 Tut tut. As any physicist should know you cannot prove anything about the physical universe. Proof is for mathematicians and lawyers, better approximations are all that physicists can hope for.

 I cannot prove how many dimensions the universe has but no string theorist has yet produced any evidence whatsoever to suggest that string theory is anything more than just fancy mathematics. I happen to think that Klein-Kaluza theory is an adequate starting point for determining how the universe works so 5 is sufficient for me.


magnetar
You know Kazue or Akiko or whatever, if you weren't so condescending towards others, you just might be believable as a real human being. lighten up! or go to a science based forum/website. We already know you feel all chess players are "nerds" (as you put it) anyways. Get off the pedestal, already!
Akiko_Ito
Sharukin wrote: Kazue_Fukiishi wrote: Sharukin wrote: Loomis wrote: I actually replaced my random number generator with a string theorist. Whenever I need a random number, I just ask him how many dimensions there are in the universe.

 5 is sufficient.


 Prove it.


 Tut tut. As any physicist should know you cannot prove anything about the physical universe. Proof is for mathematicians and lawyers, better approximations are all that physicists can hope for.

 I cannot prove how many dimensions the universe has but no string theorist has yet produced any evidence whatsoever to suggest that string theory is anything more than just fancy mathematics. I happen to think that Klein-Kaluza theory is an adequate starting point for determining how the universe works so 5 is sufficient for me.


 Well, actually, I can prove that I exist in three or four dimensions, not 5. My thesis proved a neutron shell boundary at N=60.


magnetar
Tht's a good one. How, really, can you prove you exist in four dimensions when you can't even prove it on this website w/ a picture of you "playing chess"?
BILL_5666

I'm no physicist but I am pretty sure that mini black holes have not been created in the particle accelerators, and even if they were I doubt that they would disintegrate.  I think that it was Stephen Hawkings who first proposed mini black holes, but I think they are only theoretical at this point. 

 The multi-dimensions of the universe is somehow based on the mathematics of matrices, at least that is how it was explained to me.  You cannot visualize x dimensions, but you can visualize a matrix with x number of variables.

I have never heard of sunlight or photons exerting pressure.  Are you sure that you are not confusing sunlight with the solar wind?  The solar wind is not composed of photons, but of charged particles.  It moves quite fast, but slower than the speed of light, though it does exert a pressure on earth's magnetosphere.

 Tachyons are particles which have been proposed to move faster than the speed of light.  I don't think that they have much theoretical basis, and I am virtually positive that they have not been experimentally proven.  If they do exist, it is believed that it would be impossible for them to travel slower than the speed of light. 

Light moves at the "speed of light" only in a vacuum.  It slows down somewhat as it passes thru matter.  There are no particles that can move faster than light or slower than light depending on the circumstances (unless there has been a recent breakthru in our understanding of particle physics which I am unaware of).

Last but not least, there have been many scientist who have spoken of God but were metaphorically speaking, and did not mean "God" in the sense that most of us do (ie. a benevolent supreme being who is interested in the affairs of men--no pun intended).  Einstein was one example, but there are many others.

All of these concepts are confusing and bending my brain, I need a nice relaxing game of chess.

Charlie91
Daemon_Panda wrote:

...Since nothing can have more energy than pure energy, it is therefore impossible for any object to exceed the speed of pure energy, hence, no object can exceed the speed of light. 


 The mass becomes infinite at the speed of light--that's the barrier.


Sharukin
Kazue_Fukiishi wrote: Sharukin wrote: Kazue_Fukiishi wrote: Sharukin wrote: Loomis wrote: I actually replaced my random number generator with a string theorist. Whenever I need a random number, I just ask him how many dimensions there are in the universe.

 5 is sufficient.


 Prove it.


 Tut tut. As any physicist should know you cannot prove anything about the physical universe. Proof is for mathematicians and lawyers, better approximations are all that physicists can hope for.

 I cannot prove how many dimensions the universe has but no string theorist has yet produced any evidence whatsoever to suggest that string theory is anything more than just fancy mathematics. I happen to think that Klein-Kaluza theory is an adequate starting point for determining how the universe works so 5 is sufficient for me.


 Well, actually, I can prove that I exist in three or four dimensions, not 5. My thesis proved a neutron shell boundary at N=60.


 Go on then. You might like to start by proving that three, four or any number you care to mention of dimensions actually exist. A mathematical proof will not suffice. I can prove many things exist mathematically but that does not require that they have physical existence. Then you can move on to proving that you exist. That should keep you occupied for a considerable length of time.

 Your thesis actually proves nothing of the sort, all it can do is produce a description of some aspect of the universe (in this case a neutron shell boundary at N=60). As with all physical laws it is falsifiable but never provable. You may amass evidence to support your thesis but it is always a possibility, however remote, that a counterexample will be found and a new, more accurate, description will be needed.


Redserpent2000

 Your thesis actually proves nothing of the sort, all it can do is produce a description of some aspect of the universe (in this case a neutron shell boundary at N=60). As with all physical laws it is falsifiable but never provable. You may amass evidence to support your thesis but it is always a possibility, however remote, that a counterexample will be found and a new, more accurate, description will be needed.


Wow, and I thought Karl Popper was dead!!!!Laughing

Red

Sharukin
Redserpent2000 wrote:

 Your thesis actually proves nothing of the sort, all it can do is produce a description of some aspect of the universe (in this case a neutron shell boundary at N=60). As with all physical laws it is falsifiable but never provable. You may amass evidence to support your thesis but it is always a possibility, however remote, that a counterexample will be found and a new, more accurate, description will be needed.


Wow, and I thought Karl Popper was dead!!!!

Red


 I think he is dead. I aint him but I do know about the nature of science, in particular physics. I ought to, I have been doing it for long enough.


Akiko_Ito
magnetar wrote: Tht's a good one. How, really, can you prove you exist in four dimensions when you can't even prove it on this website w/ a picture of you "playing chess"?

 That's easy, Honey, I can move back and forth, up and down, and right and left.

Can't you? 

 Can't YOU also prove it on this website w/ a picture of you playinf checkes? Or are you just another picture of a pretty girl jealous of another who may be smarter?


Akiko_Ito

RedSerpent said Your thesis actually proves nothing of the sort, all it can do is produce a description of some aspect of the universe (in this case a neutron shell boundary at N=60). As with all physical laws it is falsifiable but never provable. You may amass evidence to support your thesis but it is always a possibility, however remote, that a counterexample will be found and a new, more accurate, description will be needed.

1. How can he know my thesis proves anything or nothing when only my Universities have read it? 2. He seems to imply that he is waiting for Newton's Apple to fall "up" also, to justify his childishly outrageous claims.  Was he born with half a brain or did it just wither away?


mxdplay4
Kazue_Fukiishi wrote: magnetar wrote: Tht's a good one. How, really, can you prove you exist in four dimensions when you can't even prove it on this website w/ a picture of you "playing chess"?

 That's easy, Honey, I can move back and forth, up and down, and right and left.

Can't you? 

 


By my basic mathematical skills, that only makes 3 dimensions.

Sharukin
mxdplay4 wrote: Kazue_Fukiishi wrote: magnetar wrote: Tht's a good one. How, really, can you prove you exist in four dimensions when you can't even prove it on this website w/ a picture of you "playing chess"?

 That's easy, Honey, I can move back and forth, up and down, and right and left.

Can't you? 

 


By my basic mathematical skills, that only makes 3 dimensions.


 Worse still, saying she can do it is not evidence that she can actually do it and is certainly not proof!


TheWizard
Everything that we know is a theory. The string theory dosnt have one point to its name. The more man studies the more he takes from The Grand Creater. The answer is simple but with knowledge we make it hard.