Ask any question you want about Physics

Cheers diggers.

Another one i personally am curious about.

Q. Your in a desert. The ground is flat in all directions for hundreds of kilometers.
In the far distance of say 2km, a bright light is pointing towards the north in a concentrated beam (like a spot light. A defined tunnel of light )
If you are 2km behind the light how come we would still see it? If light moves forward and not backwards? To then bounce off your eye thereby 'seeing' the light?

originally posted by: coomba98
If you are 2km behind the light how come we would still see it?

Who says we would see it? If the beam was narrow enough and the air was clear enough and the beam wasn't overly bright, you might not see it.

It only becomes visible if it reflects off of something, like impurities in the air, maybe a little haze from pollution that's just about everywhere now, or if the beam is bright enough, it may scatter enough off the air for you to see it. This wouldn't happen in a vacuum, where you definitely couldn't see it if there weren't even air molecules present.

This is why the laser special effects in science fiction movies which usually show the laser beam traveling through the vacuum are completely wrong, you would need some kind of smoke cloud for it to show up like that.

The more realistic effects in movies are when someone is entering a high security area with light beams everywhere which if broken will trigger an alarm, and the intruder uses a thin amount of smoke so the light beams can be seen, otherwise they're practically invisible.

a reply to: Arbitrageur

Interesting, makes sense. So this would be why space in general is black.

Cheers for the response

originally posted by: Arbitrageur

originally posted by: Poon
So the only one he included was E = mc squared.

Yes and even that is simplified to the point it's "wrong", since the complete and correct equation might reduce book sales.

It is simplified but not wrong. Are you anti Einstein personality?

Just want to hear your stance on it.

Thank you.

originally posted by: Arbitrageur

originally posted by: greenreflections
I just said it in my post above. Event horizon will show tidal elongation. Since black holes never been observed as lone objects, it is hard for me to present experimental evidence.

Do you think when two black holes approach they are not affected by effects of gravity from each other? And if they do, what makes you think event horizons of both will show no sign of it?

What is at the event horizon for another massive object to pull on? Nothing. If there's nothing there then there's nothing there to distort with tidal forces. This shouldn't be a hard concept.

I tend to think of event horizon as a surface of black hole. It has to experience some how a pull from another object (gravitationally affected) according to GR. Meaning imo that outer edge of the surface will start falling into gravity affected area, experience tidal forces in other words.

originally posted by: greenreflections
It is simplified but not wrong. Are you anti Einstein personality?

If you want to cite a quote from my explanation in the OP of the thread you're referring to and describe what is unclear about that specific quote, maybe I could try to clarify that type of query. I think I already explained it clearly so I can't try to clarify it further until I know what part of the explanation is giving you trouble. In fact if you read the explanation, the way your question is phrased indicates an absolutely dismal level of reading comprehension. Perhaps you didn't even read the explanation and are asking me to explain something I've already explained? In that case why not read the explanation I already linked to?

originally posted by: greenreflections
I tend to think of event horizon as a surface of black hole. It has to experience some how a pull from another object (gravitationally affected) according to GR. Meaning imo that outer edge of the surface will start falling into gravity affected area, experience tidal forces in other words.

There's a way to resolve this. Tidal forces can be calculated mathematically, so, just calculate them. You can't calculate any tidal forces if there's nothing at the event horizon. If you would like to illustrate otherwise by showing your calculations that would be interesting, but of course we both know you can't.

Tidal forces on a physical object with an actual surface like a star, planet or moon can of course be calculated. It's perhaps a common misconception that the event horizon of a black hole is a kind of physical surface, because it's not, and that's why you can't calculate tidal forces which distort the event horizon.

a reply to: Arbitrageur

What percentage of 'gravity force' in/of the milky way is the central supermassive black hole responsible for?

originally posted by: KrzYma
a reply to: Arbitrageur

Your youtube video isn't intended to be a scientific resource so it just seems silly to argue against science by posting youtube videos like that.

haha... NO!!!
this video is not from me or for me to explain how it is
it's just some random video from the net..
actually it is the opposite of what you think..
what it shows is how MS science works !
bunch of crack heads explaining # they have no idea off
they are just parroting some text from the books and maybe think they understand it

I'm talking about how it is presented to the common population dude !

I know you know a lot about the common theory, no doubt, but every time I put some arguments that are "unthinkable" for MS theory, I get ignored or discriminated or.. yeah.. ignored !!

What I want is that science goes back to the experiments made before theory and look at the outcome of those experiments from today's pov

and the black hole problem is BS because there is none... no black holes not problem
.

That electric theory stuff started with some guys trying to sell books. They used to make hype videos to try to get gullable rebellious types to buy stuff. The science is debunked. But it's been a while since I looked into that.

You would have to post more specific things than "black holes don't exist".

a reply to: ImaFungi
The milky way black hole mass is somewhere around 4 million solar masses according to this paper (error estimates omitted to simplify, look them up in the sources if you're interested):

arxiv.org...

M_bh of 4.1x10^6 M ⊙

which can also be expressed as 0.0000041x10^12 M ⊙ for the calculation below

The mass of the Milky Way is harder to estimate, and I'm not sure if this estimation is right or not or if I even understand it accurately, but the authors broke down the Milky Way mass into three components: Disk, bulge, and halo, so you have to add all three to get total mass explaining rotation curve/star velocities if I understand the paper:

arxiv.org...

We measure...

rest is paraphrased:
halo virial mass M vir to be 0.8×10^12 M ⊙
disk mass to be 0.095 ×10^12 M ⊙
kpc and bulge mass to be 0.0091 ×10^12 M ⊙

So (0.8+0.095+0.0091) ×10^12 M ⊙= 0.9041 ×10^12 M ⊙ Total mass estimate.

Therefore the ratio of supermassive black hole mass to total mass is

0.0000041x10^12 M ⊙
-------------------------
0.9041 ×10^12 M ⊙

Which is 0.00000453 x 100% = 0.000453%

So it's just under one half of one thousandth of one percent given the above caveats.

Here is my question: in Bell's theorem, why do we assume that if local variables existed, the measurements of the particles should be linearly correlated to the angle the detectors are arranged at?

This question is fundamental to Quantum Mechanics and I cannot find an answer online. I've asked many physicists online (you know, the ask-a-physicist pages) and never got an answer.

a reply to: Arbitrageur

Ok, so I assume, we are for at least sake of that question and your response, that 'the central supermassive blackhole' is a 'single object of sorts';

So though at first thought; 0.000453%

the percentage you answered with appears small, is it correct that, considering supermassive blackhole as a single object (a single star is a single object, a single planet single object, single asteroid etc.) that it is the most massive single object in/of the milky way;

As single objects go, therefore it accounts for the largest percentage of gravity force causation, as it is the largest percentage of mass, and mass is what causes gravity force;

So is it thought, that the center black hole, is the largest concentrated mass, the largest concentrated source of gravity, and it is the central massive black holes' (it is a bit strange referring to the most massive object as a hole, but I do get it) existence which contains the shape of the milky way galaxy... to the degree prior to the need of dark matter?

I presume the black hole would have to be many more percentages more massive for there to not be needed dark matter theory, but even still, if the black hole was made incrementally more massive for sake of these theoretical checks and balances, is it thought that the spiral rotations and outer stars would 'make sense'?

if the black hold was made incrementally more massive for sake of these theoretical checks and balances, is it thought that the spiral rotations and outer stars would 'make sense'?

But if the central black hole mass was incrementally increased, for our sake of understanding the threshold of needing dark matter for theory, until dark matter was not needed, the milky way I presume would appear different, I presume the spiral would be tighter, and the orbits of the stars around the center would incrementally tighten?

It is interesting to think about how the non central black hole mass contributes to the overall gravity force;

so the percentage you gave contributes in its way, by being central, and forcing all its surroundings towards it?

There is a great deal of percentage left, how does that percentage; stars, planets, asteroids, comets, dust, gas, elements, sub atomic, etc. contribute to the geometry of the milky ways total gravity?

Without dark matter, it is thought the central mass of the milky way is not massive enough to cause the gravity force geometry to cause the total non central mass material to continually behave in a spiral, orbital, rotational like system?

Without dark matter, how is it thought that the non central mass material locally and subsequently totally would effect the milky ways spiral like existence;

If there was no dark matter in theory (theory, meaning, a theoretical nature, according to all laws of nature we know of questioning the 1, questionable theory, being discussed), in theory a central black hole of mass x, and a quantity of masses equaling various percentages of 100% - 0.000453% ;

given those quantity of masses spatial relation to the central mass, and given those quantity of masses (each having their mass which has a range of comparisons between all other masses) percentage of gravity force caused;

what would the geometry of the gravity force field be, what would the reaction be?

originally posted by: masterp
Here is my question: in Bell's theorem, why do we assume that if local variables existed, the measurements of the particles should be linearly correlated to the angle the detectors are arranged at?

This question is fundamental to Quantum Mechanics and I cannot find an answer online. I've asked many physicists online (you know, the ask-a-physicist pages) and never got an answer.

I'm not sure if I understand your question, but I'll give it a shot. In two of the most recent Bell tests, the "particles" tested were photons. We know some things about photons such as that they always travel at the speed of light, and they have momentum. Let's look at an example test, if you have a different test to discuss post a link to it:

Significant-loophole-free test of Bell's theorem with entangled photons

Two entangled photons were separated at the source, and sent via fiber optic cables to different measuring stations. With these fiber optics cables the photon is more or less restricted to traveling through the cable and so when it exits the cable you know what direction it came from. So I don't see any issue about the angle in this experiment since the range of angles where a photon can exit a fiber optic cable is limited. You could use a cone to characterize the angles at which photons exit, and you can see a slice of such a cone in the right hand point of this fiber optic audio cable where photons are exiting:

fiber optics


So if the fiber optic cable has a small diameter and you put your detector close enough to the end of the cable you shouldn't have a lot of trouble detecting the photons coming out.

Now let's say for example there are small losses in the cable and one of the photons just doesn't make it to the end of the cable because it interacts with the material the cable is made of. Such losses are very small with fiber optics, but not zero. What happens to the experiment? You may measure a photon at one station but not at the other station, so it's not possible to determine whether there was a correlation of polarization or not for that single entangled pair, so you lose one data point that way, but the vast majority of the photons make it though the fiber optic cables, and you make your measurements on those which do make it though the cable.

originally posted by: ImaFungi
the percentage you answered with appears small, is it correct that, considering supermassive blackhole as a single object (a single star is a single object, a single planet single object, single asteroid etc.) that it is the most massive single object in/of the milky way

I think that would be a good guess, but we can't see the entire milky way and we have a hard time "seeing" black holes, unless they are either "feeding" or unless there is a bright object behind them which they "magnify" via gravitational lensing. So if they can't all be observed reliably then you're guessing this based on models of evolution of the universe, galaxy formation, etc and maybe your models don't predict many other supermassive black holes besides the one at the center. Maybe it's improbable but not statistically impossible, for something like that to be hiding in a part of the galaxy we can't see.

So is it thought, that the center black hole, is the largest concentrated mass, the largest concentrated source of gravity, and it is the central massive black holes' (it is a bit strange referring to the most massive object as a hole, but I do get it) existence which contains the shape of the milky way galaxy... to the degree prior to the need of dark matter?

I don't follow the question exactly but my belief based on some limited evidence is that early galaxies tended to be somewhat spherical or at least radially symmetrical in shape, and they probably had black holes at their centers. The more modern disc-shaped galaxies like ours, and Andromeda I believe are the result of collisions from these earlier spherical shaped galaxies, so I suspect the disc shape is a result of the collision, not of the black hole.

I presume the black hole would have to be many more percentages more massive for there to not be needed dark matter theory, but even still, if the black hole was made incrementally more massive for sake of these theoretical checks and balances, is it thought that the spiral rotations and outer stars would 'make sense'?

If the black hole was more massive, it wouldn't explain the observed rotation.

But if the central black hole mass was incrementally increased, for our sake of understanding the threshold of needing dark matter for theory, until dark matter was not needed, the milky way I presume would appear different, I presume the spiral would be tighter, and the orbits of the stars around the center would incrementally tighten?

There are some pretty tight orbits already around the supermassive black hole, but yes of course if it was even more massive those orbits would be tighter.

There is a great deal of percentage left, how does that percentage; stars, planets, asteroids, comets, dust, gas, elements, sub atomic, etc. contribute to the geometry of the milky ways total gravity?

As I said I think the geometry of disk galaxies is likely the result of past galactic collisions. For a detailed answer to your question you should really read the paper I cited for the Milky Way mass, which talks about how the mass is distributed and how the mass was measured.

If there was no dark matter in theory (theory, meaning, a theoretical nature, according to all laws of nature we know of questioning the 1, questionable theory, being discussed), in theory a central black hole of mass x, and a quantity of masses equaling various percentages of 100% - 0.000453% ;

given those quantity of masses spatial relation to the central mass, and given those quantity of masses (each having their mass which has a range of comparisons between all other masses) percentage of gravity force caused;

what would the geometry of the gravity force field be, what would the reaction be?

Moffat tried to develop an alternate explanation called "MOND" which is a modified gravity theory, but most astronomers seem to think it doesn't explain bullet cluster observations. I'm not married to dark matter theory if someone else can show another theory which fits observations better, but Moffat's hasn't succeeded in a convincing way, maybe you can come up with a more convincing alternate theory?

a reply to: ErosA433
a reply to: Arbitrageur

originally posted by: Arbitrageur


[atsimg]http://files.abovetopsecret.com/images/member/48da3d162815.jpg[/atsimg]

[atsimg]http://files.abovetopsecret.com/images/member/68cbe40a92ea.gif[/atsimg]
Speaking of dumbing things down, if you get your science from TV or youtube videos instead of from a proper education you're bound to have some misconceptions and it's never as simple as the dumbed down models.

But the Heisenberg uncertainty principle doesn't prevent electrons from interacting, it only places limits on how accurately you can know the position and momentum simultaneously.

I don't get "my science" from youtube or TV,
but you should know that...

watch, listen and think...
start at 7:11


that is light ( radiation ) ?
it's an electro-magnetic wave !!

if you listen carefully, you will realize, that LHC collisions are nothing else that what he is talking about, charges creating waves in EM field.
Protons are 2000 "heavier" than electrons so I hope you can see the difference between electron radiation and proton radiation.

LHC is collecting ripples in EM field and NOT any made up particles you call them gluons photons or what else...
This names come from the math in the theory, because the theory is giving names to different ripples !

I really suggest you watch the whole series of this video

the pictures of the shape of an atom are also explained in this series so take you some time and watch it

originally posted by: KrzYma
the pictures of the shape of an atom are also explained in this series so take you some time and watch it

I've already seen that video and I don't remember it explaining the shape of atomic orbitals or explaining the rest of your word soup. What time index does it explain the orbitals?

By the way this video has some intuitive insights into atomic orbitals using Chladni patterns but if this is what you're taking about you've apparently got several different ideas and concepts jumbled up and confused:

9. Chladni Figures and One-Electron Atoms

a reply to: KrzYma

Already watched a series longer than an hour long youtube lecture... it was called a 4 year degree and a 4 year PhD... Iv worked with, designed, and operated detectors similar to that of the several LHC detectors... and no... they are not just picking up a wave

a reply to: Arbitrageur

one electron atom dude, ONE !!
it does not hold for more charged atoms, how comes you think it is true ??

this is the whole point what is wrong with the picture!

Chladni Figures... yeh.. and all other must be true


I'm talking about fields, you are talking about point like particles

a photon is an mathematical construct, a tool in a theory to get things easier...
now... you are talking about photons being a real thing, NO, they are NOT !!

there are no photons ! period !!!

a reply to: ErosA433

NO? what are they picking up other that electro magnetic waves ??

what kind of matter detects any of the particles in the particle zoo???

originally posted by: ImaFungi

I presume the black hole would have to be many more percentages more massive for there to not be needed dark matter theory, but even still, if the black hole was made incrementally more massive for sake of these theoretical checks and balances, is it thought that the spiral rotations and outer stars would 'make sense'?

I have to correct an assumption. Spiral rotations.

Stars in galaxies do not Spiral inwards, nor- are spiral arms a flow of stars/gas in towards the centre. They are simply regions of a galaxy that have high star formation. High star formation regions will tend to produce an abundance of hot blue stars that live fast and die young, when they explode, the shock of the material hitting the interstellar medium, promotes more star formation. While unobserved, the rotation of the stars is actually slower than the 'apparent' rotation of the spiral. This is because the spiral is nt actually a rotation, but a shock front formation.

guys...

what is an electric field ??
what is is made of ??

and don't tell me it's made of particles....

a reply to: KrzYma

They observe interesting and quite well understood effects called... Ionisation and scintillation, both of which allow for ion-collection or photon production and collection, typically by another intresting effect called - the photo-electric effect.

What you suggest is that waves are produced and these pass through the detector.

Why then does a trypical particle physics detector such as ATLAS...

So, question for you KrzYma,

A muon is produced in ATLAS, which detectors do you observe it in?
A High energy Proton is produced in ATLAS, which detectors do you observe it in?
A High energy Electron is produce in ATLAS, which detectors do you observe it in?
A High energy Gamma is produce in ATLAS, which detectors do you observe it in?
A High energy Muon is produced, yes, yet again in ATLAS, which detectors do you observe it in?

I ask you these because your postulate of 'waves' should give some very predictable behavour