How much does light weigh?

I don't like debating 0.9r=1 without something else to divert my attention, so I'm doing one that has a certain answer, but I have no idea what it is

I'll share my thoughts, you can share yours. I'll leave a poll at the bottom (but just because this is the Polls section!).

Why is a black hole black? Because even light cannot escape the incredible gravity. Ah, gravity. Gravity determines weight, does it not? The moon has 1/6 the gravity of Earth, so things weigh 1/6 as much. Therefore, if something is affected by gravity, it has weight, does it not? I would think so. Therefore, light must have weight.

But how can that be? Do you feel weighed down on a sunny day? On the contrary, when in a dark cave, you feel heavier, weighed down. Is this purely psychological, or is there more to it? Who knows.

I'll add more later, but I'm almost off work, so I'll leave it at this. BTW, please don't argue the existance of black holes (unless the main argument ends). I know they aren't proven fact, but they are generally accepted, and for the sake of this argument, they must be. Although I suppose that means that nobody would be able to argue that light DOESN'T have weight. So if you must, discuss black holes.

Does light have weight?
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Hm... if I remember correctly, light is a wave and therefore does not have weight.

Rob
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Reply to Arrow

Actually light is both. Don't ask unless u want me ot get into my quantum physics stuff. Hence, it hass mass.

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Reply to Flamethrower205

Weight is derived from mass. All matter has mass. Now the old debate, Does light have mass? It is actually a settled debate.

The main argument for light having mass was in energy packets or photons. They do have mass like properties i.e. momentum, but no real mass. The argument was that since p=mv, it must have a mass m to get the momentum. This m is actually called the relativistic mass. Of course there also is the famous, e=mc^2, and thus, m=e/(c^2).

The modern definition of mass of an object is its mass at rest i.e. m=e[0]/(c^2). e[0] is the total energy of an object at rest. But photons cannot be held at rest, can they?

The Blackhole part...sorry
Blackholes don't actually suck in light. They heavily distort space around them. The light gets refracted in the distorted space. the fact that you see a lot of light around the black hole must mean some light is escaping.

99% of statistics are made up!

Reply to HolyGrenade

HG is on the ball on this one.

Basically quantum physics states that light has both wave and particle properties. This leads to some insane stuff. All in all, light is the emmission of photons and they are massless.

Holygrenade brings up an excellent point too. Blackholes DON'T suck in mass. Another interesting note is that blackholes actually shrink up and dissapear with time.

God Bless America!

Reply to dhlucke

Well I would like to settle this but I forget the answer and my favourite physics text book is stored at my parents house which is 400km from where I live now.
Plus I'm too lazy to search through all the posted Internet drible on the topic.

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Reply to zpyrd

There's a bunch of physicists that are really pissing people off, by saying "There is no such thing as matter. It's all energy; some more densely packed, which gives the appearance of matter."

(buy, basically, HGitto)
=)

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Reply to ejsmith2

Actually, you don't FEEL weighed down by light, but it does exert a force on you as described by (I think) the Poynting Vector. You don't feel it because it's such a small force on your body.

One theory for space travel is to set up a solar sail. A huge, very light sail would be spread out, and tethered to a relatively small ship. The sun's radiation would push the ship away, and into space. Materials have already been designed for the sail (I saw some of this carbon fibre stuff that actually flew upwards in the air), and I think the Russians have plans to launch a test probe based on this idea.

As for light having mass, I believe the current concession is that it has no mass. Photons have a zero rest mass, and as others have pointed out, gravity affects spacetime, not mass, so there's your answer for the black hole thing.

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Reply to silverpig

Right, I've heard of solar wind sails.

So what are the exact properties of matter (everyone, not just silverpig)?
Weight and mass? What is mass?

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Reply to FatBurger

Isn't that where a bunch of people gather for church or something or other?

Nice Lizards crunch Trolls cookies....... :smile: Yummy!! :smile:

Reply to Yahiko81

The limited pysics knowledge I have comes only from high school and general ed. college courses. From what I understand, light is both a particle and a wave. Being a particle, it has to have mass no matter how miniscule the amount may be.

So, my answer to your question is that yes, light does have weight since it has mass. However, obviously weight is a direct factor of gravity, so the weght of light will vary greatly throughout the universe.

"I'm not gonna launch a $2 million missile at a $10 tent and hit a camel's butt." -Bush

Reply to njeske

Light is not both a wave and a particle... It has properties of both... That's sorta like saying that I am a tree and a rock, because my teeth are hard like a rock, but I stand up straight like a tree.

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Reply to silverpig

I think that with E=mc^2, and other physical theories, you could say that matter is a special, bound, condensed form of energy.

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Reply to silverpig

Have you seen those little fan sorta things in vacuum bell jars, in the physics labs. One side of the fan is coloured black, the other is white and starts spinning if you shine a bright light on it.

Mass<->Energy:
Have you read any of the higgs theory papers, they have to do with the relation of mass and energy. There are some nice and simple examples but most of them don't seem to make sense unless you understand a lot of the numbers and equations that come along with the examples. They just seem to go way over my head most of the time.

99% of statistics are made up!

Reply to HolyGrenade

I haven't seen those fans, but I've seen small extremely light balls being pushed around by lasers. Very cool.

I've read some material on the Higgs particle and what not, and I find it very interesting. I'm always on the lookout for more though.

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Reply to silverpig

Similar concept, I saw a ping-pong ball being suspended in air by a sound wave. That was pretty sweet

Quarter Pounder Inside

Reply to FatBurger

Really? That's cool. I've seen stuff move when I play CS too loud but nothing's ever been suspended in mid air by it. :lol:

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Reply to silverpig

I've seen a wombat suspend itself in midair - justusing fart power.

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Reply to Anonymous

I've seen a wombat suspend itself in midair - just using fart power.

You are responsible for any damage the info in your post may cause to my system.

Reply to Anonymous

When did wiggy do that?

Nice Lizards crunch Trolls cookies....... :smile: Yummy!! :smile:

Reply to Yahiko81

wiggy's a hedgehog. Have u ever seen Saved By The Bell on Nickolodeon. Well wiggy looks a bit like Screech - Just taller and lankier. Wiggy's hair's straighter and the spikes point forward instead of up.

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Reply to Anonymous

Ahh I see now, said the blind man to the deaf dog.

Nice Lizards crunch Trolls cookies....... :smile: Yummy!! :smile:

Reply to Yahiko81

Though I have picked wiggy up from work twice this week and he has farted in my car - on both occasions. He saves them up all day I think cos they are rancid(sp?).

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Reply to Anonymous

ouch. word to the wise. Don't screw around with staple pullers. Those things will rip your finger to shreads.I've now got a 1" gash that's about 1/8th of an inch deep on my index finger on my right hand. It hurts very much to type. But the post must continue.

Nice Lizards crunch Trolls cookies....... :smile: Yummy!! :smile:

Reply to Yahiko81

okay; here's the story on light:

Light has properties of both waves and particles, but according to the latest quantum theories, everything is in fact both a wave and a particle. However Light is interesting because it has no rest mass. When light is moving, it does have weight.

to put it short, here's the mass of light.

E=h*lamda (lamda is the wavelength of the light. . . approximately 500x10^-9m for visible light, and h is planks constant)

from there you can get the engergy in one photon of light.

then from E=mc^2 (where m is the mass and c is the speed of light: 3x10^8m/s) we can get m=h*lamda/c^2 .

I won't go into how much that makes one photon weigh; as its meaning means basically nothing. But needless to say; a photon of light has a mass.

As for having weight, well; it must be in a gravitational field for that. . and yet; light is affected by gravity, and actually will bend aruond massive objects such as the sun. So you just plug the mass into G*m(object)*m(light)/d^2 . where G is the universal gravitational constand, and d is the distance between the photon and the object. Of course; i'm also neglecting relativistic affects, becaus if you used the photons view point, it would have zero mass. . . . Long story there though.

Philip Garcia

Reply to Anonymous

Doesn't E=mc^2 apply only for when the object is non-relativistic? As you approach c, you have to add in the other terms (mc^2 is only the first term in a long taylor expansion right?). If I remember correctly, the other terms are ignored because they use v^2, and v << c in most cases. But since v for a photon is c, you must consider these other terms. I'll try and find the full expansion, but I'm kinda lazy right now.

AFAIK, E=mc^2 is the energy contained in the mass of the object while it is at rest. Since the rest mass of the photon is 0, it has 0 energy while at rest. As you consider a moving photon, travelling at c, I think the other terms in the taylor expansion might allow for an energy, but with no mass... can't remember though, and it'll take some looking at the equation to see it...

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Reply to silverpig

Quote :

Why is a black hole black? Because even light cannot escape the incredible gravity. Ah, gravity. Gravity determines weight, does it not? The moon has 1/6 the gravity of Earth, so things weigh 1/6 as much. Therefore, if something is affected by gravity, it has weight, does it not? I would think so. Therefore, light must have weight.

Burger, do you know what relativity is, and the curvature of space?

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Reply to Matisaro

Well, the theory of dual nature of light has long been debated, but its certainly not over. Observations tend to conclude both ways, whatever is *convinient* for that particular event. So we conclude that light does exist in both forms, continuous (waves) and particle form.

Blackholes are amazing celestial bodies, they exert such a tremendous gravitational force, that leads to very interesting effects. One effect is the one that makes you beleive a black hole is dark, but the paradox is that it is also one of the brightest objects in space!

Here is how: the gravitational force of a black hole is such that the escape velocity (the velocity needed to break free and get away from it) is more than the velocity of light. So even light cannot get away from a black hole. Now, the intensity of the gravitational force reduces as we go farther from the black hole object, beyond a certain distance this force just bends the light beams which creates interesting effects like the Gravitational lense.

That certain distance is the one where the escape velocity is exactly equal to the velocity of light, called as the Event Horizon. Here, light just continues to move around the black hole body indefinitely, it neither falls into the black hole, nor does it escape away from it! This creates a bright sphere around the black hole, which makes it a bright object in space.

Actually, the black hole isnt visible at all, it is merely indicated by the bright halo around it, the black hole is a tiny body with tremendous mass thousands of miles inside that sphere of light.

do you know how small the earth should shrink to create such a gravitational field that wouldnt allow light to pass (essentially making a black hole out of it)???

It would be just less than 2 cms across, smaller than a golf ball!

BTW Black holes do not disappear with time, they stay in space gobbling up whatever comes near them, getting bigger and bigger and stronger and stronger!

girish

Nothing is fool-proof. Fools are Ingenious!

Reply to girish

I don't know anything about quantum physics, relativity, the weight of light etc. apart from Dr Who stuff (some of which can be touching on reality).

I figure light doesn't weigh me down any, so it must be very light! :lol:

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Reply to camieabz

Yes, light is very light, it has very little mass (just that of a photon) which can be converted to energy (see E=mc^2) equivalent to your house supplied electricity for about a few tens of years only.

Of course, thats relative, you guys have 110V, we have 220V supply lines so we can use only half as long!

Nothing is fool-proof. Fools are Ingenious!

Reply to girish

240V here. 120V in U.S.

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Reply to camieabz

Blackholes have never been witnessed. The event horizon is invisible too, it's just a theoretical sphere in space from which photons can not escape. All light that crosses the event horizon is forever gone. What you are talking about is an accretion disk. Say you have a binary system with one being a star and the other a black hole. The black hole's massive bending of space time will draw mass towards it and as the mass curves inwards towards the event horizon it will be visible. Particles will decay with some going in the event horizon and some not. What we witness is not the black hole or event horizon, but the mass that heats up and brightens in the accretion disk through acceleration and gravitational forces.

Furthermore, black holes do supposedly decay with time. I don't know the exacts of why, but I can find out. I've only had a brief introduction to graduate level black hole material. Keep in mind this is all theoretical. We can be fairly certain that we are correct based on what general relativity and quantum mechanics proposes and what we observe (lensing effects for example), but we still have not directly observed a BH.

There are many who are trying different ways of proving that a black hole exists. I did a little research project on the effects that black hole novae vs neutron star novae in quesence have and basically some are trying to say that there exist proof for a black hole based on the detection of the event horizon through the different luminosities observed. If you take a system in which you know that you have a low mass star and a neutron star then you know that mass being drawn towards the neutron star will brighten when it hits the surface. However if the secondary is a BH, then it won't be as luminous. It's all very interesting, but they still have the problem of not knowing the exact distances to these Novae (fundamental problem of astrophysics) so it's not a perfect theory.

Quote :

Scientific Justification
X-ray transients are compact binary systems in which a low-mass secondary (either a main-sequence star or a subgiant) transfers mass via Roche-lobe overflow onto a black hole or neutron star primary.

X-ray transients have highly variable luminosities. They spend most of their lifetimes in a low-luminosity quiescent state, but occasionally undergo dramatic outbursts during which both the optical and X-ray emission increase by several order of magnitude. It is the elliptical orbits that are the cause of the nova phenomenon. Neutron star X-ray novae (NSXN) outbursts typically occur every 1-10 years and last for several weeks, while black hole X-ray novae (BHXN) outbursts are typically separated by 10-50+ years and last for several months.

A variety of observations indicated that, near the peak of an outburst, an X-ray transient accretes matter via a standard thin disk, thus accretion is radiatively efficient during this phase. In quiescence the situation is more complex with the spectra of BHXN not resembling a thin disk and the accretion rates calculated from the observed X-ray luminosities disagreeing by order of magnitude with predictions from the standard disk-instability model for quiescent disks.

It is difficult to explain the very low, but nonzero, quiescent X-ray luminosities of BHXN using standard viscous accretion disk theory due to the continued mass transfer from the companion evidenced by an optically bright disk. Narayan showed that the observations of quiescent BHXN can be best explained by a two-component advection-dominated accretion flow model (ADAF) consisting of an inner hot advection-dominated accretion flow surrounded by an outer disk. Only the inner ADAF contributes to the observed optical, UV, and X-ray emission of the system. The outer thin disk acts mainly as a reservoir that accumulates mass until the next outburst is triggered. In quiescence, the emission of the disk is primarily in the infrared but is hardly seen as it is overwhelmed by the emission of the secondary.

In an ADAF the energy released by accretion is stored as heat in a radiatively inefficient flow. If the accreting object is a black hole this energy will not produce observable emission once it crosses into the event horizon. If the object is a compact object like a neutron star, the radiative efficiency is much higher, and the energy will be released upon impact and radiated to infinity. Thus, the luminosity of a black hole system will be much less than that of a compact star, based on the same mass accretion rate.

BHXN and NSXN are believed to be similar in many respects. BHXN and NSXN with similar orbital periods are believed to have mass transfer rates from the secondary, measured in Eddington units of the primary, which are comparable. As long as the orbital periods are similar, it is believed that quiescent BHXN are much less luminous in X-rays than quiescent NSXN. Garcia and Narayan compared the outburst amplitudes of BHXN and NSXN as a function of their maximum luminosities and showed the observations reveal systematically lower relative luminosities in BHXN.

The argument relies on a reasonable assumption that the Eddington scaled mass accretion rate is similar in quiescent BHXN and NSXN. This assumes that the quiescent X-ray luminosities of NSXN actually result from accretion. If the NSXN sample contains short orbital period systems, the angular momentum loss through gravitation radiation is expected to be the dominant mechanism driving mass transfer from the secondary. It has been shown then that the Eddington scaled mass transfer rates are then likely to be roughly similar in BHXN and NSXN of similar Porb. At long periods, nuclear evolution is expected to drive the mass transfer rate to substantially higher values in BHXN, so these systems are less useful.

Another assumption is that, f*, the fraction of matter transferred from the secondary, which actually reaches the central star, is the same in BHXN and NSXN. Outflowing winds from an ADAF tend to reduce f*, but there is no reason to expect winds to be stronger (by a factor of 100) in BHXN than in NSXN. A centrifugal propeller and/or radio pulsar action could reduce f* in NSXN without affecting BHXN. Garcia expects f* to be lower in NSXN than in BHXN, strengthening his case for event horizons in BHXN.

Campana & Stella argue that it is not correct to compare only X-ray luminosities but that quiescent non-stellar optical and UV luminosities must be compared as well. Garcia states that the origin of the optical/UV luminosity is presently unclear, but that within the ADAF model it depends on the poorly known radius at which the inner edge of the accretion disk evaporates into the ADAF. It also depends on the strength of winds from the ADAF. However, if the non-stellar optical/UV luminosity originates in the outer accretion disk, or in the hot spot where the mass transfer stream from the secondary impacts the disk, then the similar optical/UV luminosities of BHXN and NSXN provides observational confirmation that the mass transfer rates in the two kinds of systems are similar. Garcia detected a 0.25 mag modulation in the far-UV flux of A0620-00 on an orbital time scale which suggests that the far-UV flux may be modulated with the orbital phase. This points to an origin in the hot spot.

Garcia concludes that it is reasonable to assume that accretion accounts for a substantial fraction of the quiescent X-ray luminosity in most NSXN. Garcia also concludes that the optical variability of NSXN in quiescence provides enough evidence that accretion continues during quiescence. Garcia feels that any explanation describing the dramatic difference in X-ray luminosities will require postulating an event horizon in BHXN.
By comparing quiescent BHXN and NSXN with similar orbital periods, we eliminate the uncertainty in the mass accretion rate, thus Garcia believes he has secured evidence for the event horizon.

God Bless America!

Reply to dhlucke

<A HREF="http://astro.estec.esa.nl/SA-general/Projects/Integral/integ_blackhole_animation.html" target="_new">http://astro.estec.esa.nl/SA-general/Projects/Integral/integ_blackhole_animation.html</A>

Here's a neat little animation of an accretion disk around a rotating black hole. Keep in mind that this is just one type of black hole.

Here's some other images I found in a few minutes

<A HREF="http://www.seds.org/hst/ngc4261.html" target="_new">http://www.seds.org/hst/ngc4261.html</A>

<A HREF="http://www.rkm.com.au/blackhole.html" target="_new">http://www.rkm.com.au/blackhole.html</A>

God Bless America!

Reply to dhlucke

well if 6+2+3+9-5/9+99-55*30/.6+2/100-1-66+44+3777+.47+10+.100777777-10.20111111-.000000000011033333333-.00000000000000000000000033333333=4 then yes, light is light.

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Reply to scamtrOn

Yes, luke I meant exactly that, just missed some words (and put other possibly incorrect words for them) it was a faint memory of a class 5 years ago I had taken in our college AAA (Ameteur Astronomy Association)

Anyway, recently there had been some findings, photographic evidances for existance of blackoles, I used to get a Astronomy Now newsletter in my kasparovchess mailbox, but they discontinued the free email so I cant get the links.

Anyway, there is a theory of how big a star should be if it has to become a blckhole. Not every star becomes a black hole. Depending on its mass, there can be pretty much variation in the way it dies.

A star of the size of our sun (1 solar mass) cannot be a blackhole, it would be Red Giant. In 5 billion years, it will start loosing its fuel, and start expanding, it could be 10 times today's size as seen from the earth which will be parched, all the water evaporated and all the life extinct. It will engulf Mercury and Venus, but the Earth will continue to revolve round it, charred and dead.

If the mass of a star is more than 1.6~2 solar masses, it will probably become a while dwarf, as it starts collapsing, its gravity increases which in turn pulls it inside. But the mass is not so much as to make a blackhole out of it. Still, the gravity and internal pressure (and of course density of the matter, even a spoonful of that matter can weight hundreds of tonnes!) will be such that some of them will cease to have matter in a normal sense, just Neutrons. Such a star is called as a Collapsar or a Neutron Star. Its extremely bright, its tiny and rotates round itself with very high precision. In that it sends electromagnetic signals of a fixed frequency, like 3 Hz to a few hundred Hz which can be captured and listened. This frequency can be a unique signature of such an object, often referred to as a Pulsar, a Pulsating Star. It can be used as a beacon, like a light house to find our way when we get about exploring the outer space.

Now, for larger than 10~15 solar masses, the things change vastly. The star goes beyond the collapsar stage, it is not known what kind of matter will a blackhole have, but one thing is certain, it will be a highly dense body, a spoonful of it weighing thousands of tonnes! It wont have any mountains and valleys, any surface defect will be smoothed out by its intense graviyt. It will exert such a gravitational force that even light cannot escape it. Even the space around it would be distorted.

And yes, it would be extremely tiny superdense ball of matter, which paradoxically will be quite easy to find out. Usually, a black hole will be found in pairs only, along with its victim which is being bled to death, as the pictures you posted show.

An interesting thing is the jets that it shoots along its axes, which can be several light years long. These have been discovered at many places by the HST (Hubble Space Telescope) which can be said to be a proof of the existance of the bkackhole. I might add that these jets were first proven mathematically and then found out by the telescope! Just like Pluto was discovred.

girish

Nothing is fool-proof. Fools are Ingenious!

Reply to girish

One of the links is a HST image of the "effects" of a blackhole. It's still nonetheless theoretical. I'd bet money that the theory is right, but we still can't directly observe a blackhole. I'm not sure what images you're refering to, but some of the more recent ones are very impressive. I was just browsing through <A HREF="http://oposite.stsci.edu/pubinfo/Pictures.html" target="_new">here</A>, and it's amazing what we can see now.

Another interesting fact is that the energy and gravity a Neutron star or pulsar has is so insane that they make a nuclear bomb look pathetic. If you were to blow up a nuclear bomb on the surface of a NS you would only blow the top layer of dust a few cm from the surface.

God Bless America!

Reply to dhlucke

Quote :

That certain distance is the one where the escape velocity is exactly equal to the velocity of light, called as the Event Horizon. Here, light just continues to move around the black hole body indefinitely, it neither falls into the black hole, nor does it escape away from it! This creates a bright sphere around the black hole, which makes it a bright object in space.

Whoever told you that is wrong lol.

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Reply to Matisaro

Quote :

BTW Black holes do not disappear with time, they stay in space gobbling up whatever comes near them, getting bigger and bigger and stronger and stronger!

Actually black holes emit radiation because of quantum physics, and hawking predicts the lose mass over timethe first is verified, the second is a prediction based upon the first which is most likely correct), its called Hawking radiation.

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Reply to Matisaro

Quote :

Furthermore, black holes do supposedly decay with time. I don't know the exacts of why, but I can find out.

Ill sum it up from memory dh.

Quantum theory shows that every second in space virtual pairs of particles are appear and destroy eachother, this happens in all space and has been shown to be true.

Sometimes particles which appear very close to the event horizion, will have one of the virtual particle's(from the pair) sucked into the event horizion before anihilating eachother, this means that the virtual particle becomes a real partic...darnit, I cant remember the....hold on GOOGLE to the rescue.

This thermal radiaton can be understood as the quantum mechanical pair creation of particles in the gravitational field of the black hole near the horizon. One of the particles goes in the black hole and the other produces the thermal radiation. Although the rate of Hawking radiation is very small it does mean that black holes, radiating as long as their temperature is non-zero, will evaporate and maybe disappear in due time. It turns out that the extremal solutions mentioned earlier have specifically interesting thermodynamical features which determine what happens to the black hole under consideration (total evaporation, stable state). So summarising we have the following black hole laws:

There you go.

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Reply to Matisaro

<<A star of the size of our sun (1 solar mass) cannot be a blackhole, it would be Red Giant. In 5 billion years, it will start loosing its fuel, and start expanding, it could be 10 times today's size as seen from the earth which will be parched, all the water evaporated and all the life extinct. It will engulf Mercury and Venus, but the Earth will continue to revolve round it, charred and dead.

If the mass of a star is more than 1.6~2 solar masses, it will probably become a while dwarf, as it starts collapsing, its gravity increases which in turn pulls it inside. But the mass is not so much as to make a blackhole out of it. Still, the gravity and internal pressure (and of course density of the matter, even a spoonful of that matter can weight hundreds of tonnes!) will be such that some of them will cease to have matter in a normal sense, just Neutrons. Such a star is called as a Collapsar or a Neutron Star.>>

Umm, that is mostly right. The sun will become a red giant, then a white dwarf, brown dwarf, then just a lump of space crap.

The 1.6 to 2 solar mass stars don't go straight to white dwarves... They become red giants/super giants. Then, they go nova, and what is left is a neutron star, and a nebula like the crab nebula.

The extremely massive stars (blue supergiants), become red super giants, then they go supernova, and a black hole will theoretically be left behind.

There are other dependencies, such as the type of nova (II or IIA etc...), so nothing is for sure.

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Reply to silverpig

Yep. As for the "evaporation" of black holes, that's how it's done. If you think of matter and energy being the same thing, you can sort of imagine that the gravitaional field requires mass/energy to create. Then you can see that the energy in the field can be linked to the mass of the black hole. If this energy field has a fluctuation which produces a pair of particles, then it's sort of like the mass of the black hole has had a tiny part of it moved to wherever the particles were created. If one of these escapes....

Hmm, an interesting topic on which I don't know enough to give any useful info is what happens if the positron/electron pair created at the event horizon happens to be an entangled pair. I have a VERY limited knowledge of entangled pairs, but I'd like to hear anyone else's thoughts on the subject.

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Reply to silverpig

Photons have to be subatomic particles. Why? Because matter is made of energy. Energy can be obtained from matter. All energy comes from the transmission of particles. Light is a form of energy, therefore...

Photons would be so small as to have an immesureable mass. In fact, Photons might be what Quarks are composed of. Do quarks have mass? Of course, because these are what Electrons are made of. And electrons have mass.

What's the frequency, Kenneth?

Reply to Crashman

Uh you got that mostly wrong man. Electrons are not made of quarks, only protons, neutrons etc are. Electrons are (as far as we can tell anyways) electrons. No one has yet cracked open an electron, and it'd probably take a super collider with the radius of saturn's rings to do it...

The current theory is that photons are just a particluar vibrational pattern of a one dimensional string oscillating in ~6 dimensions (not too sure on the number, and I'm having problems finding my book).

Forces come from the transmission of special "communication particles," gluons, W and Z bosons, photons, and the predicted, described, and yet undiscovered graviton. The bosons have been shown to have mass, however, the other three have not been proven to have mass at all (I'll check, but I think the theory shows that the equations describing the photon and graviton insist they are massless).

Your half-statment "Light is a form of energy, therefore..." should end with "they can be transformed into a massive particle via E=mc^2"

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Reply to silverpig

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Whoever told you that is wrong lol.

wrong huh???

maybe badly worded but its certainly correct. its not the blackhole that is visible, its the bright disk around it that makes spotting it easire, then there is the gravitational lense that produces some effects by way of which we can make out the cause, ie presence of the black hole!

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Actually black holes emit radiation because of quantum physics, and hawking predicts the lose mass over timethe first is verified, the second is a prediction based upon the first which is most likely correct), its called Hawking radiation.

>>BTW Black holes do not disappear with time, they stay in space gobbling up whatever comes near them, getting bigger and bigger and stronger and stronger!

Well, it might be a bit too melodramatic, but the fact is black holes are lurking in interstellar space sucking stars, which increase their mass and power, but then it isnt too frequent an event.

The blackhoes do lose mass over time, but that time frame must be pretty high, in terms of millions of years to lose some significant amount.

Nothing is fool-proof. Fools are Ingenious!

Reply to girish

Well, such are the horrific destinies of stars!

What intrigues is the concept of singularity. Theorotically, infinite mass packed in zero volume but practically we know its beyond imagination. It just can be unimagiable amount of mass in unimaginably small volume.

Blackholes of different sizes would have this m/V in diferent proportions although this figure would tend to infinity but certainly not be infinity.

Another interesting aspect of these blackholes are the way they distort space, give off jets along the axes. Could the conical regions along the axes of the black hole be the Light cone Dr.Hawkins predicts? Can this axis of a black hole be the tunnel in which time and distance is compressed, the warpways we see in SciFi's that can let us travels thousdands of light years in few days?

Too many questions but no answers!

girish

Nothing is fool-proof. Fools are Ingenious!

Reply to girish

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wrong huh???

maybe badly worded but its certainly correct.

So badly worded it was wrong, black holes themselves are not bright, and they dont have a field of light forever orbiting them, your first post was completely wrong.

Now, the accretion disk, thats another matter, and it is MATTER not light, and yes they exist and thats a good way for us to detect black holes.

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>>BTW Black holes do not disappear with time, they stay in space gobbling up whatever comes near them, getting bigger and bigger and stronger and stronger!

Well, it might be a bit too melodramatic, but the fact is black holes are lurking in interstellar space sucking stars, which increase their mass and power, but then it isnt too frequent an event.

YOu claimed black holes do not dissapear with time, I proved you wrong, how much time it takes is irrelevant.(by the way, the larger the black hole, the faster it evaporates, cool huh.)

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Reply to Matisaro

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The blackhoes do lose mass over time, but that time frame must be pretty high, in terms of millions of years to lose some significant amount.

A: millions of years is far from a large time fram universally.
B: try billions of years, but it still happens.

"The Cash Left In My Pocket,The BEST Benchmark"
No Overclock+stock hsf=GOOD!

Reply to Matisaro

Quote :

maybe badly worded but its certainly correct. its not the blackhole that is visible, its the bright disk around it

Yes, the bright disk of MATTER, you said a black hole was bright because it trapped a disk of LIGHT, which it does not, and even if light was trapped in a tight orbit around a black hole for all time, it wouldnt be bright at all, because for us to see light it has to escape, and if its trapped in orbit, it is not escaping now is it.

"The Cash Left In My Pocket,The BEST Benchmark"
No Overclock+stock hsf=GOOD!

Reply to Matisaro

Touche. :smile:

But yeah. Also, black holes are not the cosmic vacuum cleaners most think they are. They behave no differently than a massive star. You can actually have black holes with masses on the order of the mass of the earth, they would be no more gravitationally attractive (until you got very close, ie within the earth's radius), but would be able to trap light.

Lyrics. Wasted time between solos.

Reply to silverpig

Hmm, Well light behaves like a particle AND a wave. I would guess that you couldn't measure the mass of a photon the same way yyou cant easure it's energy and it's location. This was proven by Hisenberg.
But after all, all is relative.

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Reply to Anonymous

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