E=MC^2

[ihwip]

Einstein was the first person to realize that energy and matter could be converted back and forth. Maybe.<br /><br />Hawking was the first person to theorize that blackholes evaporate.<br /><br />There is just one problem I am trying to figure out. Hawking Radiation causes a black hole to evaporate via photons. How does energy turn back into matter?<br /><br />There should be a way that pure energy can be converted into matter, correct? I am trying to figure out what the theoritcal mechanism behind this would be.<br /><br />Thanks!

 

[kyle_baron]

Does the Big Bang, ring a bell? <img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> <p><font size="4"><strong></strong></font></p> </div>

 

[billslugg]

There are two ways I can cite:<br /><br />Fuse any two nuclei such that the result is heavier than iron, and you have to put energy in to make it happen. Thus the end product is heavier than the two original nuclei.<br /><br />Take any two photons whose energy sums to at least .511 MeV, and they can combine to form an electron positron pair. <div class="Discussion_UserSignature"> <p> </p><p> </p> </div>

 

[weeman]

<font color="yellow"> There is just one problem I am trying to figure out. Hawking Radiation causes a black hole to evaporate via photons. How does energy turn back into matter? <br /> </font><br /><br />Kyle_Baron sounds pretty correct on this matter (no pun intended <img src="/images/icons/wink.gif" /> ). The big bang was probably the most formidable event of energy to matter that exists within our current theories of science. At the time of the big bang, there should have existed only energy, since matter had not yet been formed. Immediately after the big bang, matter began to take shape. <br /><br />So, we could say that this is a prime example of energy being converted to matter. However, your question sounds like you're wondering how matter is converted into energy, and then back into matter. Is this correct?<br /><br />I'm not entirely knowledgable on this topic myself. The way I see it, it has something to do with the relationship between the matter entering the black hole, and the speed of light. When matter enters beyond the event horizon, it is accelerated to the speed of light (this being the escape velocity of a black hole once beyond the event horizon). <br /><br />Now someone correct me on this subject, because I don't think I am getting it entirely correct: Einstein stated that for a mass to be accelerated to the speed of light it requires an infinite amount of energy, because the mass of the object increases as it nears C. At .999 the speed of C a body of mass is less massive than it is when it is traveling at .99999999 the speed of C. So, the amount of energy required to take it from .999 to .99999999 to .999999999999999 will only increase.<br /><br />The area that I'm unclear on is if mass reaches C, does it then become pure energy? So, once it deaccelerates from C (i.e. exiting a black hole), does it then get converted from energy into matter?? <div class="Discussion_UserSignature"> <p> </p><p><strong><font color="#ff0000">Techies: We do it in the dark. </font></strong></p><p><font color="#0000ff"><strong>"Put your hand on a stove for a minute and it seems like an hour. Sit with that special girl for an hour and it seems like a minute. That's relativity.</strong><strong>" -Albert Einstein </strong></font></p> </div>

 

[alkalin]

E = MC^2, so write it this way: M = E/(C^2). Does it take the nonsense of black hole logic to figure it out? Since matter has formed from energy, then there are potential mechanisms that we yet do not know about that are cause.

 

[weeman]

Thanks for the info Tigerbiten <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <p> </p><p><strong><font color="#ff0000">Techies: We do it in the dark. </font></strong></p><p><font color="#0000ff"><strong>"Put your hand on a stove for a minute and it seems like an hour. Sit with that special girl for an hour and it seems like a minute. That's relativity.</strong><strong>" -Albert Einstein </strong></font></p> </div>

 

[ihwip]

OK wait...so Hawking Radiation is in the form of particles? I thought it was photon pairs on the event horizon where one goes back into the black hole and one goes out.<br /><br />Thanks for all the info!

 

[dragon04]

I believe it was derekmcd that lit my little light bulb of understanding...<br /><br />A singularity is a massive, gravitationally bound mass of disassociated fundamental subparticles with no hope of ever recombining into what we call normal manner.<br /><br />If I understand what he (and Hawking) mean, is that you're observing two separate and discrete phenomena.<br /><br />Release of energetic particles is an effect of the interaction of accelerating mass <b>at</b> the event horizon.<br /><br />BH "evaporation" is an effect of what happens <b>inside</b> the event horizon.<br /><br /><br /><br /> <div class="Discussion_UserSignature"> <em>"2012.. Year of the Dragon!! Get on the Dragon Wagon!".</em> </div>

 

[derekmcd]

"<i>OK wait...so Hawking Radiation is in the form of particles?</i>"<br /><br />Yes.<br /><br />"<i>I thought it was photon pairs on the event horizon where one goes back into the black hole and one goes out.</i>"<br /><br />Almost correct. Virtual particles arise <b><i>near</i></b> the event horizon. Heisenberg's Uncertainty Principal allows for fluctuations of energy between the beginning and end states which must be conserved. When these particles appear, they have borrowed energy which must be returned as the laws of conservation dictate.<br /><br />Should one of the virtual particles be boosted away from the event horizon long enough that it can be observed, it then becomes a real particle.<br /><br />Normally, these particles would annihilate or recombine (semantics) and return the energy they borrowed and return the system to its original state. With one of them becoming real, the energy in the real particle has to be accounted for.<br /><br />The black hole captures the virtual particle that didn't escape and is left with no choice but to compensate for the energy given to the now real particle that has been observed. Thus the black hole loses energy/mass (e=mc2) and ultimately shrinks.<br /><br />To an outside observer, it only appears as if the black hole allowed a particle to escape, but this isn't really the case. The black hole just covers up the thievery that happened in its neighborhood <img src="/images/icons/smile.gif" /> . <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

 

[derekmcd]

Thanks for that Dragon04. Coming from you, I take that as a major compliment. The intelligence in your posts humble me. Nice to know you could take something away from one of mine. <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

 

[a_lost_packet_]

Basically, the BH captures the anti-particle of the particle pair, correct? <div class="Discussion_UserSignature"> <font size="1">I put on my robe and wizard hat...</font> </div>

 

[derekmcd]

The virtual particle pairs really don't exist until one is observed and becomes real and tangible. The other then and only then becomes its anti-particle which then, yes, is captured by the black hole.<br /><br />I think that makes sense <img src="/images/icons/smile.gif" />. <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

 

[a_lost_packet_]

Aye, I forgot to include "virtual" in my above post. In this case, it really does make a difference. <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <font size="1">I put on my robe and wizard hat...</font> </div>

 

[vogon13]

The wavelength of the BH escaping photon is related to the physical size of the BH. So a big BH emits long wavelength (low energy) photons, and little ones emit shorter wavelengths with higher energy.<br /><br />As the BH evaporates down to nothing it gets very tiny indeed, and the Hawking Radiation becomes UV and X-ray and gamma.<br /><br /><br /><br />BZZZZZZZZZT !!!!!!!!!!!<br /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[one_billy]

What happens to the galaxy when the central BH evaporates? <div class="Discussion_UserSignature"> </div>

 

[MeteorWayne]

BH's as large as those at the center of galxies do not evaporate for many billions of billions of billions of years, probably far longer than the lifetime of the universe. Only VERY small BH's evaporate. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>