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About LinkBacksLet's take E=MC^2 - what is the practical use of this?
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March 29th, 2014, 08:30 AM
Let's take E=MC^2 - what is the practical use of this?
calculating enrgy yields from nuclear reactions
Details?Originally Posted by dan hunter
Calculating radioactive decay given two of the variables, for instance. Given the energy of a decay and knowing the speed of light constant, we can calculate the mass that was turned into energy.
The practical application, please?
FFS.
Details?->
meaning that a variation in mass (due to nuclear reaction) of
is magnified by a huge factor
producing a huge relaese of energy
. Makes sense to you now?
You are saying that the rate of change of energy is equal to the rate of change of mass times the 300,000,000 ^2?Details?
Did I not already say this? You can use the energy and the constant c to determine the amount of mass converted into energy during nuclear decay. Using 4th grade algebra, you can rearrange the equation to solve for either variable.
They teach algebra in 4th grade now? Do they teach you how step by step prove your answers? Or to talk like a nice decent human like xyzt did?
Now of course there is an issue in my mind as to how this type of knowledge is being beneficial to mankind? Destroying entire cities? Nuclear power plant accidents? Matter is extremely condensed potential energy, and of course if loosed it will go kinetic all over the place, but to what purposes?
Destroying entire cities using this formula was beneficial to mankind in that it stopped the war and prevented the deaths of many more people than those who died in Hiroshima and Nagasaki.
It is also beneficial to mankind in that it allows us to provide power to entire cities, using nuclear power.
Sorry if I hurt your feelings. Some of the posters on this board have me a bit exacerbated. You asked for an example, which I had previously provided, but you seemed to ignore. I was put off a little.
You cannot calculate the fallout of a nuclear disaster using a single formula. E=mc2 is a foundational formula used to do something very basic, but very important. Like most calculations, you need more complex and more numerous formulas to complete more complex equations.
If you look at the variables in the equation, it SHOULD tell you exactly what that equation does. In this case, it can calculate energy and mass changes. That's it. It's not going to allow you to calculate how to destroy a city (whatever that means).
yes.You are saying that the rate of change of energy is equal to the rate of change of mass times the 300,000,000 ^2?Details?
It is what nuclear fission does. It makes matter into energy. The energy can be used to create electricity, but by doing so, humans and other living creatures are subjected to possible nuclear ionizing radiation, and yes entire cities have been destroyed - think Hiroshima and Nagasaki and the accidents in Japan and Russia, and there have been others. What good is physics understanding if it destroys life? Are we so energy and supposed "power" hungry to use knowledge in such a manner?Sorry if I hurt your feelings. Some of the posters on this board have me a bit exacerbated. You asked for an example, which I had previously provided, but you seemed to ignore. I was put off a little.
You cannot calculate the fallout of a nuclear disaster using a single formula. E=mc2 is a foundational formula used to do something very basic, but very important. Like most calculations, you need more complex and more numerous formulas to complete more complex equations.
If you look at the variables in the equation, it SHOULD tell you exactly what that equation does. In this case, it can calculate energy and mass changes. That's it. It's not going to allow you to calculate how to destroy a city (whatever that means).
and ps. It is not possible for you to hurt my feelings.
Physics understanding has improved life far more than it has destroyed it.
Oh and a pedantic point - whilst the disasters in Fukushima and Chernobyl were the results of nuclear fission, Hiroshima and Nagasaki were the results of nuclear fusion.
If you want some benefits of physics, look no further than medicine. X-rays? Magnetic Resonance Imaging? Radiation Therapy?
This is something I have debated in myself many times. Are people really happier now than when there were Buffalo all over the US, and when we didn't have internet and TV and all this stuff? We would not have so many energy desires as to even want nuclear power - however war would still be. Lesser scale I suppose, but the human desire for greed seems philosophically problematic to me.
Do you want to:It is what nuclear fission does. It makes matter into energy. The energy can be used to create electricity, but by doing so, humans and other living creatures are subjected to possible nuclear ionizing radiation, and yes entire cities have been destroyed - think Hiroshima and Nagasaki and the accidents in Japan and Russia, and there have been others. What good is physics understanding if it destroys life? Are we so energy and supposed "power" hungry to use knowledge in such a manner?Sorry if I hurt your feelings. Some of the posters on this board have me a bit exacerbated. You asked for an example, which I had previously provided, but you seemed to ignore. I was put off a little.
You cannot calculate the fallout of a nuclear disaster using a single formula. E=mc2 is a foundational formula used to do something very basic, but very important. Like most calculations, you need more complex and more numerous formulas to complete more complex equations.
If you look at the variables in the equation, it SHOULD tell you exactly what that equation does. In this case, it can calculate energy and mass changes. That's it. It's not going to allow you to calculate how to destroy a city (whatever that means).
and ps. It is not possible for you to hurt my feelings.
1. Understand the physics behind
or
2. Gripe about SOME of its consequences?
You started as if you wanted an answer to point 1 (you got several valid answers already) but your subsequent posts clearly indicate that you have an agenda. And it isn't physics.
Huh???
I second that "huh?" It was not fusion, but fission. (Blowing apart atoms)Huh???
Either , Or And Both. I want to know more about the physics, but I want to use the knowledge to benefit, not harm.Do you want to:It is what nuclear fission does. It makes matter into energy. The energy can be used to create electricity, but by doing so, humans and other living creatures are subjected to possible nuclear ionizing radiation, and yes entire cities have been destroyed - think Hiroshima and Nagasaki and the accidents in Japan and Russia, and there have been others. What good is physics understanding if it destroys life? Are we so energy and supposed "power" hungry to use knowledge in such a manner?Sorry if I hurt your feelings. Some of the posters on this board have me a bit exacerbated. You asked for an example, which I had previously provided, but you seemed to ignore. I was put off a little.
You cannot calculate the fallout of a nuclear disaster using a single formula. E=mc2 is a foundational formula used to do something very basic, but very important. Like most calculations, you need more complex and more numerous formulas to complete more complex equations.
If you look at the variables in the equation, it SHOULD tell you exactly what that equation does. In this case, it can calculate energy and mass changes. That's it. It's not going to allow you to calculate how to destroy a city (whatever that means).
and ps. It is not possible for you to hurt my feelings.
1. Understand the physics behind
or
2. Gripe about SOME of its consequences?
You started as if you wanted an answer to point 1 (you got several valid answers already) but your subsequent posts clearly indicate that you have an agenda. And it isn't physics.
Incidentally, I only understood your equation because I already know what Delta means.
Now, what are the units used in E=MC^2?, and how was the speed of light calculated?
Agenda is never a good thing, you need to learn that first.
E[J], m[kg], c[m/s]. This is taught in 9-th grade, I think.
Now, what are the units used in E=MC^2?
It wasn't "calculated", it was first measured then it was defined. This is a non-trivial subject, you need to learn the basics first (see above).and how was the speed of light calculated?
How was it measured? Then you can tell me how it was assigned. Then maybe explain the differentials between trivial and non trivia? Seems rather subjective to me.Agenda is never a good thing, you need to learn that first.
E[J], m[kg], c[m/s]. This is taught in 9-th grade, I think.
Now, what are the units used in E=MC^2?
It wasn't "calculated", it was first measured then it was assigned. This is a non-trivial subject, you need to learn the basics first (see above).and how was the speed of light calculated?
Can you click on the links provided to you?How was it measured? Then you can tell me how it was assigned. Then maybe explain the differentials between trivial and non trivia? Seems rather subjective to me.Agenda is never a good thing, you need to learn that first.
E[J], m[kg], c[m/s]. This is taught in 9-th grade, I think.
Now, what are the units used in E=MC^2?
It wasn't "calculated", it was first measured then it was assigned. This is a non-trivial subject, you need to learn the basics first (see above).and how was the speed of light calculated?
I would rather you would explain it. I figure (I could be wrong) that we would have to have a way to measure the time it takes for light to travel a certain distance. This could I think vary according to the medium the electromagnetic waves are moving in. Am I incorrect and should I have learned this in second grade?Can you click on the links provided to you?How was it measured? Then you can tell me how it was assigned. Then maybe explain the differentials between trivial and non trivia? Seems rather subjective to me.Agenda is never a good thing, you need to learn that first.
E[J], m[kg], c[m/s]. This is taught in 9-th grade, I think.
Now, what are the units used in E=MC^2?
It wasn't "calculated", it was first measured then it was assigned. This is a non-trivial subject, you need to learn the basics first (see above).and how was the speed of light calculated?
Huh?
A fusion bomb is a thermonuclear/ hydrogen one - not developed until a few years later.
Fatman and Little Boy were fission bombs.
Fusion is an experimental technology for producing power. . Hydrogen isotopes (Deuterium and Tritium) are the primary fuel used in experimental fusion power plants.
Check out ITER
incorrect (ah, I see you've edited)
You're confusing knowledge with the abuse of that knowledge.
The understanding of physics, and physics itself, is not inherently evil. The ability to turn knowledge into evil deeds is completely unrelated to the subject.
Fire can kill us. Should we abandon all use and knowledge of it?
Come on.
Do you realize that some subjects are vast and complex and require more explanation that most of us are able/willing to post in a forum message? Instead of asking someone on here to break down every aspect of nuclear decay and every variable and constant and unit used in conjunction with all the various formulas involved, why not just take a few hours and read some introductory material on it?
I spent years in college learning about some of these things. How on Earth do you expect someone to fit all that effort into a forum post? No one here wants to spoon feed you. DO SOME WORK.
Last edited by Flick Montana; March 29th, 2014 at 01:22 PM.
Flick and all, I am on this forum to explore, to get knowledge that I do not yet have. I know no one is going to explain everything in the Universe to me here, but I expect to get ideas and theories and learn a lot here as well. I don't yet have the schooling many of you do, but I am not willing to accept canned knowledge either. I like to see how you all think of things, as well as the accepted math formulas. The reason I made the topic is about how to use this and other learnings and knowledge for practical use, and that is not a simple thing either. Our minds work in very intricate ways.
I don't only want to understand science and physics better, but how to implement them for the betterment of all of us.
You asked how we use E=mc2 practically. A question which was answered.
The issue is that you then want us to break down the derivation of the formula, the units, the methodology for achieving the c constant. All of these things can be described in well-regarded publications. What you're asking us to do would require a monumental commitment of time and energy.
Someone put the effort into construction this: Speed of light - Wikipedia, the free encyclopedia
So go give it a read if you're curious.
For Nuclear Fission.Details?
If you know the mass of a radioactive atom's nucleus and you add up the masses of the neurons and protons the mass is smaller than the weight of the nucleus.
This difference is the mass of the binding energy of the nucleus.
If you can split the nucleus into parts the mass of the parts, the breakdown products of a nuclear reaction they still have less mass than the mass of the full nucleus.
So you can use this mass difference of the nucleus before a nuclear reaction to predict the amount of energy that will be released when the nucleus splits.
It is the difference of the mass values of the binding energy that is being released in the nuclear fission reaction.
The idea that normal mass is converted into energy is not quite right here. It is the mass value of the energy which is being converted from binding forces in the nucleus into heat and radiation that is being calculated instead.
XYZT gave you the equation in the right form.
So does this mean that the so called massless thing like a photon creates mass by movement? I talked about this somewhere and got poo-pooed for the idea, but may there be such a thing as virtual mass?For Nuclear Fission.Details?
If you know the mass of a radioactive atom's nucleus and you add up the masses of the neurons and protons the mass is smaller than the weight of the nucleus.
This difference is the mass of the binding energy of the nucleus.
If you can split the nucleus into parts the mass of the parts, the breakdown products of a nuclear reaction they still have less mass than the mass of the full nucleus.
So you can use this mass difference of the nucleus before a nuclear reaction to predict the amount of energy that will be released when the nucleus splits.
It is the difference of the mass values of the binding energy that is being released in the nuclear fission reaction.
The idea that normal mass is converted into energy is not quite right here. It is the mass value of the energy which is being converted from binding forces in the nucleus into heat and radiation that is being calculated instead.
XYZT gave you the equation in the right form.
I don't see how in the world we know, how the speed of light squared is a constant. Most people think of visible light - but it is just an electromagnetic wave that can be of much greater and lesser wavelengths than the visible ones. It would maybe be a constant in a vacuum, but I don't think space is a vacuum. If it is a vacuum, why do we perceive it as expanding?
The accelerated expansion of the universe is best regarded as caused by vacuum energy-momentum. It's called vacuum energy-momentum because it looks like a vacuum. This means that one can't establish one's velocity relative to it, and the local speed of light through it is. But nevertheless, it is still a form of energy-momentum due to its gravitational effect.
This is a science forum, that means that it is not a place where you peddle your fringe ideas. You claimed that you are here to LEARN, this is not true, you are here to push your crank ideas. Please cease and desist.
Why don't you try answering the question yourself? Give us your formula which demonstrates that the movement of a photon somehow creates mass. I'm assuming you're not asking this question without having pondered the mathematics.
What I find amusing is that this thread was started by, and continues because of, the guy who claimed: As far as discussing science, I do feel pretty confident, though.
Another tick for Dunning and Kruger...
Consider the PET scan, a medical imaging system. The person is given an injection containing a small amount of a positron emitting radioisotope. As the positrons are emitted, they interact and mutually annihilate with electrons in your tissue. This will produce pair of gamma ray photons which leave the body and are detected. The specific energy and momentum of these photons allow us to form an image of the interior of the body which is very useful in detecting and locating disease.
The electron and the positron turn into a pair of gamma ray photons? I am not sure if I want that to happen to the electrons in my body. Wouldn't that be ionizing to my tissues if positrons are marrying my electrons and taking them away?Consider the PET scan, a medical imaging system. The person is given an injection containing a small amount of a positron emitting radioisotope. As the positrons are emitted, they interact and mutually annihilate with electrons in your tissue. This will produce pair of gamma ray photons which leave the body and are detected. The specific energy and momentum of these photons allow us to form an image of the interior of the body which is very useful in detecting and locating disease.
I believe it is a low-energy gamma ray. Something akin to what you would expect from an x-ray. However, Janus appears to know more about it than me, so he might have something better to add. My only experience with it is from a very basic explanation I got while studying cancer.The electron and the positron turn into a pair of gamma ray photons? I am not sure if I want that to happen to the electrons in my body.Consider the PET scan, a medical imaging system. The person is given an injection containing a small amount of a positron emitting radioisotope. As the positrons are emitted, they interact and mutually annihilate with electrons in your tissue. This will produce pair of gamma ray photons which leave the body and are detected. The specific energy and momentum of these photons allow us to form an image of the interior of the body which is very useful in detecting and locating disease.
Contrary to my first impressions, you seem like a pretty decent person to me. I am not convinced that gamma rays are low energy though. I think they are the highest frequency and shortest wavelength things that we know of. Janus' post confused me a little as it said that the electron and positron married each other into dissipation. This intrigues me in an odd way, but it was also said that they became twin gamma rays. This also confuses me. Two opposite particles became two sister gamma rays? A part of me sees them flying off into the sunset together, although I may live to regret the loss of my electrons. <OK, I can sometimes go overboard with the imaginings.I believe it is a low-energy gamma ray. Something akin to what you would expect from an x-ray. However, Janus appears to know more about it than me, so he might have something better to add. My only experience with it is from a very basic explanation I got while studying cancer.The electron and the positron turn into a pair of gamma ray photons? I am not sure if I want that to happen to the electrons in my body.Consider the PET scan, a medical imaging system. The person is given an injection containing a small amount of a positron emitting radioisotope. As the positrons are emitted, they interact and mutually annihilate with electrons in your tissue. This will produce pair of gamma ray photons which leave the body and are detected. The specific energy and momentum of these photons allow us to form an image of the interior of the body which is very useful in detecting and locating disease.
Positron emission tomography - Wikipedia, the free encyclopedia
This explains more about the use of gamma rays.
Very intriguing. The gamma rays do NOT fly off into the sunset together, but go into opposite directions! Either way I lose some electrons?
Gamma rays share an overlap in energy level with x-rays. Most people associate them with things like stellar gamma ray bursts and, I don't know, the Hulk, but they cover a much broader energetic band than that.
You've got plenty of electrons to spare.Very intriguing. The gamma rays do NOT fly off into the sunset together, but go into opposite directions! Either way I lose some electrons?
And by the way, according to Wikipedia, a PET scan weighs in around 14 mSv, which is a substantial dose, but still about 1/7 of the yearly dose needed to clearly increase your risk of cancer or 1/29 of the short term dose that will begin to cause symptoms of radiation sickness. http://xkcd.com/radiation/
But, that's why they don't just run a PET scan on anyone. If you're getting a PET scan it's for a reason and you shouldn't let the little bit of radiation bother you.
Bye bye electrons, I did love you so
Bye bye my loved ones
May you be free to be you
wherever you go
BTW I live in a sort of magical Queendom.
The electrons are free to roam
and wherever they go
they know
they will still be home.
even chemical reactions turn a very small percentage of matter into energy.
E=mc2 and binding energy. From Einstein Light
A typical chemical reaction might involve a nett energy of 30 kJ per mole, or 5 x 10-20 J per molecule. So the change in mass is 5 x 10-37 kg, which is only .0001% of the mass of an electron.
This brings up an interesting question to me.even chemical reactions turn a very small percentage of matter into energy.
E=mc2 and binding energy. From Einstein Light
A typical chemical reaction might involve a net energy of 30 kJ per mole, or 5 x 10-20 J per molecule. So the change in mass is 5 x 10-37 kg, which is only .0001% of the mass of an electron.
What is the difference between matter and energy?
ive read matter described as 'frozen energy' but this is poetic i think.
Oops, my mistake. I was forgetting that the first nuclear bombs were A-bombs (fission), not H-bombs (fusion).Huh???
Thanks for the corrections
I pondered this during waking moments between dreamtime last night.
and thought to voice a contradiction
.................
but
this is way outside my fields of expertise
................
the nice thing about dreaming, is that i can eat all the chocolate cake I want, and chug bottles of ouzo with no ill effects
...........................
while I'm here, I've another question:
Let us say that ignition within a tokamak can be achieved:
Please delineate the differences between that ignition and the H bomb.
Will H mode be sufficient to contain the energy?
I think that ITER is counting on it. Incidentally, I do that waking in dream times thing a lot too.
The simple difference is that it wouldn't explode. It's the same difference as an A-bomb and a nuclear power plant, or a fire and a lit block of TNT.
One thing that I'd like to point out about the positive use of technology: while there are many poisonings, pitfalls, abuses, and destruction that accompany technological development it's important to note that without the ability to deflect meteors and visit other stars (among other things) the human race will absolutely NOT survive. Think of technology as a part of evolution, and some of it's negative aspects are easier to bear...This is something I have debated in myself many times. Are people really happier now than when there were Buffalo all over the US, and when we didn't have internet and TV and all this stuff? We would not have so many energy desires as to even want nuclear power - however war would still be. Lesser scale I suppose, but the human desire for greed seems philosophically problematic to me.
If the past was so great, then how did we end up here? It is said that necessity is the mother of invention. The inventers of the past obviously thought that there was room for improvement in their world, otherwise they wouldn't have been inventors.This is something I have debated in myself many times. Are people really happier now than when there were Buffalo all over the US, and when we didn't have internet and TV and all this stuff? We would not have so many energy desires as to even want nuclear power - however war would still be. Lesser scale I suppose, but the human desire for greed seems philosophically problematic to me.
Happiness is a relative measurement, not an absolute measurement.
I imagine the people seeing buffalo everywhere were very happy when they got bows and arrows so they could kill and eat a few of those buffalo.
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