# Science 101

I've opened this because we seem to have completely hijacked I don't think I'm EITHER (A-Theist NOR Theist) DARE I say I'm the "Dirty Third"....being:aa and I don't think that's fair to **The Apothecary.**

That conversation moved into the realm of science definitions and meanings and I for one have benefitted from some of the explainations offered.

I'd like to start with an explanation of E=mc2. As I understand it, E = energy, m = mass and c = speed of light.

Mathematically, energy = "mass" multiplied by "speed of light" multiplied by "speed of light". Mathematically we can make it work all day long but demonstating this in the real world proves problematic because we can't achieve the speed of light let alone speed of light squared. We can infer that it works, just ask the residents of Nagasake or Hiroshima, but because we cannot practically create the elements required for the equation it remains unproven.

Corrections please.

Why can't people accept that Atheism is by definition no faith? I don't believe in Atheism, I simply am Atheist.

#1Corrections? What say you seek out a resident of Hiroshima and ask them if we can do what we clearly did?

NoMoreCrazyPeople wrote:=

#2Answers in Gene Simmons wrote:I am asking for a correction

in my understanding of the equation, not about what happened in Hiroshima, nor about the power of the bomb.Why can't people accept that Atheism is by definition no faith? I don't believe in Atheism, I simply am Atheist.

#3wkirby wrote:For the correct equation and explanation of it refer to:

http://www.physicsforums.com/showthread.php?p=156726#post156726

See Post #18 or read the entire thread, if you're interested in a correction and clarification of the popular misnomer of: E=mc2 and the maening of the correct equation.

(If the link doesn't work, you might need to join the Board AND then signnon to view the thread / URL... it's a spam free Board and it's free to join).

#4Also see:

http://www.physforum.com/index.php?showtopic=16199

BTW. you can view it w/o

joining the Board.

#5e = mc

^{2}has obvious correspondences to the ordinary, classic equation for the energy represented by a moving body, itsenergy, which can be defined as the amount of energy required to accelerate it to its current speed: e =kinetic^{1}/_{2 }mv^{2}.IOW Einstein showed that the energy equivalent of the rest mass of an object is twice the amount of energy that classical physics would say would be required to accelerate that mass to the 'cosmic speed limit'.

So if you have a problem with Einstein's equation because of "c

^{2}", you should have the same problem with ordinary Newtonian mechanics.Favorite oxymorons: Gospel Truth, Rational Supernaturalist, Business Ethics, Christian Morality

"Theology is now little more than a branch of human ignorance. Indeed, it is ignorance with wings." -Sam HarrisThe path to Truth lies via careful study of reality, not the dreams of our fallible minds- meFrom the sublime to the ridiculous: Science -> Philosophy -> Theology

#6Obviously.

#7wkirby wrote:Oh dear. Well, first of all, I don't know if Nagasaki or Hiroshima actually "proved" E=mc2, seeing as Rutherford was already performing collisions that would have lead to the bomb without the theoretical structure of the equivalence of mass and energy.

You're actually asking a very involved question, whether you know it or not. The answer is a very long course in the relationship between mathematical physics and experimental physics. I recommend the following:

Walter Lewin's Course on Classical Mechanics

Walter Lewin's Course on Electromagnetism

Walter Lewin's Course on Waves

And I'm not kidding, or being dismissive. You need to have a good mathematical base before getting into Einstein's math, and understanding the relationship between his math and the math that came before it is absolutely crucial in understanding what he means when he concludes that E=mc2.

The short version: saying that E=mc2 is "unproven" is completely and utterly false. It is as proven as anything has ever been. What you're maybe thinking is "confirmed", which it has been, by thousands of experiments in particle accelerators.

Saint Will: no gyration without funkstification.

fabulae! nil satis firmi video quam ob rem accipere hunc mi expediat metum. - Terence

#8wkirby wrote:Well, the problem here is that you did not ask a question that was sufficient to yield a good enough answer. If you want something far less dramatic than thousands of people killed and mained by a nuclear weapon, you can do the following:

Get a dozen or so people together and have them, all at the same time, write down the time on their watches. Then have them write down the time on their cellphones, again all at the same moment.

The fact is that while most people will let a watch drift by as much as several minutes before resetting it, you simply do not have the option with your cell phone clock. Those are generally synchronized via signals from the GPS satellite network to assure that you phone call to emergency services gets routed to the correct call center (at least in the US- other countries probably have a similar setup because it makes sense to do so but YMMV). Further, the GPS network is corrected every couple of days with leap seconds being added as needed so that all the satellites agree on the same standard time base. That correction is specifically connected to variations that arise due to Special Relativity.

So yes, we can set up such conditions that test Special Relativity. If we did not make such corrections, then your call to 911 (or whatever the emergency number is in your country) placed from a cell phone would routinely be answered in the wrong city. Where I live, on the Connecticut coastline, before that system was implemented, emergency calls would often be answered by call centers on Long Island (about a two hour drive) because they would be handled by the nearest cellphone tower to the location of the phone.

NoMoreCrazyPeople wrote:=

#9"The speed of light squared" is not a speed, just like the square of the length of the side of a square is not a length. In that case we can match it to an everyday concept, ie 'area'.

So of course we can't "achieve" it. That makes no sense, any more than trying to measure area with the simple ruler we use to measure length.

I don't think we can assign a simple interpretation of velocity squared, but mass X velocity squared can, as I showed, be matched to 'energy'.

Force is defined mathematically as "mass x acceleration" - the force of gravity acting on a mass m is precisely sufficient to cause it to accelerate towards the center of the Earth at 32 feet per second per second.

Energy is defined mathematically as "force x distance". IOW, 1 joule of energy is the amount of energy required to move something through a distance of one meter against a force of one Newton (the force required to accelerate one kilogram from rest to a speed of 1 meter per second in one second).

If you combine these definitions, Energy = (mass x distance per second per second) x distance

The distance an object will cover when subject to a constant acceleration from rest is equal to its average velocity since it started multplied by the elapsed time since it started to move.

An object of mass M that has reached a velocity of V after time T, from rest under constant acceleration of V/T will have had an average velocity of

^{1}/_{2}V, so will cover a distance^{1}/_{2}V x T.The constant force F required to do this is

F = M x acceleration = M x (V/T).

The distance covered is

D =

^{1}/_{2}x V x Tso Energy E = F x D = M x V /T x

^{1}/_{2}x V x T =^{1}/_{2}x M x V x V x T/T =^{1}/_{2}x M x V^{2}Hope this clarifies the concepts and the math, in the spirit implied by the title "Science 101".

Forgive if I don't work through the argument justifying " e = m c

^{2}", but I hope you can see some connection there, at least in terms of how we go from mass and velocity to energy.Favorite oxymorons: Gospel Truth, Rational Supernaturalist, Business Ethics, Christian Morality

"Theology is now little more than a branch of human ignorance. Indeed, it is ignorance with wings." -Sam HarrisThe path to Truth lies via careful study of reality, not the dreams of our fallible minds- meFrom the sublime to the ridiculous: Science -> Philosophy -> Theology

#10BobSpence1 wrote:Why didn't you say that in the first place! That answer is the the most simple and eloquent I have yet to see and I am very grateful.

I now also understand the concept of 'the Eureka moment'

Why can't people accept that Atheism is by definition no faith? I don't believe in Atheism, I simply am Atheist.

#11wkirby wrote:I wasn't quite sure just what your background knowledge was - once I saw the response to my first post, I decided I needed to post a more thorough explanation.

Favorite oxymorons: Gospel Truth, Rational Supernaturalist, Business Ethics, Christian Morality

"Theology is now little more than a branch of human ignorance. Indeed, it is ignorance with wings." -Sam HarrisThe path to Truth lies via careful study of reality, not the dreams of our fallible minds- meFrom the sublime to the ridiculous: Science -> Philosophy -> Theology

#12wkirby wrote:It's simple because it's about Newtonian physics, not about Einstein's Equation of G.R.

Einstein's Equation of G.R.

is not consistent with

Newtonian physics, or Quantum

physics or String / M Theories.

If you want to discuss Science 101, you've got to get beyond Newton, and understand Newton's "Model" does not apply to any of the subjects thst Einstein's

equations refer to.

Einstein ain't Science 101, or "everyday" concepts.

For an "everyday" layman idea of Physics, stick with Newton... that's the sort of stuff Newton's equations are accepted to apply to.

#13Treat2:

E=mc^2 is not part of general relativity. GR was published in 1918 and SR was published in 1905. The mass energy equivalence was from the fourth paper that Einstein published in 1905 and therefore it is part of SR.

SR is an extension of classical mechanics or what you like to call Newtonian Physics. Also, classical mechanics includes both Lagrangian and Hamiltonian mechanic as well as the work by Newton. Newton's work is taught in high school because it is based on mathematics that you don't need to go to college to learn.

GR is a unification of SR and classical mechanics, specifically gravitation. This had to happen because SR does not include gravitation in it's model.

Quantum mechanics also has roots in classical mechanics but then develops in directions that are quite unlike the classical works. It is mostly inconsistent with SR and GR.

String theory is consistent with both quantum mechanics and SR/GR. It is inconsistent with, well, itself. The fact is that prior to the development of M theory, there were five string theories and they were inconsistent with each other. M theory is a follow on to the five string theories that unifies them into a single theory.

Before you start posting in science threads, I suggest that you read a book (or fifty) on science. Preferably books that are written by scientists and not something that you saw when you were in line at the supermarket checkout.

NoMoreCrazyPeople wrote:=

#14Answers in Gene Simmons wrote:Ok. I got it. You're having your period, and you just broke a nail!

Take a pill.

The theory of general relativity is based on the theory of special relativity along with Minkowski's geometrical formulation of it. It can be summed up in the equation that I already posted links to as a common misnomer, and misunderstanding of the actual equation my links referred to.

Before making complete fool of yourself by copying and pasting a bunch of unrelated BS, including information I posted in this thread about 5 String Theories and M Theory, learn to read and subsequently work on your reading comprehension skills.

Yes... as per the above equation a version similar to it was written within in Einstein's Theory of SR, not GR.

BTW. Just as a note of interest, subsequent to the publication of Einstein's SR, he revised/corrected certain equations he had written within it. However, the revisions/corrections are hardly Science 101.

#15wkirby wrote:Let me rephrase into terms more traditional. There is no such thing as energy in a pure for as SciFi appears to be talking about. It always comes in some form. The units of energy are mass x length x length / time x time. The temperature of water is determined by the mass of the molecules and the speed with which they bounce off of each other. Speed is length / time. Perform a little magic to come up with the amount of mass and square the velocity and you get the energy in the water. For the same amount of energy the smaller the amount of water the higher the temperature. Thus a bathtub of ice water has more heat than a cup of boiling water. (I refuse to talk about "global warming" with anyone who cannot tell me the difference between heat and temperature because I have yet to find a melter who knows the difference so they are always talking nonsense.)

What several people before Einstein noted was that the rest mass could be represented as energy. Despite it being the only equation most people know, it was not original with Einstein. He demonstrated that known result fell out of his special relativity formulation more as a confirmation that his approach lead to the same conclusions as others.

Anyway there is no need to invoke Hiroshima or get things going that fast to show it. It explains the energy of particle interactions and decays. Otherwise it explained only handful of anomalies which were largely unknown outside of the scientific community. So one does not have to blow up a city to test it. Measuring the total mass an energy in a neutron decay works as well and is much less wasteful of cities. The resulting proton and electron have less mass than a neutron but their velocities are greater than that of the neutron. When a positron and an electron annialate the resulting two gamma rays, which have no mass, have energy equivalent to the mass of the two electrons which disappeared.

The other major question it answers is if nothing can go faster than light where does the energy that speeds is up go? Energy has to be conserved. It goes into making the object more massive. The equation that E=mc^2 falls out of describes the rate at which energy goes into increased mass instead of increased velocity.

Above where I use mass length and time is from a more general idea of dimensional analysis. Energy is always and only M*L*L/T*T. Velocity is always L/T. Acceleration is always L/T*T. Photons have energy but no mass BUT every calculation regarding photons there is an M a unit of mass in the calculation. The mass that isn't there. But the units are always conserved. There are always the same units going into a reaction as coming out of it. Conservation of energy is a special case of conservation of dimensions.

Rotation is also a dimension. Some particle reactions do not balance unless rotation is conserved even though they do not rotate any more than photons have mass. The conserved rotation is called spin. Now you know the rest of the story. But it confused people. So what quarks came along up, down, strange and charm were conserved. The things to be conserved started geting out of hand. So if these things to be conserved are just information about the particle then one can talk about the conservation of information. Then Shannon's information theory can be applied.

Shannon is also an outstanding whisky whch is the source of inspiration for much of the above.

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#16Oh shit!

Pea-brain knows how google, copy and paste!

Wow! That's an anacortes!

Question is if "Mod"ist is potty-trained yet.

#17OK treat2, if you are so all knowing in the ways of science, do please tell us who the guy in my avatar is and wht his role in the question at had was...

If you can.

NoMoreCrazyPeople wrote:=

#18You made a claim. Prove it.

#19treat2 wrote:You don't have many friends do you?

After eating an entire bull, a mountain lion felt so good he started roaring. He kept it up until a hunter came along and shot him.

The moral: When you're full of bull, keep your mouth shut.

MySpace

#20Newtonian physics applies more than adequately to anything which does not involve speeds a significant fraction of light-speed, or gravitational intensities not associated with black holes, unless extreme accuracy is required.

Special Relativity apples quite accurately at distances well away from the Planck scale, and for

velocities.constantGeneral Relativity takes into account gravity and non-constant velocities, and also applies with high accuracy at distances well away from the Planck scale, and under conditions where Quantum effects are not a major factor.

M- and string theories are some of the approaches to devising a theory to understand Quantum Mechanics and reconcile it with Relativity and other observations from cosmology and particle physics, but have yet to achieve experimental verification at any scale, unlike QM and GR.

For at least one of the links supplied where a poster claimed to have found a discrepancy with e = mc

^{2, }he had made some simple errors in applying 'gamma' to mass - it only applies to time dilation and length contraction. Links to actual reasonably authoritative sources, preferably several, rather than to disagreements among posters on a forum would be more useful to support a position onsubject.anyFavorite oxymorons: Gospel Truth, Rational Supernaturalist, Business Ethics, Christian Morality

The path to Truth lies via careful study of reality, not the dreams of our fallible minds- meFrom the sublime to the ridiculous: Science -> Philosophy -> Theology

#21spike.barnett wrote:Wait, you understand what he's saying?

Saint Will: no gyration without funkstification.

fabulae! nil satis firmi video quam ob rem accipere hunc mi expediat metum. - Terence