In 1905, Einstein derived L = D mc2, and then speculated from here E =D mc2, analogously without actual proof. Einstein derived already existing E =D mc2, strangely did not acknowledge his predecessors like de Pretto and Hasnholtz. Both have suggested E =D mc2 just one and half year before Einstein抯 derivation. However two years after i.e. 1907 when Max Plank derived E =D mc2 independently, Planck acknowledged derivation of Einstein. Planck even pointed out the conceptual and mathematical limitations of Einstein抯 method of derivation. In derivation Einstein used result of relativistic variation of light energy
l* = l http://www.wbabin.net/ajay/Image205.gifcosf ] / http://www.wbabin.net/ajay/Image206.gif (2)
where l is light energy of plane wave of light in co-ordinate system (x,y,z)., which is at rest. The ray direction i.e. wave normal makes angle f with the x-axis of the system (x,y,z). This light energy as measured in system (X,Y,Z), which is in uniform translation w.r.t. (x,y,z) along x-axis with velocity v is l*. But while deriving final result i.e. L =D mc2 Einstein interpreted the equation under classical conditions (v<<c) as below.
[*]Although Einstein started to derive L =D mc2 using relativistic variation of light energy as in Eq.(2), yet he derived final results under classical condition. Einstein interpreted the results using Binomial Theorem which is applicable if v<<c.[*]Einstein never considered any relativistic increase in mass of body as given by mmotion = mrest/(1-v2/c2)1/2
This equation was first justified by Kaufman in 1900. Further, Einstein speculated E =D mc2 for all energies from L=D mc2 without justifying that eq.(2) in essence holds good for sound, heat, chemical , electrical energy etc. If eq.(2) holds good for sound and heat energies, then L =D mc2 will be analogously transformed as
Sound energy = D mc2 (3)
or Every type of energy = D mc2 (4)
The results from eq.(3) are exciting as sound energy can be converted in mass. Einstein did not justify that how eq. (2) holds good quantitatively for heat energy, sound energy etc, but regarded it as is true for all. In nuclear Physics E =D mc2 is used as standard and all data is consistent with this. Also Einstein derived rest mass energy (Eo= mrestc2 ) from relativistic form of kinetic energy
Total Kinetic Energy = mmotion c2 = KE +moc2 as Eo= mrestc2
Max Planck
In 1907, Planck made an in-depth investigation of the energy "confined" within a body, but he did not use Einstein approach at all. Plank presented his findings in
Planck derived an expression
m-M= E/c2
and interpreted that
"The inertia mass of body is altered by absorption or emission of heat energy. The increments of mass of body are equal to heat energy divided by square of speed of light"
Then in a footnote at page 566 Planck writes, "Einstein has already drawn essentially the same conclusions". Planck maintained Einstein derivation as approximation.
Recent Developments.
In 1907 Planck even pointed out the conceptual and mathematical limitations of Einstein抯 derivation. In 1952, H E Ives stressed that Einstein抯 derivation of the formula E = D mc2 is fatally flawed because Einstein set out to prove what he assumed.
Sharma in 2003 extended E = D mc2 to E =Ac2Dm , where A is conversion co-efficient and can be equal, less or more than one, depending upon inherent characteristics of conversions process in nature. The value of A is consistent with concept of proportionality factor existing since centuries. Energy emitted in celestial events Gamma Ray Bursts (most energetic events after Big Bang) is 1045 Joule/s. It can be explained with value of A equal to 2.57碵/font] 1018. Similar is the case of Quasars. Like wise kinetic energy of the fission Fragments of U235 or Pu239 is found 20-60 MeV less than Q-value (200MeV), Bakhoum The similar deviations in experimental results are also quoted by Hambsch , Thiereus etc. It can be explained with value of A less than one.To date, E =D mc2 is not confirmed in chemical reaction due to technical reasons, but is regarded as true.
Also a particle Ds (2317) discovered at SLAC has been found to have mass lower than current estimates based upon E =D mc2. Incidentally, there are proposals for both theoretical and experimental variations (increase or decrease) in value of c ; as the fine structure constant ( http://www.nature.com/__chars/alpha/black/ital/base/glyph.gif = e2/http://www.nature.com/__chars/planck/black/med/base/glyph.gifc)is reported to be increasing over cosmological timescales, implying slowing down of speed of light, c. The proposals for variations of speed of light definitely affect the status of E =D mc2, indirectly.
Einstein and Priority of E =D mc2 Einstein did not mention Hasen鰄rl抯 work (who gave first derived expression for mass-energy equation) in any of his paper on this subject from 1900 - 1909. However Hasen鰄rl had published his paper in 1904, in the same very journal in which Einstein later published his derivation of E =mc2 in 1905.
Einstein applied his E =D mc2 derivation in 1906. In this paper he gave reference of Poincar References
1. Newton, Sir Isaac (1704), Opticks, Dover Publications, Inc., New York, p. CVX
2. Preston, S. T. Physics of the Ether, E. & F. N. Spon, London, (1875).
3. Poincar musang macam copy and paste dari wikipedia jekk.. :P:P
Reply #43 Atomic_Omnikid's post
Biarlah si musang copy paste pun....:)Sama ada orang yang buat teori itu Einstein ke,Isaac ke,kita belajar je apa yang berguna.
Kita tak perlu ingat nama tokoh-tokoh itu,tarikh lahir mereka,hobi mereka dan sebagainya....:P
Yang penting kita tahu bahawa E=mc
Aku pun nak bagi soalan maths lah...
Given that log 5=A,log 16=B and log 3=CFind log 180 in term of A,B and C.:loveliness: Originally posted by prototaip at 21-2-2007 00:46
Given that log 5=A,log 16=B and log 3=C
Find log 180 in term of A,B and C.:loveliness:
log 180 =c^2 + 4A kot....add maths merupakan subjek yg haku plg lemah :L ;P:mad:..
Reply #46 Atomic_Omnikid's post
Eh....salah.Cuba lagi ye...:loveliness: Originally posted by Atomic_Omnikid at 20-2-2007 11:23 PM
musang macam copy and paste dari wikipedia jekk.. :P:P
Ko bg link wikipedia tu...aku nak tgk Originally posted by prototaip at 21-2-2007 01:46 AM
Given that log 5=A,log 16=B and log 3=C
Find log 180 in term of A,B and C.:loveliness:
Hehehe...aku maha lembab math ni...dpt P8 masa SPM :lol: Originally posted by musang_pulut at 18-2-2007 11:58 AM
Sapa2 ada masalah kimia form 4/5, boleh utara kat sini. InsyaAllah saya boleh bantu FOC. Alal-ala online tutor gitu...hehehe..:D
:'(.....boy dah abih sekolah dah...kalo tak, memang boy tanya soalan kimia...:$..boy lemah dlm subjek ni...:$ cerita add maths ke? :lol: :lol: dah lama pakcik tinggalkan bab2 nie..:L Originally posted by musang_pulut at 21-2-2007 08:06
Ko bg link wikipedia tu...aku nak tgk
http://en.wikipedia.com
kat search button..type title yg ko nak cari.. Originally posted by Atomic_Omnikid at 21-2-2007 11:57 PM
http://en.wikipedia.com
kat search button..type title yg ko nak cari..
Aku tau la...link wiki tu tp article yg aku paste tu ada ke dlm wiki....:lol:
Reply #45 prototaip's post
Jawapan dia:log 180 = log (5 x 4 x 9) -->Faktorkan 180=20 x 9=5 x 4 x 9
=log 5 + log 4 + log 9
=log 5 + log (16)^1/2 + log 3
Reply #35 musang_pulut's post
hehehe janji dah tertunai..haa sambil2 borak tu bg lah soalan..
pemberi soalan - 20 credits
penjawab yg 1 st jawab betul - 30 credits
* pssttt jgn senang sgt soalan tu eh ;P add math?
huhu dulu kan cikgu add math laa yg chem tak suka..dgn subjuek2 tu sekali haku boikot..takde minat !!!
huhh salah perbuatan ni.. buat ler soalan lagi...seronok tgk...boleh recall benda2 yg blajo dulu...huhu..
OK...soalan Fizik pula ye...
Sebiji bola berjisim 6 kg bergerak ke arah utara dengan kelajuan tetap 12 m/s,manakala sebiji lagi bola berjisim 5 kg bergerak ke arah selatan dengan kelajuan tetap 10 m/s.Beberapa saat kemudian,kedua-duanya pun berlanggar secara tepat.Selepas berlanggaran,kedua-duanya bercantum.Cari:1)Jumlah momentum sistem.
2)Laju kedua-dua bola selepas berlanggar.
3)Arah gerakan kedua-dua bola selepas berlanggar.
Silalah jawab...Mudah je ni.:)
[ Last edited byprototaip at 24-2-2007 03:10 AM ] lamanya tak jumpa soalan ni? camna nak kira yer?
1. tak tau..
2. 2 m/s
3. utara