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Do you have a cite for Brain Cox's claim about GPS?

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djgordy
859753.  Thu Oct 27, 2011 4:24 am Reply with quote

dr.bob wrote:
djgordy wrote:
But if you were in the Dept of Defence and someone said to you "who is this Einstein and why should we listen to him?" you woulld say "he is the man who gave us the atomic bomb".


I wouldn't, because I don't believe that to be true. I think the A bomb would've been developed whether or not Einstein had existed.

Einstein did many great things, and we have a lot to thank him for, but nuclear fission is not one of them.


It may be true that if person X hadn't existed person Y would have achieved the same thing but that doesn't mean to say that person X should not, therefore, be credited with his achievements. That's why Darwin gets credited as the founder of evolution by natural selection and not Alfred Russell Wallace.

Also:
dr.bob wrote:


All Einstein did in this field was to predict how much energy would be released by the process of fission. Whilst this was, of course, important and impressive, the experimentalists would've found out how much energy was released with or without Einstein's predictions.



Correct, but the important part is that Einstein realised, as you say, about the huge amounts of energy that could be released. This realisation is what, ultimately lead to an atomic bomb being concieved. They wouldn't have thought of making an A bomb if they didn't realise that it would be more potent than just an bigger version of an ordinary bomb. It isn't really legitimate to say what would have happened without Einstein's equations because we don't know. Things might have turned out very much the same or it might have taken a few more years, the war would have been over, someone might have been distracted by something shiny etc etc.

Furthermore

dr.bob wrote:


To which the DoD person would reply "no he didn't! Rutherford, Bohr, Curie, Meitner, Frisch, Fermi, and Oppenheimer gave us the A bomb. Stop talking such nonsense. As you well know, Einstein is that annoying pacifist who tried to convince the US government to stop developing the bomb and was actively barred from the Manhattan Project over security fears."


This rather ingores the Einstein Szilard* letter of 1939 delivered to President Roosevelt which urged the US to begin research into development of the A bomb.

www.hypertextbook.com/eworld/einstein.shtml

The letter, though apparantly mostly written by Szilard, was signed by Einstein and this was vital in the establishment of the Manhattan Project.

*Einstein and Szilard alos patented a fridge.

www.fourmilab.ch/etexts/einstein/uspat1781541/www/

 
dr.bob
859757.  Thu Oct 27, 2011 4:49 am Reply with quote

djgordy wrote:
It may be true that if person X hadn't existed person Y would have achieved the same thing but that doesn't mean to say that person X should not, therefore, be credited with his achievements.


That's not what I'm saying.

I'm saying that, even if nobody had discovered the E=Mc2 equation, the A bomb would still have been developed.

djgordy wrote:
Correct, but the important part is that Einstein realised, as you say, about the huge amounts of energy that could be released.


Actually, I think I was talking rubbish there. It could be argued that E=Mc2 describes the amount of energy released by noting the loss in mass between the original nucleus and the resultant parts, but that's got virtually nothing to do with what we're discussing. At the time there was no way to measure the masses of all the constituent parts accurately enough, so the amount of energy released was not known until the experiments of Fermi and others at Columbia.

Even then, it was not obvious that this was useful since the amount of energy released by individual fissioning atoms was tiny. It was only with the work of Leó Szilárd into the concept of a chain reaction that the bomb became a real possibility. If any one person could be said to have created the A bomb, it was Szilárd.

djgordy wrote:
This rather ingores the Einstein Szilard* letter of 1939 delivered to President Roosevelt which urged the US to begin research into development of the A bomb.

The letter, though apparantly mostly written by Szilard, was signed by Einstein and this was vital in the establishment of the Manhattan Project.


Largely written by Szilárd along with fellow Hungarians Edward Teller (nicknamed "father of the H bomb") and Eugene Wigner (co-creator of the Wigner–Eckart theorem).

Unfortunately, none of them were particularly famous. So, in order to ensure that the letter was taken seriously by the US President, they got Einstein to sign it as he was already a pretty well-known and well-respected scientist.

In conclusion, about the most important part Einstein played in the development of the A bomb was using his fame to make sure FDR was made aware of the concept.

That's it.

Even if Einstein had never existed, and none of his theories had been developed by anyone else, all of the rest of the research would still have happened. Once Szilárd's ideas about chain reactions were published, it was inevitable that someone would've developed an A bomb. If FDR hadn't read the Szilárd letter, then maybe the Germans, or almost certainly the Russians, would've developed it instead.

 
djgordy
859798.  Thu Oct 27, 2011 8:05 am Reply with quote

dr.bob wrote:
djgordy wrote:
It may be true that if person X hadn't existed person Y would have achieved the same thing but that doesn't mean to say that person X should not, therefore, be credited with his achievements.


That's not what I'm saying.

I'm saying that, even if nobody had discovered the E=Mc2 equation, the A bomb would still have been developed.


You don't know that because you have no idea how the history of physics would have developed without Einstein. As I say, things may have developed in roughly the same way but everything might have been 5 or 10 years later by which time WWII may have been over, given that the bomb wasn't instrumental in ending the war against Germany and Japan was also, to all intents and purposes defeated before Hiroshima. So with the war ended it is possible that there might not have been a Los Alamos project. Of course, arguably there may have been still been an equivalent project because of the perceived Soviet threat. On the other hand, if there had been no A bomb then the history of the cold war may have been different; especially if one accepts the argument that the bombing of Japan was largely done as a demonstation of America's might to the Soviet Union.

Saying what might have been may be fun it is irrelevant to the matter in hand. Einstein did exist and if someone were to ask "who is this guy and why should we listen to him?" then saying "he gave us the A bomb", or words to that effect would be an appropriate answer. It isn't necessary to answer every question with a doctorial thesis. If someone asked you "what time does the sun rise?" you wouldn't launch into a 3 hour lecture on the fact that the sun doesn't actually rise, it is just the result of the Earth turning, then go one to explain about the history of the earth-centred and sun-centred cosmoligical theories. You'd say "half past seven" or whatever it might be because that is what the person wants to know.

I'm bored with this. Finished.

 
dr.bob
859801.  Thu Oct 27, 2011 8:11 am Reply with quote

djgordy wrote:
You don't know that because you have no idea how the history of physics would have developed without Einstein.


That's true but, since none of Einstein's theories were instrumental in the discovery and investigation of nuclear fission, I fail to understand why you think this part of physics would've developed differently without him.

To be honest, the most important part of Physics in the investigation of nuclear fission was Quantum Mechanics, something that Einstein famously didn't think much of.

djgordy wrote:
It isn't necessary to answer every question with a doctorial thesis.


Certainly it's not. Generally, though, I do try and give answers which are factually accurate. Perhaps this is not de rigueur at the DoD.

 
griffin2000
860138.  Fri Oct 28, 2011 1:17 pm Reply with quote

clack wrote:
griffin2000 wrote:
Is that the "Do you know what time it is?" episode of Horizon ? Is that available on DVD anywhere ?
Yes, that's the episode. I watched it on youtube, don't know if it's still on there.


Hmmm not sure it is from there.

Just watched it and he never goes to the GPS HQ. He does visit it during another Horizon episode ("What on Earth is wrong with gravity?") but no one there says anything like this.

 

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