Qed

Quotes

1. Immediately you would like to know where this number for a coupling comes from: is it related to pi, or perhaps to the base of natural logarithms? Nobody knows. It's one of the greatest damn mysteries of physics: a magic number that comes to us with no understanding by man. You might say the "hand of God" wrote that number, and "we don't know how He pushed His pencil." We know what kind of a dance to do experimentally to measure this number very accurately, but we don't know what kind of dance to do on the computer to make this number come out — without putting it in secretly!

   p. 129

2. 

   Why are the theories of physics so similar in their structure?

   There are a number of possibilities. The first is the limited imagination of physicists: when we see a new phenomenon, we try to fit it into the framework we already have—until we have made enough experiments, we don't know that it doesn't work. So when some fool physicist gives a lecture at UCLA in 1983 and says, “This is the way it works, and look how wonderfully similar the theories are,” it's not because Nature is really similar; it's because the physicists have only been able to think of the same damn thing, over and over again.

   Another possibility is that it is the same damn thing over and over again—that Nature has only one way of doing things, and She repeats her story from time to time.

   A third possibility is that things look similar because they are aspects of the same thing—some larger picture underneath, from which things can be broken into parts that look different, like fingers on the same hand. Many physicists are working very hard trying to put together a grand picture that unifies everything into one super-duper model. It's a delightful game, but at present time none of the speculators agree with any of the other speculators as to what the grand picture is.

   p. 149

3. 

   The scale of light can be described by numbers — called the frequency — and as the numbers get higher, the light goes from red to blue to ultraviolet. We can't see ultraviolet light, but it can affect photographic plates. It's still light — only the number is different.

   p. 13

4. 

   [O]ne additional problem.., which took twenty years to overcome.., has to do with ideal electrons and photons and the numbers n and j.

   If electrons were ideal and went... only by... direct path..: n would... be the [electron] mass.., and j its "charge" (the amplitude for the electron to couple with the photon).

   But no... ideal electrons exist.

   p. 125

5. 

   [I]nstead of including all... coupling points to... distance... zero, if one stops the calculation when the distance is very small... billions of times smaller than anything observable... (presently 10-16 centimeters)... there are definite values... n and j... so the calculated mass... match the m observed... and the calculated charge matches the observed... e. ...[T]he catch: if somebody... stops the calculation at a different distance... their... n and j come out different!

   p. 127

6. 

   People are always asking for the latest developments in the unification of this theory with that theory, and they don't give us a chance to tell them anything about what we know pretty well. They always want to know the things we don't know.

   p. 3

7. 

   You will have to brace yourselves for this — not because it is difficult to understand, but because it is absolutely ridiculous: All we do is draw little arrows on a piece of paper — that's all!

   p. 24

8. 

   The theory of quantum electrodynamics describes Nature as absurd from the point of view of common sense. And it agrees fully with experiment. So I hope you accept Nature as She is — absurd.

   p. 10

9. 

   Light is something like raindrops — each little lump of light is called a photon — and if the light is all one color, all the "raindrops" are the same.

   p. 14

10. 

    Every instrument that has been designed to be sensitive enough to detect weak light has always ended up discovering that the same thing: light is made of particles.

    p. 15

11. 

    There is a... profound.., beautiful question associated with the observed coupling constant e... the amplitude for the real electron to emit or absorb a real photon.., [and] experimentally determined... close to 0.08542455. (My physicist friends... remember it as the inverse of its square: about 137.03597... It has been a mystery... since discovered more that fifty years ago, and all good physicists... worry about it.)

    p. 129

12. 

    While I am describing to you how Nature works, you won't understand why Nature works that way. But you see, nobody understands that.

    p. 10

13. 

    It is to be emphasized that no matter how many [Probability amplitude] arrows we draw, add, or multiply, our objective is to calculate a single final arrow for the event. Mistakes are often made by physics students at first because they do not keep this important point in mind. They work for so long analyzing events involving a single photon that they begin to think that the arrow is somehow associated with the photon [rather than with the event].

    p. 75

14. 

    The most shocking characteristic of... [QED] is the crazy framework of amplitudes..! [P]hysicist have been fiddling with amplitudes for... fifty years... and have gotten... used to it. ...[A]ll new particles and... phenomena... we... observe fit perfectly with everything... deduced from... a framework of amplitudes, in which the probability of an event is the square of the final arrow... So this... has no experimental doubt..: you can have... philosophical worries... as to what the amplitudes mean... but because physics is an experimental science and the framework agrees with experiment, it's good enough...

    p. 124

15. 

    When a photon comes down, it interacts with electrons throughout the glass, not just on the surface. The photon and electrons do some kind of dance, the net result of which is the same as if the photon hit only on the surface.

    p. 17

16. 

    [T]he experimentally measured m, and... charge, e, of the electron are different from the numbers in our calculations, n and j.

    p. 126

17. 

    Will you understand what I'm going to tell you? ... No, you're not going to be able to understand it. ... That is because I don't understand it. Nobody does.

    p. 9

18. 

    When calculating terms with couplings, we must consider... all possible points... down to... two couplings... with zero distance between... [W]hen we try to calculate... down to zero distance, the equation blows up... and give meaningless answers... like infinity... [W]hen [QED]... first came out... [p]eople were getting infinity for every problem... [T]hat's where there is no n or j that makes sense...

    p. 127

That’s all the quotes.

18 quotes in the collection · come back when we add more