# Category Archives: Science

My thoughts on non-physics scienceslike evolutionary biology, cognitive neuroscience etc.

# Interpretation of Special Relativity

When we looked at Quantum Mechanics, we talked about its various interpretations. The reason we have such interpretations, I said, is that QM deals with a reality that we have no access to, through our sensory and perceptual apparatuses. On the other hand, Special Relativity is about macro objects in motion, and we have no problem imagining such things. So why would we need to have an interpretation? The answer is a subtle one.

# Speed of Light

빛의 속도가 일정하다는 것은 단순한 진술처럼 들립니다.,,en,그러나 그것에 더 많은 것이 있습니다,,en,꽤 많이,,en,이 불변성이 실제로 무엇을 의미하는지 살펴 보겠습니다.,,en,어딘가에 서 있다면,,en,그리고 오른쪽에서 왼쪽으로가는 광선이 있습니다.,,en,속도가있다,,en,씨,,en,그리고 왼쪽에서 오른쪽으로가는 또 다른 광선도 속도가 있습니다.,,en,지금까지,,en,너무 좋아,,en,이제 당신이 로켓 선에 있다고 가정 해 봅시다.,,en,오른쪽에서 왼쪽으로 이동,,en,특수 상대성 이론,,en,아인슈타인과 특수 상대성 이론을들을 때,,en,또는 특수 상대성 이론,,en,실명 사용,,en,우리는 유명한 것을 생각한다,,en,E = mc ^ 2,,en,방정식,,en,그리고 쌍둥이 역설 같은 이상한 것들,,en,그 모든 것이 사실이고 중요하지만,,en,SR이 해결하려는 문제는 완전히 다른 문제입니다.,,en. But there is more to it, quite a bit more. Let’s look at what this constancy really means. At first glance, it says that if you are standing somewhere, and there is a ray of light going from your right to left, it has a speed c. And another ray of light going from left to right also has a speed c. So far, so good. Now let’s say you are in a rocket ship, as shown in the figure below, moving from right to left.

# Special Theory of Relativity

When we hear about Einstein and the special relativity (or the special theory of relativity, to use the real name), we think of the famous $E = mc^2$ equation, and weird things like the twin paradox. While those things are all true and important, the problem SR tries to solve is a completely different one. 물리학의 기본 원리를 지키려는 시도,,en,주제 아카이브,,en.

# Quantum Mechanics – Interpretations

Whenever we talk about Quantum Mechanics, one of the first questions would be, “What about the cat?” This question, really, is about the interpretations of Quantum Mechanics. The standard interpretation, the so-called Copenhagen interpretation, leads to the famous Schrodinger’s cat.

# Quantum Field Theory

In this post on Quantum Mechanics (QM), we will go a bit beyond it and touch upon Quantum Field Theory – the way it is used in particle physics. In the last couple of posts, I outlined a philosophical introduction to QM, as well as its historical origin – how it came about as an ad-hoc explanation of the blackbody radiation, and a brilliant description of the photoelectric effect.

# Historical Origin of Quantum Mechanics

In this section, we will try to look at the historical origin of Quantum Mechanics, which is usually presented succinctly using scary looking mathematical formulas. The role of mathematics in physics, as Richard Feynman explains (in his lectures on QED given in Auckland, New Zealand in 1979, available on YouTube, but as poor quality recordings) is purely utilitarian.

# Quantum Mechanics

Quantum Mechanics (QM) is the physics of small things. How do they behave and how do they interact with each other? Conspicuously absent from this framework of QM is why. 왜 작은 일이 그들이하는 일을 하는가는 QM이 혼자 남겨둔 질문입니다,,en,이 주제로 진전하려면,,en,가장 좋은 방법은 이유를 묻는 충동을 억제하는 것입니다.,,en,자연은 그녀입니다,,en,우리의 일은 그녀가 현실 게임을하는 규칙을 이해하는 것입니다.,,en,실험과 기술에서 우리의 이점을 얻기 위해 이러한 규칙을 최대한 활용하기 위해 최선을 다합니다.,,en,우리의 이유는,,en,정말,,en,현대 물리학,,en,일반 대중에게 입자 물리학을 설명하는 데있어 가장 어려운 점은 그것이 현대 물리학에 기반을두고 있다는 사실입니다.,,en,물리학 애호가이고 고등학교 물리학에서 매우 잘 했더라도,,en,당신이 배우고 사랑한 것은 고전 물리학입니다,,en,고전 물리학과 현대 물리학의 차이점은 단순한 물리학이 아닙니다.,,en. And, if you are to make any headway into this subject, your best bet is to curb your urge to ask why. Nature is what she is. Our job is to understand the rules by which she plays the game of reality, and do our best to make use of those rules to our advantage in experiments and technologies. Ours is not to reason why. Really.

# Classical Physics

The main difficulty in describing particle physics to general public is the fact that it is built on modern physics. Even if you are physics aficionado and did extremely well in your high school physics, what you have learned and loved is classical physics. The difference between classical physics and modern physics is not just more physics, 하지만 우리 주변의 현실을 보는 완전히 새로운 방식,,en,고전 물리학,,en,뉴턴,,en,물리학 아카이브,,en.