카테고리 아카이브: 물리학

물리학은 내 첫 사랑이었다. 이 범주 내 마음에 게시물 가장 가까운 포함. 스물 년 지금부터, 이 블로그는 통과하면, 이 범주는 아마 내 대부분의 지속적인 통찰력을 개최합니다. 그리고 이백년 지금부터, 나는 전혀 기억하고 있어요 경우, 이들 통찰력이 될 것입니다; 하지 내가 사람의 종류, 걸 돈, 도 아무것도. Only for my first and last love…

인식, 물리와 철학에 빛의 역할

현실, 우리는 그것을 감지로, 아주 진짜입니다. 별은 우리가 밤하늘에서 볼 수, 예를 들어, 정말이 없습니다. 그들은 이동 또는 우리가 그들을 보게되는 시간에 의해 사망​​ 한 수. 이 비현실은 우리가 도달하기가 먼 별과 은하의 빛 걸리는 시간 때문입니다. 우리는이 지연 알고.

우리가 너무 잘 알고 심지어 태양은 이미 우리가 그것을 볼 수있는 시간을 기준으로 팔분 오래. 이 사실은 특히 심각한 인식 론적 문제를 제시하지 않는 것 – 우리는 지금 일에 무슨 일이 일어나고 있는지 알고 싶다면, 우리가 할 일은 팔분을 기다리는. 우리는 올바른 '에있다’ 때문에 빛의 유한 한 속도로 우리의 인식의 왜곡을 우리는 우리가 무엇을보고 신뢰하기 전에. 보는 같은 현상은 우리가 움직이는 물체를 인식하는 방법으로 덜 알려진 증상을 가지고. 그들은 여러 번보기 빛의 속도를 이동하는 것처럼 일부 천체가 나타나지, 자신의 '진짜 반면,’ 속도는 그보다 훨씬 작아야합니다.

어떤 놀라운 일이다 (그리고 거의 강조하지) 이 때 움직임을 감지 할 수 있다는 것입니다, 우리는 백 계산을 할 수 방법은 같은 종류의 우리 태양의 관찰에 지연을 해결하기 위해 할 수있는로. 우리는 천체가 같지 않은 빠른 속도로 이동을 참조하는 경우, 우리는 정말 '얼마나 빨리 또는 어떤 방향으로 계산할 수 없습니다’ 상기 제 특정 가정을 할 필요없이 이동.

아인슈타인은 물리학의 분야에서 새로운 기본 속성을 왜곡으로 인식 치료 및 발명에 의해 문제를 해결하기로 결정했습니다 – 시간과 공간의 설명에. 특수 상대성 이론의 하나의 핵심 아이디어는 시간에 이벤트의 질서 시퀀스의 인간의 개념은 포기해야한다는 것입니다. 사실, 그것은 먼 장소에서 이벤트에서 빛에 시간이 걸리기 때문에, 우리가 도달하기, 우리를 위해 그것을 인식하게합니다, 이제 '의 개념’ 더 이상 말이 안, 예를 들어,, 우리는 천문학을 촬영하려고했던 바로 그 순간에 태양의 표면에 나타나는 흑점의​​ 말할 때. 동시성은 상대적이다.

아인슈타인 대신 우리는 이벤트를 감지 시간 인스턴트를 이용하여 동시성을 재정의. 검출, 그는 그것을 정의, 레이더 검출 유사한 광의 왕복 여행 관련. 우리는 빛의 속도로 이동하는 신호를 보내, 및 반사 기다립니다. 이 이벤트에서 반사 된 펄스는 같은 순간에 우리를 도달하면, 그들은 동시에 아르. 그러나 보는 또 다른 방법은 호출하는 것입니다 두 가지 이벤트 '를 동시에’ 그들로부터 빛이 같은 순간에 우리를 도달하는 경우. 환언, 우리는 오히려 그들에게 신호를 전송하고 반사를 찾고보다 관찰 아래에있는 객체들에 의해 발생하는 빛을 사용할 수 있습니다.

이 차이는 헤어 분할 전문적처럼 들릴지, 하지만 우리가 만들 수있는 예측에 엄청난 차이를 만들 않습니다. 아인슈타인의 선택은 많은 바람직한 특성을 가지고 수학적 사진 결과, 더 이론적 발전을 만드는 것을 포함하여 더 우아. 그러나, 아인슈타인은 생각, 믿음의 문제로 보일 것입니다, 그 우주를 지배하는 규칙은 '우아한해야합니다.’ 그러나, 이 움직임 객체를 기술에 관해서 다른 접근법은 이점을 갖는다. 때문에, 물론, 우리는 모션에서 별을 볼 레이더를 사용하지 않는; 우리는 단지 광을 감지 (또는 다른 방사선) 그들로부터 오는. 그러나 감각 패러다임의이 종류를 사용하여, 오히려 레이더와 같은 탐지 '보다,’ 이보다 수학 그림에서 우주 결과를 설명하기 위해. 아인슈타인은 승인하지 않을!

수학의 차이는 서로 다른 철학적 입장을 생성합니다, 다시 현실의 우리의 실제 사진의 이해를 여과하는. 그림으로, 우리가 관찰 가정, 전파 망원경을 통해, 하늘에 두 개의 객체, 거의 같은 모양, 크기와 특성. 우리가 확실히 알 수있는 유일한 방법은 하늘이 두 개의 서로 다른 지점에서 전파 시간에 같은 순간에 우리가 도달 할 것입니다. 파도가 자신의 여행을 시작했을 때 우리는 단지 추측 할 수.

우리가 가정하는 경우 (우리는 일상적으로처럼) 파도가 시간에 동일한 순간에 거의 여행을 시작하는, 우리는이 '실제의 사진과 함께 결국’ 대칭 로브 더 많거나 적은 방법을 참조. 그러나 또 다른이, 서로 다른 가능성과 파도가 동일한 개체에서 유래한다는 것입니다 (하는 움직임에) 시간에 두 개의 서로 다른 순간에, 같은 순간에 망원경에 도달. 이 가능성은 또한 같은 대칭 라디오 소스의 일부 스펙트럼 및 시간 특성을 설명 할 수. 그래서 우리는 실제이 두 사진의 어느를 취해야한다? 두 개의 대칭 물체 우리가 볼이나하는 방식으로 이동 한 목적은 우리에게 그 느낌을주는? 정말 어느 하나 중요합니까 것은 '진짜'? 합니까 '진짜’ 이러한 맥락에서 아무 의미?

특수 상대성이 질문에 명확한 답변을 제공. 이 오브젝트를 모방하는 것처럼 수학 같은 방식으로 움직이는 단일 객체의 가능성을 배제. 기본적으로, 우리가 볼 것은 거기서 무엇인지. 그러나, 우리는 우리가 무엇을 인식하여 이벤트를 정의하는 경우, 의미가있는 유일한 철학적 입장이 감지되는 내용 뒤에 누워 원인에서 감지 된 현실을 끊 하나입니다.

이 분리는 사상의 철학적 학교에서 드문 일이 아니다. Phenomenalism, 예를 들어, 공간과 시간이 객관적 현실이 아니라는 견해를 보유하고. 그들은 단지 우리의 인식의 중간. 공간과 시간에서 일어나는 모든 현상은 단지 우리의 인식의 번들 아르. 환언, 공간 및 시간 지각 인한인지 구성체 아르. 따라서, 우리는 시간과 공간에 돌리는 모든 물성은 놀라운 현실에 적용 할 (일 - 인 - 더 - 세계 '의 현실’ 우리는 그것을 감지로. 기본 현실 (이는 우리의 인식의 실제 원인을 보유), 반면, 우리의인지 범위 저쪽에 남아.

그러나 철학과 현대 물리학의 관점 사이에 틈이있다. 아무것도 노벨상 수상 물리학을하지 않았다, 스티븐 와인버그, 궁금, 최종 이론의 그의 책 꿈에서, 왜 물리학 철학의 기여는 너무 놀라 울 정도로 작은 있었다. 물리학은 사실과 조건에 와서 아직 가지고 있기 때문에 아마도 그것은이다 그것은 우주를보고 올 때, 착시 같은 건 없다 – 그가 말했을 때 괴테가 무엇을 의미하는지 아마 인, '착시 광학 사실이다.’

구분 (또는 그 부족) 착시와 진리 사이의 철학에서 가장 오래된 논쟁 중 하나입니다. 결국, 그것은 지식과 현실의 차이에 관한 것입니다. 지식은 무엇인가에 대한 우리의 관점으로 간주된다, 현실, 실제로 '경우입니다.’ 환언, 지식은 반영, 또는 외부 뭔가의 정신적 이미지, 아래 그림과 같이.

ExternalToBrain

이 그림, 검은 화살표는 지식을 만드는 과정을 나타낸다, 어떤 인식을 포함, 인지 활동, 순수 이성의 운동. 이것은 물리학 받아왔다하는 사진입니다. 우리의 인식이 불완전 할 수 있음을 인정하면서도, 물리학은 우리가 점점 더 정밀한 실험을 통해 외부 현실에 점점 더 가까이 얻을 수 있다고 가정, 및, 더 중요한 것은, 더 나은 이론화를 통해. 간단한 물리적 원리는 끊임없이 그들의 논리적으로 필연적 인 결론을 순수 이성의 강력 함 기계를 사용하여 추구되는 곳 상대성의 특수 및 일반 이론은 현실이보기의 화려한 응용 프로그램의 예입니다.

그러나 또 다른이, 오랜 시간 동안 주변되었습니다 지식과 현실의 대체보기. 이것은 우리의 감각 입력의 내부인지 표현으로 인식 현실에 관하여도이다, 아래 그림과 같이.

AbsolutelToBrain

이보기에서, 지식과 인식 현실은 내부인지 구조 아르, 우리는 별도로 생각하게되었다하더라도. 우리가 그것을 인식으로 어떤 외부 것은 현실이 아니다, 하지만 알 수없는 실체 감각 입력 뒤에 물리적 원인에 상승을주는. 그림에서, 제 화살표는 감지 과정을 나타내며, 및 제 화살표인지 논리적 추론 단계를 나타낸다. 현실과 지식이보기를 적용하기 위해, 우리는 절대 현실의 본질을 생각해야, 그대로 알 수없는. 절대 현실에 대한 하나의 가능한 후보는 뉴턴 역학입니다, 이는 우리의 인식의 현실에 대한 합리적인 예측을 제공합니다.

요약하자면,, 우리는 인식에 의한 왜곡을 처리 할 때, 우리는 두 가지 옵션이 있습니다, 또는 두 가지 철학적 입장. 하나는 시간과 공간의 일부로서 왜곡을 허용하는 것이다, 특수 상대성 이론은 마찬가지로. 다른 옵션은 '이상이 있다는 것을 가정하는 것이다’ 우리 감지 된 현실을 구별 현실, 그 특성을 우리가 할 수는 추측. 환언, 하나의 옵션은 왜곡 사는 것입니다, 다른 하나는 더 높은 현실 추측 해를 제안하는 것이다하면서. 이러한 선택 중 어느 것도 특히 매력적이다. 그러나 추측 경로 phenomenalism으로 인정 된 뷰와 유사하다. 또한 현실을인지 신경 과학에서 볼 방법을 자연스럽게 리드, 어떤인지 뒤의 생물학적 메커니즘을 연구.

빛과 현실의이 이야기에 트위스트는 우리가 오랜 시간 동안이 모든 것을 알고있는 것 같다 것입니다. 우리의 현실이나 우주를 만드는 빛의 역할은 서양의 종교적 사고의 중심에. 빛의없는 우주는 당신이 불을 전환 한 단순히 세계 아니다. 그것은 참 자체가없는 우주이다, 존재하지 않는 우주. 우리가 지구가 양식 선수 '는 문 뒤에 지혜를 이해해야 이러한 맥락에, 및 무효’ 하나님이 발생 될 때까지 빛이 될, 말하여 '있으라 빛이.’

코란은 말한다, '하나님은 하늘과 땅의 빛이다,’ 고대 힌두교의 글 중 하나를 미러링하는: '어둠에서 빛으로 저를 리드, 실제에 대한 환상에서 저를지도한다.’ 비현실적인 무효에서 우리를 복용에서 빛의 역할 (무) 현실에 참 오래 이해되었다, 오랜 시간. 그것은 고대의 성도들과 선지자 우리는 지금 지식 우리의 모든 가정 진보 발견하기 시작 것을 알고 있었다 가능?

칸트의 noumenal - 현상 구분 나중에 phenomenalists 사이에 유사점이있다, 및 Advaita에서 브라만 - 마야 구분. 영성의 레퍼토리에서 현실의 성격에 지혜는 현대 신경 과학에 재 탄생한다, 이는 뇌에 의해 생성 된인지 적 표현으로 현실을 취급. 뇌는 감각 입력을 사용, 메모리, 의식, 현실의 우리의 감각을 concocting의 성분으로, 심지어 언어. 현실이보기, 그러나, 뭔가 물리학와 조건에 와서 아직 없습니다. 그러나 그 범위는 경기장 (시공간) 현실의 일부입니다, 물리학은 철학에 면역되지 않습니다.

사실, 우리는 점점 더 우리의 지식의 한계를 극복로, 우리는 인간의 노력의 서로 다른 지점 사이에 지금까지 의심받지 종종 놀라운 상호 연결을 발견하고. 그러나, 모든 지식은 주관적인 경우 어떻게 우리의 지식의 다양한 도메인은 서로 독립적이 될 수 있습니다? 지식은 단순히 우리의 경험의인지 적 표현 인 경우? 그러나, 그것은 지식이 외부 현실의 내부 표현입니다 생각하는 현대 착오입니다, 그것에서 따라서 별개의. 대신, 인식하고 인간의 노력의 다른 도메인 간의 상호 접속을 활용하는 것이 우리의 공동의 지혜를 개발에서 다음 단계를위한 필수적인 전제 조건 일 수있다.

박스: 아인슈타인의 기차아인슈타인의 유명한 사고 실험 중 하나는 동시 이벤트에 의해 무엇을 의미하는지 다시 생각해야 할 필요성을 보여줍니다. 남자가에 의해 속도를보고 역 플랫폼에 약자로 그것은 작은 역을지나 직선 트랙을 따라 돌진하는 고속 열차를 설명. 그의 놀랍게도, 기차는 그를 통과, 이 번개 볼트는 열차의 한쪽 끝을 옆에 트랙을 공격! (편리하게, 나중에 수사관, 그들은 열차와 지상에 모두 화상 자국 둡니다.)

사람에, 그것은 두 개의 번개 볼트 동일한 순간에 찍는 것 같다. 나중에, 기차 트랙에 의해 지상에 표시가 번개 강타 관광 명소 그로부터 정확히 같은 거리에 있다고 공개. 그 이후로 번개 볼트는 그를 향해 같은 거리를 여행, 그들은 사람에게 나타나 있기 때문에 정확히 같은 순간에 발생합니다, 그는 번개 볼트가 정확히 같은 순간에 강타 결론하지 않을 이유가 없습니다. 그들은 동시에 있었다.

그러나, 조금 나중에 가정, 남자는 무슨 일이 있었 숙녀 승객이 뷔페 차에 앉아 수 충족, 정확하게 열차의 중앙, 그리고 시간에 창 밖으로 찾고 번개 볼트 강타. 이 승객은 그녀가 두 번째 기차의 뒤쪽에화물 자동차 옆에 땅에 떨어 할 때 첫 번째 번개 볼트가 약간 앞서 열차의 앞쪽에 엔진 근처 땅에 떨어 보았다는 그에게 말한다.

효과는 빛이 여행했던 거리를 함께 할 수 없다, 여자와 남자 모두가 두 점 사이의 등거리 말하자면 그 번개 히트. 그러나 이들은 매우 다르게 이벤트 시퀀스를 관찰.

이벤트의 타이밍이 불일치는 불가피, 아인슈타인은 말한다, 여자가 적용됩니다로 번개의 플래시 - 그리고 멀리 지점에서 엔진 근처에 명중 곳을 향해 이동하는 경우 수하물 자동차 옆에 명중 번개의 섬광. 시간의 작은 금액 그것은 광선이 여성에 도달하는 데 걸리는, 기차 이동하기 때문에, 첫번째 플래시가 그녀의 정신과 의사로 여행을해야하는 거리, 그리고 두번째 플래시가 이동해야 거리는 성장.

이 사실은 기차와 비행기의 경우에 발견되지 않을 수 있습니다, 그러나 그것은 우주의 거리에 올 때, 동시성은 정말 이해가되지 않습니다. 예를 들면, 이 먼 초신성의 폭발, 지상에있는 우리의 유리한 지점에서 동시로 볼, 다른 관점에서 서로 다른 시간의 조합에 발생하는 것으로 나타납니다.

상대성에서: 특수 및 일반 이론 (1920), 아인슈타인은 이런 식으로 넣어:

'모든 참조 몸 (좌표계) 자신의 특정 시간을 가지고; 시간의 문이 참조하는 우리는 레퍼런스 몸을 이야기하지 않는, 이벤트의 시간의 문에 아무런 의미가 없습니다.’

Tsunami

The Asian Tsunami two and a half years ago unleashed tremendous amount energy on the coastal regions around the Indian ocean. What do you think would’ve have happened to this energy if there had been no water to carry it away from the earthquake? I mean, if the earthquake (of the same kind and magnitude) had taken place on land instead of the sea-bed as it did, presumably this energy would’ve been present. How would it have manifested? As a more violent earthquake? Or a longer one?

I picture the earthquake (in cross-section) as a cantilever spring being held down and then released. The spring then transfers the energy to the tsunami in the form of potential energy, as an increase in the water level. As the tsunami radiates out, it is only the potential energy that is transferred; the water doesn’t move laterally, only vertically. As it hits the coast, the potential energy is transferred into the kinetic energy of the waves hitting the coast (water moving laterally then).

Given the magnitude of the energy transferred from the epicenter, I am speculating what would’ve happened if there was no mechanism for the transfer. Any thoughts?

Universe – Size and Age

I posted this question that was bothering me when I read that they found a galaxy at about 13 billion light years away. My understanding of that statement is: At distance of 13 billion light years, there was a galaxy 13 billion years ago, so that we can see the light from it now. Wouldn’t that mean that the universe is at least 26 billion years old? It must have taken the galaxy about 13 billion years to reach where it appears to be, and the light from it must take another 13 billion years to reach us.

In answering my question, Martin and Swansont (who I assume are academic phycisists) point out my misconceptions and essentially ask me to learn more. All shall be answered when I’m assimilated, it would appear! 🙂

This debate is published as a prelude to my post on the Big Bang theory, coming up in a day or two.

Mowgli 03-26-2007 10:14 PM

Universe – Size and Age
I was reading a post in http://www.space.com/ stating that they found a galaxy at about 13 billion light years away. I am trying to figure out what that statement means. To me, it means that 13 billion years ago, this galaxy was where we see it now. Isn’t that what 13b LY away means? If so, wouldn’t that mean that the universe has to be at least 26 billion years old? I mean, the whole universe started from one singular point; how could this galaxy be where it was 13 billion years ago unless it had at least 13 billion years to get there? (Ignoring the inflationary phase for the moment…) I have heard people explain that the space itself is expanding. What the heck does that mean? Isn’t it just a fancier way of saying that the speed of light was smaller some time ago?
swansont 03-27-2007 09:10 AM

Quote:

Originally Posted by Mowgli
(Post 329204)
I mean, the whole universe started from one singular point; how could this galaxy be where it was 13 billion years ago unless it had at least 13 billion years to get there? (Ignoring the inflationary phase for the moment…)

Ignoring all the rest, how would this mean the universe is 26 billion years old?

Quote:

Originally Posted by Mowgli
(Post 329204)
I have heard people explain that the space itself is expanding. What the heck does that mean? Isn’t it just a fancier way of saying that the speed of light was smaller some time ago?

The speed of light is an inherent part of atomic structure, in the fine structure constant (alpha). If c was changing, then the patterns of atomic spectra would have to change. There hasn’t been any confirmed data that shows that alpha has changed (there has been the occasional paper claiming it, but you need someone to repeat the measurements), and the rest is all consistent with no change.

Martin 03-27-2007 11:25 AM

To confirm or reinforce what swansont said, there are speculation and some fringe or nonstandard cosmologies that involve c changing over time (or alpha changing over time), but the changing constants thing just gets more and more ruled out.I’ve been watching for over 5 years and the more people look and study evidence the LESS likely it seems that there is any change. They rule it out more and more accurately with their data.So it is probably best to ignore the “varying speed of light” cosmologies until one is thoroughly familiar with standard mainstream cosmology.You have misconceptions Mowgli

  • General Relativity (the 1915 theory) trumps Special Rel (1905)
  • They don’t actually contradict if you understand them correctly, because SR has only a very limited local applicability, like to the spaceship passing by:-)
  • Wherever GR and SR SEEM to contradict, believe GR. It is the more comprehensive theory.
  • GR does not have a speed limit on the rate that very great distances can increase. the only speed limit is on LOCAL stuff (you can’t catch up with and pass a photon)
  • So we can and DO observe stuff that is receding from us faster than c. (It’s far away, SR does not apply.)
  • This was explained in a Sci Am article I think last year
  • Google the author’s name Charles Lineweaver and Tamara Davis.
  • We know about plenty of stuff that is presently more than 14 billion LY away.
  • You need to learn some cosmology so you wont be confused by these things.
  • Also a “singularity” does not mean a single point. that is a popular mistake because the words SOUND the same.
  • A singularity can occur over an entire region, even an infinite region.

Also the “big bang” model doesn’t look like an explosion of matter whizzing away from some point. It shouldn’t be imagined like that. The best article explaining common mistakes people have is this Lineweaver and Davis thing in Sci Am. I think it was Jan or Feb 2005 but I could be a year off. Google it. Get it from your local library or find it online. Best advice I can give.

Mowgli 03-28-2007 01:30 AM

To swansont on why I thought 13 b LY implied an age of 26 b years:When you say that there is a galaxy at 13 b LY away, I understand it to mean that 13 billion years ago my time, the galaxy was at the point where I see it now (which is 13 b LY away from me). Knowing that everything started from the same point, it must have taken the galaxy at least 13 b years to get where it was 13 b years ago. So 13+13. I’m sure I must be wrong.To Martin: You are right, I need to learn quite a bit more about cosmology. But a couple of things you mentioned surprise me — how do we observe stuff that is receding from as FTL? I mean, wouldn’t the relativistic Doppler shift formula give imaginary 1+z? And the stuff beyond 14 b LY away – are they “outside” the universe?I will certainly look up and read the authors you mentioned. Thanks.
swansont 03-28-2007 03:13 AM

Quote:

Originally Posted by Mowgli
(Post 329393)
To swansont on why I thought 13 b LY implied an age of 26 b years:When you say that there is a galaxy at 13 b LY away, I understand it to mean that 13 billion years ago my time, the galaxy was at the point where I see it now (which is 13 b LY away from me). Knowing that everything started from the same point, it must have taken the galaxy at least 13 b years to get where it was 13 b years ago. So 13+13. I’m sure I must be wrong.

That would depend on how you do your calibration. Looking only at a Doppler shift and ignoring all the other factors, if you know that speed correlates with distance, you get a certain redshift and you would probably calibrate that to mean 13b LY if that was the actual distance. That light would be 13b years old.

But as Martin has pointed out, space is expanding; the cosmological redshift is different from the Doppler shift. Because the intervening space has expanded, AFAIK the light that gets to us from a galaxy 13b LY away is not as old, because it was closer when the light was emitted. I would think that all of this is taken into account in the measurements, so that when a distance is given to the galaxy, it’s the actual distance.

Martin 03-28-2007 08:54 AM

Quote:

Originally Posted by Mowgli
(Post 329393)
I will certainly look up and read the authors you mentioned.

This post has 5 or 6 links to that Sci Am article by Lineweaver and Davis

http://scienceforums.net/forum/showt…965#post142965

It is post #65 on the Astronomy links sticky thread

It turns out the article was in the March 2005 issue.

I think it’s comparatively easy to read—well written. So it should help.

When you’ve read the Sci Am article, ask more questions—your questions might be fun to try and answer:-)

Twin Paradox – Take 2

The Twin Paradox is usually explained away by arguing that the traveling twin feels the motion because of his acceleration/deceleration, and therefore ages slower.

But what will happen if the twins both accelerate symmetrically? That is, they start from rest from one space point with synchronized clocks, and get back to the same space point at rest by accelerating away from each other for some time and decelerating on the way back. By the symmetry of the problem, it seems that when the two clocks are together at the end of the journey, at the same point, and at rest with respect to each other, they have to agree.

Then again, during the whole journey, each clock is in motion (accelerated or not) with respect to the other one. In SR, every clock that is in motion with respect to an observer’s clock is supposed run slower. Or, the observer’s clock is always the fastest. So, for each twin, the other clock must be running slower. However, when they come back together at the end of the journey, they have to agree. This can happen only if each twin sees the other’s clock running faster at some point during the journey. What does SR say will happen in this imaginary journey?

(Note that the acceleration of each twin can be made constant. Have the twins cross each other at a high speed at a constant linear deceleration. They will cross again each other at the same speed after sometime. During the crossings, their clocks can be compared.)

Unreal Time

Farsight wrote:Time is a velocity-dependent subjective measure of event succession rather than something fundamental – the events mark the time, the time doesn’t mark the events. This means the stuff out there is space rather than space-time, and is an “aether” veiled by subjective time.

I like your definition of time. It is close to my own view that time is “unreal.” It is possible to treat space as real and space-time as something different, as you do. This calls for some careful thought. I will outline my thinking in this post and illustrate it with an example, if my friends don’t pull me out for lunch before I can finish. :)

The first question we need to ask ourselves is why space and time seem coupled? The answer is actually too simple to spot, and it is in your definition of time. Space and time mix through our concept of velocity and our brain’s ability to sense motion. There is an even deeper connection, which is that space is a cognitive representation of the photons inputs to our eyes, but we will get to it later.

Let’s assume for a second that we had a sixth sense that operated at an infinite speed. That is, if star explodes at a million light years from us, we can sense it immediately. We will see it only after a million years, but we sense it instantly. I know, it is a violation of SR, cannot happen and all that, but stay with me for a second. Now, a little bit of thinking will convince you that the space that we sense using this hypothetical sixth sense is Newtonian. Here, space and time can be completely decoupled, absolute time can be defined etc. Starting from this space, we can actually work out how we will see it using light and our eyes, knowing that the speed of light is what it is. It will turn out, clearly, that we seen events with a delay. That is a first order (or static) effect. The second order effect is the way we perceive objects in motion. It turns out that we will see a time dilation and a length contraction (for objects receding from us.)

Let me illustrate it a little further using echolocation. Assume that you are a blind bat. You sense your space using sonar pings. Can you sense a supersonic object? If it is coming towards you, by the time the reflected ping reaches you, it has gone past you. If it is going away from you, your pings can never catch up. In other words, faster than sound travel is “forbidden.” If you make one more assumption – the speed of the pings is the same for all bats regardless of their state of motion – you derive a special relativity for bats where the speed of sound is the fundamental property of space and time!

We have to dig a little deeper and appreciate that space is no more real than time. Space is a cognitive construct created out of our sensory inputs. If the sense modality (light for us, sound for bats) has a finite speed, that speed will become a fundamental property of the resultant space. And space and time will be coupled through the speed of the sense modality.

This, of course, is only my own humble interpretation of SR. I wanted to post this on a new thread, but I get the feeling that people are a little too attached to their own views in this forum to be able to listen.

Leo wrote:Minkowski spacetime is one interpretation of the Lorentz transforms, but other interpretations, the original Lorentz-Poincaré Relativity or modernized versions of it with a wave model of matter (LaFreniere or Close or many others), work in a perfectly euclidean 3D space.

So we end up with process slowdown and matter contraction, but NO time dilation or space contraction. The transforms are the same though. So why does one interpretation lead to tensor metric while the others don’t? Or do they all? I lack the theoretical background to answer the question.

Hi Leo,

If you define LT as a velocity dependent deformation of an object in motion, then you can make the transformation a function of time. There won’t be any warping and complications of metric tensors and stuff. Actually what I did in my book is something along those lines (though not quite), as you know.

The trouble arises when the transformation matrix is a function of the vector is transforming. So, if you define LT as a matrix operation in a 4-D space-time, you can no longer make it a function of time through acceleration any more than you can make it a function of position (as in a velocity field, for instance.) The space-time warping is a mathematical necessity. Because of it, you lose coordinates, and the tools that we learn in our undergraduate years are no longer powerful enough to handle the problem.

Of Rotation, LT and Acceleration

In the “Philosophical Implications” forum, there was an attempt to incorporate acceleration into Lorentz transformation using some clever calculus or numerical techniques. Such an attempt will not work because of a rather interesting geometric reason. I thought I would post the geometric interpretation of Lorentz transformation (or how to go from SR to GR) here.

Let me start with a couple of disclaimers. First of, what follows is my understanding of LT/SR/GR. I post it here with the honest belief that it is right. Although I have enough academic credentials to convince myself of my infallibility, who knows? People much smarter than me get proven wrong every day. And, if we had our way, we would prove even Einstein himself wrong right here in this forum, wouldn’t we? :D Secondly, what I write may be too elementary for some of the readers, perhaps even insultingly so. I request them to bear with it, considering that some other readers may find it illuminating. Thirdly, this post is not a commentary on the rightness or wrongness of the theories; it is merely a description of what the theories say. Or rather, my version of what they say. With those disclaimers out of the way, let’s get started…

LT is a rotation in the 4-D space-time. Since it not easy to visualize 4-D space-time rotation, let’s start with a 2-D, pure space rotation. One fundamental property of a geometry (such as 2-D Euclidean space) is its metric tensor. The metric tensor defines the inner product between two vectors in the space. In normal (Euclidean or flat) spaces, it also defines the distance between two points (or the length of a vector).

Though the metric tensor has the dreaded “tensor” word in its name, once you define a coordinate system, it is only a matrix. For Euclidean 2-D space with x and y coordinates, it is the identity matrix (two 1’s along the diagonal). Let’s call it G. The inner product between vectors A and B is A.B = Trans(A) G B, which works out to be a_1b_1+a_2b_2. Distance (or length of A) can be defined as \sqrt{A.A}.

So far in the post, the metric tensor looks fairly useless, only because it is the identity matrix for Euclidean space. SR (or LT), on the other hand, uses Minkowski space, which has a metric that can be written with [-1, 1, 1, 1] along the diagonal with all other elements zero – assuming time t is the first component of the coordinate system. Let’s consider a 2-D Minkowski space for simplicity, with time (t) and distance (x) axes. (This is a bit of over-simplification because this space cannot handle circular motion, which is popular in some threads.) In units that make c = 1, you can easily see that the invariant distance using this metric tensor is \sqrt{x^2 - t^2}.

Continued…

The Unreal Universe — Discussion with Gibran

Hi again,You raise a lot of interesting questions. Let me try to answer them one by one.

You’re saying that our observations of an object moving away from us would look identical in either an SR or Galilean context, and therefore this is not a good test for SR.

What I’m saying is slightly different. The coordinate transformation in SR is derived considering only receding objects and sensing it using radar-like round trip light travel time. It is then assumed that the transformation laws thus derived apply to all objects. Because the round trip light travel is used, the transformation works for approaching objects as well, but not for things moving in other directions. But SR assumes that the transformation is a property of space and time and asserts that it applies to all moving (inertial) frames of reference regardless of direction.

We have to go a little deeper and ask ourselves what that statement means, what it means to talk about the properties of space. We cannot think of a space independent of our perception. Physicists are typically not happy with this starting point of mine. They think of space as something that exists independent of our sensing it. And they insist that SR applies to this independently existing space. I beg to differ. I consider space as a cognitive construct based on our perceptual inputs. There is an underlying reality that is the cause of our perception of space. It may be nothing like space, but let’s assume, for the sake of argument, that the underlying reality is like Galilean space-time. How would be perceive it, given that we perceive it using light (one-way travel of light, not two-way as SR assumes)? It turns out that our perceptual space would have time dilation and length contraction and all other effect predicted by SR. So my thesis is that the underlying reality obeys Galilean space-time and our perceptual space obeys something like SR. (It is possible that if I assume that our perception uses two-way light travel, I may get SR-like transformation. I haven’t done it because it seems obvious to me that we perceive a star, for instance, by sensing the light from it rather than flashing a light at it.)

This thesis doesn’t sit well with physicists, and indeed with most people. They mistake “perceptual effects” to be something like optical illusions. My point is more like space itself is an illusion. If you look at the night sky, you know that the stars you see are not “real” in the sense that they are not there when you are looking at them. This is simply because the information carrier, namely light, has a finite speed. If the star under observation is in motion, our perception of its motion is distorted for the same reason. SR is an attempt to formalize our perception of motion. Since motion and speed are concepts that mix space and time, SR has to operate on “space-time continuum.” Since SR is based on perceptual effects, it requires an observer and describes motion as he perceives it.

But are you actually saying that not a single experiment has been done with objects moving in any other direction than farther away? And what about experiments on time dilation where astronauts go into space and return with clocks showing less elapsed time than ones that stayed on the ground? Doesn’t this support the ideas inherent in SR?

Experiments are always interpreted in the light of a theory. It is always a model based interpretation. I know that this is not a convincing argument for you, so let me give you an example. Scientists have observed superluminal motion in certain celestial objects. They measure the angular speed of the celestial object, and they have some estimate of its distance from us, so they can estimate the speed. If we didn’t have SR, there would be nothing remarkable about this observation of superluminality. Since we do have SR, one has to find an “explanation” for this. The explanation is this: when an object approaches us at a shallow angle, it can appear to come in quite a bit faster than its real speed. Thus the “real” speed is subluminal while the “apparent” speed may be superluminal. This interpretation of the observation, in my view, breaks the philosophical grounding of SR that it is a description of the motion as it appears to the observer.

Now, there are other observations of where almost symmetric ejecta are seen on opposing jets in symmetric celestial objects. The angular speeds may indicate superluminality in both the jets if the distance of the object is sufficiently large. Since the jets are assumed to be back-to-back, if one jet is approaching us (thereby giving us the illusion of superluminality), the other jet has bet receding and can never appear superluminal, unless, of course, the underlying motion is superluminal. The interpretation of this observation is that the distance of the object is limited by the “fact” that real motion cannot be superluminal. This is what I mean by experiments being open to theory or model based interpretations.

In the case of moving clocks being slower, it is never a pure SR experiment because you cannot find space without gravity. Besides, one clock has to be accelerated or decelerated and GR applies. Otherwise, the age-old twin paradox would apply.

I know there have been some experiments done to support Einstein’s theories, like the bending of light due to gravity, but are you saying that all of them can be consistently re-interpreted according to your theory? If this is so, it’s dam surprising! I mean, no offense to you – you’re obviously a very bright individual, and you know much more about this stuff than I do, but I’d have to question how something like this slipped right through physicists’ fingers for 100 years.

These are gravity related questions and fall under GR. My “theory” doesn’t try to reinterpret GR or gravity at all. I put theory in inverted quotes because, to me, it is a rather obvious observation that there is a distinction between what we see and the underlying causes of our perception. The algebra involved is fairly simple by physics standards.

Supposing you’re right in that space and time are actually Galilean, and that the effects of SR are artifacts of our perception. How then are the results of the Michelson-Morley experiments explained? I’m sorry if you did explain it in your book, but it must have flown right over my head. Or are we leaving this as a mystery, an anomaly for future theorists to figure out?

I haven’t completely explained MMX, more or less leaving it as a mystery. I think the explanation hinges on how light is reflected off a moving mirror, which I pointed out in the book. Suppose the mirror is moving away from the light source at a speed of v in our frame of reference. Light strikes it at a speed of c-v. What is the speed of the reflected light? If the laws of reflection should hold (it’s not immediately obvious that they should), then the reflected light has to have a speed of c-v as well. This may explain why MMX gives null result. I haven’t worked out the whole thing though. I will, once I quit my day job and dedicate my life to full-time thinking. :-)

My idea is not a replacement theory for all of Einstein’s theories. It’s merely a reinterpretation of one part of SR. Since the rest of Einstein’s edifice is built on this coordinate transformation part, I’m sure there will be some reinterpretation of the rest of SR and GR also based on my idea. Again, this is a project for later. My reinterpretation is not an attempt to prove Einstein’s theories wrong; I merely want to point out that they apply to reality as we perceive it.

Overall, it was worth the $5 I payed. Thanks for the good read. Don’t take my questions as an assault on your proposal – I’m honestly in the dark about these things and I absolutely crave light (he he). If you could kindly answer them in your spare time, I’d love to share more ideas with you. It’s good to find a fellow thinker to bounce cool ideas like this off of. I’ll PM you again once I’m fully done the book. Again, it was a very satisfying read.

Thanks! I’m glad that you like my ideas and my writing. I don’t mind criticism at all. Hope I have answered most of your questions. If not, or if you want to disagree with my answers, feel free to write back. Always a pleasure to chat about these things even if we don’t agree with each other.

– Best regards,
– Manoj

Anti-relativity and Superluminality

Leo wrote:I have some problems with the introductory part though, when you confront light travel effects and relativistic transforms. You correctly state that all perceptual illusions have been cleared away in the conception of Special Relativity, but you also say that these perceptual illusions remained as a subconscious basis for the cognitive model of Special Relativity. Do I understand what you mean or do I get it wrong?

The perceptual effects are known in physics; they are called Light Travel Time effects (LTT, to cook up an acronym). These effects are considered an optical illusion on the motion of the object under observation. Once you take out the LTT effects, you get the “real” motion of the object . This real motion is supposed to obey SR. This is the current interpretation of SR.

My argument is that the LTT effects are so similar to SR that we should think of SR as just a formalization of LTT. (In fact, a slightly erroneous formalization.) Many reasons for this argument:
1. We cannot disentagle the “optical illusion” because many underlying configurations give rise to the same perception. In other words, going from what we see to what is causing our perception is a one to many problem.
2. SR coordinate transformation is partially based on LTT effects.
3. LTT effects are stronger than relativistic effects.

Probably for these reasons, what SR does is to say that what we see is what it is really like. It then tries to mathematically describe what we see. (This is what I meant by a formaliztion. ) Later on, when we figured out that LTT effects didn’t quite match with SR (as in the observation of “apparent” superluminal motion), we thought we had to “take out” the LTT effects and then say that the underlying motion (or space and time) obeyed SR. What I’m suggesting in my book and articles is that we should just guess what the underlying space and time are like and work out what our perception of it will be (because going the other way is an ill-posed one-to-many problem). My first guess, naturally, was Galilean space-time. This guess results in a rather neat and simple explantions of GRBs and DRAGNs as luminal booms and their aftermath.

Discussion on the Daily Mail (UK)

On the Daily Mail forum, one participant (called “whats-in-a-name”) started talking about The Unreal Universe on July 15, 2006. It was attacked fairly viciously on the forum. I happened to see it during a Web search and decided to step in and defend it.

15 July, 2006

Posted by: whats-in-a-name on 15/07/06 at 09:28 AM

Ah, Kek, you’ve given me a further reason to be distracted from what I should be doing- and I can tell you that this is more interesting at the moment.I’ve been trying to formulate some ideas and there’s one coming- but I’ll have to give it to you in bits.I don’t want to delve into pseudoscience or take the woo-ish road that says that you can explain everything with quantum theory, but try starting here: http://theunrealuniverse.com/phys.shtml

The “Journal Article” link at the bottom touches on some of the points that we discussed elsewhere. It goes slightly off-topic, but you might also find the “Philosophy” link at the top left interesting.

Posted by: patopreto on 15/07/06 at 06:17 PM

Regarding that web site wian.One does not need to ead past this sentence –

The theories of physics are a description of reality. Reality is created out of the readings from our senses. Knowing that our senses all work using light as an intermediary, is it a surprise that the speed of light is of fundamental importance in our reality?

to realise that tis web site is complete ignorant hokum. I stopped at that point.

16 July, 2006

Posted by: whats-in-a-name on 16/07/06 at 09:04 AM

I’ve just been back to read that bit more carefully. I don’t know why the writer phrased it like that but surely what he meant was:(i) “Our perception of what is real is created out of the readings from our senses.” I think that most physicists wouldn’t argue with that would they? At the quantum level reality as we understand it doesn’t exist; you can only say that particles have more of a tendency to exist in one place or state than another.(ii) The information that we pick up from optical or radio telescopes, gamma-ray detectors and the like, shows the state of distant objects as they were in the past, owing to the transit time of the radiation. Delving deeper into space therefore enables us to look further back into the history of the universe.It’s an unusual way to express the point, I agree, but it doesn’t devalue the other information on there. In particular there are links to other papers that go into rather more detail, but I wanted to start with something that offered a more general view.

I get the impression that your study of physics is rather more advanced than mine- as I’ve said previously I’m only an amateur, though I’ve probably taken my interest a bit further than most. I’m happy to be corrected if any of my reasoning is flawed, though what I’ve said so far s quite basic stuff.

The ideas that I’m trying to express in response to Keka’s challenge are my own and again, I’m quite prepared to have you or anyone else knock them down. I’m still formulating my thoughts and I wanted to start by considering the model that physicists use of the nature of matter, going down to the grainy structure of spacetime at the Plank distance and quantum uncertainty.

I’ll have to come back to this in a day or two, but meanwhile if you or anyone else wants to offer an opposing view, please do.

Posted by: patopreto on 16/07/06 at 10:52 AM

I don’t know why the writer phrased it like that but surely what he meant was:

I think the write is quit clear! WIAN – you have re-written what he says to mean something different.

The writer is quite clear – “Once we accept that space and time are a part of the cognitive model created by the brain, and that special relativity applies to the cognitive model, we can ponder over the physical causes behind the model, the absolute reality itself.”

Blah Blah Blah!

The writer, Manoj Thulasidas, is an employee of OCBC bank in Singapore and self-described “amateur philosopher”. What is he writes appears to be nothing more than a religiously influenced solipsistic philosophy. Solipsism is interesting as a philosophical standpoint but quickly falls apart. If Manoj can start his arguments from such shaky grounds without explanation, then I really have no other course to take than to accept his descriptions of himself as “amateur”.

Maybe back to MEQUACK!