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The test of science

  1. Mar 25, 2007 #1


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    "this is a physics site. As such, discussions must be grounded in physics."

    To be grounded in physics only, we must stick to the present, where we know, and not just guess that physics applied. Unless we had some real evidence or proof that the state of the universe was the same in the past. We don't. Therefore to claim it was is religion. Is that really what this site is about???? I mean really??
    Are not claims of the early universe built in to astronomy inseparable from the "science"?? Perhaps a fresh look is needed to see if they really are inseparable? After all, science is not some priesthood, seeking to defend just it's beliefs, is it?! There is no proof the past was physical only, as the present. Is there? If so, where is it!? Can you defend it with reason, and evidence, or only by closing a thread with iseas such as this??? We shall see.
  2. jcsd
  3. Mar 25, 2007 #2
    This is going to be an interesting thread, with lots of insults and expletives flying around. :biggrin:

    But you are right to a point. We can never be sure of anything. However, I think the laws of physics would not have changed over any period of time. If they did change, they would not be laws. We can use this to estimate the state of the universe in the past.
  4. Mar 25, 2007 #3


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    I have no need to insult.
    But I do not say that they did change, since they came to be. The question is, when was that? Was it really at the beginning, or could it have been at some point afterwards, and how would we know??
    Only if we know it was the same in the deep past!. But, the problem is, we don't. So, how is it science to say we do???
  5. Mar 25, 2007 #4
    The simplest explanation is that the laws of physics have not changed (even in the "deep past"). This is both obvious (to propose change would require introduction of a parameter for the direction of change) and supported by all our historical records of mechanics and astronomical observations.

    It is science to look (in the present) at historical records or starlight (which, according to current evidence, allows us to observe the past universe), and to extrapolate.. We'd generally call it "philosophy" to ask what could have happened "outside" or "before" the domain of the observable universe.
  6. Mar 25, 2007 #5
    Hope this analogy will help you understand science better.

    A group of crime scene investigators arrive at hotel. In front of the hotel lies a man in a pool of blood. Most bones in his body is crushed, which is a result of a high velocity impact. Shreds of glass is found in his clothing and he is missing his coat. The CSI team look up, finding a large, broken window on the 20th floor. The go up and inside the room, they see a coat hanging with a name tag on it which is the same as the name tag on the wallet found in the deceased pants. The team can also successfully calculate the trajectory for something that has moved out of the window and the landing is within the uncertainness of the measurements of the position where the deceased could be found.

    Without having seen the actual jump, they can say with a high degree of certainty that the man was in that room, moved through the window and then affected by gravity, putting him on the ground with a lot of bones crushed. And all this without actually having seen the process with their own eyes...

    Compare this with someone who says that he has faith that the person fell or claimed that it had been privately revealed to him that the person fell without performing any investigation and without hearing or seeing anything of the hotel of scene.

    The actual phenomena does not need to be repeated, just the investigation of it. Science is not religion.
  7. Mar 25, 2007 #6


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    Staff: Mentor

    Good answer, Moridin.
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