How Can We Determine if a Star is Still Active or Already Dead?

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  • Thread starter Thread starter Pattielli
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Discussion Overview

The discussion revolves around how to determine whether a star is still active or has already died, considering the limitations imposed by the speed of light and the time it takes for light from stars to reach observers on Earth.

Discussion Character

  • Exploratory, Conceptual clarification

Main Points Raised

  • One participant questions how to ascertain the current state of a star, noting that the light we observe may not reflect its present condition.
  • Another participant explains that due to the finite speed of light, we can only know the state of a star based on light that has already traveled to us, meaning we cannot know its current state.
  • A further reply emphasizes the connection between causes and effects, suggesting that events must be linked by the time it takes for light to travel from the cause to the observer.
  • One participant provides an example illustrating the time delay involved in observing events at a distance, reinforcing the idea that we are always seeing past states of distant stars.

Areas of Agreement / Disagreement

Participants generally agree on the principle that the speed of light limits our ability to know the current state of a star, but the discussion does not resolve how this impacts our understanding of stellar life cycles.

Contextual Notes

The discussion does not address specific methods or criteria for determining a star's activity status, leaving open questions about the implications of light travel time on astrophysical observations.

Pattielli
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"Alive" or already "dead"

Would you please tell me how people can check out if a star is still active or already dead ? Since the lights we can see are unable to guarantee for its 'living'_ness, this is why i make this question...So please help..

Thank you very much,
 
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You mean because the light takes so long to reach us we don't know the state of the star "right now". And we don't, and can't. Information can only reach us at the speed of light, and causes can only effect us from sources whose light can have reached us.
 
You mean basing on causes and effects to know what we want to know or am i missing your points ?
 
I think you are getting there. Yes, causes and effects, due to relativity, must be connected by the ability of a light beam to get from the point of space and time of the cause to the pint of space and time of the effect. For instance, light moves at about one foot per nanosecond. Say something happens a yard (3 feet) away from me. I won't be affected by it until 3 nanoseconds have passed, the time for light to get from the something that happened to me. This isn't just about seeing, nothing about that event a yard away from me can affect me until those 3 nanoseconds have passed.
 
Thank you,
 

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