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

  • Thread starter Pattielli
  • Start date
In summary, determining whether a star is still active or already dead is not as simple as observing its light. Due to the speed of light, information and effects can only reach us at a certain rate, making it difficult to know the current state of a star. This is due to the fact that causes and effects must be connected by the ability of light to travel from the point of space and time of the cause to the point of space and time of the effect.
  • #1
Pattielli
296
0
"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,
 
Astronomy news on Phys.org
  • #2
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.
 
  • #3
You mean basing on causes and effects to know what we want to know or am i missing your points ?
 
  • #4
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.
 
  • #5
Thank you,
 

1. Is it possible for someone to be declared "alive" and then later found to be "already dead"?

Yes, it is possible for someone to be declared "alive" and then later found to be "already dead". This can happen due to a number of reasons, including misdiagnosis, delayed reporting, and medical complications. It is important to note that the definition of death is constantly evolving and can be influenced by cultural and religious beliefs.

2. What is the difference between "alive" and "already dead"?

The difference between "alive" and "already dead" lies in the presence or absence of vital signs. Someone who is "alive" will have a beating heart, measurable brain activity, and the ability to breathe on their own. On the other hand, someone who is "already dead" will have no pulse, no brain activity, and will not be able to breathe without assistance.

3. What are the signs that someone is "alive"?

The signs that someone is "alive" include a pulse, breathing, response to stimuli, and brain activity. These signs can be assessed by a medical professional using various tools and techniques, such as a stethoscope, pulse oximeter, and neurological exams.

4. Can someone who is "already dead" be brought back to life?

It is not possible to bring someone who is "already dead" back to life. Once the vital signs have ceased, the body begins to undergo irreversible changes. While there have been cases of people being revived after cardiac arrest, this does not mean they were "already dead", but rather their vital signs had temporarily ceased.

5. How are death and life determined by medical professionals?

Death and life are determined by medical professionals through a thorough examination of vital signs and bodily functions. This can include checking for a pulse, monitoring brain activity, and observing breathing patterns. Medical professionals also take into account the patient's medical history and any potential underlying conditions that may impact their vital signs.

Similar threads

I Questions on stars and planets: ratio of planet radius to star, distance between the two, temperature of a star and a planet, planet rotation speed
    • Astronomy and Astrophysics
Replies
12
Views
1K
Stargazing How can we be sure that Leavitt’s law works?
    • Astronomy and Astrophysics
Replies
16
Views
2K
B How well do we know solar activity?
    • Astronomy and Astrophysics
Replies
3
Views
2K
I Nuclear reactions in the Sun and other topics on stars
    • Astronomy and Astrophysics
2
Replies
49
Views
2K
I Why does the core collapse happen so fast in a supernova?
    • Astronomy and Astrophysics
Replies
3
Views
1K
I Where can I find publicly accessible data from observatories in Europe?
    • Astronomy and Astrophysics
Replies
5
Views
921
I Why don't we bury Schrodinger's Cat?
    • Quantum Physics
5
Replies
143
Views
6K
I Can we experimentally understand the interior of a star?
    • Astronomy and Astrophysics
Replies
3
Views
1K
B What Could Explain the Mysterious Beam of Plasma Seen in the Sky in 2017?
    • Astronomy and Astrophysics
Replies
8
Views
1K
B Why Do We Use Different Pairs of Filters to Determine the Temperature of Stars?
    • Astronomy and Astrophysics
Replies
5
Views
1K

Hot Threads

Recent Insights

Back
Top