# From physics how can we figure out how old the earth and the universe is?

• dcderek24
In summary: English speaker.In summary, an expert summarizer of content notes that radiometric dating can be used to determine the age of stars, and that this information is uncertain due to a lack of direct data. They also mention talkorigins.org as a resource for debunking creationist claims.
dcderek24
i am a former creationist that is just learning about science. I am not trying to disprove anything i just want to learn. i was hid away from science all my life growing up in a fundamentalist household and church.
anway i have learned about radiometric dating and various ways scientists can figure out how old the Earth is.
how through physics can we figure out the age of a star and the age of things of the universe including earth.

i greatly appreciate any answers in advance. I am also being bomboarded with creationist questions by my friends or old friends and family. and i just like to know for my own curiosity.

The ages of stars are a bit more complicated. For our own solar system, it's pretty easy, because we can just check the ages of asteroids using radiometric dating. This gives us a good estimate for the age of our own Sun as well.

But there are no direct methods for detecting the ages of other stars, unfortunately. Instead, we rely largely upon model estimates. The basic way this is done is to compare three variables: brightness, temperature, and mass. Main sequence stars stay about the same mass for most of their life after formation. But the brightness and temperature change as the star ages: the star becomes gradually brighter and hotter as it ages. So if the star is in a multiple-star system that allows us to measure its mass, then we can use the relationship between how bright/hot it is and its mass to give us an estimate of the age.

To get an idea of how the age depends upon this relationship, we have to use theoretical models of stellar evolution. It's unfortunate that we only really have one strong data point to confirm our theories (our own Sun). Partly because of this, our estimates of the ages of individual stars are extremely uncertain. Interestingly enough, we have a better handle on the age of the universe itself than we have on the ages of individual stars!

Anyway, you can read more on how stars age here:
http://en.wikipedia.org/wiki/Stellar_evolution

Radioactive dating is a very powerful tool for determining Earth's age. All such studies strongly indicate Earth is about 4.5 billion years old.

You need to know the http://www.talkorigins.org/origins/faqs.html" archive. This is not exactly the very first time those questions have been asked and answered.
If some specific questions remain, ask here at PF.

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Ich said:
You need to know the http://www.talkorigins.org/origins/faqs.html" archive. This is not exactly the very first time those questions have been asked and answered.
If some specific questions remain, ask here at PF.
Ah, yes, talkorigins is fantastic for debunking a wide variety of creationist claims. I particularly like the FAQ and the "post of the month" series.

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the universe they can measure the speed of exceleration, taking in mind that the universe is speeding up, and can measuse when it began :)

nickthrop101 said:
the universe they can measure the speed of exceleration, taking in mind that the universe is speeding up, and can measuse when it began :)

## 1. How do we determine the age of the earth and the universe?

Scientists use a variety of methods and techniques to determine the age of the earth and the universe. Some of these include radiometric dating, which measures the decay of radioactive elements, and the study of cosmic background radiation, which provides clues about the formation of the universe.

## 2. What is the estimated age of the earth?

The currently accepted age of the earth is 4.54 billion years. This was determined through radiometric dating of rocks from the earth's surface and meteorites, as well as other geological and astronomical evidence.

## 3. How do we know the age of the universe?

Scientists estimate that the universe is approximately 13.8 billion years old. This is determined through the study of cosmic microwave background radiation, the expansion rate of the universe, and the ages of the oldest known stars and galaxies.

## 4. Can the age of the earth and the universe change?

While the current estimates for the age of the earth and the universe are widely accepted, they are subject to change as new evidence and technologies become available. As our understanding of physics and the universe expands, so too may our understanding of their age.

## 5. How does the age of the earth and the universe relate to the Big Bang theory?

The Big Bang theory is the most widely accepted scientific explanation for the origin of the universe. It suggests that the universe began as a singularity around 13.8 billion years ago, and has been expanding and evolving ever since. Therefore, the estimated age of the universe is closely tied to the Big Bang theory.

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