Evaluating the age of a universe

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Discussion Overview

The discussion revolves around evaluating the age of the universe using Hubble's law, focusing on the methodology and implications of distance measurements in cosmology. Participants explore the relationship between recession velocity and distance, as well as the uncertainties involved in these calculations.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant suggests that the age of the universe can be estimated using the Hubble constant, proposing a rough calculation of 1/H0.
  • Another participant expresses skepticism about the accuracy of distance measurements, arguing that uncertainties in local measurements could affect estimates of distances billions of light years away.
  • A participant questions the validity of the Big Bang model by pointing out apparent contradictions in the movement of local galaxies, specifically M31 and M33, suggesting that gravitational influences complicate the interpretation of redshift data.
  • Some participants emphasize that the original question was about the technique for calculating the age of the universe, rather than the accuracy of the underlying values used in the calculations.
  • Concerns are raised about the misconceptions that novices may have regarding the reliability of redshift measurements and their correlation to distance.

Areas of Agreement / Disagreement

Participants express differing views on the reliability of distance measurements and the implications for calculating the age of the universe. There is no consensus on the accuracy of the methods or the interpretations of the data presented.

Contextual Notes

Participants highlight the limitations of current distance measurement techniques and the potential for misunderstanding among novices regarding the precision of cosmological calculations.

bigboi889
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I need help evaluating the age of a universe. Using a graphed representation of hubbles's law.
The recession velocity is on the y axis, and the x-axis is in billions of light years. How can I approach this problem?
 
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The key to your problem is that the Hubble constant has units of inverse time. The age of the universe is then roughly 1/H0. You need some detailed calculations to determine that the 1 is in fact 1 and not 2/3 or 3/2, but you can get a remarkably good estimate by simply using 1.
 
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I'm not understanding why my post was pulled. It contained some information that is debatable... but I wouldn't think it was material to just be pulled without discussion.

PLUS I said some very important things. Like the fact that we don't even know as of the last decade whether something is 6000 or 10000 LY away. How then would we necessarily be very accurate in estimating the distance of things billions of LY away? It's a self-supporting philosophy to some degree. Please review my post in the blue shift thread where I perform calculations to show that the norm in a local system of 10 million LY would be that every galaxy would be moving rather quickly towards each other. Well I just did a quick qualitative calculation but anyway... it makes the point that all things in such an area would be 100% blue shift. WHY then...the lack of blue shift objects save a few on our observations? -Bob
 
You'll have to ask the moderators why it was pulled, but I suspect it was at least partially related to the fact that it didn't answer the OP's question but instead went off on a speculative tangent.

Whether there is or is not uncertainty in the distance scale is irrelevant to the OPs question. His question was on the technique. The technique is what it is, irrespective of the actual values plugged in.
 
Vanadium 50 said:
You'll have to ask the moderators why it was pulled, but I suspect it was at least partially related to the fact that it didn't answer the OP's question but instead went off on a speculative tangent.

Whether there is or is not uncertainty in the distance scale is irrelevant to the OPs question. His question was on the technique. The technique is what it is, irrespective of the actual values plugged in.

He asked as though he thought this was a formula for *actually* calculating the age of the universe. A lot of people are naive. They think that by just taking a formula offered, you get the ACTUAL ANSWER.

And I'm just asking things like "If this whole big bang model is correct, then why is M31 moving PAST M33 towards us? I mean if you do the calculations M31 at some point was MORE distant, a few billion years ago. "

See these kinds of things right in our own local system with M31 2 million LY and and M33 3 Million now... they just don't jive because are we not the primary source of gravitational pull on M33 along with M31?"

I was just saying..there are questions. It's not all nailed down in a nice package where you can just plug numbers in and get a reliable answer.

The uncertainty about distances is important to note *because* many people who are novices think that we can reliably triangulate on things billions of LY away :-). And thus they are under the impression that it's really SOLID science that these red shifts are truly correlated to distance with some precision. Anyway..for what it's worth. -Bob
 

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