How Do We Know the Age of the Universe?

What kinds of tools do astronomers use to calculate the age of the universe, and how can they determine the speed of its expansion?

Hosted by: Caitlin Hofmeister
----------
----------
Dooblydoo thanks go to the following Patreon supporters:
Kelly Landrum Jones, Sam Lutfi, Kevin Knupp, Nicholas Smith, D.A. Noe, alexander wadsworth, سلط الخليفي, Piya Shedden, KatieMarie Magnone, Scott Satovsky Jr, Charles Southerland, Bader AlGhamdi, James Harshaw, Patrick Merrithew, Patrick D. Ashmore, Candy, Tim Curwick, charles george, Saul, Mark Terrio-Cameron, Viraansh Bhanushali, Kevin Bealer, Philippe von Bergen, Chris Peters, Justin Lentz
----------
----------
Looking for SciShow elsewhere on the internet?
----------
Sources:

Images:

[apburner]

Just ask my mother-in-law, she knows everything and I'm sure she was around in the beginning.

[Master_Therion]

"How Do We Know the Age of the Universe?"
Simple, count the number of Standard Candles on its birthday cake.

[spreadlove]

This is why I love science. Science admits their wrongs and always strive to learn and keep searching until everything make sense. This is the type of people we need in the world. People who yearn for facts and knowledge.

[themajesticbeard]

This host has seriously upped her game recently, she delivers information much more fluidly than in her earlier videos.

She's quickly becoming one of my faves!

[matejmanevski]

1. Look for old and far stars and clusters ( they will give you a rough result at least 13.2 Billion years old)
2. Expansion of the Universe ( first the speed is important, reverse the time and the Universe will be a single very small point at 13.77 Billion years ago)
3. Standards candels ( good for calculating the speed of the expansion of the Universe)

4.Redshift ( also good for calculating the speed of the expansion of the Universe, the further the star or galaxy is the bigger the redshift, in other worlds galaxies are moving away form us with a speed that is proportional from ther distense from us, or more simplify the farther it is the fasster is going away from us)
5. CMB ( evidence the Universe had a begining, we can see the Universe 380000 after its birth, also from the temperature says it was expanding)

[adaire]

Personally, I'm not convinced on the age being accurate. We seem to know so little about the universe, yet know so much from just standing on not even a little speck of dust in the universe, and I think these theories could easily be debunked later on. There has to be more to this than what we currently think.

That being said, who knows. Maybe these findings do turn out true in the end, but our theories are young in the grand scheme of things.

[BertGrink]

The wording @1:42 could have been better: People who don't know better might get the impression that the universe has only been expandinig since the 1920s ;)
Other than that, good video as usual.

[Censeo]

That awkward moment when Hubble measurement predicted that the universe is younger than many rocks on earth.

[jordanmicahcook]

Given that we discover new information constantly, and that our knowledge and fundamental understanding of the universe today barely resembles what it was a thousand years ago, how do we know that elements of the vast unknown are not distorting our studies and conclusions of the present?

[Moonbeam]

The Universe is so old, it wants you to get off it's lawn.

[dugumash]

And now we find out with the James Webb telescope that it's even older than the 13.8 billion we estimated. You did a very good job with this video because you even left room for correction.

[george]

Assuming the expansion of the universe was consistent enough to determine there was a “big bang” 13.7 billion years ago, isn’t it a pretty big presumption to call that the “beginning” of the universe?

[titusxp]

I appreciate the fact that u left room for change at the end by saying "dont' be surprised if it changes". That humility is what some scientists lack. They present the current findings as irrefutable and unchangeable truths. While still accepting that we don't yet know everything. The contradiction always gets me.

[XavierFiestaUploads]

The wording @2:05 could have been better: People might get the impression that the universe is expanding in the same way a bomb explodes when in fact the universe is expanding everywhere rather than from a single central point (the Big Bang is an explosion of space not an explosion in space). Amazing video as always though!

[robertlee]

We have not “known the Universe was expanding since the 1920s.” We’ve known since the 1920s the Universe was expanding.

I don’t understand physics but I do understand syntax.

[loqkLoqkson]

I've found that the bit people miss about light stretching is the elemental absorption and emission lines signatures.

When we say that light is stretched, It is dismissed because how could we know?
Once I explain chemical signatures first, and then explain how they are stretched, people understand how it works, and how we know the light is stretched. if you skip this bit, young earthers just ignore you since your argument doesn't make sense.

Please start discussions on light stretching with spectral lines to show how we know light is stretched. When we say the light started blue and now it is red, we just get ignored, because, maybe it started red.

The rest is really good :-)

[michaelnye]

You did an excellent job of making a video suitable for so many ages and intelligence ranges. Well done!

[ndumisomlokoti]

Hold on. I'm too stupid for this, but riddle me this:

If I'm standing at the 100m dash start line with Usain Bolt. And another man is standing at the 50m (halfway) and another man is standing at 80m (80% of the way). This means the man at 80m is older than the man at 50m and their older than Usain, who's at the 0m mark.

But this depends on my vantage point. If I'm standing at 45m point, then from my vantage point, Usain - standing at 0m - and the person standing at 90m are the same age.

I swear I'm not high. Please can someone help me make sense of what I'm tring to ask; how do we know that our vantage point is the centre of the universes expansion? Ugh. Compressing an idea or thought into words is difficult. Especially if it's not your mother tongue and especially if the concepts you're trying to express do not exist in your mother tongue.

[adheeshb]

Our universe is a marble, in a bag of marbles. Just ask the men in black 😎

[danalaniz]

Very good and clear explanation. Thank you.