Register to reply

Could gravitational lensing prove the universe to be older?

by TerryHM
Tags: gravitational, lensing, prove, universe
Share this thread:
Jan11-14, 10:08 PM
P: 5
This is only my second post and I am a novice. So please excuse me if this is a naive post.

Gravitational lensing around galaxies shows more distant galaxies hidden behind them. We estimate the universe is 13.8billion years old because that's the limit we can observe into 'the past'.

My question is this.

What if we were to look at the furthest galaxies for gravitational lensing? As the light we are observing has already travelled to the point at which we are observing the lensing effect. Is it not possible to show the universe is in fact older and bigger?

Is this a stupid question or a genuine possibility? Either way, an explanation would be appreciated
Phys.Org News Partner Astronomy news on
The Great Debate over whether the universe is small or large
Smallest known galaxy with a supermassive black hole found
Mystery of rare five-hour space explosion explained
Jan11-14, 10:29 PM
Sci Advisor
PF Gold
Chronos's Avatar
P: 9,495
There is an observational limit to the universe called the surface of last scattering. EM radiation more distant/ancient was trapped in a plasma that occupied the entire observable universe. That plasma persisted until the universe cooled enough to become transparent. We know when that occurred [about 13.7 billion years ago] and will never see anything older than that in the EM spectrum.

Register to reply

Related Discussions
Gravitational Lensing vs Gravitational Microlensing Astronomy & Astrophysics 1
Gravitational lensing Astronomy & Astrophysics 3
Gravitational lensing Special & General Relativity 1
Gravitational lensing General Physics 0
Gravitational Lensing Special & General Relativity 1