The Limits of our Knowledge

There is much in the universe we will never know, and it is equally certain that we will never know all that we do not know.

A lecture by Joseph Silk, Gresham Professor of Astronomy 22 May 2019

There is much in the universe we will never know, and it is equally certain that we will never know all that we do not know. This dilemma has not stopped cosmologists, philosophers and even theologians from exploring and going beyond the limits of space and time.

[jamesflynn]

As a layperson, thank you. This was excellent!

[rareword]

"What guaranty does the knowing subject have that his models of reality reflect reality itself. Inasmuch as, in an exclusively theoretical science, the only contact that one has with reality is afforded by means of one's knowledge, the problem seems insoluble."
Immanuel Kant,

[calotcha]

To understand anything we must go beyond man's conventional mind - and that includes science itself which is limited to our logical, linear thinking process. Without restriction, we must allow our intuition, if we are to reach outside our human limitations.

[mickymantle]

I don't have to share this but I will. I witnessed an alien craft back in 2008 above Nailsworth, Gloucestershire U.K. This craft hovered and took off at such tremendous speed...it was beyond reason. Aliens are definitely here !!

[vcoonrod]

Extraordinary. Thank you for such an interesting presentation!

[stevesayewich]

Thank you for your lecture. I needed the review. It has helped my understanding.

[doctorartphd]

Thank you for sharing this presentation.

[Smartion]

What a beautifully delivered .. and quite frankly honest lecture! ... Plenty of food for thought :)

Thank you :)

[bentonpix]

With respect to infinity, ALL possible points are legitimate centers, including the human being. So it's no wonder that we've felt like we're at the center for a long time, because on the grandest scale, we are.

[MidgetMalone]

I think our knowledge is like a puzzle. At a certain point the whole shows itself and everything falls into place of course, we are far from there. We just have a drop in the bucket and yet are convinced we have it almost full.

[MountThor]

Actually the quote is from Werner Erhard decades prior, Rumsfield just repeated it during a press conference without giving credit and everyone mistakenly attributes it to him.

[gariusjarfar]

Faster than light is where the thinking mood is at.

[davidwilkie]

Static-> metastable-> poised for change.., same actual mechanism that is the visible cross-sectioning navigation mapping of the holographic image projection drawing, Observable Universe.

[virvisquevir]

We are not geared for truth, we are geared for survival.

[trevormendez]

Let us be honest the name of this program is what we can and what we cannot tell you

[shannonchuprevich]

Never knew Lemaitre thought up "dark energy". I have a hunch the he considered the possibility that space itself is the base of all mass. Energy would just be a form of this space mass under massive pressure that divides it, gives it direction, and a spin. The same force that forged atoms and gravity will gain momentum despite how much energy our universe has concentrated, conserves, and radiates.

I suppose the notion of considering space as an infinite area would turn off many physicists, considering Einstein's reaction, YET, here we are berthed from an infinitely dense moment.

[examplerkey]

The whole antimatter theory and research falls apart if one gives a tini tiny amount of mass to the photon! Let it sink in.

[howardhdavidson]

Looking out into space is the same as looking into a living creature or ourselves size is irrelevant.We are so limited in our knowledge, as a fish living in water.

[TSulemanW]

Nicely explaination. Invisible is difficult to see

[ivtch]

Lol. I think this "Unknown" saying attributed to Rumsfield actually predates his saying of it and is put in a more graceful form of prose. I am paraphrasing it here from my memory many years ago. It says: "There are things we know we know... and there are things we know we don't know which are far bigger (in quantity)... but there are things that we do no know that we don't know which is way by far the biggest."