image-of-gravitational-lens

Here be dark matter! (Image credit: NASA, ESA, E. Jullo (JPL/LAM), P. Natarajan (Yale) and J-P. Kneib (LAM))

In, say 1975, there was only one kind of ‘stuff’ in the Universe, matter made of protons and neutrons. By 1985 there was a consensus that this was not enough, the gravity of the stars in galaxies was not sufficient to hold them together. Something else was there, vast, mysterious and imperceptible, only observable by its effects on its surroundings. Imagine HG Wells ‘Invisible Man’ moving unseen through a room until he knocks over a vase. There was much more of this dark matter out there than stuff we could experience directly.

By 2005 it was clear that there was more going on out there. Another unseen and unknown something was pushing the galaxies apart. This is dark energy, a force which permeates all space. Astonishingly weak, dark energy can still move galaxies given aeons of time.

No one knows what dark energy and dark matter are; researchers study the light of far off galaxies to see how these elusive quantities effect them. The image shows the galaxy cluster Abell 1689, light from distant galaxies is bent by the gravity from galaxies closer to us but on the same line of sight creating a text-book example of a gravitational lens. This gravity is mainly, we now know, exerted by the dark matter in the galaxies (the blue fuzz in the image is not real, it is a superimposed map of matter distribution). At the same time, however, dark energy is pushing the galaxies apart adding a subtle additional distortion to this ancient light.

Dark matter and dark energy are utter mysteries today but so were electricity, magnetism and radioactive decay once. In some future time we will understand dark energy and matter just as well. Dare I speculate that one day we shall apply them? (I’m holding out for spindizzies myself.)


5 Comments

Keshav Dayal Singh Kaushal · May 28, 2016 at 09:14

Is it this dark energy/matter that is termed Krishna, the ultimate cause of growth/expansion?

Kaala and Kaalee also means dark only.

Time seemingly can be equated with this darkness wherein shining creates visibility, movement the tangibility and understanding the bliss.

In fact, this is the limit of knowledge for human neurons.

    Keshav Dayal Singh Kaushal · May 28, 2016 at 09:29

    The human neurons today need to decipher the way, the centers of the spaces keep becoming universes/multiverses to be engaged with endlessly.

    How the dimensionless central points are perceived to be ever-expanding in infinite space with mind to experience within and without is really marvelous.

    Still, we are not able to fulfill the needs of even the humans or do not consider/perceive the need

    admin · May 31, 2016 at 07:43

    Dear Keshav, thank you for your comments. You ask

    Is it this dark energy/matter that is termed Krishna, the ultimate cause of growth/expansion?

    I am afraid the answer is no, you are taking a piece of astronomer’s jargon and interpreting it too literally.

admin · April 28, 2011 at 19:51

Some times ‘Dark Matter’ is real, remember Neptune!

Mike Tittensor · April 26, 2011 at 21:04

Dark Matter, yes, from the same school as the luminiferous ether, a balancing factor in physics equations. The worst example of this I ever saw was in some calculations for the effect of a cometary approach insystem whereby a historical record of a comet was deemed to be the one under study and the mass loss needed to balance the equation was declared to be the loss. It kinda worked until the question was raised “How do you know it’s the same comet”?

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