Your core is a filament for energy flow.  It is a column of light.  This column can be as thin as a gossamer strand, or as wide and magnificent as you create it and empower it to be.
 
The ancient yogis called this strand of light the sushumna nadi (sushumna = she who is most gracious, nadi = stream or flowline).  This central nadi is the main flow line for the energy field of your body.  It is the major central river of life of the human body.
 
This central channel works a lot like the wire filament of an incandescent light bulb.  The more prana/energy/electricity you pour through this filament, the brighter your light shines.
 
The doorway to your core is your belly, your navel and solar plexus.  Bring your attention into this core door (your upper abdomen) and access this central light channel.  Do this by feeling your skin and surface of your belly (with a helpful notice of your breath moving the belly, or the feeling of your clothing on the skin there).  Then take your attention into the depths of your belly, deep deep into the core location of the spine.  Once you “hit” the central channel you will feel a “zip” line of energy awareness from tailbone to top of skull.
 
Run your breath and your attention down to the tip of your tailbone as you breathe out, and up to the crown of your head as you breathe in.  Get your life force flowing in your central channel.  Turn on your inner light bulb!
 
Connect again to your core, your soul center. 
Then make a connection from your personal human body core to the core of the earth body.  Run your energy down through the soles of your feet, through your energy roots, deep into the soil of the earth, through groundwater pockets and bedrock, through layer after layer until you feel warmth.  This warmth leads you to the molten core of the earth.  Breathe in this liquid fire light, and offer your inner sunlight and warmth back to the earth in a feedback loop, belly to earth core.  Once you get that running, make an intention to connect with both the solid iron inner core of the earth (for strength and stability, for magnetic spin).  Then make an intention to connect to the crystalline core of the earth (a geometric lattice work of crystalline light).

Keep running this loop of your body core to earth core with every breath.  Keeping that connection, extend your awareness up up up to the sun.  It can help to reach your arms overhead and/or cast your gaze upwards.  With open arms, call in the light and warmth and full spectrum light from the sun.  Pull it with each inhale into your belly, and with each exhale extend your inner light up to greet the incoming sunlight. 

Visualize and feel a huge column of light, from earth core, through and surrounding your body and up on into the sky and extending up to the sun. Step your feet a bit wider apart and open your arms a bit wider than shoulder width.  Visualize this as a magnificent column of light, with swirling energy flowing up and down and all around in flow.

Though these instructions are detailed and your first few times of doing this may take a bit of time to focus on, once you get the hang of this it can be done in a quick instant at any time anywhere with your attention to connect to core, earth core, solar core and invoke your light column.  A quick easy fun way to raise your vibration and increase your light quotient!

Light is information. It is knowledge.  It is a stream of photons, bundles of energy.  It is a wave, a flow, a river of data through time and space. Most likely the computer you are reading this on is powered by fiber optics, signals transmitted by light.
 
Light codes are just that, information & energy transmissions.  We get light codes daily from the sun.  We get light codes reflected off the moon, off the waters and clouds.  From raindrops and rainbows.  From the stars and planets.  There are particular astronomical alignments that place the earth in just the perfect way to receive light code transmissions from within our solar system, from other stars in our Milky Way galaxy, and from further away - near and distant star systems and galaxies.
 
Light is produced by two methods, emission from something hot (incandescence) or from an electron descending from an excited state back to a resting state (luminescence) to produce a photon.  Light descends from the sun, from the stars via photons to us here on earth.
Ascension is the “on purpose” act of us reaching and rising up to meet the descending/incoming light.  
It is our human cells raising their vibration to meet the incoming stream of photons to match their frequency.

Ascension happens individually for humans, collectively for the human collective consciousness.  
And the Earth, as an aware alive being also undergoes this process.
It is a choice, moment by moment, day by day to vibrate higher, to reach up to receive the light.