The Gayatri Manttra

One of the most popular and the most widely chanted of all Vedic Mantras seems to be the Gayatri Mantra. Of course by now, it is commonly known that chanting of mantras or even Om has deep effects on the body .(this article is going to be a bit long so read it with a lot of patience as explaining a mantra and its effects are not so easy.)

OM BHUR BHUVAH SVAH
TAT
SAVITUR VARENYAM
BHARGO DEVASYA DHIMAHI
DHIYO YONAH
PRACHODAYAT.
the meaning or interpretation by the arya samaj:

Aum = The sacred syllable Om, identified with Brahman, the immanent reality and with the Hindu trinity (Lord Bhrama, Vishnu and Shivji)
bhoor = The base of the universe. The Sanskrit root 'bhu' means base, ground etc.. Thus, bhoor is the base of the universe, or the Netherworlds as used in some interpretations (see Ram Mohan Roy below). Together, bhoor-bhuvah-svaha constitute the early Vedic cosmos.
bhuva = Earth
svaha = Heaven
tat = That
savitur = Savitr's. Savitr is a name for the Sun, but specifically for the rising or setting Sun.
varenyam = Supreme/Excellent
bhargo = Radiance/ Splendour. The root word is 'bha' meaning shine. Other words derived from this root include bhaskar (sun) and prabhat (dawn).
devasya = Of the Deity (Savitr's). Here, 'deva' means deity and 'sya' is a possessive suffix.
dheemahi = we contemplate
dhiyo = Intellects (Plural of Dhihi = Mind or the intellect)
yo = Who
naha = Our
prachodayat = Awakens, rouses, inspires. 'Pra' is a prefix, the root 'chod' means drive, inspire etc. and 'yaad' is a causative suffix.

"O God, Thou art the giver of life, the remover of pain and sorrow, the bestower of happiness; O Creator of the Universe, may we receive Thy supreme sin-destroying light; may Thou guide our intellect in the right direction." Thats the interpretation by the Arya Samaj.

Now, the effects of the Gayatri Mantra ,:-The balanced qualities of the Mantra:The Gayatri is a perfectly balanced mantra, almost akin to the chinese yin and yang. The body or text of the Gayatri Mantra is feminine, and her message or invocation is masculine. Gayatri is the mother of the Vedas and this means the mother of all knowledge. She appeals to the masculine Savitur, which is said to be the radiance of perception and intelligence. This radiance, which is everywhere and in every experience, is likened to the radiance of our solar sun. In other words, all of the knowledge of the intricate ways of existence is contained within the syllables of the mantra and so too is the means and vehicle with which to go beyond knowledge as well.
Gayatri Mantra's vibrational influence on the physical body.
Silently thinking or speaking or chanting the Gayatri Mantra influences the physical body,i.e Our energy centers, levels and rhythms are activated by the measure of breaths that are drawn in through the nostrils and released during recitation of the Gayatri Mantra, (even during silent repetition clears the emotional body, leads one to the inner heart. The Gayatri stimulates and facilitates insightfulness and awakening to the Truth within all.
(even during silent repetition). This balances electromagnetic rhythm and energy currents in the body with prana. Prana is an undetectable life force energy. During recitation, all elements of the mantra are in use; even the breath is a precision instrument. It all works together, like an orchestra and the Conductor. The breath, voice, meditation and intention efficiently and effortlessly function (like the sun shines).
The Vedas are ancient (from beginning-less time) scriptures that reveal the secrets of life and the way to live it in accord with the entire universe. Not only the well-known chakra system but all energy and rejuvenating centers are activated by the sound of the Gayatri.
The mantra works in a multitude of ways, which align the energies, magnetic currents, biochemistry and brainwave patterns on a very subtle level. Immediately or in time, one will notice the wonderful effect.
By chanting the Gayatri Mantra, the mantra itself reveals the teachings within it. The Gayatri is flawless and whole. The Gayatri Mantra regenerates unobstructed perception in the same way that crops are renewed. For example, wind carries seeds onto the terrain. In time, wild flowers and wheat inherit the fields. Again and again an unobstructed flow, season after season. The earth propagates her released seeds and in turn the seeds flourish and produce another generation. The mantra works like that. Gayatri's meaning is the good season that prospers the Earth. Fruit comes forth again and again. Gayatri is like the power in the sun. How can we really speak about such a thing, is it comprehensible at all? Any definition that you hear can be compared to one grain of sand upon infinite shores. A definition can never indicate the immense significance and intensity of this mantra.
I feel a kind of magic chanting the Gayatri mantra which is in the all powerful Sanskrit Language(infact most of the vedic mantras are)
Remember that this explanation is not even a fraction of the profound possibilities lying in the secret recesses of this mantra. The Gayatri Mantra aligns precisely balanced energies, unobstructed and distinct, to generate currents, which act like lasers. Intoning a true pitch, word and meter (Sanskrit) translates sound waves, one retrogressing into another. You can visualize a still pond and as a pebble touches the surface on its way to the bottom, rings are formed. If you watch these rings for a while you would see them moving out and in at the same time. This is an illustration and not truly the pattern of Gayatri's yantra but it gives you an idea. The mantra's potency becomes more and more rarefied until it reaches a frequency that carries the inherent message within the mantra to its proper place. These sound vibrations are encoded in electromagnetic waves. They rarefy to finer and finer frequencies until no frequent vibration or information is detectable. Though no frequency is detected, information is still present (like in the case of homeopathy) on the subtlest level. The more refined the mantra frequency moves into the field of sound, the greater its power. This is true for enlightenment as well. A very subtle perception can powerfully awaken you to the "Truth". The Gayatri's message speaks of being deeply focused on that which illumines the whole of consciousness, and ultimately realizing enlightenment. Its reference is plural and impersonal. The mantra when chanted properly is indeed magical. It's a beauty. It is a joy.

Not only this, but recently, His Holiness Sri Sri Ravishankarji has also explained how the chanting of the Gayatri Mantra affects the vertebrae and the chanting ofecah syllable of the Mantra has an effect on each of the vertebrae.