What are some of India's best contributions to the world?

Very few Sensibly attributable things we can claim as the initiations of this (geographic) sub continent except empathy, Yog, Aayurved, Vyaakaran (grammar) Rural and urban planning.

Some other not in limelight but significant are as follows

1. Wootz steel.
2. Living without fear.
3. Concept of Karmvad
4. Dignity to women folk
5. Controlled sexual behavior.
6. Peaceful sustainable life style.
7. Values for Sustenance of the family.
8. Transmutation of sex in greater pursuit
9. Systematically living in the territory of abundance.
10. System of governance based upon egalitarian justice.
11. Trade practices interlinked with social responsibilities
12. Way to achieve self actualization without harming others.
13. Increasing immunization via maas pre planned activities.
14. Lifestyle wholly dependent upon agrarian system of economy

Initiation: from 2000 generation

Circle of influence: 50 generation back, sporadically till now beyond the circle                              215,301

Also see

In 1835, even Lord Macaulay, the British historian and politician had to admit before the British Parliament: “I have travelled across the length and breadth of India and I have not seen one person who is a beggar, who is a thief. Such wealth I have seen in this country, such high moral values, and people of such calibre… the very backbone of this nation, which is her spiritual and cultural heritage…..”

Source: page 1

http://planningcommission.nic.in...

Wootz steel was the pinnacle of Indian science & technology which has not rivaled by anyone of the world till 1857

For Concrete evidence to support it; please do read

What was the significance of Wootz steel in the world economy?

We can also listen one foreigner in this video about scientific advancements of India.

Science and technology in Ancient India: What are some of the science related inventions done in Ancient India which we still make use of?

1. Maavadu, Achaar or pickle which kept us healthy in our long sea voyage (several millenniums before invention of the vitamin c)
2. Production and trade of ornaments, necklace, by drilling, polishing of precise stones, pearls etc
3. Curing toothache by drilling cavity in them to fill medicine or remove cause of ache (in Mehrgarh it was proven archaeologically several millenniums ahead when rest of world still living in Stone Age.)

Image courtesy: Indus Valley Civilisation

List will go endlessly but it would be better to understand the process and motives behind the achievement in place of just bragging loud mouth.

What are some bigger secrets of Vedic Life of Ancient India?

Here are few pertinent questions we have to answer first.

1. What we meant by some bigger secrets?
2. What was Vedic Life?
3. What were the geographic boundaries of Ancient India?
4. Is Vedic life restricted only in Ancient India?

Now we take one by one the questions to answer.

1. What we meant by some bigger secrets?

• Any which secret is big until we do not know cause behind that secret.
• The moment we know it; it automatically lost significance of it.
• Just like before seeing the movie secret

• we do not know how to get success quickly?
• or take another example.
• Until we do not know the volume of water increases when it freezes; bursting of iron pipes or burning of green shoots or even entire crops was just a mystery.
• Or till we do not know volumetric expansion of water we do not know the cause of ballooning of Roti, Bhature or Poori as soon as she got the company of fire.
• So my answer would look like just common sense here as per our previous knowledge because we know very well the causes of them.

2. What was Vedic Life?

Vedic Life is only application of “Karmyog” and was governed by the utterance of words (truly experienced by oneself) with supporting hands on experiment just opposite to modern day practical which lack verbal communication in the so-called disciplined environment of our school or college.

3. What were the geographic boundaries of Ancient India?

• Here the question in itself contradictory because in the Vedic period there was not any geographic boundary which could be identified as India.
• To understand formation of India Take an example
• In a water pool one person is bathing.
• Another guy came from the outside and addressed the bathing guy by the name of Nanga
• Another outsider came, first outsider introduced to second the bathing person as a Nanga (which is what at that time he was)
• Now consider after few minutes when the bathing person came out of pool robed in his attire but both the outsiders still referencing him as Nanga (the name given by them)
• The birth of the name Hindu is happened just like that.
• When some pirates came across the Sindhu Nadi they addressed the people across the river as Hindu neither the person in pool know the meaning of Nanga nor the people living in the subcontinent knows about the name of  Hindus then Indus then India

4. Is Vedic life restricted only in Ancient India?

• The so-called Ancient India was never the boundary of restriction of Vedic life. Our brothers who adopted nomadic life has got by hearing (decoupled by hands-on-experience) the utterance and chanted them aimlessly just to fill their boring nomadic life thinking it has some invisible powers.
• They were the early adopters of Bhaktivad.
• In this process the verbal part of knowledge reached up to Siberia, Germany and all the Asia, Europe.
• The people living across river Sindhu in the subcontinent were mostly adopted agrarian system of economy (dominated by concept of Karmyog.) The persons who came Crossing River Sindhu were the mentality of pirates (dominated by concept of Bhagyavad).
• If we call a person in the name of Nanga in above example what it has any significance after a few minutes out of pool?
• Same is happened with Bharat Varsh in the name of Hindustan, India.
• Varsh is the monsoon cycle of global voyages. That was the natural boundary of people knows something about Vedic life.
• Because of this we found a lot of similarities in archaeological findings in most continents.

Now we come to our primary question

What are some bigger secrets of Vedic Life of Ancient world?

1 One most important secret was the inherent ability of copyright; lacking any chance of corruption and misrepresentation.

• All the knowledge flown via parents to kids’ generation after generation coupled with hands on experience (evolved in real-time).
• Because of that we never cared about scripting anything but owning best of best ecologically sensitive technologies in our common folks.
• The cause of our wealth was the hands-on knowledge of our ecosystem not copy of foreign things or piracy of them.

2 Second most important secret is the absence of scriptures. Vedic Life was first priority of folks living and adopting agrarian system of economy while second priority for the people adopting nomadic system of economy. In agrarian system of economy relevance of knowledge is based upon up to date evolution of microclimate not mass generalization of concepts like in pirate culture of economy.

3 Third most important secret was gene pool diversity. In the agrarian system we learned the importance of it. Because of that we have the culture of “Atithy Devo Bhav” we always welcome new verities of species, thought, people with open heart. Because we know it will increase oursustainability, our biodiversity, our wealth of new perspective.

4 Fourth most important secret was absence of fears We have not the mentality of paucity which was the root cause of fight, we has abundance of wealth created by our adherence of Karmyog (knowledge coupled by hands-on-experience was the gist of Ved which is foundation of Karmyog )

Because of that in entire Indus valley civilization

Image courtesy: Indus Valley Civilisation

we found not a single sword. Because we believed in welcoming of our guests, we were not fearful from them.

Because of it we never mind to build any which fort to protect us from enemy. The advent of pirate culture of economy triggered wide scale construction of forts in the world.

Indus script

• All the scripture things are the inventions of nomad system of economy and flourished in presence of pirate system of economy.
• Scriptures has no value in the agrarian system of economy.
• As the Indus valley civilization belongs more to agrarian system of economy finding any meanings of the seals is just futile venture for pirate mentality people.
• In current era when so called graduates accepting they do not know the language of this era how in sane mind one can ask to a passerby central Asian or European carvan about any communication with language or scripture.
• It is so simple then to identify things with picture just like depicting what is inside the sealed container.
• The portion of seal with bigger image just tells what is inside and the small images show what is acceptable in barter of that material from the receiver of the container.
• Today in India we can find ordinary shopkeepers keep their representative trade items just in front of their shop or community. Or put upon signboard the images of their merchandize.
• Archeological findings are just certificates of failure of mankind in the sense they missed the arrival of catastrophic end of their habitats.

Human Evolution

• In the human evolution process first we were hunters just like pirates then we domesticated animals became nomad. 
• Further in evolution cycle we invented agriculture from our observations during gathering habits and became agrarian folk.
• So in human advancement agrarian system of economy was the zenith of sustainable systems.
• While in nomadic life or pirate system of economy fear, uncertainty and doubts are predominant motivators for taking any action.

Which food item cannot be adulterated and is healthy for us?

• In the detail section affirmation of the possibility of adulteration is in itself a proof of the least probability.
• But here is an antidote of it.
• We have lot of sages living in Himalayas (Tibet) eating fruits plucked or picked from the canopy of trees, shrubs or herbs.

Image courtesy:Mahavatar Babaji

1. Really very small amount of food require sustaining a healthy peaceful life in India.
2. The Secret is harmony in thought and physical activity of us. (Which called Yog)
3. The moment our energy intake and off take synchronized with the thought process of abundance, peace,purpose fullness of one’s life (strictly in positive direction) our requirement reduce substantially.
4. To keep body in perfect living condition in peaceful environment very little energy actually required.
5. This could easily be taken from the sun, the fresh aromatic air, water, naturally grownup herb, shrub, trees etc.
6. The moment artificiality start dominating our thoughts; glands which secretes various hormones in our bloodstream becomes hyperactive to mitigate the situation (of the ecosystem)
7. Just imagine when you become in charge of a large stock of your favorite dish to be distributed to your beloved mass for entire day at some auspicious occasion.
8. Despite it is your favorite dish the quantity and responsibility makes you so much so satisfied that even without gulping a single piece you become completely satisfied provided the process of f its distribution go smoothly.(this is the power of abundance)
9. The moment we accept the abundance in our thought habits which called in yogic language Dharana or replace physical equivalent with strong thoughts which called Pratyahar even poison provides necessary energy to survive ( condition is we already travelled the yogic path all the way from Yam, Niyam, Asan, Pranayam, Pratyhaar, Dharana to Dhyan)
10. In conclusion it is not the physical adulteration but environmental adulteration which includes our thought process, eco system {which is again nature, era and situation} affects our wellbeing.
11. Just isolating oneself from the artificiality of everything gives tremendous power to survive (that’s preexists in our DNA called as survival instinct)
12. So positive thoughts and purposeful life are only at our disposal as the right kind of energy source for our survival. This same item on Earth cannot be adulterated and is even healthy for us?

From Kush Tripathi's answer to Are there yogis in the Himalayas who are thousands(or perhaps hundreds) of years old?

If the life sustaining mechanisms are kept healthy and if the process of cell renewal is kept intact, a human being could be kept alive for an infinite time. Genes are immortal so there is no inevitability of bodily death.

Our physical body is nourished by blood. The latter provides oxygen to the entire body. Oxygen and other nerve fluids sustain consciousness in the body. All this is accomplished through emotions. It is the thoughts and emotions that give rise to secretions of hormones. These hormones control the metabolic processes within the body. Therefore, it appears that the responsibility of keeping the body healthy rests with our emotions and thoughts which are the real essence of life.