I think the most significant discovery ever was the speed of light and the light bulb was the greatest invention.
What do you think will beat these?
Eg:
A discovery about sub-atomic particles that we can prove and utilize in some way.

I think that probably fire that the biggest discovery. It was a huge step, using it for protection, heating, food, and other usages. And you had to be brave to approach it and dare to try to use it.
I think that the biggest invention is writting and then the book. By writting you could fix "in hard" what you knew in order to let know others and make acquirig knowledge considerably quicker. Imagine if each genertion had to "relearn and rediscover" what has been done before. And in this process the invention of the book was also a huge step allowing the knowledge to spread. Now with Internet we can find information on anything instantly and learn at a very high speed. But everything started long ago and the original invention was phenomenal.
I think that fx-trading-education is right.
I think that writing is the biggest invention without a doubt. Writing allowed us to share our ideas with more people, and allowed them to build on it, re-write it and pass it on to the next person. Without writing we would not have ANYTHING that we have today.
In modern times, surely the transistor and integrated circuit are our most important inventions. These were invented in the past 50 years and have allowed us to do things that would've been unthinkable otherwise.
I think that the next major inventions will be in the area of energy generation and storage. I think that our biggest impediment in terms of technology at the moment is energy. If we can harness the right energy sources efficiently, we will be able to do some incredible things. I'm not just talking about renewable energy either. I'm talking about energy storage for portable devices, harnessing energy so that we can have more viable electric cars (which will lead to - i think - more creative forms of transport), and energy sources that could potentially help us venture further into space than we can fathom at the moment.
There are many things that we could theoretically do... if we had enough energy.
Sliced Bread!
Haha, but actually, maybe fire?
I think what will top that... Grand Unified Theory of Everything?
Why would the GUT top fire or writing?
It may help a few smart guys to understand the beginning of the universe or something like that. But it won't use us normal people. Like the theory of relativity and the theory of quants has no real use to us.
I don't know what's the greatest invention. There are so many. Like medicine, clothes, electricity...
And I don't know what could be come to be better in the future, because is unpredictable.
Maybe something that we would find great, but isn't so great after all.
I have to agree with Richard that the invention of cheap power is needed most and the current cost of power is a big impediment. Just think how much of our money goes on using an internal combustion engine to get around and what about the power necessary to run keep your home warm and cook food.
Come on brainy people you could do better with the inventions and help us less fortunate mortals.

Critical thinking.
Nothing will top it!
Not really a discovery haha
liljp617
but wot is your idea

Wheels are among the greatest inventions too.
Wheels help us save time.
Wheels make up pulley.
Aeroplanes need wheels to land.
Some trucks have 18 wheels.
Think about it.
| chasbeen wrote: |
liljp617
but wot is your idea  |
I think his idea is "critical thinking"...
| profbis wrote: |
Wheels are among the greatest inventions too.
Wheels help us save time.
Wheels make up pulley.
Aeroplanes need wheels to land.
Some trucks have 18 wheels.
Think about it. |
THat is a very good point. Without the wheel there are so many things that would not be possible. There are many tools which use wheel-like components. Remember the old computer mouse with the ball in the bottom? Inside those is a set of wheels to track how the ball moves.... NOt possible without the invention of the wheel...
Even before writing, I would have to say language was the greatest invention of human kind. The ability to express abstract ideas beyond "Ug hungry" is what allowed us to develop all the other wonderful toys we have now.
There are some studies that have shown that without language we would not even be able to think in the way we do, without the ability to express complex ideas we couldn't form them. One of these studies was done with feral children, cases of extreme neglect in which children grew up without being taught to speak. In many of these cases the children, even after receiving proper care and education, were never able to function mentally to the full degree that may have otherwise been capable of.
http://www.feralchildren.com/en/showchild.php?ch=genie
Also, there was a recent Discovery Chennel documentary about the phenomenon, but I can't find a link for it.
May be a greater discovery is yet to come. May be a clean and efficient energy source which will fulfill the world need will be the greatest.
Metal Freak
Maybe that would be the most beneficial and would be the greatest invention since the rocket. But would it be the greatest discovery ever 
I always thought elevators were the greatest invention of all time. Wouldn't want to climb all them steps all the time. Without elevators, there wouldn't be skyscrapers, but then again, the whole world would be a lot healthier and fitter. haha.
| chasbeen wrote: |
Metal Freak
Maybe that would be the most beneficial and would be the greatest invention since the rocket. But would it be the greatest discovery ever  |
Anything that propels human survival is a "greatest discovery ever."
I would agree that the greatest invention of mankind would have to be language.
The greatest discovery would be that of agriculture in the stone age. Without that, there would be no bass of survival. How long could they keep hunting down animals?
| _AVG_ wrote: |
I would agree that the greatest invention of mankind would have to be language.
The greatest discovery would be that of agriculture in the stone age. Without that, there would be no bass of survival. How long could they keep hunting down animals? |
I would argue a bit on these 2 things
I wouldn't say that language is a discovery. Language is a way to express yourself that in my opinion exists as long as you have the ability. For instance anymals have there own language but I wouldn't really say that dogs have discovered how to bark. Do you see my point?
Otherwise you could also say that "thinking" is a discovery but it is not.
About agriculture I would classify that as an invention not a discovery Because the agriculture didn't exist before the invention (not like fire or electricity for instance that always existed but then people discovered how to use it). Of course plants were always growing but for me agriculture is more the organized process of making things grow in a more efficient matter, like for instance you will select what will grow and not just pick what you find.
I think you have to first define what's meant by greatest invention.
Fire? Yeah that helped survival rates and metal/glass making, mainly seperated us from animals, that's about it not much since.
Reading/writing was around for a few thousand years without accelerating mankind much.
Discovering the speed of light is an interesting sidenote in history.
I have to vote for the transistor as the greatest discovery of all time. It has accelerated exponentialy all other advancements since then. It led to practical computer technology. Very few professions are unaffected by computers.
The thing that will surpass the transister as the greatest invention will be a practical application of quantum physics. Something that takes advantage of dimentional duality.
Come on guys......
What's the one thing we love the most..... computers, houses, plumbing, food....
Oh yes, fooooood. Good o'l the best discovery has to be flour, which leads to bread, which leads to my happiest taste buds 
Agriculture. I don't think anything will top agriculture. Without agriculture, we would still be hunter and gatherers... so basically we would have nothing without agriculture. We owe everything to agriculture.
The written word. First by hand in stone, then by hand on paper, then printed on paper and lately electronically. Ability to write down and store information. To calculate, measure and expand in the writings, formulae, theories, counter theories.
Well, you have to ask the question. What is the most useful. I agree with the above post with the writing and storing information thing.
But I'd have to say the biggest invention recently, would be the Large Hadron Collider. If everything goes to plan, I would say that some very important discoveries could be created there. Medical advances, scientific discoveries. Many unknown things could be discovered. We'll have to wait and see 
i think "the invention" of the modern century is the electricity, cause the industrialization was only on of the consequences...
The most important thing is wireless transmission of electricity
when will it come?
I would think the biggest invention since the light bulb has probably been the computer. It has changed the way the world works hugely and has allowed us to up the ability to communicate and conduct scientific experiments hugely. The biggest invention ever? Probably language if you can call it that.
There are a lot of inventions in the history of mankind
But everyone that came into being because of necessity and that served the purpose of life is a good one and the importance is relative and we cannot possibly say the best one
The periodic table of the elements and the genetic code.
Those are my inspiration...
The wheel was certainly the greatest invention ever ..... so far.
The greatest discovery was Einstein's E=mc^2.
An future invention to top the wheel might be a virtually endless supply of energy from nuclear fusion, or perhaps a cancer cure.
A future discovery to exceed all discoveries would be the discovery of extra terrestrial intelligence.