Space investment: Electronic miniaturization.

Indoor toilets and hot running water

Hitler and trump

Medical advances. When I was young, the term exploratory surgery was quite common. Major surgery to open you up to see if whatever problem you have might be something major. Think about that. They can now look at you down to the cellular level. Think about that.
When you really get down to it, it is the computer chip and the advances made in that science which has made the internet, medical scanners, and thousands of other things we take for granted possible.

Internet...

I have to say the advance of medical science. Cardiac treatments in particular. Scanning for breast cancer. Patients recognizing that their doctors are not gods and that WE are our best patient advocates.

Stem Cell research

it may not be cultural but i have to say the destruction of the middle class.
the 1% keep taking a bigger slice of the GDP pie & wealth & income inequality are the widest since the great depression.
sadly, the electorate somehow allowed this to happen.

Fifty years of hateful Right Wing rhetoric which has resulted in the destruction of the middle class and widespread corruption in politics as well as convincing the population that it's ok to give generous tax breaks to the billionaire class while shifting blame for societal ills on immigrants and foreign countries. And of course both parties serve their corporate donors. True statesmanship is a relic of the past.

rampant unfettered consumerism

practical application of transistors and modern electronics

It is the breakdown of a sense of community our towns, cities, states, and country. That breakdown is due to two things. First is the growing power of special interests with no interest in maintaining the workability and viability of the local situation. The focus of that special interest may be political and/or religious ideology, and/or personal privilege and profit.

Second is the corruption of our political process led by Newt Gingrich, Tom DeLay, Dick Armee, and Mitch McConnell. That team made ideology, not results the focus and turned politics into a win-lose blood sport. Then teaming with the special interest, they are deliberately destroying any real sense of community.

The internet and how ubiquitous it has become in our daily life...... just pull the plug as a thought experiment and see how your life would work without any of the services Internet provides now a days.

Seriously? I think it's the exposing of DNC chicanery and the Wikileaks revelations in general. Establishment Dem warmongering in service of their corporate masters is an idea whose time is long overdue for the dustbin of history.

This sets the stage for a sea change. I hope we're up to it.

The tiny steps taken towards female equality .

email and texting. Faster and cheaper than snail mail without the "right gosh darn now" element of a phone call.

I like to think it's the intellectual dark web.

My vote is going to social media.
However, it has not been "significant" in a good way.