Hello, San Francisco. I can't believe this crowd. Seriously, I can't believe that we have to come out. Now a speech from a guy with a high-school diploma.

I speak today not just to those who agree with me, to the choir, but also to those who don't. I'm assuming we begin from the same basic principles. We may differ in terms of the method, but I think we can agree on the goal: that we all want to leave a better world and life for our children, our loved ones, our communities. Science is the key way to achieve that.

If I'm going to talk about science, I want to define my terms. To begin with what is science, this morning the Internet described it to me as "the intellectual and practical activity encompassing the systematic study of the structure and behavior of the physical and natural world through observation and experiment.

It doesn't really roll off the tongue. How about this? Science is the systematic reduction of ignorance. Science is not an edifice or a citadel; it is a process. To riff off Robert Pirsig, "Science is not a thing. It is an event. It is a practice and most often this practice is done by scientists."

Claude Levi-Strauss said, "The scientist is not the person who gives the right answers, they're the one who asks the right questions." Science does not require a scientist in order to happen. It is in fact one of the oldest of human drives to explore. We are moved, we are driven, inspired to better understand our universe and ourselves.

We push ourselves to the edge of what is known and we seek to know more. We are as a singular species tinkerers, explorers, problem solvers. We are social, we are storytellers, we are question askers, we are scientists. You are all scientists. Seriously, the last time you salted your food, you were testing, tasting, making assumptions, adding more salt when the first pinch wasn't enough. You weren't just seasoning; that was the scientific method making your food taste better.

All progress has been made using this method. Looking at what is in front of us, trying to understand it by guessing what will happen if a change is made, seeing how actually happens when that change is made, rinse, repeat. Why are we marching today for science? Because science has an enemy. Our enemy is strong and it fights dirty. But science's enemy is not a person, a political party, an ideology, it is not a behavior, a budget or a law.

If science is about exploring and understanding our world, clearly then the enemy is our own proclivity as individuals and as communities to stay inside a bubble and see the world not as it is but how we wish it to be. This is called bias. Bias is the enemy of science. My dictionary says that bias, "implies an unreasoned and unfair distortion of judgment in favor of or against a person or a thing."

Bias is strong. It is in us, in our families, in our communities. It is in our institutions. It feels safe, but bias is very dangerous. It cannot only skew the results of a test, it can undermine our conclusions and the policies we make based upon those conclusions. It is imperative that each one of us confront our own personal as well as institutional bias and prejudice and to excise them in any way that we can.

A scientist knows this in their bones. This is why blind tests exist and double and triple, and I found out today, quadruple blind tests. It's because despite their commitment to the truth, a scientist knows that they can without even realizing it alter things toward a skewed or preferred result.

Mice have been used for generations in research, yet in only to 2014 a study indicated that the testosterone of male researchers could scare mice and alter their behavior. This cast doubt on thousands of published conclusions. But does this betray the weakness of science? No, it shows its strength, that science takes vigilance to ferret out the hidden mechanisms in order to better comprehend.

Gandhi says that "We must look the world in the face with calm and clear eyes even though the eyes of the world are bloodshot today." We have to be open and fearless and admit our mistakes and forgive ourselves and also to forgive the mistakes of others. Bias may be the enemy of science, but science is also the enemy of bias.

We can help science gain the upper hand. We can be part of the solution. We can witness institutional racism and bias and remove it. We demand policies based upon empirical evidence and consensus. We demand our laws to equally protect all of us and to use data to remove those that do not. We demand that our government acknowledge that global warming is happening and that we are the cause.

Look at your beautiful faces. Naomi Klein says, "To change everything, we need everyone." The hundreds of thousands of us on the streets in the United States and around the world are a confluence, a galaxy. We are a constituency. We are agents of change. More accurately, we are reagents. Each of us is a molecule, a precise geometry of atoms bonded together under unique rules and conditions. Individually on our own no single one of us can bring enough energy to an equation to accomplish something significant.

But when we band together, when we find our sisters and brothers, when we participate in our democracy, when we speak clearly to those in power from our hearts and with our votes, when we make our collective voices be heard, we can move worlds. So let us, all of us, molecules, reagents, scientists, humans, let us march to start a proper chain reaction. Let us bring about change and let's move this world.

Thank you.

Kishore Hari: All right, we need your help with a chant to get it going. Adam, will you do the honors?

Adam Savage: My personal favorite is: What do we want? Evidence based policies. When do we want it? After peer review.

So ... what do we want?

Crowd: Evidence based policies!

Adam Savage: When do we want it?

Crowd: After peer review!

Adam Savage:That is the best thing I ever heard.