I’m Sam. And I’m Rob.

Once in a while along comes a scientist who captures the 

public imagination and communicates 

their passion for science in an exciting and understandable way.

In this programme, we’ll be meeting one of America’s best-known 

popular scientists. Astronomer Neil deGrasse Tyson. He’s a man with a 

gift for communicating and inspiring people with his television shows and 

books on cosmology – the study of the origin and nature of the universe.

In his day job he runs the Hayden Planetarium in New York’s American 

Museum of Natural History, but Neil’s real mission is to encourage 

scientific thinking among the American public.

We’ll be hearing from the famous astronomer, and learning 

some new vocabulary, soon. But first I have a question 

for you, Sam. Science is ever-changing with new discoveries updating our 

understanding all the time. For centuries, the Earth was 

thought to be the centre of the Universe - but who was the 

first astronomer to have the correct idea that, 

in fact, the Earth and the planets revolve around the 

Sun? Was it a) Nicolaus Copernicus 

b) Isaac Newton c) Galileo Galilei

Hmm, I’ll say it was c) Galileo.

OK, Sam. I’ll reveal the correct answer later in the programme. 

Recent events like 

the Covid pandemic and climate crisis have put scientists under 

pressure from critics motivated by political views. Neil deGrasse 

Tyson thinks facts are not dependent on politics, 

but should be established with the scientific method, a 

process of finding the truth through testing and experimentation.

Here’s Neil explaining more about the 

scientific method to BBC World Service programme, HardTalk.

If you have a brilliant idea and you test it and it unearths so 

much of what has been known before, we’re gonna double-check that 

– the rest of us – we’ll say, ‘But did he do it? Did he cross 

his t’s and dot his i’s? Did he … Let me check the power 

that’s driving his experiment, you know, the wall current, 

let me check how that was conceived and done’. 

And if no-one can duplicate your results, it’s not a result.

Before scientists can confirm the truth of an experiment, 

their findings must be doubled-checked - making certain 

something is correct by carefully examining it again. This 

process is called ‘peer review’ - other scientists double-checking 

the experiment to make sure everything was done correctly. 

One way they do this is to duplicate, or repeat, the 

experiment to see if they get the same result.

In other words, Neil wants scientists to have crossed 

the t’s and dotted the i’s, a phrase which means paying 

attention to the small details of whatever you are doing.

A scientific approach requires an open mind and critical thinking, 

but Neil believes the most important thing is to know the difference 

between fact and opinion. People have opinions about all kinds 

of things but that doesn’t make what they believe a fact.

Yet fact and opinion are becoming harder to separate. As protests by 

anti-vaccine groups and climate change deniers have shown, many Americans, 

even presidents, seem suspicious of scientific fact. It’s a worrying trend 

that Neil thinks is a result of the US education system, 

as he told BBC World Service programme, HardTalk.

It has to do with how science 

is taught in schools. It’s currently taught as a body of information, 

a satchel of facts that are imparted upon you and then you regurgitate 

that for an exam. That’s an aspect of science, but it’s not the most 

important part of science. The most important part of science 

is knowing how to question things and knowing when 

an answer has emerged that represents an objective truth about this world.

Neil says that science is taught by encouraging students to regurgitate 

facts - to repeat information without properly understanding it.

Knowledge is important, 

but what’s also needed is a questioning attitude than can 

recognise objective truth - a truth about the natural world 

which is not influenced by human bias, opinions or emotion. 

Without that, anyone is free to call whatever 

they like a ‘fact’, which only leads to chaos.

Right. No matter how hard I believe that the Moon 

is made of cheese, or the Sun goes round around the Earth, 

believing it doesn’t make it true.

That sounds like something Neil deGrasse Tyson would 

agree with – and maybe Galileo too!

Yes. In my question I asked who first came up with the 

idea that the Earth revolves around the Sun.

And I said it was Renaissance astronomer, Galileo.

Which was the wrong answer, I’m afraid. Galileo knew the 

Earth revolved around the Sun, but the first person 

with the idea was Polish astronomer, Nicolaus Copernicus, 

in 1543 – unfortunately, centuries before the invention of television 

could spread the news of this objective truth – a provable 

truth which is uninfluenced by human bias or opinion.

OK, let’s recap the rest of the vocabulary from our chat 

about American scientist Neil deGrasse Tyson and his 

love of cosmology - the study of the Universe.

To double-check something means to make certain it’s correct by 

carefully re-examining it. One way scientists do this is to 

duplicate, or repeat exactly, an experiment.

The idiom ‘cross the t’s and dot the i’s’ means to pay close 

attention to the details of what you are doing.

And finally, if you regurgitate facts, you just repeat them without 

properly understanding them – something a true scientist 

would never do!

Once again, our six minutes are up. Goodbye for now!

Bye!