He won the Nobel Prize for physics.

But Brian Schmidt received no special treatment from the TSA when he tried to take the 24-carat pure gold medal through airport security in Fargo, Nebraska.

He was awarded the prize, made from $10,000 of gold, for co-discovering that the expansion of the universe was accelerating - a finding that has transformed our understanding of the solar system.

As he tried to take it to show his grandmother, however, the revered physicist was stopped and interrogated.

Travel issues: Brian Schmidt, pictured receiving the Nobel Prize from King Carl XVI Gustaf of Sweden in 2011, revealed he was interrogated at airport security after taking his gold medal to show his grandma in Nebraska

'It's a large gold medal': The guards were baffled by the gong which went off when Schmidt put his bag through

'There are a couple of bizarre things that happen,' Schmidt, 47, told an audience in New York last month.

'One of the things you get when you win a Nobel Prize is, well, a Nobel Prize.

'It's about that big, that thick [he mimes a disk roughly the size of an Olympic medal], weighs a half a pound, and it's made of gold.

'When I won this, my grandma, who lives in Fargo, North Dakota, wanted to see it.

'I was coming around so I decided I'd bring my Nobel Prize.

'You would think that carrying around a Nobel Prize would be uneventful, and it was uneventful, until I tried to leave Fargo with it, and went through the X-ray machine.

'I could see they were puzzled. It was in my laptop bag. It's made of gold, so it absorbs all the X-rays—it's completely black. And they had never seen anything completely black.

Shock: Schmidt also revealed he was cooking dinner when, without warning, he was called with the news

No special treatment: TSA security guards (stock image) put Schmidt through intensive questioning

'They're like, "Sir, there's something in your bag."

'I said, "Yes, I think it's this box."

'They said, "What's in the box?"

'I said, "a large gold medal," as one does.

'So they opened it up and they said, "What's it made out of?"

'I said, "gold."

'And they're like, "Uhhhh. Who gave this to you?"

'"The King of Sweden".

Life-changing: The 47-year-old physicist co-discovered that the universe's expansion rate was accelerating

'"Why did he give this to you?"'

'"Because I helped discover the expansion rate of the universe was accelerating." At which point, they were beginning to lose their sense of humor.

'I explained to them it was a Nobel Prize, and their main question was, "Why were you in Fargo?"'

Schmidt, a Harvard graduate who lectures at the Australian National University, described the encounter as he joined physicists celebrating the construction of one of the largest observatories in the world, the Giant Magellan Telescope (GMT), due to open in 2020 in Chile.

He also revealed he was cooking dinner when, without warning, he received a call saying he had won the prize.

'It’s not like you get advanced warning, he said.