Star Struck : Astronomy: John Dobson’s passion is to bring the heavens to ground level with his low-tech telescopes.

The sun is a big green ball.

The universe is raisin pudding.

And the sidewalk astronomer wants everyone to see the heavens.

So he crisscrosses the land in an old orange van, stopping where there are people. Street corners, parks, parking lots. He pulls out his strange telescopes, built of cardboard and scrap wood and portholes. Crowds gather around.

Look, he says. Peer at the cosmos.

“If they don’t see the universe, they won’t wonder about it,” he said. “What’s the use of somebody who doesn’t wonder? If they don’t wonder, they’re dead.”

It is an aerie world that John Dobson inhabits. Nebulae and quasars, dark matter and light-years. He wants you to join him up there.

But first, some plain talk and Earth-bound facts:

Dobson is 75 years old and virtually broke. He was trained as a chemist, became a monk, then revolutionized astronomy.

The “Dobsonian” telescope--as his homemade design is now called--is the first high-powered telescope that amateur astronomers can either build or buy inexpensively. Thousands of these stargazing contraptions are pointed at the sky from back yards around the world.

“He has allowed the public to look at things they could only see in pictures before,” said Stephen O’Meara, associate editor of Sky & Telescope magazine. “The ‘Dobsonian’ telescopes are probably the most popular telescope on the market.”

The inventor might have become wealthy for his efforts. But he didn’t even try; he was too busy preaching. Dobson tours national parks in summer and works the cities during winter.

He speaks in layman’s words.

Jupiter looks like a straw hat, he says. Stars orbit like lonely ships passing in the night.

A new KCET-TV series, “The Astronomers,” documents his work, among that of others, and Dobson was in town last week to publicize the show, which begins April 15. He took the opportunity to visit high schools, a college and local astronomy clubs and found time to set up his telescopes.

“Come see. Come see.”

Crowds gathered around.

“Curiosity is a characteristic of our species. Everybody wants to understand the universe,” he said. “They’re just waiting for somebody to show it to them.”

To understand Dobson and what he does, know that his life has been a curious tug-of-war between science and religion.

He was raised at Peking University, where his grandfather and father taught, then came to the United States and eventually studied chemistry at UC Berkeley. A suitable career ensued.

But equations and formulas could not answer all the young man’s questions. So, at age 28, he left it all behind to join a Rama Krishna monastery in San Francisco. Dobson went searching for ultimate truth.

Clues, he supposed, might lay in the stars.

The penniless young monk built a telescope from whatever he could scavenge. A cardboard roll served as a tube. Portholes and glass jug bottoms were ground into mirrors. Dobson used wood and plastic to make a version of an “altazimuth” mount that would someday make him famous.

Years passed and he built more telescopes, often wheeling them into the street so that passersby could look. He assumed that everybody was as fascinated by the cosmos as he was. His hobby became a passion.

Fellow monks worried. They thought Dobson was, well, obsessive. He tried to hide it. He got neighborhood kids to keep his telescopes in their garages. But there was no hiding the time he spent outside monastery walls.

“I finally got kicked out,” he said.

The year was 1967. Dobson landed on the streets and survived, as he does today, only with the support of friends. His astronomical mission continued.

Others wanted to learn to make his telescopes. He gave classes and started the San Francisco Sidewalk Astronomers. The amateur club soon attracted crowds to its nighttime stargazing parties on city streets and in Ghirardelli Square.

Word of Dobson began to spread.

Sun glittered in a sky swept blue by Santa Ana winds. It was last Wednesday, and Dobson set up his solar telescope in the central courtyard at Occidental College.

“Come see the sunspots,” he called out.

Students on lunch break drew near. Dobson had slipped into his showman’s persona, the one that caused Smithsonian magazine to call him a “carny barker for the cosmos.”

“The sun’s a big green ball,” he said, because it looks that way through the telescope’s filters. “The sunspots are magneto-hydrodynamic zits on the face of the sun.”

One of the students who approached was Christopher Del Negro. He had met Dobson last spring, when the sidewalk astronomer was giving nightly shows outside Griffith Observatory.

“He was just kicking back with his telescope in the parking lot. We were looking at Jupiter,” Del Negro recalled. “The observatory also had its big telescope focused on Jupiter, but the line for Dobson’s was much longer.”

Dobson’s telescopes are as unusual as he is. They have names and are painted colors. There is The Little One, which is at least 10 feet long. There is Stellatrope (which is Latin for “star lover”) and Ceanothus, which is blue like the flower for which it was named.

These telescopes and their mounts fit, just barely, in Dobson’s 1973 Chevy van. On this trip to Los Angeles, afternoons were the only opportunity he had to use them. The nocturnal skies weren’t cooperating.

“We have no moon to look at,” he said that evening in the Hollywood Hills. “Jupiter is much too low.”

He stopped suddenly and pointed.

“Oooh-wee! Look at that.”

A companion searched the sky, hoping to spot a cosmological wonder. Dobson, however, was pointing at the Capitol Records building and its lit “needle” that slices into the black horizon.

“What a beauty,” Dobson said.

The big-time astronomers, the ones with million-dollar telescopes and research grants, know about Dobson. Some of them appreciate what he’s done.

“Science really is fun and people in this country have forgotten that,” said Tony Tyson, a noted researcher for Bell Laboratories in New Jersey. “In the case of Dobson, his excitement infects the general public. He is basically turning people on to science.”

No one can deny his technological impact. The “Dobsonian” method for making telescopes--thin mirrors and simple mounts--is used by commercial manufacturers. Such a telescope with, say, a 10-inch aperture sells for $345. A conventional model that size could cost $3,000.

But there is another side to Dobson’s work that makes people, especially scientists, uncomfortable.

Having watched the stars, Dobson now contemplates the grand question of where they came from. He isn’t entirely sold on prevailing theories, such as the steady-state or Big Bang.

So he has a suggestion.

Dobson believes scientists are making a mistake by limiting themselves to conventional measurements of space and time. Such pure physics, he insists, have hit a roadblock. Researchers should, he says, add philosophy and metaphysics into their equations.

Again, the struggle between knowledge and faith.

During his visit to Los Angeles, Dobson tried this argument out on the physics department at Occidental College, referring to his model of the universe as raisin pudding.

“I’ll admit,” he warned them, “this is way out in left field.”

A dozen professors and students fidgeted through the lecture. Several walked out before it ended. Afterward came the protests.

“What you’re talking about isn’t physics.”

“Nobody is going to listen to you until you can come up with some numbers.”

“He should stick to telescopes,” someone whispered.

The sidewalk astronomer’s visit was drawing to a close. He would speak at Hollywood High and at one more astronomy banquet, then return to San Francisco. The trip to Los Angeles, with its hectic schedule, was getting him tired.

So, at the end of the day, he sat in his room and played guitar. The instrument was tuned to four notes, like Orpheus’ lyre. He sang words of Sanskrit to haunting melodies.

The music called to mind something that is often said of Dobson. He is portrayed as a galactic Pied Piper, luring followers with enthusiasm and charm, coaxing them on a journey to the heavens.

Dobson scoffed.

“It’s not me these people are interested in,” he said. “It’s what I show them.”

Yet he loves to quote New Zealand astronomer Graham Loftus: “What we need is a big telescope in every village and hamlet, and some bloke there with that fire in his eye who can show something of the glory the world sails in.”

That, Dobson echoes, is what we need.

We may already have it.

“John Dobson is that man with the fire in his eye,” O’Meara said. “He’s burning in that telescope in every village.”