STARGATES, wormholes and other portals in time and space will not get aliens here any quicker, according to WA science communicator John Jacob.

Unless they have defeated the speed of light, which physicists on Earth agree cannot be overtaken by any technology, their spaceships will have to bow to the tyranny of time and vast distances.

Even if they could travel at one-tenth the speed of light (nearly 300 million metres a second), how are they going to stop as they approach our solar system at 30 million meters a second? They would need to carry a similar amount of energy that was needed to launch the trip in the first place.

It is too hard, too dangerous and a good reason, according to Mr Jacob, and that is why we have not seen or heard from other technological civilisations.

The laws of physics make claims of alien sightings seem ludicrously far-fetched.
Image: Istockphoto

Mr Jacob will explain why at a talk at Gingin Observatory on August 21 as part of National Science Week.

“Physics works on other stars exactly as it does here in our solar system,” he told ScienceNetworkWA, referring to a number of tantalising discoveries over the past two years of Earth-like rocky objects around stars in nearby galaxies.

“If an alien wants to come here it has to deal with the same laws of physics as we do.”

For starters, it will take an extraordinarily long time.

“So they would have left long before they could have known there was anything here to visit.”

Mr Jacob says no technology can overcome the speed of light because nature does not allow it.

“Technology is the servant or slave of nature,” he says.

His talk will include examples demonstrating the difficulty of travelling physically between nearby stars up to 20 to 30 light years away. Light at full speed covers about 10 million million kilometres in a year.

“Going at one-tenth the speed of light, it will mean a 200-year one-way trip, at least.

“They would also have to carry their environment with them, as would we.”

Mr Jacob says our best chance of making contact is listening in on any interstellar communication than trying to physically leave the solar system.

“People with 80-year lifespans would have to travel distances many times their lifespans,” he says, adding robotic probes and orbiters made better explorers in space.

“Technology is a better explorer than humans.”

The talk will end up outside where visitors can use the telescopes at Gingin Observatory to gaze at the stars and galaxies orbiting our own.

More information on John Jacob is available at www.wallingup.com.
Information about National Science Week is available at www.scienceweek.gov.au.