Time travel is possible

[The-Sir]

Hawking is on crack.

[armchairfan]

Thanks for the rep piscinin.

 

This is a link for the astronomy lectures. If anyone wants to check out the site then there's loads on offer.

 

UC Berkeley Webcasts | Video and Podcasts: Astro C10 / LS C70U

 

Here is a direct link to all the webcasts and also if you click on the drop down link at top right you can view lectures from the last few years.

 

UC Berkeley Webcasts | Video and Podcasts: Spring 2010 Courses.

[razor]

 

I wish Dave Brock WAS Professor of Theoretical Physics at Cambridge.

 

THAT would get things moving!

 

I remember reading an article about him at Glastonbury once. He sat on the end of the stage watching Jethro Tull, I think. He was on there for the full set just grooving and what have you.

 

A few hours later he bumped into Ian Anderson backstage. "Oh, man, great to see you. What time are Tull on I've been looking forward to seeing you all weekend," he asked.

 

He recently gave an interview in which he said he was disappointed that had never been to Glastonbury. This despite playing there virtually every year in the early 70s.

 

Now what that man doesn't know about time travel isn't worth knowing.

[Charles Penrose]

If you ask me, Hawking's got a right cheek.

[Yerma'satexan!]

I'd much rather they got a move on with that whole laser propelled space ship thing, so that we can see what it's like on Mars before we die.

 

Time travel is no good to any of us posting on here!

 

I wanna see this shit...

 

Laser 'tractor beams' to tidy up space junk

29 April 2010 by Paul Marks

Magazine issue 2758.

For similar stories, visit the Spaceflight Topic Guide

 

WITH Earth's orbit cluttered with dead satellites, discarded rocket boosters and other space junk, ways to prevent the accumulation of such debris are desperately needed.

 

How about using a tractor beam to simply steer future junk aside, says space-flight engineer John Sinko of Nagoya University, Japan.

 

Sinko's idea is based on an experimental type of spacecraft engine called a laser thruster. Inside these motors, laser pulses fired into a mass of solid propellant cause a jet of material to be released, pushing the craft in the opposite direction.

 

Sinko realised that the laser did not necessarily have to be on the same craft. "These on-board motors could also be targeted remotely by lasers for tractor beaming," he says.

 

A spacecraft could fire a low-power laser beam at another craft to steer it from a distance

He has designed a series of laser thrusters that can be activated in this way. A spacecraft fitted with a laser would fire a low-power beam at a thruster fitted on another craft to attract, repel or steer it in another direction. Pushing a spacecraft away is a relatively simple matter, but more complex designs using mirrors are needed to use a beam to tug one towards the laser (see diagram).

 

Combining those designs could allow full control in any direction, says Sinko. He imagines spacecraft being fitted with remotely operated thrusters before launch, so that once they reach the end of their lives it is simple to alter their orbit or even shove them into the atmosphere to burn up - even if they have lost all power (Journal of Propulsion and Power, DOI: 10.2514/1.46037).

 

Tractor beams could be fired from up to 100 kilometres away, says Sinko, either from a spacecraft in orbit or a mirror in space redirecting a beam from Earth.

 

"It's an interesting idea that could work in principle," says Richard Holdaway, director of space science technology at the Rutherford Appleton Laboratory in Didcot, UK. Keeping a laser beam accurately trained on a distant motor would be a challenge, he adds, "but perhaps not an insurmountable one".

 

Sinko hopes to test one of his tractor beams on a 10-kilogram satellite within a few years. He is not alone in trying to develop such technology: a team at the Research Institute for Complex Testing of Optoelectronic Devices and Systems in Sosnovy Bor, Russia, is working on similar ideas.

[Uncle_Meat]

Dave Brock rocks. I shared a joint with him once in the Gents at Reading University.

[Sandman]

I wanna see this shit...

 

Laser 'tractor beams' to tidy up space junk

29 April 2010 by Paul Marks

Magazine issue 2758.

For similar stories' date=' visit the Spaceflight Topic Guide

 

WITH Earth's orbit cluttered with dead satellites, discarded rocket boosters and other space junk, ways to prevent the accumulation of such debris are desperately needed.

 

How about using a tractor beam to simply steer future junk aside, says space-flight engineer John Sinko of Nagoya University, Japan.

 

Sinko's idea is based on an experimental type of spacecraft engine called a laser thruster. Inside these motors, laser pulses fired into a mass of solid propellant cause a jet of material to be released, pushing the craft in the opposite direction.

 

Sinko realised that the laser did not necessarily have to be on the same craft. "These on-board motors could also be targeted remotely by lasers for tractor beaming," he says.

 

A spacecraft could fire a low-power laser beam at another craft to steer it from a distance

He has designed a series of laser thrusters that can be activated in this way. A spacecraft fitted with a laser would fire a low-power beam at a thruster fitted on another craft to attract, repel or steer it in another direction. Pushing a spacecraft away is a relatively simple matter, but more complex designs using mirrors are needed to use a beam to tug one towards the laser (see diagram).

 

Combining those designs could allow full control in any direction, says Sinko. He imagines spacecraft being fitted with remotely operated thrusters before launch, so that once they reach the end of their lives it is simple to alter their orbit or even shove them into the atmosphere to burn up - even if they have lost all power (Journal of Propulsion and Power, DOI: 10.2514/1.46037).

 

Tractor beams could be fired from up to 100 kilometres away, says Sinko, either from a spacecraft in orbit or a mirror in space redirecting a beam from Earth.

 

"It's an interesting idea that could work in principle," says Richard Holdaway, director of space science technology at the Rutherford Appleton Laboratory in Didcot, UK. Keeping a laser beam accurately trained on a distant motor would be a challenge, he adds, "but perhaps not an insurmountable one".

 

Sinko hopes to test one of his tractor beams on a 10-kilogram satellite within a few years. He is not alone in trying to develop such technology: a team at the Research Institute for Complex Testing of Optoelectronic Devices and Systems in Sosnovy Bor, Russia, is working on similar ideas.[/quote']

 

 

 

Sounds a lot like the laser concept proposed for the Mars Mission. Only if I remember right, the laser would be fired and operated by some sort of space station, as opposed to it being fired by the space craft.

 

Which contradicts what Richard Holdoway states above about accuracy.

 

I'd be a bit worried though if I was navigating the galaxy in a space ship that had no fuel and no control over the laser that's guiding it.

[dirty_sanchez]

You've got to start somewhere, Simon. It's not, like, an exact science.

 

It's kind of ironic that it's Simon mocking what is essentially one of the greatest scientific achievements of our time.

[William_Ulsterman]

it may be theoretically possible to time travel but physically impossible as the body would not be able to withstand the acceleration. If you were to accelerate to the speeds required at a comfortable rate the human body could tolerate it would take more than a human lifetime.

[Juniper]

it may be theoretically possible to time travel but physically impossible as the body would not be able to withstand the acceleration. If you were to accelerate to the speeds required at a comfortable rate the human body could tolerate it would take more than a human lifetime.

 

Withstand 88mph? That's hardly fast is it. We should be alright.

[William_Ulsterman]

Withstand 88mph? That's hardly fast is it. We should be alright.

 

In a Deloren? built from Quality Street tins in Belfast?

 

My next door neighbour had one and 88 mph was a white knuckle ride wondering which part would fall off first.

[Sandman]

It's kind of ironic that it's Simon mocking what is essentially one of the greatest scientific achievements of our time.

 

 

Well he is working on something better: I have an idea need help.