Category Archives: Space

Space science, exploration, etc

Dark Energy Stars, a Replacement for Black Holes ?

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Here’s an interesting thought, what if black holes didn’t exist but instead a collapsing star underwent a quantum critical phase change, turning into a rather peculiar, but QM compliant, object ?

This is what two physicists from LANL believe could be happening.

The report in New Scientist says:

[…] Chapline and Laughlin found some answers in an unrelated phenomenon: the bizarre behaviour of superconducting crystals as they go through something called “quantum critical phase transition” (New Scientist, 28 January, p 40). During this transition, the spin of the electrons in the crystals is predicted to fluctuate wildly, but this prediction is not borne out by observation. Instead, the fluctuations appear to slow down, and even become still, as if time itself has slowed down.

“That was when we had our epiphany,” Chapline says. He and Laughlin realised that if a quantum critical phase transition happened on the surface of a star, it would slow down time and the surface would behave just like a black hole’s event horizon. Quantum mechanics would not be violated because in this scenario time would never freeze entirely. “We start with effects actually seen in the lab, which I think gives it more credibility than black holes,” says Chapline.

With this idea in mind, they – along with Emil Mottola at the Los Alamos National Laboratory in New Mexico, Pawel Mazur of the University of South Carolina in Columbia and colleagues – analysed the collapse of massive stars in a way that did not allow any violation of quantum mechanics. Sure enough, in place of black holes their analysis predicts a phase transition that creates a thin quantum critical shell. The size of this shell is determined by the star’s mass and, crucially, does not contain a space-time singularity. Instead, the shell contains a vacuum, just like the energy-containing vacuum of free space. As the star’s mass collapses through the shell, it is converted to energy that contributes to the energy of the vacuum.

The team’s calculations show that the vacuum energy inside the shell has a powerful anti-gravity effect, just like the dark energy that appears to be causing the expansion of the universe to accelerate. Chapline has dubbed the objects produced this way “dark energy stars”.

A really intriguing possibility and one that, they believe, could be verified or disproved in 5-10 years.

The Star Trek Scanner – arriving shortly at a Mars Rover near you..

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Point and click identification courtesy of Raman Spectroscopy!

ABC Science Show – Mars Science Laboratory Saturday 4 March 2006

Bonner Denton has a demonstration he uses upstairs. He takes a bottle of Tylenol, a white plastic container and the pills are inside. You can shoot the Raman and a laser goes through that white plastic, it identifies the three parts of Tylenol and it tells you what the plastic is made out of. It works on leaves. I can identify the species of trees by shooting their leaves. I don’t think the biologists are aware of this yet.

Potentially very useful indeed..

Pioneer 10: Last Chance to Phone Home

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Pioneer 10 (c) NASA

Just listening to a podcast of the Planetary Society where they were talking to John Anderson (Senior Research Scientist, JPL) about their research in to the Pioneer Anomaly and he mentioned that the last possible chance to communicate with Pioneer 10 will be coming up around the 4th March this year.

To give you an idea of the difficulties they face, they will be trying to detect a signal strength of around 8 watts coming from a craft 3 times as far away as Pluto is from us. Imagine having to first of all turn on a lightbulb 90 times as far away as the Sun by sending a signal, waiting over 12 hours for it to get there and (hopefully) start transmitting back and then waiting another 12 and a bit hours for that signal to come back to Earth and then try and catch it!

If the Deep Space Network does come onboard for this, and it works, then this will be the final icing on the cake for the Pioneer Anomaly team as that’ll be yet more red shift information to add to the the almost 40GB of data they’ve recovered from both the Pioneer 10 and 11 missions.

Stardust@Home

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Here’s an interesting project I picked up from the Planetary Society’s Planetary Radio podcast – the Stardust team needs volunteers to scan images from microsope photographs of the Aerogel that has been recovered to spot the tracks made by interstellar dust grains.

I know, you’re thinking “why don’t they do it automatically?” – the reason is that the grains will only travel a very short distance into the aerogel, and make marks quite similar to natural cracks that will have appeared during the mission. It is, in fact possible – BUT:

In order for it to work, however, they would have to “train” the computer with real images of aerogel containing grains of interstellar dust. But here’s the rub: no such particles had ever been collected!

So it’s a classic chicken/egg situation – they could find them automatically but they need to find the grains to teach the program before it will work reliably.

So, now it’s time for the public! They will produce a lot (order of a million) images for people to go through one by one (after some online training) to try and spot these particles by eye. The article on the challenge at the Stardust@Home site likens it to:

…searching for 45 ants in an entire football field, one 5cm by 5cm (2 inch by 2 inch) square at a time!

At least in this case the ants won’t be moving.. 🙂

So, if you want to find out more read the Planetary Society page on the project, the Berkeley press release about the project and the Stardust@Home project page itself & think about registering to help them out. Who knows, you could be the first one to find a piece of cosmic space dust!

Pioneer Anomaly Update

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The Planetary Society has posted an interesting update on the Pioneer Anomaly especially about the fact that they’ve managed to recover almost all of the original telemetry data as well as the doppler shift information they were after.

The original tapes were to have been destroyed after 7 years, but as they say:

Fortunately, this is not what happened in the case of the Pioneer missions. Not only were the original magnetic tapes not destroyed but, in the early 1990s, before deterioration would have made the tapes unusable, they were copied to much more durable magneto-optical media. Since then, the files, about 40 gigabytes in total, have been copied to modern computers and we have now developed tools to extract information from them.