The Week in Space and Physics #12
The world’s most famous particle accelerator sprang back into action at the end of April. After a break of three years for maintenance, repairs and upgrades, the Large Hadron Collider in Switzerland is once again actively smashing subatomic particles into each other at tremendous speeds and energies.
The energy of those collisions is measured in a unit known as the “electron-volt”, often written as “eV”. When the Collider opened in 2009, the highest energy collisions carried less than two trillion electron volts. The new collider quickly exceeded that – reaching seven trillion eVs in early 2010. An upgrade in 2015 almost doubled this to thirteen trillion electron volts, a so far unbeaten world record.
The latest upgrades will let the collider push to even higher energies: close to fourteen trillion electron volts. But, more importantly, the upgrades have also boosted the intensity of the particle beams. That should increase the number of particle collisions taking place where they meet. In turn, that raises the chance of spotting rarely seen particles spinning out of the debris.
When the Large Hadron Collider opened, physicists were optimistic it would quickly find many such particles. That, they expected, would have revealed new and deeper laws of physics. As the years passed, however, little new emerged from the collider. The higher energy collisions, though never seen experimentally before, appeared exactly as predicted.
That – despite being a tremendous success for our theory of fundamental physics – came as something of a disappointment. Lacking unexpected results, physicists have little to point them to new theories of nature. This upgrade, in a way, is another chance for the Large Hadron Collider to change that. Another - perhaps the last - chance to discover something new.
If it does not, physicists will face a difficult question. Many will suggest probing even higher energies - hoping that more extreme conditions will finally break our theories. Ideas for bigger colliders have already been suggested. Each, though, comes with a price tag running into the billions of dollars. Given the failure of the Large Hadron Collider to find new physics, the value of that investment will be questioned.
Are, indeed, ever larger particle accelerators the right direction for physics? Could that money be better spent elsewhere? Perhaps we could probe the mysteries we do know about – antimatter, neutrinos and dark matter – more carefully? Other kinds of experiments will certainly be able to make faster and cheaper progress.
The best outcome, of course, will be for the upgraded collider to show clear evidence of something new. Or, failing that, at least a sign in which direction more evidence might lie. Should it not, a tough debate about the future of physics is sure to follow.
Russia and the Space Station
Will Russia quit the International Space Station? Several recent reports suggested that Russia has already decided to pull out, giving a year’s notice to partners on the station. Yet on closer inspection these reports are mere repetitions of rumours, rather reflecting serious efforts to withdraw.
The threats came from Dimitry Rogozin, the director of Russia’s space agency Roscosmos. Though people in such roles usually watch what they say carefully, Rogozin has a history of provocative statements. Rarely, however, have his words been backed up by action.
Since the invasion of Ukraine, and imposition of sanctions on Russia, Rogozin has often threatened the space station. In March, for example, he joked about stranding American astronaut Mark Vande Hei on the station. He also suggested Russia could send the station crashing back to Earth if sanctions were not lifted.
Neither, of course, came to pass. Mark Vande Hei returned safely to Earth at the end of March, and the station itself has shown no sign of plunging Earthwards. NASA has also confirmed that Roscosmos has given no formal notice of their intention to quit the station. That suggests Rogozin’s latest threats are little more than empty words.
Indeed, withdrawing from the space station would make little sense for Russia. Despite frequently expressed intentions to fly a new station of their own, or to build a base on the Moon, Russia’s space program consists of little more than the Space Station. Should they withdraw, Russia would have nowhere to send its astronauts and little use for its rockets or launch pads. That, despite the bluster, would be a sad end for the Russian space program.
Photographing the Galactic Black Hole
The first photograph, three years ago, of a supermassive black hole made headlines around the world. The target, known as M87*, was vast: six billion times heavier than the Sun and stretching across a distance of forty billion kilometres. That immense size compensates, somewhat, for its distance – M87* sits at the heart of a giant galaxy fifty million light years from Earth.
Last year astronomers released images of a second black hole: one lying at the centre of Centaurus A, another nearby galaxy. This black hole is much smaller – merely fifty-five million times heavier than the Sun – but is highly active, shooting out the jets that give Centaurus A its distinctive appearance.
Now astronomers are preparing to target another, even more intriguing, black hole. Sagittarius A* sits at the centre of the Milky Way, just twenty-seven thousand light years from Earth. Its presence has been known for decades. Yet detecting it directly is hard: the centre of the galaxy is obscured by clouds of dust, gas and stars.
Sagittarius A* is also rather small, at least as far as a supermassive black holes go. In diameter it is at least a thousand times smaller than M87*, which means that although it is closer it will not look much bigger through our telescopes. Still, capturing an image of the black hole will be a major accomplishment, one likely to be heralded by astronomers and journalists alike.
When might the photograph be ready? Scientists at the Event Horizon Telescope - the organisation behind the black hole images - have scheduled a press conference for May 12. Expect to hear, they say, a groundbreaking discovery in the heart of our galaxy.
RocketLab Catches, Then Drops, Booster
Catching a plummeting rocket booster never promised to be an easy task. Yet last week, briefly at least, Rocket Lab succeeded, plucking one from the air with a helicopter.
That is no mean feat: the booster falls at a peak speed of five thousand miles per hour. As it does, it reaches such searing temperatures that the slightest error means certain destruction. Most of that speed and heat is carefully lost as the booster falls: a series of parachutes brings it down to a more gentle twenty-two miles per hour.
It is at this point that the helicopter swooped in and caught the booster. Then, if all had gone to plan, the helicopter would have flown back to base, bringing the booster safely back to land, ready to be refurbished to fly again. In the event, however, the helicopter pilot was forced to drop the booster shortly after the capture. Rocket Lab are now investigating what exactly went wrong – and no doubt preparing for another attempt soon.