Been having a binge watching of How the Universe Works, and lately Secrets of the Universe, which has some new stuff—on cosmology: estimates of universe age I’ve seen range from 13.7 billion to 13.8.
But size… size is something else, because it’s all expanding. So there’s a difference between the ‘observable universe,’ that ‘13.7 billion lightyears 13.7 years ago…’—and what it is now. And theory now is that the range beyond our vision is mindbogglingly vast…and getting vaster. Quite an interesting program. There’s an awful lot of ‘out there’ out there. 😉
Another good streaming program, if you have Amazon Prime, is Hidden Killers in the Victorian and Edwardian Home. It’s a wonder our great-grandparents survived to reproduce. Being well-to-do was no defense: affluence only brought new ways to die.
Does anybody know why SpaceX is so interested in these landings at sea? One might suppose liability issues, but landings of a mostly empty ship can hardly be less dangerous than launching ones full of fuel! Some of us of a certain age probably remember films of some of the self-destructions of early rocket launches.
Paul, I believe one reason is that the energy budget works better if they don’t have to turn around and fly all the way back to land. As to danger, yeah having a big booster fall on you would be bad, especially if it didn’t slow down — bur a lot of the fuel is gone, so the explosion is significantly less than when a launch accident happens (such as the Antares the blew up at Wallops Island).
Plus of course, it’s way cooler to land on a barge than on the land. As good a reason as any 😉
the video they published that I saw said that if they launch from say, Wallops Island in the Chesapeake Bay, and the trajectory of the launch vehicle is toward the east, once separation of the first stage is complete, it would have to turn around back to the west to return to launch point. If the recovery platform is in the ocean, then the primary stage can drop to earth down from where it separated from the rest of the vehicle. The platform can also be moved in the ocean, not always possible on land, especially if near a mountainous area or forested…….
Also, if the vehicle does fail to land properly, there is less damage to the surrounding area…….
The question is how many stages there are to the Falcon 9 and how far out it is when the first stage separates.
Falcon 9 is a two stage rocket, which minimizes the number of separation events. There are 9 engines on the first stage…
I just enjoy the fact they named the barges after ships from the Iain Banks Culture universe 🙂
Entirely off topic; have you ever tried using a liqueur as a flavouring with your soda stream?
With my Soda Stream you add the flavoring after you charge the bottle. So I think it would be like a liqueur with soda. Grand Marnier soda?
Okay, why can’t I post a reply…I’ve tried 3 times…..
Falcon 9 is a two-stage rocket designed and manufactured by SpaceX for the reliable and safe transport of satellites and the Dragon spacecraft into orbit. As the first rocket completely developed in the 21st century, Falcon 9 was designed from the ground up for maximum reliability. Falcon 9’s simple two-stage configuration minimizes the number of separation events — and with nine first-stage engines, it can safely complete its mission even in the event of an engine shutdown.
never mind, I got part of my reply to Paul’s question posted…..www.spacex.com/falcon9
A project to send probes to Alpha Centauri!
It looks serious, and has just been announced today. The idea is that they will send nanoprobes, weighing only a few grams. They will be propelled by light sails, and accelerated by a 10GW array of lasers from earth to 20% of light speed.
Russian billionaire Yuri Milner is putting up $100 million to kick things off. It’s estimated that research and development will take about 20 years, the probes will take another 20 years to reach Alpha Centauri, and it will take 4 years to get the data back from 4 light years away.
http://www.nytimes.com/2016/04/13/science/alpha-centauri-breakthrough-starshot-yuri-milner-stephen-hawking.html
For more articles search Google News.
I wonder how far the probes will go before the lasers from Earth will no longer provide enough energy to continue the acceleration.
The lasers will only accelerate the probes for 2 minutes, by which time they should be up to .2 light speed at 60,000 Gs acceleration. The first challenge will be to build nanoprobes that can survive that!
Full video of the press conference:
Stephen Hawking and Yuri Milner announce Sharshot initiative
https://www.youtube.com/watch?v=c7VPHGjT8A4
Apparently Mark Zuckerberg is also involved.
Neat!