Tag: Astrophysics

The Nearest Earth

Well, it’s 24 trillion miles away, but at least we now have somewhere to go once Clintrump send us on a spiral of doom:

In this golden age of exoplanetary science the announcement of a planet 30% more massive than the Earth, in an 11.2 day orbit around a low-mass star with a luminosity 0.15% of the Sun’s would usually elicit little more than a raised eyebrow.

Except for the fact that this world orbits the nearest star to ours; Proxima Centauri.

It means that at a cosmically trifling 24 trillion miles (4.243 light years) from where you are at this instant is an alien system with a planet that could conceivably harbor life as we know it. That planet is estimated to be around 4.9 billion years old, it receives about 65% of the Earth’s stellar irradiation, and its skies – whatever else is in them – are bathed in the red-hued rays of a diminutive star only 12% the mass of our Sun.
Say hello to the closest truly alien world.

The planet was discovered by the very small doppler shift its orbit induces in Proxima Cen. Way back in 1993, I did a presentation in my astrophysics class in which I claimed that this was the best approach to finding extrasolar planets. My professor — who was and is a good friend and a brilliant man — thought I was crazy, that we would never be able to measure doppler shift precisely enough to find Earth-like planets. So every time we do find one this way, I still feel a little thrill of vindication.

There are actually plans to send a probe to a nearby world. Russian entrepreneur Yuri Milner is funding a program to send a tiny probe at a significant fraction of the speed of light to a nearby star. It would be a very quick visit. But talking with my exoplanet colleagues this summer, it sounds like he’s serious and this could be done. The main hurdle to be overcome is how to pack it with enough power to transmit a signal back to Earth.

The more we look at the universe, the more ubiquitous we find planets to be. So I’m not entirely surprised by this. The universe is teeming with planets and the number of potentially habitable planets almost certainly numbers in the billions. If we live long enough, we will see a space telescope get a spectrum of a nearby planet’s atmosphere. And then it’s only a matter of time until we find a signal of life in another star system.

In the meantime, let’s hope we one day get off our butts and get moving. The universe is at our doorstep.

Oh oh…

Looks like some people are postulating that “The Big Bang May Not Have Spawned The Universe After All” and have an alternative theory.

This new explanation suggests that the universe might actually be the result of the collapse of a four-dimensional star–a crazy black hole the likes of which we can’t even imagine. Some explanation:

In that model, our three-dimensional (3D) Universe is a membrane, or brane, that floats through a ‘bulk universe’ that has four spatial dimensions. [The] team realized that if the bulk universe contained its own four-dimensional (4D) stars, some of them could collapse, forming 4D black holes in the same way that massive stars in our Universe do: they explode as supernovae, violently ejecting their outer layers, while their inner layers collapse into a black hole.

The idea is that black holes as we know them–3-D black holes, in our known universe–have as a boundary a 2-D membrane, which is called an “event horizon.” But in the event of a 4-D black hole, the event horizon would be a 3-D event horizon–and according to models run by the team, a collapse of a 4-D star would spew material into the 3-D event horizon, slowly expanding over time. That event horizon could be, well, our universe.

Interesting shit. For some reason this is not the first time I have heard this challenge to the Big Bang mentioned, but this is definitely the first time I have heard that someone modeled it and actually did the work to prove it could be what happened. If this can be proved, I think the big question is where did that 4D star and the universe it resides in come from? What would it look like there? And does this thing keep going on ad infinitum with 5D to nD systems existing and infinite universes, each with the possibility of their own infinite offspring, which can then again have their own infinite number of n-x universes, going up and down the chain. And do we then have a 2D hanging out of every black hole in our universe? What the hell would any of that all look like?

The more we think we know, the less it really seems we do and understand. This is some seriously complex stuff out there. This may all be premature and nothing could come from it, but wow, if it pans out, if the reasearch and science prove this could be the reality of how our universe came about, this is really going to shake things up. Lots of work here to chec this out. Exciting stuff. and it may all go nowhere.