Space is full of dirty, toxic grease, scientists reveal
theguardian.com
theguardian.com
The way projectfu describes it shows a clever but clear line of problem solving from 'we have x and we know y, how do we figure out z'.
Still miraculous, of course.
I think it's inspiring to see that it's not too different the fundamental problem solving process that many of us use in our daily lives.
Yes, there is a whole field of organic infrared spectroscopy. Before we had more powerful instruments like NMR, it was one of the key ways molecular structures were elucidated.
You can get a good sense as to what functional groups are on a molecule with IR alone.
https://socratic.org/questions/helium-was-discovered-on-the-...
"Until now there has been uncertainty over how much carbon is drifting between the stars. About half is expected to be found in its pure form. The rest is chemically bound with hydrogen in either a grease-like form, known as aliphatic carbon, or as a gaseous version of naphthalene, the main chemical component of mothballs."
Of course, this is also talking about downvotes, so...
Hydrogen fuses into helium. Helium (by the triple-alpha process) fuses into novel isotopes of lithium and beryllium, which decay in attoseconds back into helium, unless the beryllium is fused with a third helium nucleus/alpha particle to form stable carbon-12. That carbon is in the presence of hydrogen, and is then blown off of the star surface, so you get interstellar mothballs wherever you have stars.
Clearly, the someone was whoever not within but above and before our universe. They wanted to guard their physics simulation against interdimensional pests.
I've sort of decided one of the possible solutions for gamma ray bursts is just starships exiting to realspace.
What would happen to radio transmissions from an Alcubierre drive fitted space ship while in transit?
I'm not an expert on the physics involved, but I imagine they would probably just get reflected back as Hawking radiation or something.
The point of the bubble is to separate an object entirely from our own universe, because while there is a limit to information travelling at the speed of light, and relativity makes it impossible for an object with mass to approach lightspeed, there are no such limitations on spacetime moving through spacetime.
If anything can cross the threshold and get into or out of the bubble in transit, then there is some degree of quantum entanglement and information transfer and it still counts as a "thing" in our universe, so I would assume the trick only works if the bubble is essentially a black box.
speculatory edit: this also seems to suggest that a ship in an Alcubierre bubble would be blind and unable to actually steer. I don't know if the bubble itself would decay (possible due to collisions with interstellar matter or some inherent instability) or would have to be collapsed from the outside. If the latter, then you need an existing infrastructure of stargate-like things already in place (either moved by conventional means or constructed) and just have to hope they're working and where you're aiming when you set off. There might be models that overcome these issues, I don't know.
If it turns out that Alcubierre drives are the only viable means of FTL, then one possible solution to the Fermi Paradox might lie in the complications inherent to using them - the civilizations that survive tend to be the ones that don't progress beyond simple rockets and radio telescopes, and FTL civilizations are still limited to expansion at below relativistic speeds, and even then the inherent complexity and risk means FTL travel isn't likely to be common.
I'm not sure even having stargates/mass relays would be enough if the bit about collected stray particles turning into omni-directional death-rays upon exiting the bubble is true. You'd need to somehow actually carve a clear path in space-time between any two points.
Alternatively, you might be able to create some sort of limiter and only do "short" hops that limit how much energy gets ejected upon exiting. If you're building up energy inside the bubble though, wouldn't it be putting some kind of strain or pressure on whatever has to maintain the bubble? Seems like that alone would create an upper limit on how much you can "charge" it up.
And since heat and radiation may be factors inside the field, available shielding might also be a limiting factor.
And then I would solve the particle problem by saying the field somehow converts real particles into virtual particles and then put bars on my windows to protect against the bricks thrown by physicists ;)
It's probably no more a factor than how thick the paint is on the hull.
The whole thing is also a case for building spacecraft with as small a cross section as possible, less chance of hitting something large.
A long spear is an even better shape, though.
Low density regions of interstellar medium can have as few as 10e-4 particles per cubic centimetre. At 0.1c, that density works out as 3e10 particles/m^2/s. At that density and energy per particle, 0.0895 W/m^2. Low enough you wouldn’t care.
Molecular clouds, on the other hand, can be up to 10e6 particles/cm^3. Most of those molecules are hydrogen, so they don’t hit as hard on average… but that’s a rounding error compared to the density, so let’s say about half a gigawatt per square meter.
TL;DR — go around the molecular clouds until you invent a Trek-like navigational deflector.
It’s a great series, but it’s not hard sci-fi, just a great storytelling mechanic.
At best, it sometimes tried, depending on the writer, to make nods to actual science. The original series seemed to have input from actual engineers and scientists, which is why you have the nacelles separated (to protect from radiation) and Bussard collectors, but then as time went on, it sort of became magic particles and subspace and not even bothering with the pretense.
Call it a distributed probability modulation drive. Just don't get entangled in the math.
https://www.theguardian.com/news/2017/jul/28/is-the-world-re...
It could just as well be true for all of them as well (assuming it is for the rest of course).
The "but now X group has rights" argument doesn't mean much. Such rights are a small, and rather insignificant part of life. Women, gays, lesbians, and racial minorities had huge great movements and tons of fan in the 70s in their everyday life as well. It's not like their whole existence was diminished by how others conceived them or whether they had this or that law.
A black who had a steady Detroit job in the 70s in a nice home, family and so on, felt much better off than an unemployed same-aged man in Detroit today, even if the second has more nominal rights and articles about him now (not to mention that there are probably more police shootings of blacks today than in the 70s, and let's not even compare Trump to Carter or even Nixon on that regard).
Or go talk to gay people, and see how they feel about the 70s and 80s, and various scenes that existed then compared to today. You'd be surprised Living in a looser and laxer decade can be more important than having some right in some law book (gays then partied far more widely and extravagantly than the meagre contemporary scene where they have rights, sure, but society is run by prudes and money spoilt most scenes).
Heck, in the same period we had a full blow military dictatorship in my country, and people can still wax poetically about the times and the fun they had. Even people persecuted then and even tortured by the police at this point or another.
But yeah, it doesn't make that much sense.
Ie. explaining the “missing” mass of the universe
Besides, it's just tiny part of the galaxy (1E37 kg vs >1E42 kg).
Edit: got it, trillion.
But yes, why use "packs of butter" as a unit? I mean, what size pack? Pounds? Kilos? Pats?
Edit: OK, 250 gm packages, standard in the UK, and generally outside the US.
40 trillion trillion trillion packs of butter.
Toxic butter.
I have a new favorite unit of volume.
And also it's almost impossible to get upvotes. Why are we so toxic on here?
HN's official policy is that it isn't reddit and doesn't want to be reddit. In my opinion, intolerance of jokes is the entire distinction between the two.
There's also the issue that jokes are often misunderstood and end up causing even more wasted text.
That's its culture, there's no "official policy" along those lines.
In fact, the guidelines used to warn people not to claim that Hacker News was turning into Reddit, calling it a "common semi-noob illusion."
I'd rather not comment at all when comments on here seem to mostly displease other people.
Toxic does not mean "anything that I don't like".
Usually I end up with -1 or -2, even on normal serious comments.
Meh...
So sure you could harvest the volume of the earth in deep space and get 21 kg worth.
How do you figure? I'd think gravity would cause it to clump up, and draw it toward massive bodies.
And this material would also probably not get trapped inside solar systems to a large degree, because as the article notes, the solar wind has a greater infuence on it than gravity.
(Sorry... couldn't resist...)
We know so much more about the universe, discovered a huge number of exoplanets, and still hold on to these traditional ideas. Carbon is essential to life as we know it, that's it.