NASA Poised To Topple a Planet-Finding Barrier (nextbigfuture.com) 66
schwit1 shares a report from NextBigFuture.com: Babak Saif and Lee Feinberg at NASA's Goddard Space Flight Center in Greenbelt, Maryland, have shown for the first time that they can dynamically detect subatomic- or picometer-sized distortions -- changes that are far smaller than an atom -- across a five-foot segmented telescope mirror and its support structure. Collaborating with Perry Greenfield at the Space Telescope Science Institute in Baltimore, the team now plans to use a next-generation tool and thermal test chamber to further refine their measurements. The measurement feat is good news to scientists studying future missions for finding and characterizing extrasolar Earth-like planets that potentially could support life. To find life, these observatories would have to gather and focus enough light to distinguish the planet's light from that of its much brighter parent star and then be able to dissect that light to discern different atmospheric chemical signatures, such as oxygen and methane. This would require a super-stable observatory whose optical components move or distort no more than 12 picometers, a measurement that is about one-tenth the size of a hydrogen atom.
Space based? (Score:1)
I am clearly no astrophysicist, but would it not be more effective to stick 4 or 5 hubble sized optical telescopes working as one large one in the L1 or L2 points?
I know that it is more expensive, but with the cost of launches dropping as fast as they are, I should imagine this would be affordable by the time they can actually build the things.. which I guess is at least 10 years.
Ideally they would put a research lab there as well.
Re: Space based? (Score:2, Informative)
I guess you haven't heard of the James Webb Space Telescope (JWST).
Now launching in 2019 unfortunately. :-/
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Re:Space based? (Score:4, Informative)
Re:Space based? (Score:4, Informative)
To make multiple telescopes work together "working as one large one", you have to control the positions of their mirrors relative to each other to a small fraction of a wavelength. That's what this is about.
I'm not sure what they need picometer accuracy for, though. That seems more than the requirement.
Dude, forget gravity! (Score:2)
Magnets, how do they fucking work?
Re:Perhaps they will explain gravity (Score:5, Informative)
Yeah, and then they went and discovered that pesky neutron. Oh, and quantum mechanics. And don't forget, quantum field theory, an absolute plethora of particles, neutrinos, and both special and general relativity! But even before these developments drove a stake firmly through the heart of "gravity as electromagnetism in disguise", as you note:
Attempts to unify the two basic forces of the universe, usually by reducing gravitation to electromagnetism, was part of the electromagnetic program, but in spite of much work, no satisfactory solution was found.
Now, of course, just because they didn't find a satisfactory solution doesn't mean that there isn't one. However, in the meantime, solutions that ARE satisfactory have been obtained that describe gravitation as an interaction that is very much not reducible to E&M, or as curvature of space-time by mass-energy that need not be (and in the literal bulk of cases, the quark-quark interactions that govern nucleons and nuclear binding energies, is not) electrodynamic in origin. While I agree that to a large extent particle "mass" is the self-energy of its local field structure and might end up ALL being field energy in the end (once we unify field theory properly and completely), there are more fields than just gravitation and electromagnetism and more elementary particles than just electrons and "nuclei", which is about all that was known in 1904. Also, Maxwell's Equations simply don't have any ROOM for gravitation, with or without magnetic charges (symmetric completion). Whatever the TOE turns out to be, it (almost certainly) isn't "just" going to be MEs classical or quantum or QED tied to ELECTRONS. You see, sir, there are those pesky definitely-not-an-electron neutron, neutrino, muon, quark, photon, gluon, heavy vector boson thingies, many of which we can directly "see" in modern collider experiments, others which we can almost directly infer (quarks BOTH from structure AND from observations of jets).
And then there is the Higgs particle, which has possibly maybe mostly been seen but which awaits a few more sigma and which (sigh) sure, might turn out to be a chimera once again. But it is a pretty compelling theory and it, not MEs, does appear to provide an explanation for mass.
Perpetuation of an old idea in the teeth of all of the evidence accrued in the meantime that it was incorrect requires a sort of wilful blindness and is indeed the sign of either a crackpot or a troll. OR you could just be kidding on the trollish side of things, but reposting an old thing from well over 100 years ago... really?
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Me too. But then we'd have to RTFA, right? And sadly, I have to teach instead.
I'm guessing that they use something like embedded nanoscale electronic devices that are sensitive to surface expansion/contraction or the like. I could see measuring a change in capacitance at that scale as the separation between plates varies, or piezoelectric responses ditto. After all, atoms themselves are very rigid, so actually compressing one to 90% of its ordinary diameter requires a LOT of energy on that scale -- ther
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Using photons.
LIGO is effectively a big laser tape measure. You split a laser beam and send it down each arm where it hits a mirror and comes back. The beams will interfere constructively if they've travelled the same distance, less so if the distances differed by some fractional multiple of a wavelength.
If you're not sensitive to small enough changes with that, you make the arms longer or bounce the beam up and down them more than once.
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Well, or...
You could consider existing science as the solution to a complex optimization problem in a very large dimensionality, where what you are trying to optimize is the probability that your whole interconnected network of beliefs is correct.
In which case, while I absolutely agree that one should remain skeptical of the existing set of best beliefs, and while there is no doubt that there have in the past and no doubt will be in the future major rearrangements or even paradigm shifts, there remains the
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One straightforwardly physical way to explain gravity is as a distortion of electron orbitals
Then why is there gravity on a neutron star?
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One straightforwardly physical way to explain gravity is as a distortion of electron orbitals
Nope. Simple though experiment:
All EM fields are constrained to curved of space time. A side effect of this is that none of these fields may cross the event horizon of a black hole from the inside. No fields or particles inside can get out. Except gravity. Because how else would a black hole work? If gravity were some manifestation of electromagnetism, then the matter inside the black hole (from a collapsed start, for example) would not be able to influence matter on the outside. And this is clearly not th
Information escapes black holes too (Score:1)
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Besides Hawking radiation
My (simplistic) understanding of how Hawking radiation works: virtual particle/antiparticle pairs are created just outside the event horizon. One gets pulled 'through' the event horizon, leaving the other as a real particle, free to escape. So the real particle never actually passed back out through the horizon.
I don't know if the black hole merger constitutes information 'leaking out' of a black hole. We got a signal that may only have depended on the two objects masses and angular momentums. That is info
I can't wait... (Score:2)
to find planets we'll never be able to reach! ;)
Actually, with nanites to repair our bodies after being frozen for transport, we should be able to get to some of these planets in millions of years. However, you got to figure that homo-superior will be exterminating the last of our kind by then so we'll probably get exploded during transport.
What a great time to be alive! ;)
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If intelligent life 15 light years away can give us schematics for FTL drives, we could go there within a lifetime. That's a pretty good reason to invest in telescopes that can find life. Although if they detected a signal we sent them, they'd probably just come here first, since we probably wouldn't detect a FTL data signal if we were sent one.
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If intelligent life 15 light years away can give us schematics for FTL drives, we could go there within a lifetime
There are maybe 100 stars within a 15 light year radius, and the chance that any of them happen to have intelligent life right at this moment is very slim.
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Let's say there are exactly 100 stars within a 15 light year radius. Going by the process of elimination, we already know there's only 99 of those stars which could contain intelligent life around them.
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Let's say there are exactly 100 stars within a 15 light year radius. Going by the process of elimination, we already know there's only 99 of those stars which could contain intelligent life around them.
As has just been proven by this logic/maths. ;-)
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That depends on how long intelligent life typically lasts on a planet (as well as how often it evolves in the first place). Maybe it's typical for intelligent life to last billions of years. We don't know enough to say if it's likely or unlikely. The fact that we're a young species tells us nothing.
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Maybe it's typical for intelligent life to last billions of years
We've already seen the rise and fall of two dozen major civilizations here on Earth, so I wouldn't put my money on us surviving billions of years in a state capable enough to support interstellar communications.
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>If intelligent life 15 light years away can give us schematics for FTL drives
Then we have proof that either the Laws of Nature vary with location (because FTL is absolutely impossible here), or an alien prankster has control of the transmitter.
Re:I can't wait... (Score:5, Interesting)
yet the train is going at 1.2 light speed when measured against the outer ring.
No, it's going 0.88235 light speed when measured against the outer ring, because you have to apply the Lorentz transformation when adding relativistic speeds. The relative velocity of any two objects can never exceed the speed of light no matter how clever you set it up.
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Damnit AC, I'm a Web Monkey, not a physicist!
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If you want a quick working model of relativity, consider that you measure speed as distance per time. The trick is that as you observe things going different speeds from you, your time scale is different from theirs. You could be observing two objects travelling opposite direction at nearly light speed and say "they passed eachother at nearly 2x light speed" but neither object was passing you at faster than light speed, and from the relative perspective of each object, the thing that passed them was not
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I'm also not a physicist, but I'm pretty sure we could get lots of places farther than 15 light years "in the space of our lifetime" if we were able to accelerate to nearly the speed of light, since time would nearly stop for the ones making the journey. We would be "frozen" just by virtue of relative speed, without all that temperature freezing cell destruction hassle.
Can a knowledgable physicist confirm my other thought, that in the relative frame of a photon itself, no time passes at all between the time it is emitted and absorbed no matter how far it traveled? So if we had a way to convert our entire bodies into light and back, we would experience instantaeous transportation no matter how far we travelled?
To the first paragraph, yes, given say 1G constant acceleration and deceleration, time dilation comes into play. The longer you accelerate, the slower the spaceship time goes compared to the rest of the universe. It approaches an asymptote which effectively means the spaceship can reach anyplace within it's Hubble limit by a maximum time. IIRC, that time is around 24 years.
It's hard to say how a photon experiences time. It has a frequency and that can change due to various reasons, however, it doesn't reall
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That's the Lazarus Long method (of Robert Heinlein fame) of breaking the light barrier -- get right up next to it then give 'er the gun!
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Frame of reference error. If the train achieves 0.6 C, and the ring below it is accelerated to 0.6 C, then the train would be stationary compared to that ring. The energy required to accelerate the train further is not dependent on the arbitrary speed of the ring below it. The train will not be able to reach C regardless of how many rings are stacked below it. If the ring were spun in the opposite direction as the train was traveling an observer on the ring could approach the train at a speed subjective
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If a train is going 0.6c relative to a ring going 0.6c relative to me, I'm not going to see the train going faster than light. Velocities don't add like that in Special Relativity. Similarly, you can't do anything to see anything coming at you faster than the speed of light. If those 50mph cars were actually doing 0.5c, they wouldn't be doing the speed of light approaching each other.
Special Relativity isn't that hard once you realize that "simultaneous" and "when" and "where" aren't defined by anythi
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We don't actually know that FTL is absolutely impossible. It's just as possible as time travel backwards, and not everyone's convinced that's impossible.
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Re:I can't wait... (Score:4, Interesting)
>to find planets we'll never be able to reach!
It is entirely possible there are 'habitable' planets within reach of our technology - if we're willing to invest in building a heavily redundant generation ship and live forever in domes when we arrive at the destination, totally dependent on advanced technology for survival.
If I were a gambler, I'd say finding a Mars-equivalent would be like hitting the jackpot...
Re:I can't wait... (Score:4, Funny)
You never heard of atmosphere processors? It's a one terawatt fusion reactor power plant, about 1500 metres in height, manufactured by Weyland Corp.
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You never heard of atmosphere processors? It's a one terawatt fusion reactor power plant, about 1500 metres in height, manufactured by Weyland Corp.
For Mars, there's not really enough atmosphere to process, so what they really need is a smelter. it would take the iron, silicon, and aluminium oxides that are common on the planet and process them into building materials while pumping oxygen into the atmosphere. Other gases such as hydrogen and nitrogen would probably have to be shipped in from the satellites of Jupiter.
Overuse of the word "Barrier" (Score:2)
Chuck Yeager and the X-1 breaking the sound barrier is the archetype of this figure of speech. That genuinely was a barrier, because the aeronautics of supersonic flight are different than subsonic. There is a significant crossover - not exactly a discontinuity, but certainly an abrupt change - when going transonic. Progress in flying airplanes
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"NASA Poised To Topple a Planet-Finding Barrier" is the headline. Was there really a barrier to overcome here, or is it a milestone in improving capabilities?
Welcome to the English language, and the even worse news headlines. As someone who remembers the Watergate scandal, I'm tired of every scandal being named something-gate. The abuse of the word "literally" I find downright confusing at times. But I started to become inoculated against some of this when my daughter became a teenager. If the barrier thing is bothering you, just try sitting in a room full of teens and listen to them communicate in their pseudo English sometime.
This means build the TMT, now! (Score:3)
China has astronomically qualified sites on the Tibetan Plateau at over 17,000 ft (5200 m) and is already a partner in the Thirty Meter Telescope project. Rather than waiting for the American legal gears to grind away into eternity, site it there and get it built. Because its southern hemisphere companion instrument is already under construction in Chile, the long-baseline possibilities are unparalleled.
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To look at more than one thing at a time?
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The ELT is also in Chile, which has made astronomy into a real industry. It needs a companion instrument in the northern hemisphere, to see different stars and to eventually do advanced long-baseline observations in the band that both instruments have in common.
basic question (Score:2)
This is a great advance, but if we're talking solely about light-occlusion detection techniques*, aren't these results preconstrained by simple geometry to an astonishingly low subset of potential stellar systems?
This requires:
- the stellar main body must be physically occluded by the planet's orbital path (0.01% of systems at best, unless a) there's some sort of 'general ecliptic' for our galaxy AND b) we happen to be right on it)?
*and*
- the planet must actually be in that place in it's orbit; considering
1/20000 of a wavelength? WHY? (Score:2)
I'm having trouble understanding the significance of 25-pm distortions (0.025nm) in an optical telescope, where the light you're bouncing around has wavelengths on the order of 20000 times more than that (400nm-650nm, longer for IR). Does interferometry really let us detect phase differences that small?