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NASA Poised To Topple a Planet-Finding Barrier (nextbigfuture.com)
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.
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! ;)
Anons need not reply. Questions end with a question mark.
I guess you haven't heard of the James Webb Space Telescope (JWST).
Now launching in 2019 unfortunately. :-/
I think that's what this is about - making multiple telescopes work together. To get a high resolution from that the light has to interfere. The more accurate ths interference is controlled, the more accurate the image can be.
You've basically described the James Web Telescope, it has 18 such mirrors. It's IR, but that is optical for cosmological distances.
Magnets, how do they fucking work?
#DeleteFacebook
"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?
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 faster and faster went quickly during and after WWII, but stalled for a bit before we achieved supersonic flight.
But since that time, there is this notion that any kind of big discovery or technological achievement is somehow breaking a barrier. My favorite was in the early 2000s, when increasing processor clockspeed was all the rage: "Intel's new chip breaks the 3 GHz barrier!" Well, no, 3 GHz was not a barrier - the chip was not fundamentally different in its construction or operation as one running at 2.9 GHz, or 3.1 GHz. At best, 3 GHz was a milestone - a nice round number that looks good on advertisements. But it's only a round number due to how humans measure things; if our definition of one second were different, or if we didn't count base-10, then that clock speed would be some other, not-so-advertiser-friendly number.
So I'll reiterate my opening question: is this new optical technology really breaking a barrier, or is it a (significant and praiseworthy) discovery that lubricates the wheels of our ever-expanding progress?
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?
Even when the experts all agree, they may well be mistaken. --- Bertrand Russell.
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.
One straightforwardly physical way to explain gravity is as a distortion of electron orbitals
Then why is there gravity on a neutron star?
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.
http://www.geoffreylandis.com
I would like an explanation of how we can talk of 1/10 diameter of a hydrogen atom. I have read similar dimensions in talk of how far the mirrors in LIGO wiggle. Less than the smallest atom, so, using STUFF how do you measure things smaller than, than, stuff? I presume it is an average of all atoms in the mirror, but still
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 that the first confirmed detection was only 25 years ago, and CONFIRMATION really takes 3 'hits', we wouldn't have yet detected any Jupiter-orbital body in a Sol-similar system (period 11+ years)
- that we haven't moved enough in the meanwhile gathering those 3 'hits' that we've lost the favorable geometry in the first place.
My point is that I haven't heard much discussion about these odds?
If the system is likely to only detect 0.01% of planets, and has already detected hundreds, it's a near-certainty that there are hundreds of thousands that we HAVEN'T detected, no?
*Yes, we also detect planets by stellar primary motion now, but it would seem that those detections are subject to a number of other possible explanations, and thus have larger error bars.
-Styopa
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 -- there is energy to work with.
I'm also guessing that they do not use any sort of wave -- it would have to be fairly high energy gamma rays to have that sort of wavelength.
But then, we should RTFA.
Even when the experts all agree, they may well be mistaken. --- Bertrand Russell.
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 the case, as evidence for the existence of black holes is their gravitational effect on external objects.
Have gnu, will travel.
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?
"Only gravity escapes a bh". Besides Hawking radiation - Take the merger of two black holes. We did detect two black holes, circling each other, each inside the other's event horizon (for a fraction of a second). This is information leaking out - we know how long the "merger" took.
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.
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 simple fact that a) new ideas (like relativity and quantum mechanics) tend to embrace their predecessors and preserve their functionality in the appropriate domain; and b) THEY ARE EVIDENCE BASED. In the end, advancing hypotheses that have been soundly rejected by oh, a century's worth of work is just plain crazy.
This is for very good reason. In order to be credible, a "new" theory has to completely embrace everything that the old theory gets right AND get some new stuff right. Things like neutrons, neutrinos, atomic structure, nuclear structure, the actual particles observed to be created by nuclear collisions, and ever so much more.
In the meantime, maybe you should try to understand things like Gauss's Law and 1/r^2 force laws (and their underlying geometry) vs atoms "resonating together" sort of like the completely quantum mechanical DIPOLE INDUCED DIPOLE interaction seen in the SHORT range Van der Waals force. Until you do, it is difficult for me to even begin to explain why your assertion is absurd, and the "documentary evidence" supporting it, all from right BEFORE the major paradigm shifts that generated modern physics as we now best understand it, is utterly irrelevant and incorrect.
I also have no idea what "dead end" you are referring to in cosmology, and what your evidence is for considering the observations coupling gravitation to mass, which date back to Galileo, and the even stronger evidence coupling electrodynamics to not mass but charge, to be fundamentally incorrect. Note that I'm not addressing the difficulty reconciling general relativity, newtonian gravity, and quantum mechanics, because your remarks above seem to have nothing whatsoever to do with that, and because your proposed solution isn't even an ACTUAL proposed solution. That would require the support of a hell of a lot of real math and the demonstration that the new theory embraces the old and has actual quantitative explanatory power as well as direct evidentiary support, none of which exist.
Even when the experts all agree, they may well be mistaken. --- Bertrand Russell.