AMS Has Found Something
AMS-02: Shining light on elusive dark matter, ESA
“The findings hint at a new phenomenon but it is unknown whether the positron ratio comes from dark energy particles colliding with each other or from pulsating stars in our galaxy that produce antimatter.”
First Result from the Alpha Magnetic Spectrometer on the International Space Station: Precision Measurement of the Positron Fraction in Primary Cosmic Rays of 0.5-350 GeV, Physical Review Letters
“These observations show the existence of new physical phenomena, whether from a particle physics or an astrophysical origin.”
We’re lucky to be living in interesting times. Today science is starting to get answers to questions that weren’t yet formulated not too many years ago. Of course, researches into the nature of the universe have a habit of introducing two new questions for every answer found.
It seems to me that the more data we acquire, the more questions we have to ask.
Thats the way science works. Unless you are content with something like “42”
Science expects as much. There will never be a moment when anyone can say, “Aha! Science has found everything and is done.” There will always be more questions generated by each new discovery. That’s the power of science.
Folks:
AMS has found something… and it’s not evidence of ‘dark matter’.
The universe is a simple place. There’s no room in it for the kind of math magic some physicists use to explain dark matter’s existence.
Simple, like this: e=mc²
tinker
Tinker, seriously?
So the mathematics describing general relativity, which Einstein had to take a break in order to learn before he was able to complete his theory, is ok and “simple” – but the mathematics behind dark matter isn’t? (I take it you’re quite versed in general relativity, right?)
Or do you think that general relativity is described by E=mc²?
And “some scientists”… You do realize the Einstein, in his time, was “some scientists”, right?
Sorry for being snappy like this, so here’s a more moderate response.
Einstein himself said that the theory should be as simpler as possible – but no simpler!
GR was an incredible complication over Newtonian physics. I’ve taken physics as an EE. Special relativity is sort of within my grasp. General relativity is complete madness. Start here: http://en.wikipedia.org/wik… … and tell me when your head explodes for the first time. Took me about two paragraphs.
All this, because Newtonian physics couldn’t explain observations. There was no simpler way to fix it, and obviously you consider it simple enough today.
Right now, physicists can’t account for most of the observed mass of the universe. So either General Relativity has to be modified, or we’re missing some mass. There are multiple observations that support option #2, including detailed mapping of this unobserved mass.
So when you denigrate the bulk of science into “some scientists” and “magic math” and add a clever “the universe is a simple place” statement, as if this bit of wisdom somehow counteracts their conclusions – you’re actually just simply out of line.
Tinker,
I think it’s fair to say that, at this point in time, what AMS has done is made some observations, unique observations, and nobody knows yet for certain what those observations are evidence of, or not evidence of. Like all such science, we need to give the experts some time to confer and think and come up with their opinion(s). Then we can debate their interpretations. Also, I always like to keep in mind that in the history of science it’s quite common that the the first answer proposed to something new and complex is often a wrong answer, and the same applies to our own ideas. Let’s wait and see.
Steve
And lets all remember – evidence can only disprove a hypothesis. So whatever AMS shows can only invalidate some, and bolster other hypotheses, but never PROVE anything.
That’s correct, and it appears that the AMS data is consistent with what would be expected from the WIMP theory of dark matter. That’s still big news.
Yeah, it’s only a result whose data is what would be expected according to the WIMP theory of dark matter.
I note that you use some “magic” to wave a wand over what physicists do in order to dismiss that work. Do you have any actual information to support your “dismissal”? FYI, you’ve chosen the wrong energy/mass equivalency expression. The one you selected only expresses total energy in rest mass and does not factor in kinetic energy or relativistic effects.
If you’re going to poo-poo something, you really need to have more in hand.
As far as simplicity goes, you are far off the mark. There is no requirement nor any implication that the universe is or needs to be a simple place. Taking a few science classes like thermodynamics (physics not engineering), modern physics, or a few others would show you that.
Every day finds examples of the complexity of the universe. Heck, it’s likely you avail yourself of that complexity every day. Do you have a GPS? If so, then that device requires “math magic” to work. Special Relativity is needed to correct time moving more slowly for the orbiting GPS satellites, and General Relativity is needed to correct for time moving more slowly deep in Earth’s gravity well, here on the surface of our planet. Without those corrections, GPS accuracy would go to hell in a hand basket. Lest you think otherwise, SRT and GRT are anything but straightforward and “simple”.
Lucky for all of us, science follows a strict script in the form of the Scientific Method, and it has no room for baseless belief, such as the belief that the universe is a “simple” place.
The AMS is the solid science that the ISS was supposed to accomplish. Years ago it had been speculated the AMS alone might be worth the entire ISS project! And it darn near was cancelled when NASA was in a hurry to stop the space shuttle flights. Thank goodness it wasn’t.
This is *very* exciting! It’s one of those rare discoveries that has a possibility of making an important change in our understanding of how the universe works. Way to go NASA!
This result is exciting, if not yet completely clear as to what it is telling us. However, to give NASA credit is to not understand the history of the experiment. AMS is only there because Dan Goldin was taken with Nobel Prize winners, in this case Dr. Sam Ting, the PI on AMS. The NASA after Dan left tried very hard to kill AMS, but like Gravity Probe B, it survived in spite of NASA.
Even if some people in NASA worked against AMS, NASA as an organization ending up playing a key role in it. Nothing but the shuttle could have put it on the ISS. So, I believe NASA deserves credit for that.
Of course, lots of other organizations and individuals also deserve credit — just look at the list of authors on the paper! But this is NASA Watch, not ESA Watch or Texas A&M Watch. We’re here primarily to discuss NASA, so let’s give NASA some credit for something very important that they did right.
Without getting into a debate about the merits of the Shuttle, in the interests of future capability, I’m curious about whether or not “only the Shuttle could have done this” is accurate.
The dimensions of AMS-02 appear to be a roughly 3m cube, weight 6,717 kg. That’s well within the capabilities of an Atlas V 541 with a 5.4m fairing, and leaves 1500kg for attaching a small propulsion bus to guide the AMS to the station for capture by the station’s arm. Russia has launched station components such as Pirs (comparable dimensions, but lighter) using this method. If the propulsion bus needed to be heavier, a larger Atlas or a high-medium Delta IV seem like they would also be options.
Pardon, I was looking at the wrong numbers for the Atlas V. A 541 would have 10,000kg of room for the propulsion bus (and fuel), not 1500k.
Sure, you could do it that way, but what you call a “small propulsion bus” I’d call an orbital tugboat. This orbital tugboat would need to be a fully functional spacecraft, with propulsion, guidance, attitude control, thermal control, etc. And it would need to be certified by NASA for proximity operations in the vicinity of the ISS, which probably means a lot of redundancy and fine control capability, and something like DragonEye for precise positioning information relative to the station. This is doable, but it’s not trivial.
When I said that only the shuttle could do it, I meant without developing something else new as an alternative, and I would consider this tugboat something new that would have to be developed.
Sounds like a useful device, though. An adaptable upper-stage with advanced prox-ops capability, compatible with multiple expendable launchers, and turns any payload into a “smart” payload. [Kind of like the JDAM kit does for dumb-bombs.]
It would be a good project for a new round of multi-vendor COTS.
[Obvious use in ISS large-component delivery, but also would be useful for everything from satellite recovery to fuel-tugs.]
[Edit: Even better, standardised bolt-on prox-ops kits for existing upper-stages.]
Paul, I completely agree, it would be a very nice tool to have in the toolchest, and a new COTS-like program would be the best way to get that capability developed.
When faced with this exact issue, the Russians simply took their existing Progress craft and chopped off the pressurized cargo module. Surely SpaceX or Orbital could achieve something similar with their respective spacecraft. Given the differences in their designs, it’s probably something Orbital could do with less effort.
That’s why way back in the early 70s when the term “Space Transportation System” or STS was coined, it included three parts: Shuttle, Station, and the reusable Space Tug, to move payloads to and from the Station. By the time Shuttle program was cancelled in 2004, the AMS had been sesigned for a Shuttle launch and was so far along that to redesign for ELV launch would have been unaffordable. We are lucky the Obama administration elected to extend Shuttle by a couple of flights, partly because of AMS.
totally kewl.
Does anyone know if they had used the more sensitive super conducting magnets that were cooled with liquid helium would they have had more accurate and possibly more definitive results?
I never really understood the swap out of this part of the instrument. After all, the ISS is man tended so I don’t understand why the liquid helium couldn’t have been replenished.
The superconducting magnet would have used superfluid helium to maintain an operating temperature of 1.8 K. It would have had both the helium tank and magnet enclosed together inside of a vacuum case. Apparently with this design it was either not possible or not practical to make it refillable on orbit. The inevitable boil off of helium is what limited the originally planned AMS lifespan to three years, however at the time they didn’t think that ISS would last that much longer anyway.
The permanent magnet that they wound up using was considered a better fit for what is now an extended ISS lifespan. Also the permanent magnet had already been flight tested on the AMS-01 Shuttle flight so they had less to worry about in terms of delays caused by problems. Considering that they barely squeaked onto the second to last Shuttle flight they probably made the right decision.
As to what AMS might be missing by not having the more powerful superconducting magnet, I don’t know if they have said if there are any specific tests or theories that won’t be possible. Of course the primary purpose of AMS is to search for the unknown, so it’s probably hard for them to say what they might miss by not having a superconducting magnet. I would guess that discoveries made by AMS-02 and the theories that come out of it will eventually lead to a superconducting AMS-03, although depending on the timeframe that would probably be on a post-ISS platform.