Joe over at It’s Okay to be Smart, hates waking up to bad news, in this case the news that NASA is dialing back some of their outreach due to sequestration budget cuts. I have already noted that the GOP was shocked, shocked! that the White House was canceling tours so that they could deploy secret service agents, and that (IMO) the Smithsonian was making a tactical mistake by hiding the effect of their cuts and crippling their future.
While I hate to see it happen, I think it’s the proper course of action, so that the voters can see the effect of a dysfunctional congress.
[T]his picture is far more exquisite than any that came before. In the early 1990s, the COBE satellite gave us the first precision, all-sky map of the cosmic microwave background, down to a resolution of about 7 degrees. About a decade ago, WMAP managed to get that down to about half-a-degree resolution.
But Planck? Planck is so sensitive that the limits to what it can see aren’t set by instruments, but by the fundamental astrophysics of the Universe itself! In other words, it will be impossible to ever take better pictures of this stage of the Universe than Planck has already taken.
Planck being an ESA satellite mission to measure the cosmic microwave background differences down to a resolution of a few parts per million.
If you go their youtube page you’ll see they’ve done several Beatles songs.
Slowed this much it sounds a bit like a whale-song chorus. Not for foot-tapping, but maybe for background/relaxation. I’ve played with slowed songs before but I’ve only gone to 3/4 or 2/3 speed; Linda Ronstadt’s “You’re No Good” gives me the mental image of a singer in a black dress, single spotlight in a smoky bar when it’s slowed down. Elvis’s “Burning Love” is definitely more bluesy. There are a few Heart and Blondie songs I like as well (some with the slowed voice pitch, some preserving the original; the Amazing Slow Downer app I use allows one to adjust that. However, it’s limited to 20% of the original speed, or a slowdown of 5x. Still, interesting sounds.)
This may be a tad long for some people, but I think it’s worth it. Neil DeGrasse Tyson patiently explaining many of the reasons the so-called evidence for UFOs is rejected. It also couples nicely with why you should think like a scientist over at Uncertain Principles, because the UFO crowd could use a good dose.
Specifically,
Stripped to its essentials, science is a four-step process: you look at something interesting in the world, you think about why it might work that way, you test your idea with further observations and experiments, and you tell everybody you know what you found.
Any group falling into the argument-from-ignorance pit that Tyson describes are skimping on step 2, when they leap to the conclusion that, e.g. what they saw is an alien, rather than thoroughly thinking about/investigating other possibilities, and then they completely omit step 3, proceeding straight to 4. (5, of course, is right out)
Tyson gives one example of step 3 — grabbing some physical object if you’re ever abducted. There are other possibilities, but they have to better than blurry pictures or videos. There’s really no excuse, either, because there are plenty of amateur/citizen scientists out there, doing quality, rigorous work. The UFO crowd refuses to live up to that standard, and they will continue to be marginalized as a result. (They’ll be marginalized if/when they come up empty-handed, of course, but that shouldn’t stop someone who is convinced they will find the crucial evidence)
Caveat emptor: he’s doing a radio show, so there’s a necessary downconversion of the depth of the discussion. He does err when he implies that massive objects traveling at c is a technological/engineering barrier, and we just haven’t figured it out (like breaking the sound barrier), rather than a physics barrier that would demand that current theory be wrong or incomplete, with some new physics necessary to explain what’s going on.
In general the “photons don’t experience time” is a bit of a tiptoe in the mine field, because we can’t definitively say what things look like from a photon’s perspective — relativity doesn’t afford us a description of what things look like to a photon. The Lorentz transforms — what we use to see what things are like for massive objects — “blow up” when v=c, which means that the photon is not in an inertial frame, and all that physics we do is for objects in inertial frames. The reason I hesitate is that an equation diverging from some infinity showing up means that the equation has failed, so the fact that a term is tending toward infinity (or zero) as it fails isn’t a guarantee that infinity (or zero) is the right answer when the equation no longer applies.
The idea does paint a nice picture, though, and seems consistent with the QED path-integral idea that photons sample all paths and most of them destructively interfere, and what we see is the result, but I think it’s easy to take the idea too far and imply things that don’t have any experimental backing to assure us they are true.
A fun stroboscopic effect. The water isn’t really spiraling, of course, the effect is because the frame rate and sound wave frequency are the same, so the locations here the sound displaces the water (or doesn’t) is the same whenever a frame is recorded. Or close to the same, when he goes 1 Hz in either direction. Same effect as wheels looking like they are revolving backwards in some movies. You’re sampling images at the difference frequency.
