“Thinking isn’t agreeing or disagreeing. That’s voting.” -Robert Frost
Our first week of may has gone by here at Starts With A Bang, and we’re just $26 in pledges short, over on Patreon, of unlocking our next goal! In addition, we’ve also guest-starred on a Podcast/radio show over at Science For The People, on stories from Beyond The Galaxy:
- Can we use quantum entanglement to communicate faster-than-light? (for Ask Ethan),
- Curiosity’s first visit to the Martian dunes, in visuals (for Mostly Mute Monday),
- The science of atomic bombs, and how we stopped Hitler’s,
- How do we know the distance to the stars?,
- Top 10 facts about the Big Bang Theory, and
- Science is not a democracy, and never can be one.
The next Starts With A Bang podcast — on dark energy — will come out next week (I’m stoked!), and for those of you who can make it to Centralia College on May 20th at noon, I’ll be speaking there on the Fate of the Universe. And now that you’ve gotten the weekly redux, let’s jump into it without further delay: your Comments Of The Week!
From Ragtag Media on the possibility that entire scientific fields are driven by non-scientific forces: “Surly you trust Scientific American on at least the potential?
”An Epidemic of False Claims
Competition and conflicts of interest distort too many medical findings”
It’s important to consider what’s happening and why it’s happening whenever you evaluate the scientific truth or feasibility of something. In the medical field, we have an interesting combination of circumstances:
- Patients have problems, and the causes of those problems are often difficult to identify.
- The symptoms that occur in patients may not always overlap, so it’s a difficult task to determine which set of symptoms correlate with which root cause.
- Initial attempts at treatments (or studies of any type) are often done on small sample size groups.
- Only positive (not null or negative) results are ever reported in the literature.
So you wind up with a situation where — even independent of conflicts of interest — initial medical results are hard to reproduce. But this is part of the luxury of physical sciences: we can collect so much data over such long periods of time and so robustly that we’re not stuck chasing 2-sigma results looking for a signal. 4-sigma, 5-sigma and even better results are common, and allow us to deduce scientific truths about the Universe that are far less ambiguous. I know climate science is your core area of distrust, so why don’t you go and take the (publicly available!) global temperature record for yourself and do the analysis, and see what you find as the trend for warming over whatever time period you choose. I’m curious what you’ll conclude?
From Michael Kelsey on what happens to a thin solar/laser sail traveling at ~20% the speed of light: “But protons will see the whole atom via electromagnetic interactions, and the total ionization cross-section is as large as the whole atom (typically reported in units of 10^-16 cm^2, or 100 Mb), so this suggests that ionization (and hence some form of heating) will occur for nearly every collision.”
For those of you hoping to travel through interstellar space at ~20% (or more) the speed of light, I hope you like ionization. (Or I hope you have a great magnetic deflector to avoid it!) Unless your goal is to send a tattered stream of ions to the stars, I think this is yet another legitimate obstacle for the breakthrough starshot.
From JG Bennet on faster-than-light communication: “If a spacecraft had a sail and a satellite based laser shot that sail and pushed it to almost the speed of light and the craft had a communications laser pointing to another satellite, like the wire on a wire guided missile to its controller, could you see a live feed if the connection never broke even if the craft is 20 light years away?”
Nope; the problem is that light all massless particles in the Universe travel only at the speed of light, and all massive ones (which you want to send the signal through) are restricted to travel at under the speed of light. Your “live feed” would be at least 20 years out of date by time it arrived.
From Paul Dekous on quantum indeterminism: “I’m simply saying that according to QM, the particle doesn’t have an actual axis, until you try to measure it.”
This is actually weirder than you imagine. Imagine you’ve got some spin-1/2 particles, that could either have spin +ħ/2 or −ħ/2. Let me ask you, now, if you measure the spin along the x-axis, what the spin is? You’ll get some that are +ħ/2 and some that are -ħ/2.
But what if you now measure the spin along the y-axis? You don’t get zero; you get either +ħ/2 or -ħ/2.
So what if you took the ones you measured to be +ħ/2 in the x-direction, then measured the y-direction and got either +ħ/2 or -ħ/2, and then measured the x-direction again?
You’d find, quite puzzlingly, that 50% of the particles would have a spin of +ħ/2 and the other 50% would have -ħ/2. In other words, by making one measurement — along the y-axis — you randomized (or threw back into an indeterminate state) the spins along the other two axes. For lack of a better term, it “remembers” what you did to it.
From Ragtag Media on defeating the speed of light… with your mind: “I think perhaps only Ethan can relate to my concept of the minds imaginations ability to conceptualize faster than light concepts.
In one’s mind you can go from imagining hovering over the surface of the sun in one moment to walking on Pluto the next.”
This is the most hippy-dippy thing you’ve ever said, Ragtag!
No, just kidding. You can imagine whatever you like, and in terms of shadows or other “non-physical” signals, you can have them go infinitely fast. But if you want to program them to “make signal A or signal B,” you can only begin creating those signals at the speed of light. Other than that, you’ve got to cheat spacetime itself, which you’ll need things like wormholes or some sort of “space contractor” or folder to get there. Good luck to you with that.
From Sinisa Lazarek: “We generally associate mars with red, yet this close up shows very blue-ish hues. One can see the hints of red and yellow beneath, but almost looks like top soil is blue-grey. Is this because of lighting in this particular case..or is it due to chemical composition.. or is it ice in form of sand.. ?”
Although Michael Kelsey had a great response to this, I’d like to declare that these are definitely false-color images. Why? Because having Mars appear in 256 shades of red isn’t all that informative or interesting. The atmosphere itself causes everything to be red, and the geology itself is red. There are other colors at play, though, and so we do a whole slew of image processing to make them appear more clearly. “True color” images aren’t very informative. Here’s an iconic photo of Victoria Crater as imaged by Opportunity, often cited as “that’s gotta be Earth!”
Beautiful! Spectacular! Earth-like! Amazing!
But this is in false color. What did the true-color original look like?
Also amazing, but far more alien and, well, Mars-like. But that’s because this is Mars, and yet we encode this planet’s information to make it more visually informative. Hence the false-coloration. Sorry if it misleads you to think it’s more like Earth than it actually is.
From schnablo on World War II: “Not only heavy water in Norway,
‘you’ also bombed my physics department. (No hurt feelings )
Greetings from Leipzig”
You can take the quotes around ‘you’ away. I may have been born in 1978 in New York, but I’m pretty sure I’ll take the fall for that. But this underwater nuclear bomb test, shown above, didn’t happen until 1946.
From skepticscott on Hitler’s atomic bomb program: “Whatever technical know-how Germany had regarding the construction of an atomic bomb, they simply did not have the infrastructure and resources to succeed at it in any practical sense. On the US side, it was the biggest and most expensive scientific project ever undertaken, by far, and had Germany thrown all of the resources into it that would have been necessary to create a working bomb, it would have compromised their war effort in many other ways.”
This is probably quite fair. The Wehrmacht really devoted practically all of their resources towards conventional war efforts: land, sea and air. The bombs and rockets they developed were incredibly damaging and expensive, but also represented pretty much all of the German funds available. Meanwhile, the US poured in the equivalent of ~$2 billion into atomic bomb research, having the luxury of being a continent away from the main action. One of the surprising things I read in Bascomb’s book was that when Roosevelt and Churchill met, the latter expected some sort of deal to need to be made in order to share intelligence and resources on atomic bomb research. Roosevelt basically gave a, “what’s ours is yours and what’s yours is ours” deal to Churchill on that, and never renegotiated.
From See Noevo on something that I would be ashamed to think: ““1.) Einstein first dismissed it outright when it was presented to him as a possibility.”
Meaning he later did *not* dismiss it?”
Yes, absolutely! Einstein dismissed it because his predispositions were biased to go down another route. But when the evidence came in that showed his preferred explanation (of a non-expanding Universe) was a no-go, and that the Universe was expanding, Einstein thoroughly embraced this as a legitimate possibility that necessitated investigation.
If this is not how you approach or think about science, there is an internal journey you must take before you’ll be able to properly think in scientific terms. I hope you get there.
Also, as (obliquely) requested, the above map shows the CMB fluctuations, or departures from uniformity, whose magnitude are on the tens-to-hundreds of microKelvin scale. The galaxy is also subtracted out.
While this map shows the temperature of the CMB with the (monopole) signal superimposed on it. The galaxy is present, and is the only non-uniform signal visible. Why? Because this signal is more than 10,000 times as strong as the signal from the fluctuations, which is why you cannot detect the imperfection in the roundness of a billiard ball. Looking for the imperfections in the CMB is like looking for paramecium-thickness fluctuations in the smoothness of your basketball court. Which is to say, it’s quite uniform.
And finally, from Narad on star formation and what’s still not known: “‘You can Google “star formation theories” and the top non-wiki hit includes [sic] this’
Yes, it’s a 1971 paper from Rep. Prog. Phys. That’s just embarrassing. Go try to figure out how to use ADS or something.”
The most important thing I can add to this is the perspective that science often progresses steadily and incrementally, and only sometimes in great, exciting leaps. When it comes to any scientific topic — and star formation is a fine example — we never reach the point where we say, “that’s it, this is done; this is completely understood and all problems of arbitrary complexity are solved, and this field of science is over.” Instead, we have a set of well-understood pieces, a set of partially-understood pieces and a set of poorly-understood pieces, and we strive to better understand everything in all categories, and sometimes even meet with surprises. But we have to keep asking questions and listening to what the Universe tells us when we ask. That’s the only way we progress with any sort of meaningful knowledge.
Thanks for a great week, and I’ll see you back here tomorrow for more wonders of the Universe on Starts With A Bang!