“You cannot escape the responsibility of tomorrow by evading it today.” -Abraham Lincoln
As you’ve come to expect, it’s been another fantastic week of science here on Starts With A Bang!? There’s a chance I’ll be in Las Vegas next month for the official Star Trek convention, and in addition to all we’re doing, there’s a chance that there will be a new YouTube video series coming out that features me and the fusion of sci-fi/fantasy with science. Sounds fun? You bet it does! Also, for those of you in and around Portland, OR, join me at 2 PM at the Oregon Historical Society today to catch my talk on the Last Great American Eclipse. You won’t want to miss it!
With all that said, here’s what the last week has held in terms of our new stories:
- Could we save the Earth by migrating it away from the Sun? (for Ask Ethan),
- Discovery of a young, dead galaxy creates a huge puzzle for astronomers (for Mostly Mute Monday),
- How a solar eclipse first proved Einstein right,
- The Universe itself may be unnatural,
- Sorry, Donald Trump, it can’t be infinity, and
- Is it possible to pull something out of a black hole?
With that out of the way, let’s all enjoy the best of our comments of the week!
From Pentcho Valev on the Universe’s beginnings and dark energy: “You have vacuum full of energy, detectors in contact with this vacuum which register strange noise coming from all directions, and you conclude that the noise is not produced by the vacuum energy but comes from the miraculous beginning of space and time.”
Yes, that is correct. Except, the way you’ve framed it indicates that you’ve misunderstood how everything about the physical Universe works. I’m happy to clear that up, but I want you to stay with me afterwards, too.
Yes, we have a vacuum that is full of energy, because we measure the zero-point energy of space thanks to the effect that such energy has on the Universe’s expansion. That is the only way we detect this energy, the energy inherent to space itself, in a quantitative fashion. Everything is in contact with this vacuum only to the extent that everything exists in space, which is what “the vacuum” is: empty space. The detectors, then, that you’re talking about, aren’t detecting energy from the vacuum, but rather from the external Universe. How do we know? Because if you build a “shield” (i.e., a conductor) around your detector, the “strange noise” goes away. Because it’s coming from an external source: the surface of last scattering from when the Universe was transitioning from an ionized plasma to a state full of neutral atoms. What you call strange noise is actually well-measured, quantified, well-defined, and simple: it’s blackbody radiation redshifted by the expansion of the Universe.
With that established, I want to clarify something for you: I am happy, in these comments, to address whatever physical gaps you may have in your knowledge. Whatever you’re curious about, or want to know more about, I’m happy to share my knowledge — as a professional astrophysicist and cosmologist — with you. If you have questions about facts, my opinions, or anything else, I’m happy to respond.
But I am most definitely not interested in your alternative, pet theories to well-established theories. I am also not interested in rehashing old points, particularly if they’re not even relevant to the article at hand. I would recommend you look to the good behavior of Paul Dekous as an example. Paul does not believe in LIGO’s results, and he reminds us of that whenever a discussion of gravitational waves comes up, along with his reasons for his skepticism. But he does not bring them up otherwise, nor does he bring up the same talking points over and over when a certain matter has already been explained to him. He is not convinced that things are a certain way, but he only brings up his pet ideas in context and when there’s a new story out.
Things I have noticed here that run contrary to that come from those opposing special relativity, those furthering cold fusion, those pushing their own pet ideas about a fragile, tearable spacetime, those pushing an aether theory, and so on. Keep it relevant or take it elsewhere. These comments are for commenting on the topics discussed, not for whatever it is you have an axe to grind about. The axe-grinding is for me to decide. That’s why it’s a blog, not a wiki.
From Elle H.C. on similarities between LIGO and resonance: “The controversy around LIGO’s GWs has shown us how delicate it is to detect something shaking but not (yet) breaking, just like how difficult it is to see the glass shaking ‘significantly’ until … without the high speed camera.”
Not at all, actually. What the controversy around LIGO’s gravitational waves show is how difficult it is to detect a small effect at the limit of the sensitivity of your detectors, and in particular in the presence of difficult-to-quantify noise! The shaking is very easy to detect, if it’s of large enough magnitude. For example, if you set up an interferometer and blow on the back side of the mirror at one end, you can simply see the effects, visually. (And yes, you can see them better slowed-down, but that’s simply using a better detector than your eyes.) When you are at the limit of what you can detect, that’s where you have difficulty detecting it. But if you were to improve on LIGO by making longer arms, reducing noise further, or putting it in space, the delicacy of the signal becomes far less significant. It’s a question of the technology and sensitivity, not of the phenomenon of shaking.
From Sinisa Lazarek on saving the Earth from the warming Sun: “It will take billions of years for the sun to enter the red giant stage where this question becomes relevant. But the largest asteroids.. several kilometers large (like the dinosaur-wiping-ones) are on the frequency of several million years.”
Humans are far more likely to go extinct for reasons other than asteroids, IMO, long before this occurs. When you say “several” million years, we are likely looking at frequencies that are more like ~100 million years, which is normally much higher than what we consider to be several (which I estimate as somewhere between three-and-seven). But in 100 million years, the Sun will be outputting 101% of its energy today. My point is that we have long-term problems with can start thinking about now. Just as in life, I shudder to think of people avoiding important matters because there are urgent-but-not-so-important matters to attend to. For humanity, I think it’s important to remind us of those big, long-term problems every once in a while. But no exaggeration, please!
From Omega Centauri on an alternative strategy for migrating the Earth: “Can we cheat and transfer orbital energy from other solar system bodies via gravitaional interactions. One suggestion is to manipulate the orbits of asteroids, so that they repeatedly have gravitational encounters with the earth, which transfer some energy and angular momentum from the asteroid to the earth.”
Sure! But if you want to do a large momentum transfer, you’re going to eject the asteroid/comet/KBO in question. If you want to know how many of these objects you’d need, the answer is around 1,000,000 of them if you’re talking a large-ish asteroid. So about one per thousand years over the next billion years. This is, to me, a frightening proposition. If you miss your mark by just a little bit, you’ll wind up with an impact even larger than the one that wiped out the dinosaurs! Better hope the errors on your asteroid deflection system give you much less than a one-in-a-million odds of collision!
Remember, the total mass of the asteroid belt is less than the mass of the Moon; the total mass of the Kuiper belt is between 4-10% the mass of Earth. We’d need to clear out a large chunk of it to migrate the Earth, and if you wanted to significantly change the mass of another body, you’d need a better source than those places!
From skl on why even worry about galaxies and stuff: “Why do you spend so much time with your head in outer space when we’ve got a crisis down here on earth?”
Because there is more to life than worrying about every single crisis that comes up all the time. There is art, there is music, there is science, there is wonder, there is joy. Yesterday, I got up at 6 AM, wrote a letter to the newspaper, and then worked on volunteer stuff for my town from 7 AM until after 10 PM. But you know what I did at about 8 PM? I took five minutes to just look to the east, and watch the moon rise. It was full, it was yellow, and it was beautiful. Because there’s more to life than focusing on “OMG all hands on deck to stop this latest catastrophe right now.” Yes, it’s something that is important to do. But so is being aware of what’s going on in the Universe. So is the pursuit of knowledge. So is being curious. So is learning. So is trying to make existence more enjoyable and educational and informative for everyone. That’s a way I can impact the world, positively, in a fashion I’m inexhaustibly passionate about.
From Denier on exactly that catastrophe: “Yes Ethan! Why do you continue to ignore climate change!?? Can’t you see what happened to Venus when Trump pulled out of the Climate Accords on that planet? …And now Trump’s doing it here and you stay silent? Didn’t you hear Hawking? 250 degrees! That is not even American degrees. That is European super-hot degrees. Being that Trump only realistically has 3 1/2 years left in office that means Earth will be hot enough to melt lead on its surface in a short 40 months from now! We’re all dead! Me. You. Everyone. Dead!! By your silence I can only assume your payment from Big Oil came through.”
Obviously my real terraforming goal is to turn Earth into Venus II. Then we’ll all live in blimps above the clouds, while the fire people live down below. I’m attaching my tether to the politicians of the great city of Chicago. I hear they’re all full of hot air.
From David on scientific history: “It’s fairly easy to find scientists from the era 1915 – 1923 who denigrated Einstein and his theories. There was an active group that fought a long hard battle to deny the Nobel prize to Einstein. They were motivated partly from anti-semitism and partly from reluctance to embrace a strange theory that many simply didn’t understand.”
We have this image of Einstein as the crazy-haired old man, silly, grandfatherly, and kind, but his ideas were like scientific heresy to many. To defy and replace Newton? Absurd! To create a new physical view of the oldest known-and-understood phenomenon, one that stood unchallenged for over 200 years? How dare you! The reaction to General Relativity by many was not unlike the reaction to heliocentrism in the 1500s and 1600s. But in science, as in all things, the evidence is key. It lined up with Einstein’s predictions, and still does, under all the stringent tests we’ve ever performed. You must listen to the evidence — not logic, not common sense, not your own biases, not the words of a false authority — if you want to reach the correct conclusion. That’s why Einstein’s theory is so powerful.
From rich r about confirming Einstein with a solar eclipse: “Ethan, you wouldn’t be baiting the resident anti relativity nuts with a post like this now, would you?”
I have a feeling that saying the word “Einstein” or talking about physics in general is all it takes to bait some people. But you may have heard about a little event coming to our world this August… and perhaps I’m just a little excited about it. I’ll likely write about it again, soon, too.
From Paul Dekous — hey, what a coincidence — on some commenters here: “Can you guys please stop spamming the comment section. I come here to read Ethan’s articles and comments related to those articles. There’s a line between honest criticism and slander, and you guys are moving more and more in the direction of the latter. Sure one can be rude every now and then, but when it’s day in and day out, it starts to become sickening.”
Agreed. If you can’t keep your irrelevant comments about your pet theories confined to the articles where they are relevant, it’s off with your hea… err… commenting privileges here. Some of you will take being banned as a badge of honor. I’d rather you just knock off the bad behavior and continue to help everybody learn.
But I will give you an opportunity to defend your viewpoints: what would it take to convince you that Einstein was right about special and/or general relativity?
From Yiorgakis Pantoulis on a new ‘theory of everything’ I suppose: “Perhaps the mechanism that forces the known values, protects the masses, stretches the Universe’s curvature, suggests a new symmetry that suppresses CP-violation and governs these apparent coincidences and hierarchies is the high-energy field created by the mere act of observation by an Ultimate Conscious Observer. A Supreme Mind that supersedes time-space and knows very well how to keep the secrets of the Energy of His Thought.”
Sure! So how can you turn that idea into a testable hypothesis? If you can do that — complete with quantitative predictions — you’ll have an interesting theory. Remember, you have three things you must accomplish:
- Reproduce all the successes of the old, leading theory.
- Make a successful post-diction of at least one observation that cannot be successfully explained by the old theory.
- Make a new prediction that we can then test against the old-and-new theories, to discern between the two.
Do that, and you’ve got an interesting scientific theory. Fail to do that, and at best you’re engaging in pure mathematical, philosophical, or theological speculation.
From CFT, on me daring to write about Donald Trump and his use of infinity: “So….you really have nothing to say this time? Maybe you should keep your mouth shut then…until you actually have a topic of conversation besides ‘Trump isn’t using the word infinity correctly.’ Sheesh Ethan. Get a life, or at least a clue.”
Hmm… so that’s your takeaway? Because here’s mine, from the article I wrote:
The most frustrating thing about the President’s statement is that he’s very clearly talking about something that he hasn’t bothered to learn the basics of, yet wants to sound intelligent and authoritative when it comes to it. “It could be infinity” is code for, “I don’t need to know any more than I currently do, and neither does anyone else.” Maybe that’s true, but there are people who study this for a living. If you’re curious about it, you can get that information in any number of places… but you won’t find an awareness or an appreciation for it in the nation’s highest office.
As dean noted: “People wonder why the current president is viewed as a massive embarrassment: his meaningless jumble of words in that “speech” should be one of the primary points of evidence.” I think it’s worse than that, though. It’s the fact that what he says has no bearing on what the actual, known information is. It’s like that part of it is irrelevant. I used his statement to share the actual knowledge, and to raise awareness of the importance of actual knowledge. You may disagree that such a thing is important, but you are not going to convince me that ignorant ramblings that end in “you can’t prove me wrong” are equal in validity or their inherent interesting-ness to actual, robust, scientific knowledge.
And finally, from Naked Bunny with a Whip on falling into a black hole with a tether to the outside: “Why wouldn’t it [the tether] snap? The atoms of the rope are held together by electromagnetic forces. If the atoms that are inside the event horizon can’t emit any virtual photons outward anymore, then what keeps the rope connected enough to slurp it in?”
Imagine you’re in free-fall, and you’re on a trajectory so that part of your ship will go inside the black hole while other parts remain outside. Now, you’re in free-fall in a gravitational field, so Einstein’s equivalence principle holds. You can’t tell the difference between gravitation and uniform acceleration. Are you telling me that your ship must be torn apart by the event horizon’s existence, even if the tidal forces are tiny at the event horizon? It’s also possible that an additional force can draw the outside part in; remember a lack-of-force in one direction is the same, effectively, as an extra force in the opposite direction. What’s not possible is that you can pull something that falls in back out.
Thanks for keeping it real, everybody, and I’ll see you back here tomorrow for more science, more stories, and more wonders of the Universe here on Starts With A Bang!