Why Do Universal Constants Show Up and Why Can We Get Rid of Them?

[@AstroChuie]

Great video! Time and space having the same units is kind of mind blowing. But i love the concept of thinking about constants as conversions for two things that are related, or really just the same thing. Really cements the concept of spacetime.

[@webx135]

It's a fun one to think about. You can think about how many meters into the future something will happen. (Spoiler, it's a uselessly-long number). Or how many meters long you are in time. (I'm 2.71e17 meters far along my total length, which should be about 7.8e17 meters in total. Or one thing to think about is that you are ALWAYS travelling at C. Everything is travelling at C. It's just that the slower it travels in space, the faster it travels in time.

[@craigsimpson9561]

6:45 The "speed of light" is determined by the permittivity and permeability of free space or "vacuum", or in modern parlance, the ratio between the "electric constant" ε0 and the "magnetic constant" μ0... so the answer to "Why?" is that electromagnetic propagation throughout any medium is a function of its resistance, and the vacuum is no exception - it is simply the least resistant "material" which we have measured...

[@altrag]

Sure, but that just reframes the question to be "why does the vacuum have exactly that resistance"? The problem is your last phrase - "which we have measured". There is no theoretical basis for these values. Its just what the universe gave us and we have no idea why that's any deeper than the anthropic principle ("if they were much different, we wouldn't be here"). But that's not terribly satisfying either since we don't _know_ we wouldn't be here. We know whatever was here would not be exactly like humans with near certainty, but we can't really say for sure (beyond some extremes like "matter doesn't form") that "we" wouldn't be some other type of intelligent life that evolved in some other universe with other values for those constants pondering the same question about their own measurements. String theory gained such high esteem because it _did_ provide a theoretical basis for these constants. In string theory there is really only one "constant" you have to choose - the specific structure of the Calabi-Yau manifold that defines the universe. Unfortunately while it reduces the number of constants to one, that one constant also has an absurd range - on the order of 10^500 possibilities - and so far nobody's come up with a way to even know which of those possibilities corresponds to our universe, never mind trying to figure out _why_ that specific one happened to be chosen. The intractability of that problem is (one of) the reasons string theory has kind of lost prominence over the past 20 years (though the biggest reason still remains its inability to be tested, but I suspect if ST is even close to correct we'll be able to come up with a test long before we sort out the manifold issue.. not that my guess is particularly educated in this instance, just the feeling I get about the relative difficulty of the two problems).

[@nishit7147]

I read books, and all of them say Relativity cannot be joined to Quantum mechanics. I never really knew exactly the reasons, but this video explained one of them.

[@zapphysics]

I should say that this is more of a symptom than a source of the problem itself. The reason why the two don't work together is actually much deeper. If you want to look into it, it has to do with the fact that general relativity in "non-renormalizable" when we try to quantize it. The idea is that when we take certain classical fields and turn them into quantum fields, certain situations come up and you get things going to infinity. a renormalizable theory just means that we can patch these infinities and still have something meaningful. When we try to quantize the gravitational field, this whole process breaks down and these infinities are unfixable, so we get answers that don't make sense.

[@De_Angel_trades]

Wow I realized this all throughout my acid, mushroom and DMT trips. I just didn't know how to put it in a equation past many different ways of saying all is one. In my opinion you cant get rid of what makes our universe unique, I think they describe our exact evolution from the beginning of this cycle, Possibly evolved from the last cycle? I think we only make half steps until we make the last step to the goal. Thinking of our consciousness as nothing but the universe observing itself, we are after all as far as I know being pulled around by the same forces as everything else, the only way we have free will is if we are the universe, which is also a part of this working theory of everything I'm just copying from our history. You should also look into enlightenment, from my experience thinking objectively is the equivalent to it and that's what it takes to see the truth.

[@Rocknrolldaddy81-xy8ur]

I think we should look at geometry & ratios. What shapes gives us those values? Perhaps a clue as to how information is packed?

[@EugenethePhilostopher]

You explain the concept really well.

[@TheOneMaddin]

I don't get the part about the Planck mass. Why can you simply throw in a new constant into the formula that no one has asked for and no one ever measured?

[@cogwheel42]

If we imagine starting from the natural units and analyze the behavior of systems described with them, it leads to different kinds of things happening at different scales. The size of quark-quark interactions is described by the physics in terms of natural units, which leads to the size of hadrons. The charge of hadrons and leptons causes atoms to be the size they are, which leads to the sizes of chemicals, cells, organisms, etc. Then we come along and measure things arbitrarily at the scale we happen to find ourselves. The exact values we find for the constants are a coincidence of whatever reference objects we chose for our system of units. But the ballpark of those values are just consequences of scale, IMO.

[@webx135]

I think the last question would make more sense if it were reversed. Instead of thinking "Why does c happen to be ~300million km/s?" we should be thinking "why is a meter a 300 billionth of c" And then the answer becomes clear: OUR units have weird values in relation to NATURAL units because our units were created arbitrarily based on something useful. It's for the same reason you see 5252 when converting torque and RPM to power. It isn't there because of the physics. It's there because of the arbitrary units.

[@AllenProxmire]

what about dimensionless constants?

[@watdafact2]

underrated video. this reminds me of minute physics

[@jerryberonilla3953]

I liked: *BUT WHY*

[@zoltankurti]

No theory could ever predict the values of these constant with dimensions. Their value entirely depends on the arbitrary definitiona of units we choose. In a sense it isn't even meaningful to ask what if they were different, because in planck units every law would look like the same thing, nothing would change.

[@davidreynolds9744]

I enjoyed the video. I both appreciated the understanding of the conversion nature of many of the constants, as well as the transparency that many of the observed constants still do not have an explanation. There are theories from multi-verse to design and so often educational videos take that leap into the debate of philosophy. This had a nice balance. It is what science should be, admitting there are things to which we may find an answer, but to date we just don't know.

[@PrettyMuchPhysics]

This universal constant _a_ was a nice example! Great video!

[@zapphysics]

Thanks! I appreciate it!

[@SpearedPage]

Your videos are inspiring and illuminating. You really nail the right balance of challenge and simplicity!

[@jdalton4552]

Dewey Larson's Reciprocal Theory reduces the number of universal constants down to two, the discrete values for space and time.

[@TheOneMaddin]

Haven't you just answered your "But Why?" questions yourself? At leasts the constants that you listed have the values that they have just because of convention, exactly as the factor between m and km is 1000 by convention. It's an artifact of our units. The real mystery are the values of dimensionless constants, but you haven't touched these, and in fact, one should mention that your video only applies to constants with units.

[@tanvirfarhan5585]

man zap physics why are you soo, underrated bro

[@Higgsinophysics]

Brilliant example and video once again. I personally think the sound can be a little bit louder. RIP in peace eardrums 6:42 :D

[@zapphysics]

Lol glad you enjoyed the video, man

[@achillesmichael5705]

I was laughing so hard at that I nearly choked

[@abertj.7365]

Great explanation, many thanks!

[@aidenwatler7153]

Love the videos man! Really unique angle on this one!

[@richardventus1875]

Excellent video which answers all the questions I've had in my head!

[@kayrstar8965]

Great presentation and explaination...Thank u

[@Natalija379]

Very nice, useful and well-made video! I was wondering if universal constants were just one part of the equation... Like, there should be more non-comstant parameters in some equation, parameters we still know nothing about, to fully complete the relation between them.

[@ghinahmaidosh5457]

The vest video I've watch in a while Wooooh some ideas gave me goosebumps

[@playitback-os7mh]

Impressive video!

[@diracchristoffel7045]

Damn, I finally understand the point natural units. Why is it so hard for people to explain that? It seems so unnatural at first, to set these constants to one and get weird units as a results compared to the normal SI units. Because it is so unnatural, I would expect people to explain the reasoning but most people just say "yeah well we set these to one just to make things more convenient k thx bye" .

[@zapphysics]

Lol I have no idea why a lot of people don't justify their use of natural units. I had always heard "it's so we don't have to drag constants around everywhere" but I agree, just throwing them away didn't feel right. Then I heard Leonard Susskind use this argument and it all made sense.

[@Shanksdan]

keep up the good work man!

[@BrainSlamAnimatedScience]

Have you ever looked at science books that uses the imperial system? The constants there are a nightmare from feet to inch to miles :P I like your question on the end I was also often thinking about that and similar things our nature is truly fascinating great video👍

[@zapphysics]

I haven't ever seen that, no. But good lord that sounds horrifying. Glad you enjoyed it!

[@BrainSlamAnimatedScience]

@@zapphysics Yep we use once a US physics book it was fun :P

[@alienallys]

Great video!

[@mtbabels]

Keep up the good work :D

[@AncientAccounts]

New video!

[@Hackgamer13333]

Wow Amazing

[@honestarizona4301]

Why are there at least 15 physical constants we know of and need to exist? Intelligent Design. No theory needed. Just Sayin, Honest.

[@narfwhals7843]

Intelligent design is a theory.

[@honestarizona4301]

@@narfwhals7843 Darwinian evolution is an old theory, quickly debunked by modern microbiology. Smh, Honest.

[@narfwhals7843]

@@honestarizona4301 Yes, darwinian evolution is a theory as well. Darwins original proposal was crude and the modern version, also a theory, fits the data extremely well. Intelligent Design is also a theory.

[@honestarizona4301]

@@narfwhals7843 Oh Really Narf??? The 3 Billion base pairs of human DNA when broken down from nibbles to binary, takes at least 78 MILLION lines of code just to make the blueprint. RANDOM??? And if you're off by just one digit, you have jello, not life. ACCIDENT???? Add to this, our lack of understanding on morphogenesis and the critical necessity of our human biome consisting of at least 70 TRILLION living cells of which only 30 trillion have your DNA. The rest live on you and in you with their own DNA. AND, if you don't have them, you won't live long. Hmmm. And don't forget, we now know, your DNA has genes for all colors of hair and skin, it's just a question of what is active. SO, just these facts alone make it super difficult to believe you are a random accident. So much so it makes Darwinian theory sound like a joke. Heck even Stephen Hawking gave up on evolution before his death and speculated PANSPERMIA was the reason for life. Not to mention YOU, yourself, said his theory is changing over time. Creation doesn't and you've got a good example in the development of A.I. You can't just throw a few one's and zero's into a bucket and release it on the net, hoping it will turn into A.I. that is soooo silly. There has to be a designer or two or three. Nope Narf, what your belief really spells out, is that you'll do anything to avoid the truth so you can keep on keeping on, living your life how you want to live it with no accountability. Many in modern science want so badly for it to not be true, they dismiss any knowledge supporting creation in any way and cling to false beliefs to maintain the status quo. TRUE scientific study applies to ALL, not just cherry picked theories standing against the truth/GOD. Because the reality is, if you do have a creator, it changes everything for you. These false beliefs make it easier you to justify how you want to live. Truth is truth. Honest.

[@narfwhals7843]

@@honestarizona4301 Truth is truth, sure. We just don't know what the truth is. So we make theories to describe systems. Long term Evolution is a theory. Intelligent design is a theory. There is no contradiction there. Several theories can describe the same system equally well. Evolution is _not_ random. It is a continuous change that is guided by the environment. Each individual change may be a "random" mutation, but the process is not. "There _has_ to be a designer" is just as silly. You can't just demand that. You can argue about how good a theory each is but both _are_ theories we made up to describe the system. You'll also note that I have made no mention of my personal beliefs. But "These false beliefs make it easier you to justify how you want to live." applies equally well to all religions.

[@wulphstein]

Wrong!