HN Theater @HNTheaterMonth

⬐ blutack

Seeing as the original site has now fallen over, the actual youtube link is

https://www.youtube.com/watch?v=E43-CfukEgs

⬐ nmeofthestate

And for the violently impatient, the actual drop: http://youtu.be/E43-CfukEgs?t=2m52s

⬐ shangxiao

"Violently impatient" - I must remember to use that one myself

⬐ zwp

Fortunately you beat me to it. I was going to post the later sequence at: https://www.youtube.com/watch?v=E43-CfukEgs&feature=youtu.be...

But on closer viewing that is a disastrous montage: the first few seconds (before cut away) show the feathers fluttering and the bowling ball starting to accelerate away; the slow-motion segue is under vacuum conditions though. The film editor's intention is that the two shots appear contiguous. We can speculate why they might have done this (no close up shot taken under vacuum conditions?) but it really tramples the whole point of the article :(

⬐ jacquesm

You can get rid of the air but you can't really get rid of gravity.

⬐ 4ad

What do you mean? The close-up shot at 2:52s is under vacuum. The "fluttering" you see is the elastic wave in the feather caused by the sudden drop in internal tension. The feather is an elastic object (to a first approximation). When the feather is hung, there's internal tension keeping it stationary and giving its shape. When the feather is unhooked, this internal tension doesn't just disappear instantaneously, rather an elastic wave travels through the feather at the speed of sound in the feather. Because the feather is not a perfect elastic medium, the effect you see is a damped harmonic oscillator, but it takes non-zero finite time to dampen sufficiently.

This is true for the big ball too, except that the speed of sound is orders of magnitude faster in it, and the spring constant of the material (steel?) is also many order of magnitude larger than the spring constant of the feather.

The center of mass of both objects falls at the same rate. At t=0, d^2x/dt^2=0 for the points closer to the ground and d^2x/dt^2=2g for the points that were just unhooked. Also see https://www.youtube.com/watch?v=mAA613hqqZ0

⬐ gus_massa

There are two slow motion initial drops closeups:

* 2:52 -> http://youtu.be/E43-CfukEgs?t=2m52s

* 4:51 -> http://youtu.be/E43-CfukEgs?t=4m15s

The second one (4:51) looks like a drop in the air, because the barbules (the small parts of the feather) go "up" and flutter.

The first one (2:52) looks like an actual drop in vacuum. But I think that the oscillations are not related to the speed of sound in the feather, because I think that the sound travels too fast to be visible in this video. (I'd like to see some measured data.) I don't see waves traveling in the feather.

Initially the barbules hang down. After the feather is released, the feather is gravityless (in the non inertial reference frame) so the barbules go to their natural position, so they go "up", but only slightly and the flutter is minimal.

⬐ 4ad

(Hope the Unicode math symbols appear correctly. )

> After the feather is released, the feather is gravityless (in the non inertial reference frame) so the barbules go to their natural position, so they go "up", but only slightly and the flutter is minimal.

You're saying the same thing as I did in different words, in fact my analysis was also in the accelerating frame :-).

So, in the accelerating frame at t=0 (the drop), we have an deformed elastic object that acts very similar to a harmonic oscillator, with some initial deformation Δx. It's not exactly a simple harmonic oscillator because the mass is distributed throughout, and the effective mass is NOT the mass of the spring (in fact it's one third of that), but it's relatively easy to show it moves like one (to the first degree for small displacements), albeit not in a Hacker News discussion. It will move according to

    D²[x] + 2ζωD[x] + ω²x = 0

where ζ=c/2√(mk) is the damping ratio, ω=√(k/m) is the undamped angular frequency and m is the effective mass. For a feather, it might well be that the oscillator is overdamped, of course. The ball most certainly has a much larger Q factor than the feather.

Elasticity and sound waves are very closely related. Sound is a particular kind of wave traveling through an elastic medium. For an approximately linear object, we only have longitudinal waves that move with c=√(Y/ρ). Y is Young's modulus and ρ is the density. You can immediately see that small values of Y give rise to small values of c.

For ideal springs of length X and cross-section S we can prove that (exercise left to the reader) that:

    Y = Xk/S

so

    kΔx/S = Y Δx/X => F/S = Y Δx/X => Y = FX/SΔx

I can estimate X=0.2m and S=1E-5 (maybe larger than you expected because we need to consider the whole feather as the spring, not just its stem (wrong term?). Under it's own weight the feather seems to move approximately Δx=1E-2m so X/Δx=20, F is of course half the weight. It's hard to get good estimates on the internet for the weight of a feather. The most reliable estimates seem to be 8.2E-6kg for a chicken feather. Chicken feathers are small, let's say 5E-2m so our feathers have a mass of 8.2E-6kg·(X/5E-2m)^3=0.5E-3kg. Half a gram for the giant feather. Doesn't sound implausible.

Plugging all values in we get Y=5248Pa. Speed of sound is c=√(Y/ρ)=c=√(Y/(M/V))=√(YSX/M)=4.58m/s, a very low value indeed and quite consistent with the slow motion video.

Just for kicks, the speed of sound in rubber 60m/s. It shouldn't surprise us at all that the speed in feathers is smaller than for rubber. Feathers are much weaker springs than usual rubber springs. (Note that if we had a spring made of rubber coils, the speed of sound in the spring would also be much smaller than the speed of sound in a rubber rod).

The approximations made above are all pretty wild, but the point I was trying to make is that waves travel quite slow in weak springs. The exact values don't matter. Just get yourself a long spring made of plastic or thin metal wire and create some waves. You can see the propagations, they move very slowly.

⬐ gus_massa

I think that your model is correct, but I think that it's possible to add a few simplifications.

If the speed of sound is ~5m/s and the feather length is 0,2m then the time to for a signal to travel from one tip to the other is ~1/25s. That is approximately one frame in a standard camera (PAL/NTSC). So if they are using a standard camera, it's possible to assume that the drop signal travels almost instantly.

The system is totally overdamped, so I think that it's better to model it as a movement in a fluid with hight viscosity (like a spring inside honey). If you drop the acceleration term and you get

2ζω.D[x] + ω²x = 0

where 2ζω/ρ is something like the apparent viscosity that see a barbule moving inside the "fluid" of the other barbules.

The solution is

X = A exp(-ω/2ζ t)

So the relaxation time is ω/2ζ. When it's overdamped the system almost don't oscillates. Watching at the video, after it falls 1-ball-diameter the barbules reach the final position. I guess the ball is ~0,3m, so I guess that ω/2ζ ~= Sqrt(2h/g) = 0,8 seconds ~= 20 frames in a standard camera. But I have not idea about a sensible value for ζ.

⬐ janzer

He's referring to the sequence starting at 4:15. Compare the close up real time shot that starts the later sequence to the slow motion at 2:52. The feather and ball leave the frame almost simultaneously in the earlier one but with ~25% of the feather still in frame in the latter.

After looking at it I agree with zwp, the editor really did make quite a mistake when assembling the last sequence.

[Edit: Screen grab of both http://imgur.com/EAKB5FK and I agree with the over all editing comment below. The slow motion shot as the first shot of falling in the vacuum was the thing that really stood out and I thought was bad on the first play through.]

⬐ 4ad

Oh, I see what you mean now. Yes, definitely editing mistake :-). Apart from that, editing was bad altogether. There should have been many shots with the real-time fall. In fact, the first shot of the drop should have been in real-time.

⬐ pshinghal

Certainly a lot of us know what to expect in this experiment, but the thing I never really thought about was a that the feathers would bounce back up after impact. Seems obvious in retrospect, but it was pretty cool to see.

⬐ revscat

Commander David Scott did this same experiment as part of Apollo 15 in August of 1971, in an even larger vacuum:

https://www.youtube.com/watch?v=KDp1tiUsZw8

⬐ ColinWright

That's one reason why I posted the link to this site, rather than directly to the YouTube video, as explained here:

https://news.ycombinator.com/item?id=8556363

The text of the site I submitted has kindly been posted by DanBC[0] here:

https://news.ycombinator.com/item?id=8556409

[0] https://news.ycombinator.com/user?id=DanBC

⬐ revscat

No worries, mate.

⬐ paddyoloughlin

I love how professionals who work at that facility and have probably deeply understood those principles for decades still display so much wonder at seeing this experiment with their own eyes.

⬐ hudibras

I might be cynical, but I think they were putting on a show a bit. They already had some sort of apparatus set up to do the simultaneous drops.

My guess is that it's a standard demonstration for visiting dignitaries and the like.

⬐ aylons

I agree you're being a bit cynical.

They are used to the chamber and with experiments in the chamber, but this simple experiment with a feather and a iron ball is very different from what they usually see.

They probably usually see only heavy objects and mechanisms for space projects being tested there. Such a graphic and basic experiment must be well outside the norm.

⬐ JTon

Perhaps their excitement no longer stems from the experiment itself, but from the reactions of the newcomers. Probably a terrible analogy, but sort of like witnessing a child's first experience hearing a musical instrument live. It can be energizing.

⬐ smackfu

>They already had some sort of apparatus set up to do the simultaneous drops.

Why do you say that? They could have easily made the apparatus for this experiment.

⬐ Too

The button he pressed when dropping had a label that said something like "launch jet sequence" (don't remember exactly). They probably have a modular set of actuator and rigs they can easily mess around with . :)

⬐ HCIdivision17

You'd be amazed how a simple experiement can be fun. These guys work on this enormous vacuum chamber to build space ship things, and that's their day job. As in, at some point, it gets routine and a bit dull. (Ever find high power lasers boring? You will after your safety training...)

Now, they are recreating an experiment last performed at this scale on the moon. It's an unusual break from the norm, and I'm sure half of their grins were the phenomenal waste of power to perform such a silly experiment. (Seriously, that chamber was hauled down to a couple torr in three zarking hours!) Professionally goofing off is immensely fun.

(Tiddlywinks with a forklift would be another, and there was a guy who used the armor coating a Blackbird uses in a robot wars competition.)

⬐ None

None

⬐ thorntonbf

This was my favorite part of the video, and I think it was genuine. The guy in the blue shirt and the one with grayer hair immediately afterward seemed like school kids seeing something amazing for the first time. I'm sure their day-to-day work is quite serious. Sometimes maybe it takes something simple to make you step back and realize that you really have some things in your life that are quite amazing.

⬐ jgrahamc

Worth reading http://en.wikipedia.org/wiki/Equivalence_principle if you don't understand the last part.

⬐ bjackman

I guess this is a pretty superficial complaint, but this is a 2nd-generation clickbait-site link (posted on io9, reposted on thekidsshouldseethis.com). Why not post the Youtube link directly? This isn't really Hacker News material, anyway.

⬐ ghshephard

A multi-story vacuum chamber on earth is pretty freaking amazing. Certainly stimulated my intellectual curiosity.

⬐ teach

Especially since the linked site is starting to hit resource limits. I had to refresh a few times before it would load.

Here's the youtube link: https://www.youtube.com/watch?v=E43-CfukEgs

⬐ vixen99

A version without Cox would definitely pile on the views. As it is I will forgo the pleasure.

⬐ colinramsay

> What to Submit

> If you had to reduce it to a sentence, the answer might be: anything that gratifies one's intellectual curiosity.

https://news.ycombinator.com/newsguidelines.html

⬐ DanBC

> Please submit the original source. If a blog post reports on something they found on another site, submit the latter.

⬐ ColinWright

Yes, although I thought the site I submitted actually had an interesting comment. The IO9 site less so, and hence in my judgement, on this occasion, the link I submitted was in some sense "better" than the raw youtube link.

I think the guidelines are mis-guided in this sense. Sometimes the original, raw content is somewhere else, but a page that points to it can sometimes add context, or otherwise enhance that original post/material.

But this is meta, and getting off-topic. To go meta-meta, I do wish there were somewhere sensible to discuss these sorts of issues.

⬐ Xurinos

Perhaps something like a Talk page on a MediaWiki platform? It would be out of the way but directly connected to the page you are on, a second set of comments accessible by a MetaTalk filter.

⬐ DanBC

for people who can't load the linked article:

---begin quote--- …though in this case, “the hammer” is a bowling ball. In this [excellent clip]{https://www.youtube.com/watch?v=E43-CfukEgs} from the BBC’s [Human Universe: Episode 4]{http://www.bbc.co.uk/programmes/p0276q28}, Professor Brian Cox visits NASA’s Space Power Facility in Ohio, home of the [world’s biggest vacuum chamber]{http://facilities.grc.nasa.gov/spf/#}, to test Galileo Galilei‘s Leaning Tower of Pisa experiment, circa 1589:

[If you drop a brick and a feather at the same time]{http://www.planetseed.com/laboratory/galileo-drops-ball-virt...} the brick will probably hit the ground first. But this is because of differences in the amount of friction between these objects and the air around them, not because their masses are different. If there were no air…

What happens? How does a hammer, brick, or bowling ball move in comparison to the feathers when you remove any air resistance? Watch.

Then watch this next: Apollo 15 Commander David Scott famously conducts this [same experiment in 1971… on the moon]{http://thekidshouldseethis.com/post/31056368331}. ---end quote---

⬐ giarc

Things that aren't HN material will be downvoted by members. This is currently sitting at #3, and therefore the HN community has determined that this is indeed HN material.

⬐ norlowski

Experiment, curiosity, huge NASA buildings, near vacuum. I'd rather read about this than mark zuckerberg.

⬐ None

None

⬐ cryowaffle

Can someone explain to me the last part about the items standing still and no force acting on them? Isn't gravity acting on them, pulling the earth and items together?

⬐ gradi3nt

Imagine being inside of a closed box like an elevator. Without leaving the box there is no way to tell the difference from being in free fall towards Earth versus floating in interstellar space. Therefor, general relativity take the perspective that gravity is a fictitious force (like centrifugal force) that arises from the shape of spacetime.

⬐ josu

>versus floating in interstellar space

Versus being inside that an elevator that is being accelerated in interstellar space

This seems like a pretty good explanation: http://www.astronomynotes.com/relativity/s3.htm

⬐ bweitzman

gradi3nt had it right

Free fall feels like floating Standing still (in the presence of the Earth's gravity) feels like being accelerated.

⬐ joshvm

All the best facilities have big buttons labelled "Mega speed trigger".

But in seriousness, does the Moon not count? Surely space is the largest vacuum chamber we have access to!

⬐ dia80

I know how this will turn out but my intuition is screaming otherwise.

⬐ saalweachter

This is a great example of the 'Reality is Unrealistic' trope. The feathers just look so photoshopped falling next to the bowling ball, motionless, unfluttering.

⬐ oneeyedpigeon

I find it interesting that Brian Cox, the presenter and avowed scientist, obviously finds it so 'surprising' as well. Maybe that's the true meaning of being a scientist, though - he doesn't truly believe it until observing it with his own eyes.

⬐ pbhjpbhj

I just watched this today - I've studied physics at Uni - I've done many experiments and known this result for a long-long time. However, this was actually the first time I've seen it myself.

It is awesome to see something so un-intuitive but so well known actually occurring - like if you could actually see quantum tunnelling happening. If you don't find the world awesome then doing physics has got to be a pretty hard slog.

But then I'm over-awed just about every time I use a mobile [aka cell-phone] or computer at the physics and engineering that's happening, the maths being applied, ...

A computing equivalent might be seeing Babbage's Difference Engine[1] or a valve based computer at work for the first time - you know the maths, the algos work, you know the science well enough (certainly in the mechanical computers) but seeing it all chug away and produce the result has a certain enthralling beauty. Maybe it's more like seeing a visual emulator [2] working on assembly code? You know it works, you know why it works (at some level at least) but it's doing it, it's awesome!

[1] http://www.youtube.com/watch?v=jiRgdaknJCg

[2] http://www.visual6502.org/JSSim/index.html

⬐ oneeyedpigeon

This does quite a nice job of it, for me :)

https://www.youtube.com/watch?v=GcDshWmhF4A

⬐ pbhjpbhj

That is awesome. I wonder how well that would do for teaching place values to primary school kids - despite having done binary/octal/hexadecimal and other types of number representations with my kids they still struggle to see how decimal uses places and how carrys work.

⬐ sambeau

>Brian Cox, the presenter and avowed scientist,

I think you mean "Brian Cox: Professor of High-energy Particle Physics, member of the High Energy Physics group at the University of Manchester, and the ATLAS experiment at the Large Hadron Collider at CERN (who also presents popular science programmes in the UK)"

I think his career as a scientist deserves a little more recognition than "avowed".

And, as for his career in popular science he has been awarded both a Faraday and a Kelvin prize.

⬐ vacri

Still, I wish he'd use SI units, instead of things like 'cubic feet'.

⬐ oneeyedpigeon

Sorry; I have every respect for Brian Cox, unlike others on this thread. I think I'm merely using totally the wrong word.

⬐ sambeau

Sorry; I read "avowed" as a deliberate slur. I suspect some of the negativity about him here must have got to me. For an unknown reason I picked on your comment – I now see there are plenty worse :)

⬐ shittyanalogy

Just imagine the air to be made up of a bunch of tiny physical balls. The bowling ball does a good job of getting them out of the way fast but the feather trips and stumbles on them as it makes it's way. With none of these tiny air balls in the way both objects move unimpeded until they hit the earth.

⬐ t__r

I find it a bit easier to understand if I imagine similar size and shape objects with a different weight. Say, a bunch of balls with equal radius but different weights. Does a near-zero-weight ball fall with a near-zero speed? Of course not. Etcetera.

⬐ derekp7

One way of adjusting your intuition is to imagine the bowling ball and the feather standing still, and the ground coming up really fast and smacking them like a giant ping pong paddle. That's the only way I can get my eyes to agree with what the brain is thinking.

⬐ iterationx

Yes, you already know the ending, but its worth watching just to see the massive structure.

⬐ aaron695

It interesting some people think a vacuum means a lot of pressure but really it's the same as 10 meters under water at sea level pressure.

⬐ Cthulhu_

^, explosive decompression in space also isn't as explosive as coming up from a few meters underwater in one go (it's from 1 to 0 atmospheres, instead of 100 to 1).

Not that I advocate explosive decompression in any circumstance, mind you.

⬐ thearn4

SPF is an awesome and unique facility, I wish more of the public would get to see it in person.

If you want to see more of it in video, it's also where the opening scene to "The Avengers" was filmed. Plum Brook Station has a whole collection of really cool (though mostly single-purpose) buildings.

⬐ Animats

If you want to see more of it in video, it's also where the opening scene to "The Avengers" was filmed.

It's appeared in a lot of movies, "Futureworld" (1973) being one of the first.

That's where the nuclear rocket upper stage for Apollo was supposed to be tested.

⬐ italophil

The space and aerospace programs of the sixties produced some really impressive technologies and facilities. Too bad government spending on technology research went down, just imagine what could be possible.

⬐ frozenport

From another perspective, these technologies left us with little science of utility (Tang?) while developing intercontinental ballistic missiles that loom over humanity like the Sword of Damocles. When historians from far off planets visit our nuclear wasteland they will see our thinly veiled space program as the beginning of end. :-)

⬐ None

None

⬐ baldfat

Quick list of more inventions that are not Tang http://en.wikipedia.org/wiki/NASA_spin-off_technologies

⬐ noselasd

Even something as mundane as error correction coding were developed at NASA, for communicating with spacecraft - technology that's now present in e.g. CD/DVDs, and every mobile communication system.

Now, if they hadn't developed it, someone else probably would, but perhaps not at that time - leaving us at years behind where we currently are with e.g. the speeds on our mobile devices.

⬐ kens

I think the credit for error correcting codes goes to Hamming in 1950.

⬐ btoptical

Error Correction Coding is hardly mundane and in modern communication systems far from trivial. There is a lot more to ECC than Reed-Solomon. Basically nothing in our digital world today would work very long without it. You think of it as mundane only because it just works.

⬐ rglover

Anybody else catch the NASA engineer wearing a SpaceX Dragon t-shirt? Nice.

⬐ Marcus10110

I'm wearing mine to Interstellar tonight!

⬐ fdomig

I love science. This is a very nice example of it.

⬐ Shivetya

I think my favorite part of this is not that they were able to demonstrate it so well but instead the reactions of people expecting it to actually occur.

⬐ None

None

⬐ rajdevar

I live in Ohio, Never knew that the biggest vacuum chamber is here until now.

⬐ th0ma5

Yup yup, it is NASA Plumbrook, the old reactor south of Sandusky. On the way to Cedar Point as a kid I was always in awe of the place as it was so big and you could only get within a few miles of it. My sixth grade teacher claimed a three eyed frog he had in a jar came from a nearby pond.

⬐ Freestyler_3

They could also have put a toy helicopter in there, just to add more fun.

⬐ z3t4

So if they aren't falling. What are they doing?

⬐ kentf

Science is amazing.

⬐ vertikal

Its brilliant

⬐ IgorPartola

Serious question: why do we keep repeating this experiment? Not that I mind, I just am curious why do we keep building bigger and bigger vacuum chambers just to drop a feather and a hammer over and over.

⬐ 4ad

I seriously doubt they emptied the huge vacuum chamber for this experiment. Most likely it was used for some other experiment and it was very cheap to do this experiment as well. As to answer your actual question, because it's very televisual (this was for a TV show, after all) and sells well. It's something very simple, something (almost) everyone understands yet something almost nobody has ever seen. It's a powerful experiment for the general population.

But to answer a more general question. We shouldn't stop repeating experiments just because they were done before. The scientific method works as long as we keep reproducing results. Sure, this is a trivial result, but it's something every kid should have done by its own in the school physics lab.

⬐ vacri

Before they pump the air out in the video, the presenter explains what the facility was made for and is currently used for.

⬐ chatman

The presenter was wearing a wicked smile when the feather hit the box.

⬐ Ad_Nauseam

Dropping feather and hammer isn't the only use of vacuum chamber

⬐ mturmon

I assume the BBC paid a fee for the use of the facility. Maybe they piggybacked onto some testing or scheduled activities that were being done anyway. I'll bet once the location scout saw those huge doors close, the deal was set. ;-)

Similar large facilities exist at many national labs, and they are used only sporadically. For instance, in the Bay Area, NASA Ames has a very large (11 foot square) wind tunnel that can reach Mach 1.45 (http://www.nasa.gov/centers/ames/orgs/aeronautics/windtunnel...).

The inflatable bags that landed Spirit and Opportunity on Mars were tested in Mars air pressure at the Glenn vacuum facility: http://www.nasa.gov/centers/glenn/about/history/marspbag_prt... . Many spacecraft undergo "thermal vac" testing meant to simulate space conditions.

⬐ paddyoloughlin

I wish the producers were less enamoured of their slow-mo and showed us the whole thing in real-time.

The "weird" thing is seeing feathers plummet to the ground and I wish we got to see more of that.

⬐ thaumaturgy

Somebody on Reddit took that scene, sped it up to something close to normal time, and made a gif:

http://gfycat.com/GentleMeaslyFattaileddunnart

⬐ christiangenco

The acceleration looks wrong. It looks like the show altered the footage to have constant speed, and Reddit just sped it up.

⬐ mhartl

Not wanting to wait through the prologue, I skipped ahead in the video, where I searched in vain for the real-time drop. It's bizarre that they apparently didn't show it even once, especially since it can't have taken more than a few seconds (the chamber's height is 37.2 meters [1], so t_max = √(2h/g) = √(2×37.2/9.8) = 2.75 s).

[1]: http://www.dailymail.co.uk/sciencetech/article-2819205/Testi...

⬐ danielweber

With the HTML5 player you can double the speed; it's entirely in browser, so you can probably capture the Javascript event and make it go at 5x or 10x or whatever is needed to play at full speed. (It'll be up to you to then dub in Yakety Sax.)

⬐ apcherry

For me the "weird"/unusual/interesting thing is seeing the feathers bounce after hitting the ground.

⬐ shangxiao

I actually like the slow-mo as it reaffirms the fact that there is no air in that chamber.

When the feathers first drop you see a slight sway in the feathers, but only due to the acceleration. It's actually quite a sight to see feathers accelerate so quickly and stay so still.

⬐ paddyoloughlin

I'm not against them using slow-mo at all.

But they showed the drop several times, and I would have preferred them to show it at real speed at least once.

⬐ ghshephard

According to this, http://en.wikipedia.org/wiki/Equivalence_principle, posted lower, the feathers aren't under acceleration. Which is pretty cool once you think about it.

⬐ kyberias

Exactly. I was frantically searching the video for this. Did they show it?

⬐ zelos

This is a Brian Cox show we're talking about, not a science show. I'm surprised there weren't more slow mo shots of Cox doing his "boyish wonder" face.

⬐ ytturbed

The value of his 'boyish wonder face' is that he's emotionally open, relatively speaking, and therefore we perceive that he's not consciously deceiving us in ways that he thinks important. It shouldn't matter, of course, since explanations either stand or they don't. But it seems that so much public discourse is infected with paranoia and conspiracy theory, including around space history.

⬐ nly

His 'boyish wonder', although personally I think it's genuine, does get annoying to those of us who have their own wonder to contend with. Though, perhaps, those completely devoid of it themselves appreciate the cues.

I really don't mind Cox... what I despise is the trend of putting comedians in to science and politics shows in an attempt to relieve the dowdiness (Sorry Dara). Then again, I'm one of those people who used to sneak downstairs in the early hours to watch the dusty math and science stuff the BBC used to broadcast for teachers to record on VHS.

⬐ ambler0

Alan Alda has done a great job of bringing charisma and humor to science shows without dumbing anything down. The key is to find a comedian/actor/whatever who has a genuine interest in the material.

⬐ gadders

I agree. Have you ever tried listening to The Infinite Monkey Cage on BBC Radio 4? [1]

It's motto seems to be "Look at us! We're scientists but we're so wacky!!!111"

http://www.bbc.co.uk/programmes/b00snr0w

⬐ JonnieCache

Robin Ince certainly has a lot to answer for.

Ben Goldacre is the master of this style of science communication. Friendly and fun and enthusiastic, but in a way that appeals to both laymen and his peers. I suppose epidemiology is somewhat more human than astrophysics, so its easier.

⬐ gadders

Frontiers [1] also on Radio 4 is good.

[1] http://www.bbc.co.uk/programmes/b006qy5p

⬐ None

None

⬐ apetresc

For what it's worth, Cox isn't a comedian. He has a PhD in physics, has supervised PhDs of his own, has been a research scientist at some of the best groups in the world, and currently works in Geneva with the LHC.

Surely he's qualified to demonstrate F=ma, even to someone with a sense of wonder as evolved as your own.

⬐ eevilspock

Do you not have kids or rarely interact/play with kids?

Kids are no, even though I know the relevant laws of physics and was intellectually not surprised, I was still in awe and it still violates my instinctive expectations. A visual equivalent to stepping onto a broken escalator.

⬐ scottlocklin

Glad to know I'm not the only one who finds Cox incredibly annoying. FWIIW, the exploratorium in SF and the Boston Science Museum both have experiments of this nature. It is a cool vacuum chamber though. Reading some of the NASA early docs on building such things can be quite fun.

⬐ smackfu

I think the backlash against Cox is almost cliché at this point.

⬐ anigbrowl

I'd never heard of him before this morning, but this style of overly-polished TV production is common in the US as well. One of the things that irritates me about it is that they expend significant budgets on presenting and dramatizing quite basic things in science (which is a good thing) but all this experiential/eye-candy stuff comes at the expense of covering less material.

⬐ lobster_johnson

If you're looking for science documentaries with a little more depth, look at the series done by Jim Al-Khalili (eg., "Atom", "Absolute Zero" or "Chemistry: A Volatile History") and Michael Moseley ("The Story of Science").

In "The Story of Science", Moseley covers much the same ground as James Burke's famous "Connections" (and also his highly-esteemed "The Day thee Universe Changed") -- albeit in a more literal and less literary angle -- or indeed Sagan's eminent "Cosmos".

Al-Khalili is a physicist, though, and I think his documentaries are more to the point than Cox's, even if they're also full of excellent photography. Definitely less bubbly.

⬐ res0nat0r

This is appealing to the userbase who would never watch a dry boring scientific show in the first place, not hardcore science geeks.

⬐ aragot

I too though this "boyish wonder" face was phony. And yet the "boyish wonder" face will change the fate of the whole video when I show it to my 7yo. The rest is concrete and iron, not really appealing to kids, despite the potential awesomeness of the huge vacuum chamber.

⬐ djrogers

I was laughing and giggling the whole time myself - I'm pretty sure I had a similar look on my face. In fact almost everyone else in the video had a similar goofy look at one point or another!

It's one thing to know that this will happen, it's another entirely to see it happen.

⬐ zelos

Indeed, but the show is on primetime BBC2, not CBBC or CBeebies.

Ah, I guess anything that brings more viewers to science content is good. I just miss the old days of Horizon.

⬐ muglug

Me too. I grew up on Horizon, Tomorrow's World and QED.

⬐ antimagic

What? No! I don't know about you, but I would have a silly grin on my face too if I actually got to see this experiment live - I mean it's such a classic result - we've all been told that this is what would happen, but very few of us actually get to see it. It's like the experience of seeing the moons of Jupiter the first time that you look at it through a telescope - yes, you know the moons are there, you've even seen photos of them in high-def colour, but there is something special about seeing it first hand.

So no, I don't think that that's a fake grin. But then, as with most female geeks, I have a huge Brian Cox crush, so I may be biased ;)

⬐ anigbrowl

I find this perplexing. Obviously few of us would get to see a feather drop due to the lack of a huge vacuum chamber, but you can derive almost as much experimental entertainment by dropping, say, a ping-pong ball and a similarly sized marble or ball bearing.

Really, I think the slow-motion camera has much more educational value than the vacuum chamber (cool as that is). When I was in school and we'd debate such things, I liked to do experiments but dropping things of different weight off the roof only takes you so far, as people might object that they hit the ground a fraction of a second apart but too little of an interval to notice given the relatively low height etc. If I was doing it now I'd just use my camera to tighten things up, and although it's slo-mo capabilities are limited several current consumer models deliver that functionality at affordable prices.

⬐ mfisher87

The demonstration that air resistance is the cause of the difference in fall duration is what you gain from this. You don't get to remove air resistance from the equation in any other way. It's easy for an ignorant person to assume there's no way air, something we "feel" no resistance from in our daily lives, would be able to fight the force of gravity to such a degree. This experiment makes that concept clear, where dropping a stick and a lead pipe from equal height would not.

⬐ mkagenius

> but you can derive almost as much experimental entertainment by dropping, say, a ping-pong ball and a similarly sized marble or ball bearing.

in a vacuum chamber, right? In air they wouldn't behave same.

⬐ anigbrowl

Ping-pong ball was a thoughtless example, but many things of different weights will be Good Enough for the junior experimenter, eg plastic ans steel pipe sections dropped straight downwards.

⬐ colomon

I demonstrated it to my son this morning by filling up one of two boots with coins and demonstrating both boots still fell at the same speed despite the weight difference.

⬐ Joeri

One of my science teachers demonstrated it in class with a vacuum glass tube containing a small feather and a small lead weight. I remember being equally amazed to see it. As pointed out, there is a difference between being told something and seeing it.

⬐ shangxiao

I would've also had a silly grin on my face due to the epiphany I would've experienced.

⬐ macrael

I was giddy just watching this video! I'm sure his joy was genuine. It's just amazing to see feathers fall straight and bounce(!) when they hit the ground.

⬐ chatman

The gay smile. Made me giddy too.