The Tunguska Mystery 100 Years Later (2008) | Hacker News Reader

The Tunguska Mystery 100 Years Later (2008)

scientificamerican.com

94 pointsolivermarks76 comments

"First expedition to depths of Lake Cheko close to epicentre of Tunguska event to start in February", Siberian Times, February 2022

https://siberiantimes.com/other/others/news/first-expedition...

Seems that there were follow up studies after this one in 2008 which raise doubts about the conclusion that the lake was formed by an impactor. https://en.wikipedia.org/wiki/Tunguska_event

The article on the lake itself [1] seems to paint a different picture - contradictory evidence and a lack of certainty.

While the recent 2017 study cites core samples, earlier studies suggested that sediments were not a part of the lake formation. I don't think there's enough detail in the Wikipedia articles to really shed light on this. Every study seems to reach different conclusions.

[1] https://en.wikipedia.org/wiki/Lake_Cheko

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Edit: You nerd-sniped me. Here's a meteor that produced an earth-grazing fireball over Utah and exited back into space:

https://en.wikipedia.org/wiki/1972_Great_Daylight_Fireball

I gotta get back to work...

Seems very romantic. That fireball is still out there somewhere. We might never see it again.

The ball is. At least it was considerate enough to leave it's fire behind.

Related. Others?

A Tunguska size burst destroyed Tall el-Hammam, Bronze Age city in Jordan Valley - https://news.ycombinator.com/item?id=28603118 - Sept 2021 (344 comments)

The Tunguska Event - https://news.ycombinator.com/item?id=12061852 - July 2016 (119 comments)

The Tunguska Event - https://news.ycombinator.com/item?id=11155701 - Feb 2016 (71 comments)

Tunguska Event - a blast from the past [ Meteroite hit on Siberia 1908] - https://news.ycombinator.com/item?id=5229807 - Feb 2013 (4 comments)

The Tunguska Event - https://news.ycombinator.com/item?id=2314154 - March 2011 (1 comment)

The Siberian Blast (or the Tunguska event) Visualized in a Supercomputer - https://news.ycombinator.com/item?id=257373 - July 2008 (1 comment)

> We sought evidence that the little lake existed before the event. Reliable, pre-1908 maps of this uninhabited region of Siberia are not easy to come by, but we found a czarist military map from 1883 that fails to show the lake. Testimony by local Evenk natives also asserts that a lake was produced by the 1908 explosion.

this is about as suggestive a set of facts as you're ever likely to get. We don't need any exotic theories about Tesla or aliens.

> The first step in preparing ourselves would be to decide whether the cosmic object that affected Siberia was an asteroid or a comet.

What would we do differently if we determined conclusively which it was? A comet could strike Earth, even if Tunguska was not one. Knowing that it happened doesn't make it any more likely it could happen again.

One is more common that the other. And size matters. The smaller this object was, the more likely it will be to happen again. So it's exact size and composition matters when calculating future likelihoods.

well, it caused a city-killing explosion. What would we do differently if the projected size estimates varied by 10x?

It's scientifically interesting. Nothing wrong with that.

It might make the difference between ignoring a potential city-killer impact, and an all-or-nothing attempt to save us from civilization-ending event. To make such decisions we need to know what a particular type of incoming object might do. That means careful study of the few examples we already have in our history.

OK. And the debate about "what should we do about that massive object out there heading for Earth" would be calm and rational, and the voices saying "hey, don't worry, it's just going to be Tunguska-sized, we can ignore it!" would win out?

Please. It's an interesting question, and that's it.

Depending on the projected costs and other risks, yes, that could happen.

A tunguska-sized event would be ignored, paticularly as most of earths surface is water. Such an explosion over the pacific would not be worth the cost of any redirect attempt.

Well, a 10x situation probably wouldn’t end civilization. But, yes we should learn what we can from what evidence is available! Fully agree.

> What would we do differently if we determined conclusively which it was?

We probably *couldn't* do much differently, but Newton-for-Newton a bloody great big squashy snowball hitting us with a certain amount of energy would have a different effect - and maybe different mitigation - from a smaller harder rock with the same energy.

> We probably couldn't do much differently

and yet the DART experiment did succeed in changing the path of an asteroid.

Comets, because they tell all the way down the gravity well from the kuiper belt, are faster than relatively stable orbit asteroids.

Kinetic energy is a square of velocity....

A similar event in or near a populated area today might be interpreted as a nuclear attack.

The entire world would have detected the meteor that large and been warned

The Wikipedia page for the Tunguska event says it was “a stony asteroid about 50–60 metres (160–200 feet) in size.” How far out would something that size be detected? This is very much out of my area.

The other mentioned much smaller one has a whole article on it https://en.wikipedia.org/wiki/2023_CX1

This one was 1 m wide and it seems like it was detected about 6 hours before coming down.

But, as someone mentioned in another comment, the fact that we can detect a 1 m objects doesn't mean that we can detect all of them, far from that. Same for larger ones, we just have more chances of detecting those than 1 m-sized ones.

No, we routinely get hit by rocks we didn’t see coming.

Detecting incoming asteroids, especially small ones, is really hard. The recent 1-meter meteor that exploded over Europe, was only the seventh instance of a successful detection.

https://www.telegraph.co.uk/science/2023/02/13/asteroid-expl...

But it is the big ones, we are interested in, because they can do a lot of damage and not only fireworks.

Tunguska was a lot bigger than a metre across. Even the Chelyabinsk meteorite was a lot bigger, 18 m diameter, 9 000 tonne. So if we cn detect 1 m meteors I think we should be able to detect Tunguska scale objects.

We may notice some small things, but that doesn't mean that we've found all large things.

According to https://www.nasa.gov/planetarydefense/faq we only know about 40% of the rocks sized 140 meters+ that cross Earth's orbit. If one of the 60% we don't know about came at us from the direction of the Sun, our odds of seeing it before impact are fairly small.

https://en.wikipedia.org/wiki/Chelyabinsk_meteor

> The Chelyabinsk meteor was a superbolide that entered Earth's atmosphere over the southern Ural region in Russia on 15 February 2013 at about 09:20 YEKT (03:20 UTC). It was caused by an approximately 18 m (59 ft) diameter, 9,100-tonne (10,000-short-ton) near-Earth asteroid that entered the atmosphere at a shallow 18.3 ± 0.4 degree angle with a speed relative to Earth of 19.16 ± 0.15 kilometres per second (69,000 km/h; 42,690 mph).

> [...] The asteroid had a total kinetic energy before atmospheric impact equivalent to the blast yield of 400–500 kilotons of TNT (about 1.4–1.8 PJ), estimated from infrasound and seismic measurements. This was 26 to 33 times as much energy as that released from the atomic bomb detonated at Hiroshima.

If it had been at a slightly sharper angle, or slightly larger, or moving slightly faster, and if it had hit the right location, it could have destroyed a city. Fortunately it disintegrated in the upper atmosphere, so it only blew out windows across a large area as it burned brighter than the sun across the sky.

There was no warning. The Tunguska rock, if it was a rock, was only a few times wider. I don't think we can reliably detect those, either.

Do you actually need to have detected it as it was coming in to be able to say 15 minutes later "oh that was a meteor" detection and forensics are different... it's just really if the forensics happen fast enough to avoid a counter strike. Eg if some nuclear capable countries capitol just evaporated with no nuke early warning systems going off and no one could look up and see the massive trail coming in and had not streamed it on the internet first.

There is space surveillance network tracks things in orbit. I don't think that covers all of the sky and could miss a rock.

There are early warning satellites that look down for ballistic missiles. I don't know if the infrared detectors would see the rock. They are probably best as negative signal with no rocket being detected.

The main signal that wasn't nuclear weapon would be the size and location. Nuclear weapons don't explode as high as Chelyabink meteor. Nuclear weapons aren't as big as Tunguska event. Also, hitting a city is unlikely, hitting one dead on is really unlikely. There would also no nuclear fallout detected.

Space-based nuclear weapons surveillance systems monitor for X-ray burst and the characteristic double-flash pattern. Neither would be present in the case of a meteor, which would rule out a nuclear detonation immediately. Infrared systems likely would detect the meteor entering but the projected flight path would be, well, unreasonable for a missile.

By lay-observers, probably. But probably not by the systems actually designed to detect nuclear explosions, because those systems can distinguish nuclear explosions from other sorts of very large explosions by looking for characteristic emissions signatures, like x-ray emissions and the double flash: https://en.wikipedia.org/wiki/Bhangmeter

pretty sure the main focus is on detecting launches instead of explosions (detecting explosions doesn't help very much with holding up the end of the MAD bargain, so to speak)

https://en.wikipedia.org/wiki/Space-Based_Infrared_System

They definitely detect the explosions themselves, not just missile launches (remember that ballistic missiles are only one method of several for delivering nuclear weapons). This is for monitoring compliance with nuclear test bans, as well as just generally knowing what is going on. If a nuclear weapon goes off for any reason, the US government and other nuclear powers obviously want to know about it. These systems would also be able to distinguish non-nuclear explosions such as bolides from nuclear explosions, which is important for MAD if you don't want an accidental war. The systems to do so are now built into GPS satellites.

https://en.wikipedia.org/wiki/Vela_(satellite)

https://en.wikipedia.org/wiki/Nuclear_MASINT#Space-based_Nuc...

https://en.wikipedia.org/wiki/Global_Positioning_System#Mili...

Have to mention the Tesla/Robert Peary conspiracy theory. The date Tunguska happened Tesla had asked Robert Peary to observe any unusual weather phenomena. None were reported.

Tesla had reputedly activated his energy transmitter at Wardencliff, focused on Peary's location. If you draw that line (Wardencliff to Peary's expedition location) and double it, you have the Tunguska forest.

Hm..

> In 1946, for instance, science-fiction writer Alexander Kazantsev explained the puzzling scene by positing a scenario in which an alien spacecraft had exploded in the atmosphere.

Maybe Tesla shot down a UFO, and it self-destructed to prevent their technology from falling into our hands.

Or, as in Strugatsky brothers plot, the aliens were moving back in time so they continued living on in the age XIX, and perhaps left after repairs.

Known to the Beta-Centaurians as The Earth Event. It essentially scuttled all further exploration of our solar system.

since its now written down, its basically established facts. /s

Tomorrow in your friendly neiboorhoud LLM outputs !

There's no doubt that Nikola Tesla possesed some, let's not say a weapon, but knowledge about a very advanced way to cause mass destruction for it's time.

In a way, his mind was that weapon. And it's a good thing, too. Imagine someone else with that kind of knowledge.

I think there's a lot of doubt, actually. He was very smart but he was not a magician.

Have you not seen the documentary "Prestige"?!

Which makes me want to share my new favorite conspiracy theory about the movie(you know a story is good when there are wild theories about an event that was entirely imaginary in the first place, that is a sign of first class world building). anyway,

The entire tesla arc never happened, the whole thing was an elaborate con. "but " you exclaim, "we saw the machine, the hats, the trip to america", to which I reply this is a case of second person narrative the only source for this information is the diary(which the movie dutifully animates) and the diary was planted, the diary was the con.

I absolutely love this theory. Now I definitely need to re-watch the movie

In the vein of fan theories about imaginary events, a favourite of mine was that James Bond died in Blofeld's brain drill chair and the second half of Spectre was hallucinations as his brain shut down.

The release of a subsequent film with the same actor sadly disproved it.

I think that was another movie :)

"basically An Occurrence at Owl Creek Bridge" is a perennial category of fan theory, along with "they were dead/in purgatory/hallucinating in an asylum all along" and "$X is a Time Lord." The latter i've also seen about James Bond.

And of course Nikola Tesla. Which probably makes Edison The Master. There's definitely an AU fan fiction in there somewhere, which in its Golden Age (electropunk?) Lovecraft-noir incorporates "Edison's Conquest of Mars[0]," an influential but otherwise garbage sequel to H.G. Wells' War of the Worlds. Sorry, what was I.. oh yeah. Tunguska. Obviously Tesla accidentally reversed the polarity of the neutron flow.

[0]https://en.wikipedia.org/wiki/Edison%27s_Conquest_of_Mars

And of course Nikola Tesla. Which probably makes Edison The Master.

OK, sure, fine... but then who was The Rani??

You don't have to be a magician to make a doomsday weapon.

In fact, he likely did not make it. He just possesed enough knowledge to imagine such a weapon possible in theory.

There's a reason why I said knowledge about a weapon.

To this day, nothing in Tesla's body of work is relevant to any weapon of mass destruction. There's no evidence whatsoever that he had any specific knowledge [0] about the means to create a weapon of mass destruction. The idea "big weapon make big boom" predates Tesla by numerous centuries. Saying he "just possessed enough knowledge to imagine such a weapon" isn't a falsifiable claim, and could reasonably be claimed about any 19th/20th century inventor.

[0] I would say that the "death ray" doesn't count, because he's not the first to come up with it. The teleforce is not a weapon of mass destruction.

He didn't have more knowledge than we do now, 100 years, trillions of research dollars and millions of engineers later. He had a very amazing and intuitive sense of electricity, mechanics and physics in general, as well as an eidetic memory but it's not like he was conjuring mystical secrets out of the aether, any more than, say, OpenAI is today. And that's about how his inventions were received: with surprise that such things were possible, followed by credulity and wild predictions over where it might go, mostly relayed by people who didn't understand the technology.

Electricity simply doesn't provide a practical mass destructive capacity in the way that, say, the strong nuclear force does. However, from the breakneck rate of electrical technology from the 1890s onwards, you could see why an extrapolation of those capabilities could make it plausible that it could eventually get there.

While it's no doubt true that he didn't have substantially more knowledge than we do now, it's important to consider that some areas he was working in have only recently come to bear similar fruit. Specifically wireless power transmission, for example, was patented by him in 1916 and only in recent years were similar effects actually put into practice on a small scale (functioning in a nearly identical way as described in the patent).

There's been plenty of times in history something has been lost or buried due to the death of the creator or societal / political pressures.

Consider the EV1 and the legal fight against California's Zero Emissions legislation, some 20 years before Tesla Motors would shake things up.

> wireless power transmission, for example, was patented by him in 1916

So what? Perpetual motion machines, and a lot of other junk that never could work, have also been patented both before and since. Not only Einstein but also a lot of idiots have worked in patent offices around the world.

There's lots of doubt on that. I doubt it, for one, and probably lots of other people too. So where do you get this ridiculous “there's no doubt” from?!?

Until there is some proof that Tesla possesed an “advanced way to cause mass destruction” there is nothing but doubt about that.

The energy of the Tunguska event is estimated at around 60,000,000,000 megajoules. Assuming no transmission losses whatsoever, this can only mean that Tesla built the world's first nuclear power plant and that it still dwarfs the output of all modern nuclear power plants today -- combined! He was truly a remarkable inventor.

Actually you can reconcile this. Maybe Tesla’s transmitter acted like one of the laser targeting pods the military uses. The laser itself is minuscule energy, but it serves as guidance to a bomb or missile that is a lot more energetic. Maybe Tesla was in league with the aliens who wanted to test one of their missiles. Not wanting to cause a lot of casualties, they talked with Tesla about where they could target. Tesla used his device to help them target a very remote area of Siberia.

Why would these super advanced aliens need Tesla? They can just target whatever themselves.

Tesla was actually the equivalent of an alien spy/special forces. Just like In Afghanistan, the US used embedded special ops forces on the ground to do targeting for missiles launched from fighters at high altitude.

How about we compromise and say that Tesla made a Magnabeam from Forts[0], and that guided an iron-rich meteorite to Tesla's target?

[0] https://forts.fandom.com/wiki/Magna_Beam

From "Tesla Wireless and the Tunguska Explosion"[0]:

"Tesla said his transmitter could produce 100 million volts of pressure and currents up to 1000 amperes, with experimental power levels of billion or tens of billions of watts.(18) If that amount of power were released in 'an incomparably small interval of time,'(19) the energy would be equal to the explosion of millions of tons of TNT, that is, a multi-megaton explosion. Such a transmitter would be capable of projecting the force of a nuclear warhead by radio."

"18. Tesla, Nikola, New York Times, 'How to Signal Mars,' May 23, 1909, pg. 10. He claims to have sent 'a current around the globe' on the order of '15,000,000' horsepower or 11 billion watts."

"19. Secor, H. Winfield, 'The Tesla High Frequency Oscillator,' The Electrical Experimenter, March 1916, pg. 615."

[0] https://web.archive.org/web/20040203060110/http://www.frank....

Tesla said a lot of shit, some of it was even true.

This. He was a smart guy ahead of his time. He also had some wacky not-true ideas, which honestly couldn't be disproven at the time.

I expect some of our most brilliant minds today may end up with a similar retrospective.

Good to know the venerable "credulously repeat what the charismatic technology man said" school of journalism is now well into its second century of utility.

> Tesla said his transmitter could produce 100 million volts of pressure and currents up to 1000 amperes, with experimental power levels of billion or tens of billions of watts.(18)

Where did this power come from?

> If that amount of power were released in 'an incomparably small interval of time,'(19) the energy would be equal to the explosion of millions of tons of TNT, that is, a multi-megaton explosion.

Err what?

Watts is a measure of 'rate' not total energy. The smaller the unit of time the less the total energy transferred.

1 megaton of TNT is equivalent to 1.162 trillion watt hours. If you could generate and transmit 1 billion watts of energy, you would need to do this for 48 days and 10 hours before you've released the equivalent of a single megaton.

Or, flipped around, 1 gigawatt over say 0.1s is only ~23.9 kilograms of TNT. A decent amount of energy, but nothing on the order of Tunguska.

Even those 1-10GW numbers aren't enough.

  (60000000000 MJ) / (1000000000 watts) = 2 years
     (69.4 days if you have 10 billion watts)

Going the other way around, releasing that energy in 0.1 seconds requires:

  (60000000000 MJ) / (0.1 seconds) = 6E17 Watts

or almost 60 million times more energy than what Tesla himself claimed he could do.

Your source, Oliver Nichelson, seems to have done the wrong math (or perhaps I did?). 1 megaton of TNT is 4.184E15 J

  (4.18400E15 joules) / (1 000 000 000 watts) = 48.4 days
     (4.8 days if you have 10 billion watts)

48 days is not an "incomparably small interval of time". And if released in 0.1 seconds:

   (4.18400E15 joules) / (0.1 s) = 4.1E16 Watts

or about 4 million times more powerful than what Tesla claimed he could do.

Also, it doesn't seem like Nichelson is clear about the difference between power and energy.

Power is the energy transferred or converted per unit time. That's why it's measured in watts = Joules/s or the equivalent in other systems.

Energy is just the Joule part of that term. The phrase 'If that amount of power were released in 'an incomparably small interval of time,' is imprecise. It should be 'that amount of energy', which would then give the needed J/s for power. But there's no reference to what that amount of energy was.

Thing is, the power supply was already given, as "tens of billions of watts". You can't release tens of billions of watts - J/s - in an incomparably small interval of time because that's meaningless - power isn't measured in J/s/s.

What you can do is release tens of billions of energy in an incomparably small interval of time. But it would take time - months or even years - to build up that energy with only a 1-10 GW power supply.

The essay you link to doesn't describe how that energy is stored before release. At best is says "build up electric fields", but it still takes days to get that much energy in the first place.

Since the math doesn't work out, since the author seems to be confused between power and energy, and since there's no explanation of how Telsa could have generated 60000000000 MJ of energy, much less release it in a split second, I think it's appropriate to discount the thesis of that essay.

Or it somehow 'grounded' the entire ionosphere, producing the mother of all lightning discharges.

I think that'd be possible by inducing a standing wave reaching from ground to the ionosphere. That would ionize the air in between and create a channel to induce the lighting strike.

Why would you double the line?

Because you get right answer that way. Why would you want the wrong answer?

Half-wave vs full-wave was a common error.

Was there a follow-up? This was written fifteen years ago.

“115 years later” doesn’t have as nice a ring to it :)

Related: Sandia Labs did some impressive simulations of that event entering the atmosphere. A couple of the resulting videos; well worth a minute to watch.

https://www.youtube.com/watch?v=0yY34uWty_0

https://www.youtube.com/watch?v=Gr7i33UhmC8

June 30, 2008

I'll just leave this here:

https://en.wikipedia.org/wiki/Leonid_Kulik

http://scihi.org/leonid-kulik-tunguska-event/

I_am_not_saying_it_was_aliens.gif

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