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Y Combinator And Mithril Invest In Helion, A Nuclear Fusion Startup (techcrunch.com)
380 points by gwintrob on Aug 14, 2014 | hide | past | web | favorite | 192 comments

It's interesting that you can justify this investment in at least four separate ways, independently:

1) Even if there is a low chance of success, it would be wildly profitable if successful, and investing early gets you a good share if it's successful.

2) Fusion power would make the world a better place; investing in this way, when you already have huge returns and it's someone else's money, is actually rational even if you think it's not the best financial investment.

3) This looks like an amazingly smart team; even if they fail at fusion, they might find something worthwhile in the process. Just handling magnetics and high power well could be a useful toolkit for other problems.

4) "Halo effect" -- both because it's awesome science/engineering and because it shows a willingness to take extreme risks -- boosts YC (which probably doesn't need it) and Mithril (which is maybe even more awesome than YC, but nowhere near as widely known). If it loses $1.5mm but makes it more likely the next Facebook comes to either of these funds, it's a win.

The risk of #3 is that they don't create fusion but they do develop a machine that can emit streams of hot plasma which is then turned into the Navy's weapon of choice for close weapons support on carrier battle groups.

That said, I am looking forward to at least one of the fusion efforts bearing fruit. I'm something of an optimist here but I expect a durable solution to the 'energy problem' to emerge from our developing understanding of both quantum mechanics and particle physics. I am also cognizant of the fact that it also raises the bar on both good and bad things that humans can do. The tricky parts are in the transitions, pre and post event.

We've already weaponized nuclear fusion into the most destructive bomb ever created. It probably couldn't get a whole lot worse than that.

I think there are other paths to sustainable energy, but certainly viable fusion power is the holy grail.

Nuclear bombs aren't that dangerous though... in the grand scheme of things. That's because their use could trigger a chain reaction which creates a virtual apocalypse scenario. Basically ensuring their use impossible.

What's scary is a weapon that can cause massive damage, that we are actually willing to use.

In the grand scheme of things, the situation that held during the Cold War was a historical accident. Not every nuclear bomb in the future will necessarily be possessed by nations who are facing adversaries who can respond in kind to the use of nuclear weapons. Nuclear weapons are very scary indeed, and we are very lucky to have made it decades since they have last been used in war. I have good faith that we will make it to a century, but I would not make a bet that they will never, ever be used in anger ever again.

I think MAD between a small number of (mostly rational) actors was the best case scenario.

Sure, nuclear states vs. non-nuclear traditional states is the most likely use right now, but we're not that far off from non-state actors being able to make nuclear weapons. Right now the only real protection is limiting access to fissile material.

What's worse, it's gonna soon be trivial for non-state actors to do similar (or worse) damage via bio. Fun times ahead.

With respect to nuclear weapons, the question isn't just with their use but also their misuse. There have been a non-zero amount of incidents in North America with non-nuclear detonations (fortunately).

Source: https://en.wikipedia.org/wiki/List_of_military_nuclear_accid...

I don't understand why this was downvoted. I'm not going to discount the possibility to invent something worse then our most powerful fusion bomb, but if we talk probability here, developing processes that allow greater control is likely to result in a worst case scenario where we have a weapon that is at most as powerful as what we already have, but more focused.

IMHO focused fusion destruction is likely to be far more humane than the indiscriminate destruction caused by the weapons currently in our arsenal. i.e. a highly focused weapon is likely to to result in instant death for the victims instead of minutes to months to years of suffering for victims depending on their exposure levels.

I regret posting this comment due to all the completely unrelated commentary it generated, detracting from the startup in question. If you read this comment, please skip my comment above and all the replies. Your time is better spend reading about what this startup is doing.

I'll never understand being able to kill someone in a humane way(through acts of war). You're killing someone.

I won't deny it's complicated, but there's more to thinking about how we conduct war than just the proximal individual act of killing. Two cultures that, for instance, respect military vs. civilian distinctions may war with each other with much less total damage than two cultures that practice Total War, even if the political outcome is the same in the end.

Just because war is bad does not mean we are forced to throw up our hands and stop making distinctions between degrees of badness. War is not simply infinitely bad... that's ultimately a very sophomoric view.

War, itself, is a pretty damned sophomoric thing.

This is a simplification. Defending yourself against unprovoked attack is not juvenile, although there are moral systems that advocate rolling over and giving up if you are attacked. And there is a whole spectrum of combat actions where "defense against unprovoked attack" is one extreme.

In industrialized countries, wars of aggression are usually never profitable, but the same can unfortunately not be said for less-developed societies. Even Europe didn't find this obvious until after World War 2. So I guess it ends up being a question of how you define "sophomoric".

Actually, wars of aggression are almost never profitable. Accumulating riches via conquest is almost always a myth, because armies a) destroy much that is of value and b) are unbelievably expensive.

"Wealth through superior firepower" has hardly ever been achieved. Even Rome mostly got rich through trade after its armies conquered Europe and North Africa, and a lawful peace was imposed. Had everyone been economically rational pretty much the same end could have been achieved through trade (spoiler: not everyone is economically rational.)

Simple looting of the kind the Spanish engaged in in the New World was never a very good path to wealth, partly because its first effect was to create massive inflation (if you use gold as money and inject vase amounts of gold into your economy without increased productive capacity, you get inflation, not wealth.)

So the conditions of gaining wealth by war are very, very narrowly defined. It's not impossible, but it's amazingly difficult.

There are defensible moral reasons for engaging in mass organized violence--I support the current American efforts to kill people in Northern Iraq, for example--but economic rationality (profitability) is never one of them, because the first step to creating wealth is never to engage in the wholesale destruction of everything the creation of wealth depends on.

Interesting that wars of aggression have almost never been profitable; this fills a hole in my understanding. I've always understood that this fact only became obvious after WWII, and almost 10 years of terribly destructive fighting in Europe and elsewhere.

Interesting, you know more than me but afaik it is correct. Both in facts and arguably in moral.

Since you brought up Rome in discussing payback for warfare, you could also ask "Cui bono" here -- "who benefits?"

A war is potentially just like a gold rush, the people getting rich are the ones selling the tools to dig or make war.

Just look at my native Sweden, we managed to stay out of a few wars and shamelessly sold high quality steel to the countries fighting. It made Sweden go from the bottom to the top in Europe.

What this implies about lobbying and how wars starts I'll leave to the imagination.

(I might also add that IS has declared war on the democratic world. So trying to stop their expansion is arguably self defence.)

"Sophomoric" is not merely an empty insult, to be flung at whatever you don't like. It is a specific thing. It can not apply in this case... only a particular justification for a war could be sophomoric, not the whole act.

If you were going to have to die some way, would you prefer to die from 3rd degree burns over most of your body and with your retinas burned from a bright searing light or would you prefer to die from a lethal dosage of heroin?

The outcome may be the same, but there's a whole lot more humanity in subjecting someone to the latter.

Sometimes situation dictates that someone is going to die, and you have the option of deciding who and how - best it happen to the "most deserving" in the least painful/agonizing way possible.

It's like humane slaughter of animals for food - there are ways that don't cause unnecessary pain, others that do.

Sounds like a misuse of the word to be honest.

humane (hjuːˈmeɪn)

2. inflicting as little pain as possible: a humane killing.

which dictionary did you pull this from? I see "characterized by tenderness, compassion, and sympathy for people and animals, especially for the suffering or distressed"

The most common definition is a synonym of compassion, but the definition of limiting pain/suffering is also very common.

I pulled it from http://thefreedictionary.com/humane which cites 'Collins English Dictionary – Complete and Unabridged'.

Suffering and harm are distinct things, and being humane is about the former.

How about if we put it like this?

When a democracy has a war with a dictatorship it is similar to when the police defends civilians from violence.

(So this don't get into a shouting match: Check "democratic peace theory". I am aware of that the police can misuse their position. A democracy often also do cynical realpolitik when it isn't its voters that gets harmed.)

Edit: You might want to do the distinction of a junta that do a general draft, so there are soldiers for the dictator which didn't volunteer. It isn't an easy solution, but citizens in a country can theoretically overthrow their dictator. Hopefully with more help than the Syrians got from Obama.

Edit 2: I assume that you don't think it is immoral to sell weapons to police. If you are that pacifist, then I think you should move to some place without police to protect you... I hear they have good weather in inner Somalia and southern Yemen. Both are traditional clan societies without police.

Edit 3: Ah, you have a 60s style of police racial violence discussion in the USA right now. I get the down votes.

Go back to Ferguson.

This is true, but a focused bomb is also one more likely to be used because you're not laying the countryside to waste using it.

Regardless of everyone's feelings on whether weapons research is or isn't a good idea, this strikes me as a grossly unlikely application.

The problem with direct-fire weapons is not something like "bullets don't do enough damage." It's aiming and range and so forth. A plasma weapon seems unlikely to have good range or good aiming, and if it does not come with a fusion reactor alongside it, it's also kind of hard to see how you'd power the damn thing.

I'm sure someone can imagine some upside to such a weapon, but in practice, the odds that that particular result would come instead of a million other variations that would be inferior to just shooting bullets at things seems deeply unlikely.

And as everyone has already said, we already have fusion bombs. And for that matter small tactical nuclear weapons for more battlefieldy uses.

Rather than a literal plasma gun, I think they were just saying the risk is that the team will pivot into weapons research. But no one has thus far explained why weapons research would be anything but a positive thing.

Yes, using weapons is unfortunate. The decision to ever use a weapon should be made with the utmost discretion. But when it comes time to use a weapon, it seems hard to argue against having the most effective weapons that also have little collateral damage.

Maybe people are worried that a new, extremely effective weapon will be discovered which happens to have high collateral damage. That's a concern, but it's never been possible to delay the advancement of technology. If something is possible to discover, then it seems like some diligent researcher will eventually discover it. But the concern itself seems misplaced: most new weapons have less collateral damage, not more.

And what I'm saying is that regardless of the ethics of it, why should we regard it as in any way plausible that this company would pivot into weapons research?

By a huge margin, the most plausible military application of anything this company develops is "a fusion reactor on an aircraft carrier."

And I say that as someone who regards it as deeply unlikely that this company will create any major step towards a fusion reactor.

Not big enough for a carrier, and that last generation is already designed.

But about right for a submarine.

I think people are worried about a low-collateral-damage weapon which means political leaders can be more likely to deploy it. Observe the objections to the use of precision-guided munitions fired from long-hovering remote-controlled drones.

> The risk of #3 is that they don't create fusion but they do develop a machine that can emit streams of hot plasma which is then turned into the Navy's weapon of choice for close weapons support on carrier battle groups.

The possibility of pivoting your business model to "building plasma cannons for the Navy" is less of a risk and more of an awesome opportunity. I mean, defense contracting is a bit of a drag and there's tons of red tape, but if there's anything as cool as building fusion reactors small enough to replace diesel generators, it's building plasma cannons for the Navy.

"I mean, defense contracting is a bit of a drag and there's tons of red tape"

Not to mention the tremendous moral hazard. I am unclear as to how anyone can function as a reasonable moral actor when they profit from war.

Calling it "defense" does not solve that problem.

Generally I would expect direct fire weapons to have much less collateral damage than bombs.

Building a better bullet can save lives.

And of late someone has: guided .50BMG bullets which can adjust their flightpath to assuredly hit a target (which, one can presume, is being shot to prevent others from being killed). EXACTO .50-caliber demonstration: http://www.darpa.mil/NewsEvents/Releases/2014/07/10a.aspx

Plasma cannons don't kill people, people kill people, and we've already invented those.

Changes in topology kill people.

We'd certainly be concerned about those kinds of applications. Fortunately we don't use beams in this approach. The plasma used in the Fusion Engine is akin to a balloon or pillow, granted - a really hot pillow, but luckily a terrible projectile.

Do you have an opinion about Bussard/Polywell?

The risk of #3 is that they don't create fusion but they do develop a machine that can emit streams of hot plasma which is then turned into the Navy's weapon of choice for close weapons support on carrier battle groups.

Why is that a risk? I'd like to live in a country with that technology, because otherwise other countries will have it and we won't.

It's a risk to the investment firms because it would deplete an upside they get from this investment: the halo effect.

Depending on the military application, it might still have a halo effect.

Great skill in manipulating magnetic fields would probably be useful for: MRI. Detecting landmines and UXO in a field from a UAV or otherwise safe distance. Detecting submarines, including those by terrorists or rogue states transporting NBC weapons.

While those are military applications, they're fairly unalloyedly positive.

Even the hypothetical plasma rifle isn't necessarily a bad thing; if a plasma rifle allows rich countries like US, Japan, etc. to overmatch poor countries and thus prevent war, that's kind of a plus.

But it would create a financial upside. They are a fund after all, and you'll find plenty of institutions investing in LMT, NOC, and friends.

You might lose some of the halo effect for one audience, but gain it from another. Not everyone things defense (or if you prefer weapons, or arms dealing) is a bad sector to be in.

No doubt they could come up with something dangerous, but I wouldn't worry about that particular mode. Plasma doesn't travel far.

A nice portable high intensity directed neutron radiation source might be pretty nasty, though.

There are already commercial oilfield tools that use neutron generators with relatively low power input requirements. I'm not seeing how to make a useful weapon out of something like that, though. What can it do that isn't already done better by normal guns and bombs?

I guess you could use it to attack people inside a building without directly destroying the building, but I would figure that if you got a high enough neutron flux to reliably kill everyone inside the building, you'd also get enough activation radiation to render the building uninhabitable for at least weeks. You might well need fancy decontamination, and possibly to demolish the building and haul away parts of it. Seems easier to just use a bomb.

Sadly enough, those already exist:

"Fusors have also been developed commercially, as sources for neutrons by DaimlerChrysler Aerospace" http://en.wikipedia.org/wiki/Fusor

But you're right, plasma is not the deadly weapon. Neutrons are.

The biggest fear of carrier groups are mach 7 ramjet antiship missiles launched from hundreds if not thousands of miles away, way too fast to destroy with anything even laser (you barely see them coming at you) and on top of that relatively cheap at maybe half a million a piece compared to the billions a carrier costs, meaning the enemy could launch tens of them at each ship.

It would be pretty difficult to weaponize a closed system design without significant R&D. The only risk I see would be if some small component of their design was transferred to an existing military weapon to make it better.

It's insanely cool that YC is now part of this. Also love that pg credits Sam for making it happen.

On a somewhat related note. Despite the setbacks and the bad rep nuclear gets, fusion really could be a better future. The energy density is in a class of its own, compared to that of renewables. Prof David MacKay demonstrates this quite effectively here[1]. This of course is not to take anything away from renewables or imply we shouldn't pursue funding both.

One group of companies I find particularly interesting, are those attempting aneutronic fusion.[2]

Like many good ideas, that became bad ideas (in the 60's), it appears to now be back in fashion.[3] Theoretical advancements have pushed the achievable temperature ceiling northwards, allowing a move towards commercialization.

Whether this particular line of fusion innovation will ultimately pan out, is perhaps anyone's guess. Personally however, I suspect there is a chance it can work. The benefits would be almost too good to pass up. Small, modular, cheap and safe (with almost no radioactive waste)

Some examples in the industry:

Raman-budget: Focus Fusion [4]

Secretive and heavily funded: Tri Alpha Energy [5]

[1] http://www.ted.com/talks/david_mackay_a_reality_check_on_ren...

[2] http://en.wikipedia.org/wiki/Aneutronic_fusion

[3] https://www.sciencenews.org/article/proton-boron-nuclear-fus...

[4] https://www.indiegogo.com/projects/focus-fusion-empowerthewo...

[5] http://en.wikipedia.org/wiki/Tri_Alpha_Energy,_Inc.

> On a somewhat related note. Despite the setbacks and the bad rep nuclear gets, fusion really could be a better future.

It sure could be a better future but the "bad rep" problem is bigger than I ever thought. The coalition of green parties in the European council (or Commission? Parliament? EU bureaucracy is confusing-) have the following in their program (paraphrased): "Cancel the funding of all nuclear power projects, like the ITER project".

This is a purely political move that is made solely to appeal to the feelings (not intelligence) of their voters. Nuclear fusion should be the project for the Green movement, but instead they are doing the complete opposite, just because of the reputation issues.

Pandora's Promise is a very interesting documentary about plain nuclear fission power, created by an environmentalist who decided to think for himself and investigate the power source that his movement hates.

The film highlights much of the misinformation campaign about fission, with particular emphasis on Chernobyl. I highly recommend watching, no matter the what you believe about nuclear power.

> "Cancel the funding of all nuclear power projects, like the ITER project"

This is so very sad indeed. Fusion and fission are entirely different technologies, and both show immense promise to meet the energy needs of the future.

I was interested for a source, so I found this:


"23. Calls on the Commission, the Member States, the European Investment Bank (EIB), the European Bank for Reconstruction and Development (EBRD) and other public banks to freeze public funding for nuclear fusion, including ITER, or fission, except for the decommissioning of nuclear facilities;"

What the hell? I just don't understand the Green parties sometimes and could never support them while they still do rubbish like this.

It's because even ITER produces radioactive waste, and the greens are only interested in clean energy. In their view, with hydro, geothermal, wind and solar we have all the clean energy sources we need, if people cut back their energy consumption. That is, ofcourse, a big if.

Prof Mackay's talk pretty much says that in order to use renewable energy the whole UK would have to be covered in electricity generating equipment.

However, 15% of UK energy is generated from renewables (excluding nuclear), which would mean that currently one seventh of the landmass of the UK was covered in wind turbines etc. Which it isn't. You'd be able to tell.

So, one of us has made a mistake with our calculations somewhere.

To start with, you're talking about electricity generation, where he is talking about total energy requirements. So your 15% figure doesn't include the energy consumption of cars, aeroplanes, many types of heating etc.

I believe he also includes the embodied energy of imports (this was in his book), where if goods are manufactured overseas and imported, it may make sense to count the energy used to manufacture them, depending on what you're measuring exactly.

For example, there's little difference between importing aluminium, or importing energy and bauxite and smelting it yourself.

Also, area use will not increase linearly with the addition of many renewables, because in many cases the best sites are taken first. Hydro can generate a lot of energy around the clock, but you quickly run out of the best locations. Wind strength varies across the country.

In a small country like the UK, solar isn't going to vary much by latitude, and you can probably build it out all over the country. But time shifting of demand isn't always possible, so even if the panels were free, using them to push from (say) 50% of energy from renewables to 100% is going to involve some kind of storage system, which is either going to be very expensive (probably exceeding GDP) and unproven (eg hydrogen fuel cells, lithium ion batteries), or require a ton of space and specific terrain, like pumped water. So that's going to cost a lot of space.

Lastly, electricity isn't always the desired final form. If you're powering jet planes, you're going to need some type of biofuel, which is very inefficient per unit area. If and when hydrogen planes are developed, this will stop being an issue (electric cars have already proven their viability).

I highly recommend his book. It's a brilliant read, he nicely boils down the issues, and is thoroughly committed to stopping global warming - it's not some doom and gloom oil industry sponsored thing. But he doesn't have his head in the sand about how hard a switch to renewables is going to be, unlike (unfortunately) a ton of the green movement seems to.

Ok, if we're talking total energy, then 5% rather than 15%. The point still stands.

I've no idea why he would include imports. Does he exclude exports? It seems a bit mad. There's a huge difference between me buying some aluminium and having to generate the electricity at my home to smelt it myself as a kind of cottage industry! (A case of he who smelted, dealt it?)

The point about area use not increasing linearly is a good one. However, Prof Mackay doesn't do this. He consistently states that - even giving renewables every advantage and pretending they'll always work at peak efficiency - you'd still have to blanket the country with them to make them effective.

I've read his book and it's where I first started to think there was something a bit off in what he was saying. Yes, he's very full of the idea that he's the hard-nosed realist and anyone who disagree must have their heads in the sand. I've heard that tactic before.

If your goal is sustainability, there is no difference. Pushing your energy consumption out to another country is just shifting the problem. Though yes, you would want to exclude exports in this model.

Picture a hypothetical country that solely consists of stay at home programmers making large sums of money, powered entirely by solar, but importing vast amounts of physical goods manufactured in environmentally unfriendly ways. The country would by traditional measures be a perfect model of sustainability, but it is simply paying others to do unsustainable actions on its behalf.

The book isn't really "saying" much, for the most part. The vast bulk of it is simple, back of the envelope calculations for energy consumption which shows working. I realize you might not want to take a half hour to find specific faults in it, but it is not helpful say there is "something a bit off" with a work like that, when the source code is published for all to see.

For instance, that he counts embodied energy of imports, and you do not wish to, makes a big difference to the bottom line. Just skimming the chapter headings is enough to point out a concrete disagreement.

Fair point about the hard nosed realist tactic often being used to discredit dissenting views. That wasn't my intention, I was more trying to say that the conclusions presented should not be used to infer some political position of the author.

There are a ton of studies paid for by the oil industry that paint all kinds of pictures, I just meant it's not a book like that. If I realized you'd already read it, I wouldn't have included that part.

Having read the book the specific fault with it is that the results it comes up with from its simple back of the envelope calculations, bear no resemblance to actual reality and are therefore wrong.

Including imports is wrong. In your hypothetical country, fixing those unsustainable actions is up to the country they're importing goods from. Show that they can't use wind/solar on their landmass if you want. The idea that every area of a country (or indeed the world) are equally good at generating power is obviously incorrect. Claiming that this makes wind and solar power unusable is equally incorrect.

The book reads like it was paid for by the nuclear industry (I don't think it was; it just reads that way).

If your talking total energy then you need to include food and farms already take a lot of land.

So, while close it's vary misleading as going 100% renewable would take less new land than he is suggesting. Add to that you can mix wind farms and regular farms at the cost of less than 1% of the farm land. Not to mention off shore wind farms. Which further reduces the land requirements well below his calculations.

Also, Hydro is vary efficient built in storage using it 24/7 is vary wasteful.

Wind is 24/7, and solar aligns with peak demand fairly well. Anyway, rather than storage your better off with extra wind capacity that's often wasted, with solar to meet your daily peak and hydro to fill in the gaps.

PS: Adding a few peaking power plants is still a good idea, going 80% renewable is a much more reasonable goal until most of the world is at that point. It's silly to chase a few extra % when china is using so much coal power.

According to [1] in 2012 for the UK renewables provided 11.3% of electricity demand and 3.94% of total energy demand. It's an important distinction, because petrol natural gas and jet fuel aren't renewable.

MacKay is the author of a book - "Sustainable Energy without the hot air" - which lays out all his calculations and the rationales behind the inputs. And it's available online [2]. So if you want to audit his calculations, have at it!

[1] https://en.wikipedia.org/w/index.php?title=Renewable_energy_... [2] http://www.withouthotair.com/

I've looked at the book, there's when I checked his figures and they seemed to disagree with reality.

So, electricity is about 1/3 of total energy. The 15% figure is the latest one for the last quarter of 2013[1] (PDF, see page 13). That means that (according to Prof Mackay) 5% of the UK is covered in renewable electricity generation.

No, it's still not.


> However, 15% of UK energy is generated from renewables (excluding nuclear), which would mean that currently one seventh of the landmass of the UK was covered in wind turbines etc. Which it isn't.

Most likely brought in from other countries, and the wind parks in the North Sea.

Many local utilities in Germany hold stakes e.g. in a Norwegian (iirc) dam project, so they recieve a given amount of electricity output. This increases Germany's renewable-source amount even if the energy itself isn't produced in Germany.

Nope, Scotland over produces and sells to England, but that's still UK, at least for another month ;-)

Offshore wind was included in the impossible. There's something off in his figures. Perhaps wind turbines have become more efficient since he first made his calculations?

It may also be diminishing returns, not all land is equal for wind turbine placement. If all the "good" spots can't generate enough for the UK's needs you might need to start using less suitable locations.

By far the most efficient wind turbine placements are offshore. We have plenty of coast, and so far very little of it has offshore wind farms.

We also have a good few estuaries that could create electricity relatively easily - using known and proven technology, which fusion certainly isn't.

Bottom line is these figures are either incompetent or disingenuous.

I'm old enough to remember fusion being touted as the Next Big Thing for literally all of my life. Commercial containment fusion seems no closer now than it did fifty years ago.

There are alternatives, but they're highly speculative. Dropping YC cash on them makes sense as a long shot, but the science doesn't suggest it's wise to expect them to make good.

I would also add that YC investment boosts nuclear stuff as a legitimate thing. Could lead to copycat investment (which we dearly need in the nuclear field).

Well if they really "Developed complete self-supplied He3 fuel cycle" like it says on their website, that is number 3) right there.

Nature had a fun article a few weeks back on the current trickle of VC into fusion startups.


It's certainly interesting, and I wish these companies all the best. The consternation I see occasionally over a company like this getting a (relatively) small amount of funding confuses me. There are so many software startups that receive equivalent or greater funding that eventually die or pivot into something else. Here, you have physical cutting edge engineering with potential implications that blow something like Slack, or Square, or even Uber away. Personally, I love seeing companies in the physical space get in on today's Silicon Valley high.

Semi-related, but I've been to NIF (National Ignition Facility), since I spent a summer at LLNL, and the inside of that facility is like the dream vision of every little kid that was into science and science fiction. Unfortunately (as my physicist significant other who was not working there found out) the public tours are far more restricted and you don't get to see the cool stuff.

> or even Uber

Talk about an understatement. Uber is just a cheaper cab. Commercially viable fusion is a game-changer on a planetary scale: Halting global warming by replacing fossil fuels, hydrogen fuel cells become viable by generating hydrogen through hydrolysis, energy-intensive desalinization plants deliver fresh water for drinking and irrigation.

I was trying to be nice. I'm a strong environmentalist via academics (BS/MS in environmental science), and currently a research analyst in renewable energy economics, so I have very strong feelings (and I like to think a well-grounded sense) about how fucked the environment and incentives around it are.

I was giving a (very) charitable reading of the occasional claim that Uber will change the way everything works via its framework. A more tempered tone normally does better on HN, but to be totally honest, I don't think any of those companies I mentioned could even come near what Helion would achieve if successful.

Maybe offtopic, but what do you think about the economics of plug-in hybrid cars (like the Chevy Volt)?

You didn't ask for my opinion, but I'll give it anyway. We need cheaper batteries, period. That's the limiting factor to wider spread adoption of electric vehicles.

Planetary? Try Intrasolar. Don't forget the goal of diversifying the human race beyond Earth. Fission power is currently infeasible due to the shielding problem.

  Safe: With no possibility of melt-down, or hazardous nuclear 
  waste, fusion dose not suffer the drawbacks that make 
  fission an unattractive alternative.
Eyeroll. D-He3 fusion produces less neutron flux than D-T, but it's hardly aneutronic-- otherwise they couldn't breed He3 from it. After a decade, the whole reactor will be nuclear waste.

I wonder what the service interval on an installed reactor will be? Or are they doing isotope separation on the produced helium on-site?

(Fun fact: you can get deuterium from water[1] but helium comes from natural gas fields![2] It's literally a fossil gas, which is why we're running out of it: http://en.wikipedia.org/wiki/Helium#Occurrence_and_productio... )

1: Commercially, heavy water is a byproduct of electrolysis plants: since deuterium doesn't electrolyze quite as easily as light water, it tends to accumulate in electrolysis stacks

2: The same rock formations that trap natural gas also trap helium.

>D-He3 fusion produces less neutron flux than D-T, but it's hardly aneutronic-- otherwise they couldn't breed 3He from it.

You can't "breed" 3He; you have to breed tritium, which decays to He3 with a half-life of 12 years. D-3He reactors do produce some neutrons, roughly 1% of the flux of D-T, and almost entirely from D-D side-reactions.

Actually, a big problem with D-3He as of today is the lack of neutrons -- since you only get one neutron per 100 (e.g.) reactions, you can't possibly breed enough tritium to break-even. You have to come up with some other neutron source, or send rockets to Jupiter.

>After a decade, the whole reactor will be nuclear waste.

Fusion reactors are generally made from boron carbide -- a material unique for the fact that it does not become very radioactive when irradiated with neutrons. 14C which is produced can be extracted by oxidation and centrifuging, and in any case is not nearly as scary as, say, 90Sr. No other concerning radioactive isotopes exist with atomic masses between 10 and 21 (cf 22Na).

>commercial helium comes natural gas fields! It's literally a fossil gas, which is why we're running out of it:

Nope, that's 4He. There's basically no 3He in natural gas (because the helium there is radiogenic), so obtaining fuel that way wouldn't work even if we wanted to.

Great reply. The wiki also has a long discussion about Helium 3. http://en.wikipedia.org/wiki/Helium-3 Fusion produces neutrons either in the first or secondary reactions, but there are ways to minimize the amount of them and their energy (and damage/radioactivity)to where you don't generate "nuclear waste". There is an interesting continuum of fusion reactions from pure D-D (which produces little energy, but lots of lower energy neutrons) to D-He3 (that produces some neutrons and lots of energy) to pure He3-He3 (that is called 'anuetronic').

D-D fusion makes Tritium (that decays into He3), Helium 3, or Helium 4 through the fusion process itself, with no breeding.

We believe that there is a correct ratio called Self-Supplied in which you have a small amount of 2.4 MeV neutrons, only deuterium as an input fuel, and the majority of the energy is from the Helium 3 fusion. The hard part is how to separate out the right isotope mixture from the exhaust between pulses.

He3 is never added? How long can a reactor run without supplying He3?

(This thread is having a hard time settling on a single isotope notation.)

The best way to make Helium 3 is with Deuterium fusion. Its a very interesting bootstrap question -- how do you build new reactors, if you have to have working reactors to generate fuel?

So really it's a mixed-mode D-D/3He-D reactor? How much more common are D-D reactions than 3He-D reactions while the reactor is running normally?

How much does the initial charge of 3He cost, given that the stuff costs $7,000 a gram?

  You can't "breed" 3He; you have to breed tritium, which 
  decays to He3 with a half-life of 12 years.
Huh, I didn't know that. Helion directly claim they've "developed [a] complete self-supplied 3He fuel cycle", though. How did they manage that? Are they just massaging the truth, by saying that warehousing the tritium exhaust for a decade, then putting the 3He back in the reactor, still counts as a closed fuel cycle?

I imagine you could produce 3He by hitting deuterium with a proton beam, (or doing something exotic with 4He, or 6Li) at incredible cost per litre of produced 3He, but that's not really a "fuel" cycle, since the power reaction isn't involved in any way...

  Fusion reactors are generally made from boron carbide
??? Source? I've never seen a vacuum chamber cast from boron carbide, and you certainly can't make magnets out of it, which have to be centimeters away from the reaction, and therefore get irradiated. Are there any running fusion experiments that use internal boron carbide cladding to shield the vacuum chamber walls?

>Helion directly claim they've "developed [a] complete self-supplied 3He fuel cycle", though. How did they manage that?

I have no idea.

The D-3He reaction is: D + 3He >> p + 4He + 18 MeV. The D-D side-reaction is D + D >> n + 3He. Maybe they're recovering 3He from the side-reaction? But D-D is harder to ignite than D-3He.

This would hardly be aneutronic (you'd have one neutron per two nuclear collisions, instead of roughly per 100 with exogenous 3He), but it does provide a way of making 3He. I should stress that I am only guessing.

>Are there any running fusion experiments that use internal boron carbide cladding to shield the vacuum chamber walls?

Germany's new stellarator, Wendelstein 7-X: http://www.sciencedirect.com/science/article/pii/S0022311504...

[1] http://www.sciencedirect.com/science/article/pii/S0920379697...

Actually, ITER uses beryllium[1]. This has the same high cross-section and low propensity to create dangerous radionuclides as B4C, but is expensive and toxic. It is, however, much easier to make things out of, because it is just a metal. Older projects use tungsten, which does create dangerous radionuclides (181W and 185W). I was mostly aware of research re: B4C, but had been ignorant of beryllium.

So I should have said "modern fusion reactors generally use first-wall materials like boron carbide and beryllium, which do not become radioactive when irradiated". In practice, it's not worth holding up experiments on containment to make safe walls (ITER isn't built to last). In any case, the question of irradiated reactor walls is slowly becoming a solved problem.



According to wikipedia D-D is the second easiest reaction behind D-T. Half the reactions produce 3He directly. The other half produce a proton plus tritium, which decays to 3He with a 12-year half-life.

You'll get some D-T from the tritium you produced, but the pulsed reaction probably helps a lot.

"Assuming complete removal of tritium and recycling of 3He, only 6% of the fusion energy is carried by neutrons."


Actually the D + D reaction has two equally probable branches (and one very improbable one that makes an alpha particle and a gamma ray, which is mostly ignored), one makes Tritium and a Proton and the other makes D + He3. So the D + D reaction will breed He3 fuel, along with Tritium. The resulting proton from the Tritium branch can also combine with Deuterium and create Helium 3 as well in the right conditions. Under carefully control, the right conditions, and with some engineering work I would wager you could bias the reactions and side reactions towards creating more Helium 3.

> You have to come up with some other neutron source

Just throw chunks of Californium 252 at it ;-)

(That is one of the most expensive practical materials on earth, probably hundreds of dollars per microgram)

What's the plasma configuration of the machine? I think there's a research group at U of Washington working on merging spheromaks which create a field reversed configuration. Is this a spinoff of that group?

edit: looks like it is - this is the group: https://www.aa.washington.edu/research/plasmaDynamics/phdx.h...

Yes! Prof. John Slough is the Chief Scientist at Helion and the inventor of the Fusion Engine. UW has been leading the field of 'alternates' fusion for decades. Our 'About Us' page has a short blurb: http://www.helionenergy.com/

There's a video of him talking about his earlier fusion rocket engine prototype http://on.aol.com/video/peripheral-vision-003--professor-joh...

Can someone explain why this team is confident that they can build a commercially viable reactor in 3 years? Conventional wisdom is that nuclear fusion is "decades away". What does this team know that others don't?

My bet is either:

(1) They have a solid lead we don't know about; or

(2) Saying you are 3 years away generates hype and interest that keeps netting you the funding to work on something as long term as decades away.

Even if they secretly think it is exactly one decade away, it is in their interest and the interest of the current investors to say it's only a few years away since they will depend on other investors to get piling in on this investment in 1-2 years time.

My advice to anyone working on inventing something truly new instead of putting a startup together from off the shelf parts: Never under-estimate the value of optimism in your time frames and communicating that optimism and timeframe often. Every truly big idea I can think of has depended on a similar optimism since it's the only way to actually net you the amount of money needed to accomplish something truly novel.

Even Kennedy did this when he talked about putting a man on the moon by the end of the decade. It took 8 years, one month and 26 days from the date of his speech to accomplish something that was pretty far fetched in 1961. Only those willing to make bold claims are capable of taking such bold claims to fruition. That's how you raise the money you need and recruit the people you need to make that a reality. Moonshot startups require a moonshot attitude.

This is something I've struggled with - I am always the cautious type. This is good advice I think for many projects , even those that are not quite moonshots.

The type of Nuclear Fusion they are talking about is quite different than what ITER is working on. It's on a much smaller scale - around 50 MW, which is on the scale of a large diesel generator. The cost is also not that ground breaking - around $0.04/kWh, which is around where Natural Gas and Coal plants are.

To say that electricity from fusion at a price similar to coal is "not that ground breaking" is quite the understatement. That would be huge.

And since this will be magnitudes cleaner than natural gas/coal, you might be able to get some "green" alternative energy subsidies from various governments, which might make it more cost effective.

Because it is so small that you could actually control most of the variables.

E.g they generate a magnetic field and they recover the energy from the same magnetic elements generating electricity instead of having to add a completely independent turbine generator with all the heat and radiation problems associated with it.

Even if they don't reach the goal, they could discover something useful.

Can someone with some knowledge on nuclear energy explain to me how this solution varies from say, General Fusion (http://www.generalfusion.com)? They're a company more local to me, and while these companies are looking to accomplish the same thing, their approaches are wildly different.

Both GF and us (Helion) are attempting to dramatically shrink the size and cost of fusion reactors. We are doing that by compressing a fusion plasma repeatedly to generate energy, rather than trying to heat and confine it for long periods. The main difference is that Helion uses high field pulsed magnets to compress the plasma, GF uses pistons to generate liquid metal shocks.

Are you guys thinking in a crowdfounding campaign, I'll give money to help projects like yours.

Not yet, right now we are focused on pushing the technical milestones as fast as possible. This is a great question, what do people here think about a crowdfunding campaign for something like fusion, is it worth it?

I helped out with the recent Focus Fusion crowdfunding. Our goal was $200K, we raised $180K, but it also brought in some new investors who took us well over the goal, and who gave the crowdfund the credit for their interest.

We had a very low budget so our marketing was bare-bones.

We had a lot of excitement, but also a lot of skepticism and pushback. Our hired marketing team insisted on an extremely optimistic presentation and that turned a lot of people off. Of course I don't know whether we would have done better with a more measured approach. With LPP being such a small team and so far off the beaten path we faced a lot more skepticism to start with.

The Solar Roadways campaign ran on Indiegogo at the same time and raised over $2 million. They managed to make a video go viral.



That's very interesting. So what do you think solar roadways did better? Or is their concept just more reportable by media because it's more understandable.

What role did you play? Do you think a marketing team is necessary for a successful campaign?

By the way, email me if you want to chat sometime. I've been kicking around an idea for a better kickstarter.

This video helped a lot: https://www.youtube.com/watch?v=qlTA3rnpgzU

I don't know whether they had a bigger marketing budget or were just good at it. It does seem like an easier-to-understand hook. Various people have criticized the idea's practicality but say "solar roadways" and you've got the concept. That probably helped media coverage. For us, it was complicated to explain why it was more than "here's another guy in a garage who thinks he's solving the world's energy problems."

I'm on the board of the Focus Fusion Society so I debated and voted on various decisions, got interviewed a couple times, and spent a lot of time commenting online various places, mainly reddit.

A marketing team at least helps do a lot of legwork. If you want to pay more for expert advice it can be hard to determine who's expert enough to give good advice for your particular situation.

I'll email later.

Well there've been campaigns out there that have reached above $1 mill. It's difficult but doable, I don't know what kind of money will you need this three years, probably it's not worth the (PR) risk of failing to reach the goal quantity. On the other side it could be a way a good PR move on it's own. I'm sure there is some people at YC that are able to give an autoritative opinion.

There it's also the option of getting some scientific teams(universities, institutes) to help in a crowdsourcing way. For no money, just stock and the possibility to help with a world changing project like yours.

I know it's possible because I've got some high level volunteers (NASA, European level matematic institute, Airbus ingeneers) in contact with Dirk Ahlborn (Jumpstart) to work on the Hyperloop (they got more than 80 volunteers selected).

I don't know if having ingeneering, designers and matematician teams working remotely could be helpful to you at this moment, but it's another way to get people around the world to help, and now that you have YC backing it'll be easier.

What kind of money would make such an attempt worthwhile? I'd imagine we're talking sums well above your average Kickstarter.

they try to do the same - pulsed inertial confinement. Pulse of some force upon a speck of fuel (or a small plasma cloud of the fuel). Similar to compression stroke in ICE, specifically - diesel. Whoever masters the 250TW (that's "terra", like burning of 1g of gasoline in under 0.1 nanosecond) of power pulse delivery - wins the race. My bet is on Sandia Z-machine though to break even first. DPF (that Helion seems to be a kind of) is the next best contender (and probably more practical/efficient approach for household scale fusion reactors when we will reach that stage) i think.

The New Yorker wrote an amazing article on ITER and the pursuit of nuclear fusion: http://www.newyorker.com/magazine/2014/03/03/a-star-in-a-bot....

> Helion Energy [...] says it has a plan to build a fusion reactor [..], a challenge whose solution has been considered decades away for, well, decades. Helion CEO David Kirtley says that his company can do it in three.

Three decades? Either this is a very long-term investment, or a very confusingly written article.

Yeah, that's a clumsy sentence. He means 3 years.

In this article, he estimates commercial viability by 2019:


Guess that explains this:


I had office hours today with a co in the current YC batch whose (genuine) TAM is so big I worry investors won't be able to parse it.

YC used to get a lot of criticism for only funding "trivial web companies". You don't hear that so much these days.

I'm not up to date on everything YC funds - what other non-web companies have they funded?

They're doing some non-profits, which i'm not sure if that's what he was getting at... but is still pretty cool.

Cruise Automation, for example, is working on self-driving cars.

There are some biotech companies too, but I don't know much about those.

There a number of hardware companies as well.

They're using a deuterium reaction? That's not bad (per se), but the neutron production can create difficulties: major regulatory hurdles (can be used for nuclear material refinement?), difficult to extract energy, and causes a lot of nearby material fatigue.

Another big contender (IMHO) is Tri Alpha's aneutronic approach: http://en.wikipedia.org/wiki/Tri_Alpha_Energy,_Inc.

Either way, cool stuff!

Fwiw, high school kids build small reactors and fuse deuterium with basically no regulatory hassle at all. Lots of larger fusion experiments use deuterium too and do fine. Getting permission to experiment with fission is far more difficult. I'm sure there will be some regulation but it's unlikely to be very burdensome.

Boron fusion is pretty much the ultimate of course.

> Helion CEO David Kirtley says that his company can do it in three.

Three... years? Decades? Days? Millennia?

We are hoping three years, three decades is just too late to matter. Part of what was not mentioned are the years that we have put into this already. Fusion is definitely a tough problem, but one that is worth it to solve.

Best of luck to you and your team, I really think that alternative paths to Fusion should have been explored since Farnsworth. Instead we have the crazy massive superconducting cathedral's that are literally trying to blow themselves apart when you turn them on. Your team and the teams investigating other approaches (General Fusion, Tri-alpha, the late Bussard's Polywell, Lerner's Focus Fusion) all should get several tens of millions to investigate and do hard science and try for the big payoff. Congrats on getting some more initial funding, I wish you the best of luck.

Forgive me if this is forward, but are you guys hiring? I'm in no way a physicist, but I do know a few with strong experimental backgrounds (mostly in nuclear), and I try to keep my ear to the ground for intriguing job opportunities for my friends.

We are hiring for Redmond, WA, but only people that are excited and forward! Our Contact page http://www.helionenergy.com/ has the link.


Well, there is a kind-of-joke that commercially-available fusion energy is perpetually described as "30 years away". It always appears to be stuck at least a generation away... hopefully someone finds a breakthrough.

To put this in context, even the international ITER project is 'experimental' (with a budget of € 15 billion, expected to be switched on in 2019), and is expected to be followed up with a demonstration plant in 2040...

Later in the article it mentions three years. So I assume that first mention was a case of forgetting to type a word.

As much as I hope this succeeds and as glad as I that HN is betting on such "moonshots", I remain skeptical about the practicality of nuclear fusion as a commercially viable power source.

Fusion works particularly well for stars because of gravity. We're trying to use magnets to contain superheated plasma.

The Sun generates less energy on a kg-for-kg basis that compost [1]. And it has gravity to contain the byproducts (other than energy).

But the real problem is neutrons. To start a fusion reaction with a small amount of matter we use heavy isotopes of hydrogen (specifically deuterium = 1 neutron, tritium = radioactive isotope with 2 neutrons). The fusing material releases neutrons that damage the containing reactor.

This is using the most "promising" deuterium-tritium reaction.

Alternatives are suggesting using He3. Unfortunately that's super-rare, which kinda defeats the point of "free" energy.

I remain skeptical but hoping to be proven wrong.

[1]: http://www.abc.net.au/science/articles/2012/04/17/3478276.ht...

The second-easiest reaction is deuterium-deuterium. Half the time it produces He3, and the other half it produces tritium, which decays into He3. So start with D-D and bring in He3 as you get it to reduce neutron output.

Even with D-D alone the neutrons are a lot less energetic than with D-T.

I think these guys are using MagLIF (Magnetized Liner Inertial Fusion).

Here's an article about MagLIF research using the Z Machine at Sandia Labs: http://www.nature.com/news/triple-threat-method-sparks-hope-...

Close but with some important differences. We've tried that approach and it has some interesting potential applications but, when it comes to building a power plant that has to last decades, we think the engineering is just too difficult. Instead of pushing on a liner that then pushes on the plasma, we directly push on the plasma with magnetic field. The engineering, while still difficult, is much easier to tackle.

Is this a purely magnetic approach? I recall recently reading about a MagLIF variant that used lasers for pre-heating.

It is. We use electromagnets to make the plasmas, move them, and finally compress them all without moving parts, just magnetic field.

Amazing that this kind of research can be funded with a mere .0015 Instagrams (or even better, .00008 Whatsapps).

When talking about breaking even, does that include the energy needed to make the deuterium? Or rather to collect it, considering it has to be extracted from water or something. IIRC deuterium costs quite a lot of energy to produce and as a result for a while it was only produced by countries having large amount of hydroelectricity available.

Not exactly related, but this made me wonder : inside a tank full of liquid hydrogen, do the DH and DD molecules lie on the bottom? Is it possible to just siphon them from there?

That's a good question. The short answer is the energy that it takes to extract D2 from water is so small compared to the fusion energy released it isn't a factor. That is reflected in the cost of D2O at about $0.70 per gram. In a fusion reactor, even with inefficiencies, that gram of D2O will create about $1000 worth of electricity.

Yeah that makes sense. Now that I think about it, I realise the energy needed to extract deuterium is related to the chemical energy binding water molecules together. This chemical energy is orders of magnitude lower than the nuclear energy released by fusion. So the cost of fuel production will likely be irrelevant for fusion power.

Anyone have more insights into how this works?

The figure, deuterium fuel is confusing as deuterium is an isotope and am unsure what they mean 'extraction' (how?).

Right now we just buy deuterium off the shelf, it is low cost and plentiful. You can get deuterium by electrolysis of heavy water, see here: http://en.wikipedia.org/wiki/Heavy_water

Perhaps low cost (25L, ~$600) is relative, depending on the purity, but am unsure how much scale a project like this would use.

I love this question because it helps illustrate just how different fusion is from other energy sources. If it works, a 50 MW Fusion Engine would run for 5-10 years on a single 55 gallon drum of heavy water.

I wouldn't be surprised if that cost is still a drop in the bucket compared to salaries though. How much deuterium is a startup like this likely to go through in a month?

Totally correct. Right now we simply purchase D2 gas in small quantity so the price is relatively high. But even at those prices we'll probably spend on the order of only $100 per month on D2 when we're operating.

Their patents are easily found.

https://www.google.com/patents/US20140023170 https://www.google.com/patents/US20110293056

It's not a completely novel approach, and it's probably not a great investment compared to some other fusion startups, though I am glad people are investing in this rather than idiotic app companies. Kudos to the big-Y for taking on some useful risk. $1.5M is cheap, and should be dished out to many such companies.

Interestingly, the inventor seems to be interested in using the technology to build rockets. If they achieve > break-even, this might actually be a better use for the technology, as it is not obvious how to extract power from the plasma based on their patents, but it would be real easy to just shoot some plasma out one end of the thing for a dandy rocket engine. I guess MHD would work, and would not be a patentable innovation, but this really looks like a space rocket to me.

Heavy water (oxygen + deuterium) bonds slightly stronger then normal water (oxygen + hydrogen). So you cascade water over electrosis (pump voltage though water causing hydrogen and oxygen to separate). And you get a higher and higher percentage of deuterium with each stage.

This how the German's did it in WW2.

It's probably just referring to the separation of heavy water from normal water, which is then electrolyzed to produce the deuterium.

Am I the only one who finds the names in this headline SO FRICKIN AMAZING?!

They are all so apt -- A steampunk-sounding mechanism for combining things[1], a mythical element/alloy of magical powers, and a naked Helium nucleus. It just tickles something very artistic for me.

Edit: [1] ok fine it's actually a math function, but I like my perception of the name better.

For that kind of money they could've just kickstarted it.

Focus Fusion tried that, and it netted them only $180k plus some private investments.


True but their goal was only $200k, and they started with minimal funds for marketing.

The funny thing is if this was a kickstarter campaign, all the comments on this post would be super negative.

They're using deuterium, but the figure mentions that they're fusing it with helium. But helium-3 is very expensive, and I'd been under the impression that deuterium / helium-4 fusion required impractically high temperatures to work?

helium 4 is stable (it's the alpha particle) so fusion with helium 4 either doesn't produce energy or it produces very little.

It's possible that the reactor does two reactions: 1) D + D -> 3He + n, 3He + D -> 4He + p.

One thing that I am curious about: What does it mean by "the expanding plasma is converted directly into electricity" ?

Directly how? No boiling water driving pistons, no intervening steps at all? It seems a bit like "and then a miracle occurs" to me.

There's a couple of ways of doing it: http://en.wikipedia.org/wiki/Direct_energy_conversion

This whole discussion about weapons seems strange. It's true that the words "nuclear fusion" appear in the article, but my reading of the article doesn't make me feel that this research will lead to some terrible, existential risk to mankind.

For comparison, consider robotics, drones, nanotechnology, and AI. I am fascinated by these subjects (and, apparently, so are many other HN readers), but I have some concerns that these non-nuclear technologies may end up having very negative consequences. Yet these high tech areas, with which I would guess the HN readers have a better understanding than fusion, don't engender such negative reactions here.

Excellent news, I can't wait to drive a Tesla powered by fusion power.

I don't think mobile fusion reactors are what they're going for. And if you're looking to reduce global carbon emissions try walking, biking or using public transportation. It's true electric cars don't emit carbon the way a fuel based car does, but the production and maintenance of an electric vehicle certainly does.

My reading of "a Tesla powered by fusion power" was that the electricity charging the batteries would come from a fusion generator source. And indeed, a clean electrical source makes electric transportation much more environmentally attractive.

fusion plant -> mains electricity -> your tesla

Yes that's what I meant, I think this is the future of transport.

The reasons Nuclear Fusion presents a difficult problem:

1.) There's no chain reaction mechanism. 2.) The probability of a reaction constrains reaction size. 3.) The absurd amount of heat generated by fusion. I think I once heard it was 100M degrees.

Curious, anybody know how they design around this? Are they using some form of magnetized containment?

Excited to see this funded.

> 1.) There's no chain reaction mechanism.

There's something like it. Fusion happens because plasma is hot -> fusion products heat the plasma to keep it hot -> more fusion happens. A chain reaction is exactly what you don't want in a nuclear reactor.

> 2.) The probability of a reaction constrains reaction size.

Can you be more specific? The probability of reaction does constrain the design, but via the Lawson criterion [1].

> 3.) The absurd amount of heat generated by fusion. I think I once heard it was 100M degrees.

That's about right, but temperature != heat. Even though the plasma has a very high temperature, it is also extremely diffuse: about 3 million times less dense than air.

The main concern is keeping it hot in the proximity of colder stuff and managing the electromagnetic energy (the fields have many times more energy than the thermal energy, and has the potential to all be dumped in a single spot), not necessarily worrying about the heat.

[1] http://en.wikipedia.org/wiki/Lawson_criterion

edit: lots of silly typos

> Curious, anybody know how they design around this?

Usually the stuff is hidden in a vacuum, which is a pretty good shield for heat.

Nuclear fusion is a good investment for the world. Truthfully, fusion power is the final answer to our future energy needs. http://www.youtube.com/watch?v=u8n7j5k-_G8

is this the equivalent of throwing shit at the wall and see what sticks?

why do vcs with a specialty in software suddenly stray into completely unknown territory? nothing left to fund in software? rarely does this end well.

I think it's more a matter of there not being any VCs who specialize in fusion. There just isn't the deal flow to sustain any VC specializing in it, and so far the success rate has been 0%. Of course, because there are so few fusion startups (lets see, I can think of less than 10 in the past 25 years), its hard to know what the real statistics are: is the chance of failure 100% or really just 99%?

From the point of view of a fusion startup, if you try 100 software VCs, you might find 2 or 3 who will be interested. However, you will wait forever if you want to find a VC specializing in fusion.


The NIF has never reached "break even" in the sense that most people might understand that phrase. Orders of magnitude more energy went into the system than could have been extracted from the resultant fusion reactions. However, post-analysis of a bunch of shots showed approximately two where, if you accept a model for the amount of laser energy that was incident on the target, somewhat more than that amount of energy was produced from nuclear fusion. Several other shots in the same series, under the same conditions, failed to produce this "break-even" energy. This is all in the actual papers, not, of course, in LLNL's press releases.

Sam switched from physics to software, so no. Not really

Expected value.

I would guess either personal interest or PR, rather than a solid return calculation. YC doesn't want to be seen as the "web startup incubator", even if that's where they can best maximize ROI. And besides PR, the principals likely don't want to be that, either, but have loftier goals. Which is perfectly fine; maximizing investor returns is rarely a good way to do anything important or interesting.

Slightly tangental but "end energy dependance on other nations" grates me. It sounds so nationalistic.

It's not really a nationalistic sentiment, but rather one of economic independence. See, for example, Europe kowtowing to Russia because they supply a large fraction of their natural gas.

$1.5 million is not much runway.

$1.5 million from YC is known as "smart money". You don't use smart money as runway, you use it to build runway.

especially for a product that is just hoping to break even on power generation.

They break even and are billionaires. They manage to create 2+ EROEI and we are talking trillions.

or dead; possibly both (i dearly hope not for both cases!). a working fusion reactor with advertised properties will disrupt the current political balance of power on the planet. intelligence agencies of certain fossil fuel-driven countries might get orders to not let the situation go that far. hopefully certain other intelligence agencies will be able to protect the effort.

This is needlessly conspiratorial. Oil companies and sovereign wealth funds are some of the biggest investors in renewables on earth. Everyone knows we will reach peak oil at some point, whether through increasingly costly extraction/taxation or increasingly cheap renewable competitors. There is no 'grand conspiracy' to quash alternative energy sources.

He takes it a bit far... but its true that fuel is a primary driver of politics in our current times. What that means though is a bit less known. Honestly i'd assume it would be a stabilizer more than anything. It could lead to the end of propping up regimes in the middle east for instance.

i'm not talking about any grand conspiracy, i'm far from it. what i'm concerned about is what is happening about a thousand miles east from where i live - in eastern ukraine - and what happens to russian economy when europe stops buying their natural resources because we don't need them anymore.

I believe they mean lossless energy conversion

The most important question: what are the demographics of the founding team?

another perpetual motion machine?

No, they're not quacks.

They might be a little foolish expecting (and suggesting they can deliver) net positive fusion reactors in three years, but what they're doing is solid physics. It's a high risk, high reward investment and I'm glad it's happening even if I don't think it's likely to work because someone _soon_ is going to be successful in creating a commercially viable fusion reactor, and more separate groups trying makes the chances of success higher.

Nah. Just a very risky investment. ITER uses "safe" physics that we know how works - it's a magnificent engineering exercise, but there are no new insights in fusion per se required. These guys seem to be aiming for an alternative solution with more eccentric science behind it. It will probably not work out, but neither does most start-ups.

What is meant by eccentric science? Would you be specific?

Well, I don't know much about the subject, but the way I've understood it there's ITER and then there are a couple other reactor projects. Everyone except ITER is violating some kind of popularly held belief among physicists - they could be cheaper and better, but it's far from certain that they'll work at all. This just looks like another one of those.

I don't think it violates physicists' beliefs, it's just that they're more confident in tokamaks like ITER because they've been studied a lot more.

The same attach was levied against AC Power.

In general the goal is for an exothermic reaction. It should be possible. Perpetual Motion Machine would be one that could sustain itself without fuel. This one can't. It has to use heavy water and helium to form the plasma. To be an actual perpetual motion machine, the system would have to create enough energy to be converted into hydrogen (E=MC^2 and all), then feed itself with the new fuel. Even at 8 times the energy output, they can't get enough energy to create parts of the fuel.

You know fusion reactors burn fuel like any other power plant, right?

The same kinds of dismissals were probably said about everyone who tried to make an airplane. Someone eventually made it work, though.

Yes, and it was a prominent physicist who most famously said it: "heavier-than-air flying machines are impossible"

- Lord Kelvin, 1895 http://www.nasa.gov/audience/formedia/speeches/fg_kitty_hawk...

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