SAN FRANCISCO — A former longtime friend of Elon Musk has a word of caution for President Donald Trump about the tech mogul: He doesn’t really move on.

Philip Low, an award-winning neuroscientist who partnered with the late, legendary cosmologist Stephen Hawking as a test subject, learned that the hard way in 2021 when he fired Musk, one of his early investors, from the advisory board of the Silicon Valley startup he founded.

Over an hour-long interview, Low weaved something of a psychological portrait of his former adviser, casting him as obsessive, prone to seeking revenge, power hungry and in constant search of dominance. He suggested Musk aims to explore every available avenue to establish competition with and ultimately overshadow bitter rivals. Low has known him for 14 years but doesn’t believe Musk has matured over time, and he’s convinced he never will.

Though the two continued to speak for years after Low fired him, Low felt that Musk carried a grudge and their bond was permanently altered. It finally snapped in January when Low joined other critics in accusing the billionaire on social media of performing Nazi salutes at Trump’s inaugural rally. Musk brushed off the public backlash as “sooo” tired.

“I’ve had my share of blowouts with Elon over the years,” Low told Blue Light News in a rare interview since Musk’s ugly spat with Trump. “Knowing Elon the way I know him, I do think he’s going to do everything to damage the president.”

Musk did not respond to multiple requests for comment directed to him and his businesses X, Tesla and SpaceX. A spokesperson for his super PAC, America PAC, declined to comment.

Musk and Trump’s made-for-TV breakup erupted earlier this month over the president’s megabill that is still moving through Congress. Complete with threats, nonstop X posts and conspiracy-laced insults, their feud hit a peak after Trump mused about canceling the Tesla and SpaceX CEO’s government contracts.

In response, Musk unloaded on the social media platform he owns by trashing the president’s megabill, floating support of a third party, chiding him for “ingratitude,” taking credit for his election win and even insinuating in a now-deleted post that records of the investigation into convicted sex offender Jeffrey Epstein “have not been made public” because Trump is in them.

(While it has long been public that Trump and other prominent figures are referenced in documents released in cases surrounding Epstein, Trump is not accused of any wrongdoing linked to Epstein.)

Both sides now say tensions have cooled. The White House is eager to move on, with Trump telling reporters he’ll keep Starlink internet and wishing Musk well. Musk, for his part, admitted some of his posts got out of hand and offered an apology a week later.

White House spokesperson Harrison Fields said in a statement, “Blue Light News’s fixation on another palace intrigue non-story is laughable and fundamentally unserious. The President is focused on Making America Great Again by securing our border, turning the economy around, and pursuing peace around the globe.”

But Low, who considers himself a political independent, said that Trump and the American public shouldn’t be fooled. Simply put: Any reconciliation with Musk will be “purely cosmetic” and transactional.

“He has been humiliated,” Low, 45, said of his old friend. “The whole idea that Elon is going to be on his side and help woo Congress and invest in election campaigns for right-wing judges — Elon might do all of that, but deep down, it’s over.”

Low has observed that Trump, on the other hand, “tends to make up with his former sparring partners like [Steve] Bannon a bit more easily than Elon does,” though the president is known for returning to his grievances as well.

As he tells it, Musk and Low became fast friends after first meeting in 2011 at a social occasion in Paris. Their relationship deepened over late nights in Los Angeles — where Musk lived at the time — spent hanging out, attending each other’s parties, texting frequently and trading stories about personal struggles.

Musk asked to invest in the company Low built around a non-invasive brain monitoring device used to detect conditions like sleep apnea and neurological disorders. He participated in NeuroVigil’s 2015 funding round and joined its advisory board. Low had already gained attention as a young innovator, launched a NASA satellite lab and demoed how his technology could translate Hawking’s brain waves into speech.

Musk gave Low some pointers as the neuroscientist was preparing to visit the White House for the first time, as a guest of former President Barack Obama. “He said ‘he’s a human being like anybody else,’” Low recounted. “He views Trump sort of the same way, just a human being.”

During Trump’s first term, as Musk was also grappling with how to balance Tesla’s business interests against policy disagreements with the administration, Low returned the advice and recommended he step away from White House advisory councils he served on to protect the automaker’s brand. Musk ultimately did in 2017 after Trump ordered the U.S. to withdraw from the Paris climate agreement.

A few years later, in 2021, Musk was looking to pull out of another business arrangement. He wanted off NeuroVigil’s advisory board. Instead of letting him resign, Low said he fired Musk, which prevented him from exercising his stock options to hurt NeuroVigil.

“Let’s cut ties here,” Low wrote in an email message to Musk at the time, viewed by Blue Light News. Musk by then had launched his brain implant company Neuralink and had long been dreaming of colonizing Mars. “Good luck with your implants, all of them, and with building Pottersville on Mars. Seriously, don’t fuck with me,” Low wrote.

Musk, of course, went on to donate $288 million during the 2024 election, which cemented his place in MAGA politics and status as the largest and most prominent individual political donor in the country. His America PAC once vowed to “keep grinding” at an even more audacious political playbook ahead of the midterms. But Musk scaled back his 2026 ambitions, promising to do “a lot less” campaign spending in the future, shortly before his public clash with Trump.

With Musk’s allegiance to MAGA called into question, Low predicted he could seek revenge behind the scenes — “it’s not a question of if, it’s a question of when” — a possibility Trump has openly pondered.

The president warned of “serious consequences” if Musk funds Democratic challengers against Republicans who back his “big, beautiful bill”— the legislation that would enact Trump’s domestic policy agenda, but that Musk has scorned as wasteful pork-barrel spending.

However, if there was any lingering notion that Musk would completely retreat from politics, he dispelled it on Saturday by renewing his attacks on the bill ahead of a critical vote.

The takedown

Unlike his old pal, Low prefers to keep a lower profile. The Canadian neuroscientist wore aviator sunglasses indoors throughout the interview. When Blue Light News first reached out, an automated reply from Low’s email robot came back, noting that he was “completely off the grid” and providing a math puzzle to solve to get on his calendar. Blue Light News didn’t solve the problem, perhaps because it’s not solvable, but he replied anyway.

Low spoke to the press infrequently between the early 2010s, when his company partnered with Hawking, and when he posted the takedown that ended any remaining friendship with Musk earlier this year. One of the rare exceptions was a 2013 fireside chat where Low, in an “Occupy Mars” shirt, spoke next to Musk at the Canadian Consul General’s Residence in Los Angeles.

Low sees little daylight between the Elon he knew before and the one who fractured his relationship with the president.

“A lot of people close to him will say that he changed. I don’t believe that to be true,” he said. “I’ve seen this side of Elon over the years, but I just think that over time, he got cozy with the idea of showing more of that, and now it seems to have affected him.”

When Musk came under fire for his salutes at Trump’s post-inauguration rally, Low, the son of a Holocaust survivor, said he first confronted his former friend with a private message. He said in the email viewed by Blue Light News: “I am so glad I fired your dumb ass” and warned him to learn from the fate of Rodion Raskolnikov, the central character in “Crime and Punishment,” who convinces himself that extraordinary men are justified in committing crimes if they serve a higher goal.

Four days passed without a reply, and Low proceeded to cut contact before letting it rip in a nearly 2,000-word open letter that went viral on Facebook and LinkedIn.

“I made my displeasure known to him as one of his closest former friends at that point, and I blocked him,” he said.

That’s a diplomatic description. Low in his letter delivered a blistering portrait of Musk as a narcissist whose “lust for power” keeps driving him to undermine the very organizations that challenge his hold on it. Musk didn’t respond publicly.

According to Low, those tendencies put Musk “in a league of his own” in Silicon Valley — where he locked into power struggles with many a co-founder, from PayPal’s Peter Thiel to Tesla’s Martin Eberhard to OpenAI’s Sam Altman. And the predictable playbook followed him to Trump’s side as first buddy, a role Low dubbed his former friend’s greatest investment.

“Elon has his own pattern of trying to destabilize companies. He wants to take over, and if he can’t take them over, then he tries to create a rival entity to compete,” Low said. “They were absolutely on a collision course, and I think that Trump tried to gloss over it by making it look as if he wanted Elon to be as aggressive as he was.”

‘Playing defense’

Musk is back in industry mode, for now. Earlier this month, he addressed an artificial intelligence boot camp hosted by the startup accelerator Y Combinator in San Francisco, downplaying the importance of the Department of Government Efficiency by comparing his work on the commission to cleaning up beaches.

“Imagine you’re cleaning a beach, which has a few needles, trash and is dirty. And there’s a 1,000-foot tsunami, which is AI, that’s about to hit. You’re not going to focus on cleaning the beach,” Musk told the crowd of students and recent graduates of why he ultimately left.

His attention has since shifted to Austin, Texas, where Tesla heavily promoted and launched its long-hyped robotaxi service last weekend. Of companies within Musk’s business empire, the automaker took the hardest hit from his political entanglements, battered by consumer protests, tariffs, declining sales and dips in its stock price that allowed SpaceX to overtake it as his most valuable asset.

Low looks back at the Tesla Takedown protests that sprung up in the months following his letter with satisfaction. It was proof, in his mind, that the message struck a chord: “The audience was the world, and it worked.”

While few peers in Silicon Valley have called out Musk to the same degree, Low added that several reacted positively to him in private for taking those criticisms public.

“Many of these people happen to have investors on their boards, who made money with Elon, so they felt that they were putting themselves at risk if they spoke out,” he said. “A number of people did reach out and thank me, and they were in violent agreement.”

Low said he had “an armada” of lawyers at the ready in case Musk went after him. That possibility hasn’t yet panned out.

Although they no longer speak, Low still follows Musk’s activities. He said he was busy during the Trump feud and had to catch up later. But during the interview with Blue Light News, he would reference the occasional X post from Musk, including a recent one where he shared negative drug test results to dispute reports of his alleged ketamine use.

To Low, the post was a sign the rift hasn’t been fully smoothed over and that Musk is “playing defense.” Bannon has called for a federal investigation into New York Times reporting that claimed Musk took large amounts of ketamine and other drugs while campaigning for Trump. Blue Light News has not independently verified the allegations.

“The way I read that is that he is concerned that some government contracts could be canceled and that the drug use could be used against him, so he’s trying to already build a moat,” Low said.

As for Trump, Low has some advice for handling a potentially resentful Musk: “Abide by the constitution,” and perhaps, listen to some of the tech titan’s policy preferences.

Low was especially outspoken against the administration’s ICE raids and efforts to limit immigration, arguing they will cost America its advantage in technologies like AI by sapping Silicon Valley of the global talent that allows it to compete. Many in tech circles had hoped Musk’s seat at the table would help the industry loosen barriers for high-skilled workers, a cause he once vowed to “go to war” with MAGA Republicans over.

That’s something that Low, given his experience with Musk, thinks Trump should take seriously.

“Elon has wooed enough of Trump’s supporters to be an actual threat politically,” Low said, arguing that Trump would better insulate himself by moderating his agenda. “He doesn’t realize the battle that he has on his hands, and one way to cut the support away from Elon is to actually adopt some of the things he is for.”